Do you use nitrogen?

[A Squared]

A Squared,

You CANNOT take atomic nitrogen and break it down into molecules.

OK, then, I see we're really into the basics here. You don't break atoms down into molecules, you break atoms down into electrons, protons, neutrons, quarks gluons....etc. These are calleed subatomic particles.

Molecules are built out of multiple atoms, liuke when you bond two nitrogen molecules together to make a .....molecule.

Here's a link that explains the difference between an atom of nitrogen and a molecule of nitrogen. Notice that the question is asked by a 12 year old boy

I stand corrected that nitrogen occurs nearly exclusively in the diatomic form, and that is in fact what is used in aircraft struts and tires.

Yeah, and the diatomic form is a molecule. What else would it be? It's not an atom.

 

[CFIintraining]

Regulations to the use of Nitrogen

Nitrogen is required use in the tires of many if not all turbine aircraft. So putting the question of Nitrogen vs. Compressed air aside, I would like some info on some of the regulations governing its use.
I recently was at an FBO and was asking if they had Nitrogen to fill one of the main landing gear tires. I found out that they did have nitrogen but where not willing to fill the tire stating that this procedure requires an A&P.
First off is it true that this requires an A&P?
If No can anyone or at least the owner/operator do this?

If this procedure requires an A&P the regs are whacked. I would rather a incompetant person filling my tire with Nitogen than filling the O2 system on the aircraft.

Thanks

 

[ackattacker]

Nitrogen is required use in the tires of many if not all turbine aircraft. So putting the question of Nitrogen vs. Compressed air aside, I would like some info on some of the regulations governing its use.
I recently was at an FBO and was asking if they had Nitrogen to fill one of the main landing gear tires. I found out that they did have nitrogen but where not willing to fill the tire stating that this procedure requires an A&P.
First off is it true that this requires an A&P?
If No can anyone or at least the owner/operator do this?

If this procedure requires an A&P the regs are whacked. I would rather a incompetant person filling my tire with Nitogen than filling the O2 system on the aircraft.

Thanks

In theory, filling tires with nitrogen does not require an A&P since it falls under preventative maintenance. However if the aircraft is Part 135, Part 129 or Part 121 (which many turbine aircraft are) then an A&P is required. In practice, most FBO's have the nitrogen equipment under the control of A&P's and they won't want you touching their stuff.

If the tires require nitrogen it will be in the stated in the AFM. I don't think you'll find it in the regs...

This whole arguement about nitrogen vs. oxygen has gotten really stupid. Ultimately, as several people have stated, it really comes down to moisture. You really don't want ice or steam in your tires when you are dealing with high-flying high-brake energy turbine aircraft. As water approaches 100C the pressure rise is dramatic. "Shop Air" is not as dry as bottled Nitrogen, even with a water trap. I will add a few things to the "scientific discussion", however:

Many people are trying to prove "thermal stability" using the Ideal Gas Law. The Ideal Gas Law is not reality... it is only for Ideal Gass, which doesn't exist. Real Gasses have deviations from Ideal behavior due to van der Waals forces. Oxygen has more deviation from Ideal behavior than Nitrogen. For more information read the following link:

http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/waal.html#c1

However, the difference is small enough that it really doesn't matter much. It does matter more in high-pressure tires than in low pressure, however.

When you are talking about Freon or similar compounds then you are in a whole different realm. Freon (much like Butane or Propane) is near it's condensation point at room temperature and hence easily undergoes a phase change (liquid to gas and vice versa) with changes in temperature or pressure. None of the "gas laws" apply. The pressure change when you boil a liquid is dramatic for only a minute temperature change. The energy associated with this transition is large, however, which is why Freon is used to transport heat energy in a refrigeration system.

 

[Almerick07]

you are all wrong, everyone knows they fill tires and struts with beer.....A BUNCH OF FREAKING IDIOTS!!!

 

[NuGuy]

Heyas All,

For those that care, rate of effusion is based on molecular weight. At any given temperature, molecules of different gases have the SAME kinetic energy, which is represented by 1/2MV^2.

However, as each gas has differing molecular weight (N2 is 28 g/mol, while O2 is 32 g/mol), the velocity of each gas molecule will be different as at a constant temperature Ma(V^2)a = Mb(V^2)b. Rearrangement yields Vb/Va = (Ma/Mb)^1/2. Thus the larger the molar mass of your gas, the slower the effusion.

Anyway, the important thing to remember is that air is a mixture, not a compound, and that the aggregate rate of effusion of air will be slower than just N2.

As for the corrosion issue...puhleeze...how many cars have you seen that had the wheels fall off due to corrosion? Steel wheels are so overbuilt its ridiculous and alloy wheels are corrosion resistant by design, so putting N2 in auto tires is as pointless as arguing on FI.

Nu

 

[retired guy]

Hey edmulroy...I`ll bet you sorry you asked.....

 

[Gryphon]

you are all wrong, everyone knows they fill tires and struts with beer.....A BUNCH OF FREAKING IDIOTS!!!

Nah, can't be.... who would want to waste thier beer that way?

 

[Wankel7]

. Do some aircraft tires really require 270 PSI? Well even if they do, there are air compressor systems that can easily handle it. Not every air compressor is like the one out in your garage.

Yeah, but would you want to roll it out the airliner sitting at the gate that needs air? I would think rolling out a nitrogen tank is easier.

Wankel

 

[avbug]

In theory, filling tires with nitrogen does not require an A&P since it falls under preventative maintenance. However if the aircraft is Part 135, Part 129 or Part 121 (which many turbine aircraft are) then an A&P is required. In practice, most FBO's have the nitrogen equipment under the control of A&P's and they won't want you touching their stuff.

Ah, no.

Applying compressed gas to a wheel assembly isn't preventative maintenance, it's servicing, and it may or may not require a mechanic. the presence of an AD may require a mechanic, as may the nature of the operation required to service the tire. Servicing the wheel assembly is more than merely inflating to a given pressure; a good inspection should be made of the tire and wheel and brake assembly any time that the pressure is checked or adjusted. Making even minor changes in pressure, up or down, has on occasion resulted in wheel explosions which have maimed or killed mechanics and line servicemen. It's not something to be taken lightly.

While 14 CFR 43 Appendix A cites removal, installation, and repair of landing gear tires as preventative maintenance (assuming no complex assembly operations are required), servicing of the tire is not listed. Further, the required tools, proceedures, materials, and publications (current and in-date) must be used, and the work must be done to publication specifications and industry standards.

Upon filling,the valve stem should be checked for leakage. Bolts, boltheads, nuts, cotter keys, fasteners, weights, etc, should all be checked for security and condition. The wheel assy should be visually inspected for signs of cracks, stress risers, etc. The bead area must be inspected for impact damage, nicks, thermal damage, etc. Thermal or blow plugs should be inspected. Brakes should be inspected for thermal damage, leakage, etc. If inflation charts apply due to ambient or wheel temperature, then these must be taken into account and applied both when checking the temperature, and when altering it by applying nitrogen or releasing it.

Most nitrogen bottles are filled to 2,000 or 3,000 psi. Improper use of regulated compressed gas can result in rapid overfilling, temperature changes that affect the inflating pressure (false readings), safety burst or explosion issues. Small wonder that many facilities don't want someone other than their own personnel using their nitrogen. Of course, use of oxygen in place of nitrogen, by mistake, can result in a deadly explosion at the time of filling, or in operation of the wheel assy.

It's more than just shooting in a little air. In some cases a mechanic may be required, in most cases, a mechanic should be used.

Ultimately, as several people have stated, it really comes down to moisture.

No, it comes down to manufacturer requirements and flamability issues. When a tire overheats (and considerable heat is generated from a normal landing, let alone an overheat condition from braking, stopping, taxiing, or operating under pressure), hydrocarbon gasses are released into the tire assy; this can become explosive. Mixing with high pressure air in a tire can result in ignition or explosion. Nitrogen is inert, and does not support combustion.

In 1987, AD 87-08-09 was issued by the FAA, for MD, Lockheed, Airbus, Boeing and BAE aircraft. It specifically calls for nitrogen or other inert gas having less than 5% oxygen, due to the possibility of a chemical reaction between tire gasses and oxygen.

Where an AD applies, a mechanic may or may not be required to perform the service and the attendant signoff; the AD will specify what can or cannot be done.

AC 20-97A discusses the fact that air diffused into a tire carcass lead to reduced tire life due to inner degradation and ply delamination.

Tire temp changes can be significant merely from taxiing, but numerous factors affect internal pressures and temps. A pressure drop means an underinflated tire, which will heat more rapidly than a properly inflated tire. More heat means reduced tire life, and an increase in the gassing process internally. Tire gassing is highly flammable. A 5 degree OAT temp change leads to approximately a 1% internal tire pressure change. The tire naturally diffuses, which occurs at a slower rate with nitrogen. Standard daily diffusion occurs at the rate of .02% in a 24 hour period, and specific allowable rates are specified in maintenance publications. The tire has vent holes which are part of the manufacturing process to release trapped moisture and gasses, which also lead to loss of pressure. Normal operation builds considerable heat.

Temps as low as 220 degrees F can significantly shorten the tire life. The bead area of an underinflated tire can become 50% hotter than a properly inflated one for any given operation, with respect to weight increases. Given that diffusion rate is greater for air or shop air than nitrogen, and that shop air supports combustion whereas nitrogen does not, little wonder that virtually all tire and aircraft manufacturers recommend or require the use of nitrogen in their products.

 

[avbug]

Ultimately, as several people have stated, it really comes down to moisture. You really don't want ice or steam in your tires when you are dealing with high-flying high-brake energy turbine aircraft. As water approaches 100C the pressure rise is dramatic. "Shop Air" is not as dry as bottled Nitrogen, even with a water trap.

Steam isn't an issue, though corrosion is. Particularly with magnesium wheel assemblies. Wheel assemblies are expensive; reduced moisture and condensation in the tire assembly means reduced corrosion inside the wheel.

Do some aircraft tires really require 270 PSI? Well even if they do, there are air compressor systems that can easily handle it. Not every air compressor is like the one out in your garage.

Where nitrogen is used, bottle pressure will always be considerably higher than the tire demands, or the bottle must be set aside for refilling.

High pressure shop air isn't supplied by a compressor, but by a strut pump...which can also be used to boost low bottle pressure with nitrogen and oxygen (but should not be interchanged in use).

As for the corrosion issue...puhleeze...how many cars have you seen that had the wheels fall off due to corrosion? Steel wheels are so overbuilt its ridiculous and alloy wheels are corrosion resistant by design, so putting N2 in auto tires is as pointless as arguing on FI.

This statement is one example of why trained personnel should be servicing wheel assemblies. Corrosion is a major issue. It's one of the main reasons for rejecting wheel assemblies in automotive applications (alloys are more susceptible to corrosion, not less, in most cases), and steel corrosion is very common. In aircraft applications, most all wheel assemblies are alloy, often aluminum and or magnesium, and these are always highly susceptible to corrosion.

Wheels falling off due to corrosion? How aboutleaking down due to leakage around the valve stem or around the tire bead due to corrosion...leading to under pressure and a blowout or explosion? Not uncommon at all.

If this procedure requires an A&P the regs are whacked. I would rather a incompetant person filling my tire with Nitogen than filling the O2 system on the aircraft.

You choose incompetence for servicing your aircraft? You want to choose between an incompetent person filling a wheel assy with nitrogen, vs. an incompetent person filling your oxygen system? What kind of a stupid statement is that? You want a well trained person doing either operation; either one involves dangerous compressed gasses that can kill, which can result in an explosion and injury or death, and both operations can hurt you after the fact if done improperly.

A competent, trained person should be doing either operation, period. And is required to be so, by the regulation. Even preventative maintenance must be done using all the tools, equipment and proceedures required by the maintenance publications and must be done to industry standard. If the work doesn't require a mechanic, it always requires the work to be done to the same standard as a mechanic would do, and the person performing the work will be held to that same standard. It must be done while referencing a current maintenance publication for that operation by the manufacturers involved. Most importantly, unlike the post above, it must not be done in ignorance.

If the tires require nitrogen it will be in the stated in the AFM. I don't think you'll find it in the regs...

Bear in mind that while referencing the maintenance publications, often more than one is required. The aircraft manufacturer may have specific direction on the operation to be performed. However, so may the wheel manufacturer, and certainly the tire manufacturer...and the user must have access to and reference each publication in performing the work.

This applies regardless of w(h)eather the operation is conducted under Part 91 only, or under air carrier regulations such as parts 121 or 135.

However, now that you mention it, any requirments specifed in any of the approved documentation is not only necessary to the continued airworthiness of the aircraft (don't follow them, then the airworthiness certificate is invalidated...see line 6 of your airworthiness certificate and the explaination thereof), but also regulatory. 14 CFR 43.13 provides the performance requirements that make this so...is is VERY regulatory...every jot and tittle of that maintenance pub, flight manual, pilot handbook or any other approved data (including AD's) applicable to your operation:

§ 43.13 Performance rules (general).

(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in § 43.16. He shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator.
(b) Each person maintaining or altering, or performing preventive maintenance, shall do that work in such a manner and use materials of such a quality, that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition (with regard to aerodynamic function, structural strength, resistance to vibration and deterioration, and other qualities affecting airworthiness).

(c) Special provisions for holders of air carrier operating certificates and operating certificates issued under the provisions of Part 121 or 135 and Part 129 operators holding operations specifications. Unless otherwise notified by the administrator, the methods, techniques, and practices contained in the maintenance manual or the maintenance part of the manual of the holder of an air carrier operating certificate or an operating certificate under Part 121 or 135 and Part 129 operators holding operations specifications (that is required by its operating specifications to provide a continuous airworthiness maintenance and inspection program) constitute acceptable means of compliance with this section.

 

[Gatorman]

AVBUG. you are my hero.

I read this thread when it first started (thinking that it should be on the mechanic's forum) and I knew it was going to be a great thread.

Thank you for setting them straight - and by the letter by gosh!


Now, if they will take the time to read and absorb the info.......the next question will be "Where is a good place for BBQ?"

 

[ackattacker]

While 14 CFR 43 Appendix A cites removal, installation, and repair of landing gear tires as preventative maintenance (assuming no complex assembly operations are required), servicing of the tire is not listed.

While nobody has every claimed that the regulations make perfect sense, are you going to seriously argue that I could take the tire off a Piper Arrow, repair it, repack the wheel bearings, reinstall-it, fill the strut with nitrogen (servicing of struts is listed as preventative maintenance), and then I'd have to call an A&P over to put some air in the tire? I think a reasonable person would assume that the authority to "repair" a tire includes the authority to service it with air (or nitrogen if required).

14 CFR 43 Appendix A doesn't cite replenishing engine oil. It does cite replenishing hydraulic reservoirs. We better warn everybody to stop adding their own oil to their engines. What about adding fuel... you know "servicing the fuel tanks?" That's not listed either. Lot's of AD's apply to refuelling. It's very dangerous, people get killed all the time. I don't see mechanics coming out to refuel aircraft though.

Obviously if an AD specifies a mechanic then you need a mechanic. In the absence of that, I stand by my statement that a part 91 pilot can fill his or her own tires with nitrogen, if nitrogen is called for. I didn't say it was necessarily wise or safe. Plenty of "certified mechanics" have killed themselves by attaching unregulated 3000 psi nitrogen bottles to aircraft wheel assemblies.

 

[ackattacker]

I did some followup research and question asking.

I believe the problem is in how you interpret the intention of Appendix A. Appendix A is a list of "Allowable" pilot-performed maintenace items, which are then specifically excluded in air-carrier operations. So the point is, is it a list of ALL the things you (part 91 pilot) CAN do, or is at list of things which an (air carrier) pilot CANNOT do? In general, "routine servicing" is NOT maintenance. Hence "servicing the fuel", "servicing the oil", and even yes "servicing the tires" is not even considered maintenance at all, UNLESS it is specifically listed in Appendix A, which makes it a "maintenance" item.

Those items which are listed in 14 CFR 43 Appendix A as "servicing" are to be interpreted as service items which ARE considered maintenance and hence CANNOT be pilot performed under 135, 129, and 121. Hence a pilot under 135 cannot add hydraulic fluid, but CAN add engine oil. (So long as the procedure doesn't require the removing of a cowl, which would be "preventative maintenance")

Under this interpretation even a 135 pilot CAN service the tires, provided it doesn't involve any removal of cowls or such. Avbug, if you can prove me wrong go for it.

 

[avbug]

Under this interpretation even a 135 pilot CAN service the tires, provided it doesn't involve any removal of cowls or such. Avbug, if you can prove me wrong go for it.

That would be a FAA Chief Legal Counsel Interpretation, would it? Or your opinion? Prove your opinion wrong? Your opinion stated above lacks so much understanding of the regulation, in particular maintenance regulation, that there's no need to "prove" anything.

Appendix A is a list of "Allowable" pilot-performed maintenace items,...

No, it's not. It's a list of preventative maintenance items, to define the performance standard set forth by 14 CFR 43.13, as described in my prior posts. Merely because something is listed in Appendix A, subpart C, preventative maintenance, does not mean a pilot may perform it. Numerous additional requirements exist, as I have already outlined, and as you have clearly missed. Read again.

...which are then specifically excluded in air-carrier operations.

Are they?

§ 43.3 Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations.

(d) A person working under the supervision of a holder of a mechanic or repairman certificate may perform the maintenance, preventive maintenance, and alterations that his supervisor is authorized to perform, if the supervisor personally observes the work being done to the extent necessary to ensure that it is being done properly and if the supervisor is readily available, in person, for consultation. However, this paragraph does not authorize the performance of any inspection required by Part 91 or Part 125 of this chapter or any inspection performed after a major repair or alteration.

(f) The holder of an air carrier operating certificate or an operating certificate issued under Part 121 or 135, may perform maintenance, preventive maintenance, and alterations as provided in Part 121 or 135.

(g) Except for holders of a sport pilot certificate, the holder of a pilot certificate issued under part 61 may perform preventive maintenance on any aircraft owned or operated by that pilot which is not used under part 121, 129, or 135 of this chapter. The holder of a sport pilot certificate may perform preventive maintenance on an aircraft owned or operated by that pilot and issued a special airworthiness certificate in the light-sport category.

(h) Notwithstanding the provisions of paragraph (g) of this section, the Administrator may approve a certificate holder under Part 135 of this chapter, operating rotorcraft in a remote area, to allow a pilot to perform specific preventive maintenance items provided -
(1) The items of preventive maintenance are a result of a known or suspected mechanical difficulty or malfunction that occurred enroute to or in a remote area;
(2) The pilot has satisfactorily completed an approved training program and is authorized in writing by the certificate holder for each item of preventive maintenance that the pilot is authorized to perform;
(3) There is no certificated mechanic available to perform preventive maintenance;
(4) The certificate holder has procedures to evaluate the accomplishment of a preventive maintenance item that requires a decision concerning the airworthiness of the rotorcraft; and
(5) The items of preventive maintenance authorized by this section are those listed in paragraph (c) of Appendix A of this part.
(i) Notwithstanding the provisions of paragraph (g) of this section, in accordance with an approval issued to the holder of a certificate issued under part 135 of this chapter, a pilot of an aircraft type-certificated for 9 or fewer passenger seats, excluding any pilot seat, may perform the removal and reinstallation of approved aircraft cabin seats, approved cabin-mounted stretchers, and when no tools are required, approved cabin-mounted medical oxygen bottles, provided -
(1) The pilot has satisfactorily completed an approved training program and is authorized in writing by the certificate holder to perform each task; and
(2) The certificate holder has written procedures available to the pilot to evaluate the accomplishment of the task.

So the point is, is it a list of ALL the things you (part 91 pilot) CAN do, or is at list of things which an (air carrier) pilot CANNOT do?

Both, and neither. Do a little more research.

In general, "routine servicing" is NOT maintenance.

Too wrong, mate. In many cases, routine servicing certainly is maintenance. In some cases, routine servicing may require a maintenance record entry, such as putting oil in a turbine engine. Any case of AD compliance requires a maintenance log entry, as does any inspection or required inspection.

Hence "servicing the fuel", "servicing the oil", and even yes "servicing the tires" is not even considered maintenance at all, UNLESS it is specifically listed in Appendix A, which makes it a "maintenance" item.

Quite incorrect. Part 43 Appendix A does not presume to identify what constitutes maintenance; it specifically identifies some items which under some circumstances constitute preventative maintenance. Not all items identified as preventative maintenance under Appendix A are always preventative maintenance. You cited removing a cowl; this becomes a complex disassembly in many cases, and does not permit the operation to fall under the guise of preventative maintenance, even though it may be listed. Again, more applies than a simple reading of this one appendix.

An item does not need to be listed in Appendix A to be a maintenance item, nor to be an item or function that requires a particular level of certification (eg, Mechanic, Repairman, etc) to execute. Your understanding in this area is severely lacking, and could quite easily get yourself, or someone who chooses to listen to you, into serious trouble.

You seem to fail to understand that frequently understanding a particular regulation or concept necessitates understanding multiple other regulations and concepts; more than one regulation frequently applies. Attempting to understand the concept on the basis of a single regulation is a dangerous approach which may place you in legal and physical jeopardy.

 

[avbug]

Those items which are listed in 14 CFR 43 Appendix A as "servicing" are to be interpreted as service items which ARE considered maintenance and hence CANNOT be pilot performed under 135, 129, and 121.

Again, completely incorrect. Upon what basis have you determined that servicing becomes maintenance, whereas "routine servicing" is not maintenance? Your attempt to understand the regulation is disjointed and nonsensical. Items listed under Appendix A may or may not require the services of a certificated mechanic. The word "servicing" has no bearing on the topic, and does not define what constitutes preventative maintenance, nor does it have any bearing on what a pilot can or cannot do. Further, those terms, and your useage thereof, have no bearing upon their applicability to certificate operations such as Part 135.

Hence a pilot under 135 cannot add hydraulic fluid, but CAN add engine oil. (So long as the procedure doesn't require the removing of a cowl, which would be "preventative maintenance")

Again, a concept you have dreamed up, with no basis in regulation or fact. Why exactly might a pilot not be able to add H-5606 fluid, yet be fully legal in adding Turbine Type II oil, instead? Particularly with respect to maintenance items, a certificate holder may obtain authorization to enable a crewmember to perform almost any operation, so long as all the requirements to perform that operation are met and the operation is conducted in accordance with that authorization. This could include fluids, gasses, removal and installation of seats, panels, plugs, gauges, etc. The ability of a certificate holder to obtain this authorization lies in the abiity of the certificate holder to ask for it.

While nobody has every claimed that the regulations make perfect sense, are you going to seriously argue that I could take the tire off a Piper Arrow, repair it, repack the wheel bearings, reinstall-it, fill the strut with nitrogen (servicing of struts is listed as preventative maintenance), and then I'd have to call an A&P over to put some air in the tire? I think a reasonable person would assume that the authority to "repair" a tire includes the authority to service it with air (or nitrogen if required).

What you think is largely irrelevant, and judging from your rendering of the regulation, superfluous. I'll not argue the point at all, as no specific information is provided. You may not be able to remove the tire at all...let alone perform the required work. Assuming you have available the current maintenance publications for the tire, the wheel assembly, the landing gear, and the airframe--all from different sources--and you have the appropriate calibrated tools, approved materials, and the ability and training to perform the work to industry standard using all the practices and proceedures required by the approved data referenced, to the same standard expected of a certificated mechanic, you're still limited by complexity of operations, airworthiness directives, and other information you've probably not yet considered. Chances are that most often, you still can't legally perform the operations listed in Appendix A. This is often the case.

Once again, if you can't legally do it, and you do it, you've invalidated your airworthiness certificate. Read the fine print, as given in my prior posts.

Many wheel assemblies require numerous specific functions when changing a tire from the wheel assy...replacement of the wheel half packing, stripping the wheel assy, nondestructive testing such as zyglo or magnafluxing, and often magnetic particle inspection of the wheel bolts. This information usually isn't in your maintenance manual, which doesn't tell the whole story...it's often in the maintenance publications for the wheel assembly itself.

When you change that tire, do you bother to balance the tire, and do you know the standards and limitations in applying that balance? If you don't, you've invalidated your airworthiness certificate (remember line 6?). Do that and fly the aircraft, and you're flying an unairworthy aircraft, and are inviting a host of violations and penalties. You knew that too, right?

Lot's of AD's apply to refuelling.

Really? Which ones?

We better warn everybody to stop adding their own oil to their engines.

While you're warning them, you might add a warning that adding oil in many cases is indeed a maintenance function and requires a maintenance entry. You knew that, of course?

Plenty of "certified mechanics" have killed themselves by attaching unregulated 3000 psi nitrogen bottles to aircraft wheel assemblies.

Actually no, you'd find that to be an extremely rare occurence. More frequently, injuries or fatalities come from loosening the wheel halves prior to deflating the tire. It's an easy mistake to make. Additionally, damaged wheel assemblies, weakened bolts, boltheads, or threaded portions, serve to cause injury or death when inflating or deflating the tire. You have stats on the numbers of mechanics killed by using unregulated nitrogen, do you? Another one you pulled out of thin air to support a 100% incorrect point? Good grief. Read the regulation, get to know it a little bit, and then cry about it.

 

[Almerick07]

Nah, can't be.... who would want to waste thier beer that way?
Gryphon is offline Report Bad Post Reply With Quote

Im pretty drunk right now and have decided youre right....beer in tires and struts is a bad idea....unless avbug can prove me wrong

 

[ackattacker]

Once Again, AvGod has spoken and it appears very definitive. But was has he actually said?

Applying compressed gas to a wheel assembly isn't preventative maintenance, it's servicing, and it may or may not require a mechanic.

OK, we've established that "servicing a wheel" is not preventative maintenance but "repairing" a wheel is. It "may or may not require a mechanic". Depending upon what, exactly? Where does it say I can service a wheel, and where does it say I cannot? You seem hellbent to argue with anybody. I guess if I said I can do it I'm wrong and if I say I cannot I'm also wrong. The correct AvGod answer is maybe you can, if I you get permission from AvGod.

Upon what basis have you determined that servicing becomes maintenance, whereas "routine servicing" is not maintenance?

YOU are the one who claimed that applying compressed gas to a wheel assembly is servicing, but not repair. YOU find it in the regulations.

Items listed under Appendix A may or may not require the services of a certificated mechanic.

Wrong, items listed under Appendix A DO NOT require the services of a mechanic under part 91. That much is clear. And I am talking about legality, not whether or not the particular pilot in question has the proper manuals, tools, and skills.

The word "servicing" has no bearing on the topic, and does not define what constitutes preventative maintenance, nor does it have any bearing on what a pilot can or cannot do. Further, those terms, and your useage thereof, have no bearing upon their applicability to certificate operations such as Part 135.

Appendix A references "servicing" no less than 3 times. For example, it says that "Servicing landing gear shock struts by adding oil, air, or both" is preventative maintenance. And again, YOU are the one who rather authoritatively said that adding air to tires is "servicing". Clearly it does have some bearing and does define what a pilot can or cannot do.

Again, a concept you have dreamed up, with no basis in regulation or fact. Why exactly might a pilot not be able to add H-5606 fluid, yet be fully legal in adding Turbine Type II oil, instead?

Because, adding H-5606 is clearly defined in the regulations as an item of preventative maintenance but adding oil (Turbine or otherwise) is not. Clear enough?

Particularly with respect to maintenance items, a certificate holder may obtain authorization to enable a crewmember to perform almost any operation, so long as all the requirements to perform that operation are met and the operation is conducted in accordance with that authorization. This could include fluids, gasses, removal and installation of seats, panels, plugs, gauges, etc. The ability of a certificate holder to obtain this authorization lies in the abiity of the certificate holder to ask for it.

True. A certificate holder can obtain authorization for pilots to perform certain items of preventative maintenance. It does not need to obtain an authorization to do things like add oil, which is NOT an item of maintenance preventative or otherwise. I have added oil to a part 135 aircraft with an FAA PMI standing right in front of me, and I didn't have a waiver. I added air to the tire of a C172RG of my initial CFI checkride and the Fed helped me do it. I ain't loosing any sleep over it.

14 CFR 43.3(a) Except as provided in this section and §43.17, no person may maintain, rebuild, alter, or perform preventive maintenance on an aircraft, airframe, aircraft engine, propeller, appliance, or component part to which this part applies. Those items, the performance of which is a major alteration, a major repair, or preventive maintenance, are listed in appendix A.

14 CFR 1.1 (definitions)

Maintenance means inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance.

Major repair means a repair:
(1) That, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
(2) That is not done according to accepted practices or cannot be done by elementary operations.

You may not be able to remove the tire at all...let alone perform the required work. Assuming you have available the current maintenance publications for the tire, the wheel assembly, the landing gear, and the airframe--all from different sources--and you have the appropriate calibrated tools, approved materials,

etc etc.

Irrelevent, as is the rest of your rambling about magnafluxing and so on. The question is the legality, not whether I understand the proper way to do it or have the tools.

Really? Which ones?

(referring to refuelling AD's)

here's one.

49-31-02 REPUBLIC: Applies to All Model RC-3 Airplanes.

Compliance required not later than October 1, 1949.

In order to eliminate the possibility of engine failures resulting from fuel starvation due to incorrect procedures of checking the fuel tank capacity, the following placard must be installed in the vicinity of the fuel tank filler neck:

"WARNING - Do not check fuel with engine running, or within 5 minutes after shutdown. Always insert stick with calibrated side facing ground."

While you're warning them, you might add a warning that adding oil in many cases is indeed a maintenance function and requires a maintenance entry. You knew that, of course?

Sure. It requires a maintenance entry under 121, because that's part of our approved maintenance program. It requires a maintenance entry if you have to remove a panel or cowl. Otherwise, it's not. It's routine servicing, no different then adding fuel.

Actually no, you'd find that to be an extremely rare occurence. More frequently, injuries or fatalities come from loosening the wheel halves prior to deflating the tire. It's an easy mistake to make. Additionally, damaged wheel assemblies, weakened bolts, boltheads, or threaded portions, serve to cause injury or death when inflating or deflating the tire. You have stats on the numbers of mechanics killed by using unregulated nitrogen, do you? Another one you pulled out of thin air to support a 100% incorrect point? Good grief. Read the regulation, get to know it a little bit, and then cry about it.

Interestingly, I learned about the dangers of filling tires with unregulated nitrogen bottles while searching for the AD which you mentioned, AD 87-08-09, which, incidentally, does not specify that it needs to be complied with by a mechanic, only that it needs to be incorporated into the air carrier's maintenance program. Anther one I pulled out of "thin air" to support a "100 % incorrect point"

http://www.boeing.com/commercial/aeromagazine/aero_05/textonly/m03txt.html

Thousands of airplane tires are inflated during routine maintenance each day around the world. On occasion, a mechanic or other ground service employee has been severely or fatally injured in an explosion caused by use of unregulated pressure from an air or nitrogen tank. The latest reported incident occurred in 1998 when a mechanic was inflating a nose wheel/tire assembly on a 737 airplane. A total of five similar incidents have been reported as the cause of severe injury or death to maintenance personnel

 

[Gorilla]

By regulated, I assume you guys refer to the act of placing a pressure regulator on a cylinder of Nitrogen, and not some legal status.

Anyone who uses a 3,000 PSI cylinder to directly inflate any tire should have their ticket revoked permanently. Stupid doesn't begin to describe such an act.

 

[ackattacker]

By regulated, I assume you guys refer to the act of placing a pressure regulator on a cylinder of Nitrogen, and not some legal status.

Anyone who uses a 3,000 PSI cylinder to directly inflate any tire should have their ticket revoked permanently. Stupid doesn't begin to describe such an act.

I'd say that some of the people that did try it already "got their ticket permanently revoked"... if you catch my meaning. If you read the link it does talk about how most high-pressure tires now incoporate high-pressure relief valves to guard against such stupidity.

 

[avbug]

OK, we've established that "servicing a wheel" is not preventative maintenance but "repairing" a wheel is. It "may or may not require a mechanic". Depending upon what, exactly? Where does it say I can service a wheel, and where does it say I cannot?

Why do you insist on being wrong about everything? We have established no such thing. What specific operation on what specific wheel assembly, using what references and what equipment, and by whom? Depending on the nature of the operation, mate.

Where does "it" say you can service a wheel or that you cannot? That would really depend on the operation involved now, wouldn't it? Your comprehension skills are low, as we see, but by now hopefully you've learned that multiple references must be used to make such a determination, and are case specific for your operation, and must be counterbalanced against your own qualifications, equipment, experience, and ability to comply...you did catch that, did you not?

YOU are the one who claimed that applying compressed gas to a wheel assembly is servicing, but not repair.

Negative. Wrong again. It would be either, or both, depending on the operation. Judging from your responses, you're best off staying clear of doing anything more complex than turning a phillips screwdriver, however.

Wrong, items listed under Appendix A DO NOT require the services of a mechanic under part 91. That much is clear. And I am talking about legality, not whether or not the particular pilot in question has the proper manuals, tools, and skills.

Again, you speak incorrectly about things which you do not understand. The nature of the operation determines if a mechanic certificate is required. Merely because an operation is listed in Appendix A does NOT mean you can do it as a pilot without a mechanic or repairman certificate. The operation must not involve complex disassembly (or reassembly). You must have and use and reference the current maintenance publications (all of them) while performing the operation. You must use all the tools, practices and proceedures called out by the maintenance publications. You must be able to perform the work to industry standards and the same standards called for in the pubs, to the same standards required of any mechanic, and you must execute all the relevant documentation, log entries, etc.

That merely because an operation is listed in Appendix A does not mean you can do it is common knowledge...except to you, apparently. Learn whence you speak then open your trap...you seem to be proud of ignorance. Don't be that way.

Appendix A references "servicing" no less than 3 times. For example, it says that "Servicing landing gear shock struts by adding oil, air, or both" is preventative maintenance. And again, YOU are the one who rather authoritatively said that adding air to tires is "servicing". Clearly it does have some bearing and does define what a pilot can or cannot do.

No, it really has no bearing, as the operation is the determining factor. Servicing an item may require a complex disassembly, and may prevent a non-repairman/non-mechanic from performing the job on his or her own. This may be as simple as changing a tire; numerous errors may be introduced in the simple changing of a wheel assembly on a light aircraft that can kill someone; the nature of the work, depending on the specific operation, may very well require a certificated and trained person. Servicing or not. In many cases, servicing is a maintenance function, though it's not a repair. Accessing something to service it, or the act of servicing it, is often a maintenance function that cannot and should not be performed by a non-certificated mechanic. Often to service a tire, brake disassembly and removal is required...the operation, if requiring more than merely sliding one wheel assembly off and another on, can quickly become a complex operation which you are not permitted to execute.

But of course you knew that, expert.

Because, adding H-5606 is clearly defined in the regulations as an item of preventative maintenance but adding oil (Turbine or otherwise) is not. Clear enough?

No, not clear enough at all. Adding H-5606 to a propeller assembly in an overservice proceedure...servicing with hydraulic fluid...is far outside your means, rights, or ability, but is servicing none the less. It may be listed in Appendix A, but that doesn't mean you can do it, and that doesn't require complex disassembly. Doing it incorrectly can result in blown seals, loss of propeller control, ultimately loss of engine control, as well as an operational inflight fire or flame-out. It's a simple operation, and it involves hydraulic fluid...but is an example of an operation that appears to be listed in Appendix A, but really isn't something you can or ought to do without specialized training and supervision, at a minimum.

Again, you do not understand the regulation in the least. You make the assumption (remember what happens when you make assumptions...it happens to you a lot, doesn't it?) that if something is listed in Appendix A you can automatically do it, and if it isn't listed, you can't. You're wrong on both counts.

You still fail to grasp that a quick reading of Appendix A doesn't make you informed on the subject of maintenance. Why do you suppose that years are required to make a mechanic, vs. merely reading a few paragraphs and going to work? More to the subject exists than what you find in Appendix A. Get it?

 

[avbug]

True. A certificate holder can obtain authorization for pilots to perform certain items of preventative maintenance. It does not need to obtain an authorization to do things like add oil, which is NOT an item of maintenance preventative or otherwise.

Again, you are wrong, which is consistant...as you've been wrong about everything you've stated from the outset. Adding oil may be complex in nature, and for a certificate holder, may require an authorization and documentation of training. The Piaggio Avanti, for example, requires that one climb onto the wing, remove fifteen self-locking internally threaded (and expensive) screws, remove a panel, and remove a cannon plug before unlocking and removing the dipstick to check the oil...which must be done within 10 minutes of engine shutdown. Not quite the same as dropping a quart in your 172 is it, pal? Add too much, blow a seal, lose the engine...not good. If operated by a certificate holder, adding oil requires FAA approval, an approved training program, certification of completion of that training program, and pilot approval to check or service the oil.

Numerous aircraft require more than flipping a latch and unscrewing a dipstick to check fluids or service them...but your experience with your examiner in your 172, over which you won't be losing any sleep, has made you an expert on that subject, so we needn't say more. Need we?

etc etc.

Irrelevent, as is the rest of your rambling about magnafluxing and so on. The question is the legality, not whether I understand the proper way to do it or have the tools.

Hardly irrelevant, as the question of legality with respect to your ability to perform any given operation demands that you meet all the requirements of the operation. If changing a tire requires that the wheel halves and bolts be magnafluxed, then it must be done, and if you're not qualified to do it, then you can't do it, and you can't change that wheel out. It's very relevant, indeed. You need to know this from reading the current publications for that wheel assembly...all of them. This includes wheel manufacturer, tire manufacturer, brake manufacturer, and airframe manufacturer, as well as applicable airworthiness directives, and in most cases, research in the aircraft logs to determine cycles, previous work and compliance, etc. All of this before you can touch the part. Very relevant.

W(h)eather you have the calibrated tools called for in the approved documents, know how to use them, have the training and experience to perform the work to industry standard, and the ability to execute all the necessary documentation, is extremely relevant, as it's the crux of the legality of the matter. But you knew that too, didn't you, expert?

Sure. It requires a maintenance entry under 121, because that's part of our approved maintenance program. It requires a maintenance entry if you have to remove a panel or cowl. Otherwise, it's not. It's routine servicing, no different then adding fuel.

In a piston engine, true. Not in in a turbine engine.

49-31-02

AD 49-31-02 involves installation of a placard. It requires one-time compliance, in installing the placard. It does NOT require compliance or a log entry during fueling, as compliance is satisfied by installing the placard. What AD's have you located specifically regarding fueling the airplane? I'll give you one. AD 60-13-03 requires compliance at each fueling in certain Lockheed aircraft...and if compliance is necessary, a maintenance entry is necessary. Fly anything with a required fuel additive? Is it mandated by an AD? Even if it isn't, is it blended to spec by weight or percentage, and have you made that determination? Does an AD require the use of certain fuel tank treatments in your aircraft, and if they've been done, have you checked to determine the legality of adding fuel and by what percentage you can do the mix? You knew about that, didn't you? If you didn't and screwed up, you were unable to perform proper servicing of the aircraft, allowed in theory by Appendix A or any other location...and it needed to be done by a certificated mechanic. But you knew that too, right?

Flown a Mooney? Know about AD 2004-25-04 and compliance with each fueling, depending on the specifics spelled out in the AD? Depending on your AMOC, a log entry may be required every time you fuel or preflight...and that for your "routine servicing." Go figure.

But this thread isn't about fueling or hydraulic fluid, though you've certainly attempted to make it so. It's about Nitrogen. Nobody's addressed this regulation so far, but 14 CFR 25.733(e) specifically requires nitrogen, as a function of certification (and subsequent airworthiness for aircraft certificated under Part 25) in large aircraft over 75,000 lbs:

(e) For an airplane with a maximum certificated takeoff weight of more than 75,000 pounds, tires mounted on braked wheels must be inflated with dry nitrogen or other gases shown to be inert so that the gas mixture in the tire does not contain oxygen in excess of 5 percent by volume, unless it can be shown that the tire liner material will not produce a volatile gas when heated or that means are provided to prevent tire temperatures from reaching unsafe levels.

Moving right along...

Anther one I pulled out of "thin air" to support a "100 % incorrect point"

Your point was that...

Plenty of "certified mechanics" have killed themselves by attaching unregulated 3000 psi nitrogen bottles to aircraft wheel assemblies.

To which I correctly replied that this is an extremely rare occurence.

Of course, the article that made you an authority and expert on the subject claims that...

Thousands of airplane tires are inflated during routine maintenance each day around the world. On occasion, a mechanic or other ground service employee has been severely or fatally injured in an explosion caused by use of unregulated pressure from an air or nitrogen tank. The latest reported incident occurred in 1998 when a mechanic was inflating a nose wheel/tire assembly on a 737 airplane. A total of five similar incidents have been reported as the cause of severe injury or death to maintenance personnel

According to you, plenty of certificated mechanics die from this action...your point is irelevant because it doesn't apply to anything under discussion...nevertheless, you introduced it...plenty of mechanics die doing foolish things during routine servicing. According to the evidence you introduced, thousands of tires are serviced daily. Being a multiple of a thousand, let's stick with the minimum number of two thousand, and multiply that by 365, as these thousands are being serviced daily. This gives us a minimum of seven hundred thirty thousand tires serviced annually, times eight years, as the reported 737 tire explosion occured in 1998...in the intervening years, eight in total, we can see a minimum of fifty eight million, four hundred thousand tire inflations by maintenance personnel. Of these, five have been reported to have been done directly from the bottle, for a microscopic rate that apparently establishes your definition of "plenty."

Your definitions are clearly skewed, as are your examples to support incorrect points, your incorrect use of inappropriate and inapplicable airworthiness directives that are off-topic and irrelevant (did you read them?). The one link you did provide includes one paragraph of use, which does apply to the topic at hand, as follows:

Inflating wheel/tire assemblies only with nitrogen.
Tires must be initially inflated only with nitrogen. However, air can be used to top off a low-pressure tire if the airplane is in a location where nitrogen is not readily available, provided that the oxygen content does not exceed 5 percent by volume. Optional procedures for ensuring that the oxygen content in the tire will not exceed 5 percent are typically found in chapter 12 of the AMM. These procedures include a table that lists the maximum refill pressure versus the initial tire inflation pressure. The sum of all air pressures added to a given tire cannot exceed the pressure shown in the table for the corresponding initial inflation pressure.

Thanks for playing.

 

[avbug]

From Advisory Circular AC 43-12A, Preventative Maintenance:

4. PREVENTIVE MAINTENANCE.

a. The holders of mechanic and repairman certificates, persons working under the supervision of these mechanics and repairmen, repair stations certificated under Part 145, and air carriers certificated under Parts 121, 127, and 135, are authorized to perform preventive maintenance. These persons are also authorized to perform other maintenance. Therefore, it is of little consequence to them how a particular function is classified, since they are authorized to perform the function as either preventive maintenance or as other maintenance. Further, the procedures used in approving for return to service and recording are identical. This AC will, therefore, consider preventive maintenance from the owners/operators point of view.

b. FAR Part 1, Section 1.1, defines preventive maintenance as "...simple or minor preservation operations and the replacement of small standard parts not involving complete assembly operations."

(1) FAR Part 43, Appendix A, paragraph (c) contains the list of those functions determined by the FAA to meet this definition. If a function does not appear in this list, it is not preventive maintenance. Further, because of differences in aircraft, a function may be preventive maintenance on one aircraft and not on another. To provide for this, paragraph (c) contains the limitation, "Provided it does not involve complex assembly operations" on the aircraft involved. Owners and pilots must use good judgment in determining that a specific function may appropriately be classified as preventive maintenance.



--Merely because an item is listed in Appendix A, does NOT mean that a pilot can perform that function as preventative maintenance!!




From FAA Publication P-8740-4A, Safety Guide for Private Aircraft Owners:

12. PREVENTIVE MAINTENANCE
"Preventive maintenance" means simple or minor preservation operations or the replacement of small standard parts, not involving complex assembly operations.

a. Who May Perform Preventive Maintenance
The holder of a pilot certificate issued under Part 61 of the Federal Aviation Regulations may perform preventive maintenance on any aircraft owned or operated by him that is not used in air carrier service (ref. FAR 43.3(h)). All other maintenance, repairs, rebuilding, or alterations may be performed by persons authorized to do so by the Federal Aviation Administration.

b. Methods, Techniques, and Practices
When performing any of the preventive maintenance items that are allowed, you must use methods, techniques, and practices acceptable to the FAA. You must do the work in such a manner and use materials of such a quality, that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition. As modern day aircraft becomes more and more intricately engineered, preventive maintenance on some of the aircraft components is an exacting job, even for the experienced aircraft mechanic.



From 14 CFR 1.1, Definitions:

Preventive maintenance means simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations.

Standard parts are defined by 14 CFR 21.321(b)(3) as included in Class III parts:

(3) A Class III product is any part or component which is not a Class I or Class II product and includes standard parts, i.e., those designated as AN, NAS, SAE, etc.

Standard Parts are also defined as spelled out in the Federal Register Preamble (Volume 62, number 43), dated March 5, 1997:

"Standard part" is not otherwise defined in Title 14. Section 21.303(b)(4) has come to be understood by the aviation and manufacturing public as meaning a part, the specification for which has been published by a standard setting organization or by the U.S. government, and the FAA has traditionally regulated parts production with that understanding. Examples of such "traditional" standard part specifications include National Aerospace Standards (NAS), Air Force-Navy Aeronautical Standard (AN), Society of Automotive Engineers (SAE), SAE Aerospace Standard (AS), and Military Standard (MS). The FAA will continue to consider parts conforming to these specifications as standard parts.

Therefore, preventative maintenance means simple or minor preservation and replacement of small standard parts designated by an AN, NAS, SAE type standard designation...not anything involving a complex assembly. One should note that complex assembly doesn't mean the difficulty of assembly, as some often erroneously assume. Complexity of assembly involves the type of assembly and the complexity of its' nature, or overall design.

Note the following as indicated in Advisory Circular AC 21-29B Detecting and Reporting Suspected Unapproved Parts:

Note: Standard parts are not required to be produced under an FAA Approved Production Inspection System, therefore it is incumbent upon the installer (and the producer) to determine that the part conforms. The part must be identified as part of the approved type design or found to be acceptable for installation under part 43. Refer to AC 20-62, for additional guidance on this matter.

This places an additional burden on the individual performing preventative maintenance to determine that a part conforms to published standards. Merely because one has purchased a locknut from Aircraft Spruce or some other retailer or supplier, does not mean the part is a valid conforming part; if you torque, install or use that part in any way, you are responsible for compliance and the authenticity of that part, legally. If that part should fail, you are also responsible for the failure. A seldom appreciated aspect of preventative maintenance. You must be able to verify parts compliance to legally perform the function, right down to the cotter pin you use.

Additionally, to be legal, you must be able to determine that a standard part which is authentic is in compliance. For example, a fiberlock nut must not be turnable with the fingers once the fiber material meets the bolt threads. If the part is authentic, but doesn't meet specification or industry standards (see AC 43.13), the part isn't legal, the work isn't legal, and the operation may not be performed. If the person performing the preventative maintenance (eg, private pilot, for example) cannot make this determination, the work may not legaly be performed.

More to legality than may meet the eye.

Note the following paragraph from the same Preamble cited above:

It is important to remember that 14 CFR Part 21 § 21.303 deals with the production of parts for sale for installations on type certificated products. Installation of replacement or modification parts including owner/operator-produced and standard parts, must be accomplished in compliance with part 43 of Title 14 of the CFR (Part 43). Generally, a standard part may be replaced with an identical standard part, in accordance with the manufacturers maintenance instructions, without a further demonstration of compliance with the airworthiness regulations. Substitution of a standard part with another would require a demonstration of acceptability in accordance with part 43.

Swapping one type of fastener for another, such as using a castelated nut in place of a fiberlock or visa versa, will require a demonstration of acceptability, and until that's accomplished, the part remains unairworthy...even though both parts may be standard and authentic per spec.

The point is that more exists with relation to maintenance than merely reading appendix A and executing what's listed there. An item may be listed, but you may not be able to do it...and if you do, there's a whole lot more involved in being legal in doing it than you may think.

 

[avbug]

etc etc.

Irrelevent, as is the rest of your rambling about magnafluxing and so on. The question is the legality, not whether I understand the proper way to do it or have the tools.

Again, to touch on your assertion that this is a question of legality...the following addresses the minimum that is required to be legal...including the fact that merely because an item is listed in Appendix A, doesn't mean you can do it, legally...

AC 43-12A:

b. FAR Part 1, Section 1.1, defines preventive maintenance as "...simple or minor preservation operations and the replacement of small standard parts not involving complete assembly operations."

(1) FAR Part 43, Appendix A, paragraph (c) contains the list of those functions determined by the FAA to meet this definition. If a function does not appear in this list, it is not preventive maintenance. Further, because of differences in aircraft, a function may be preventive maintenance on one aircraft and not on another. To provide for this, paragraph (c) contains the limitation, "Provided it does not involve complex assembly operations" on the aircraft involved. Owners and pilots must use good judgment in determining that a specific function may appropriately be classified as preventive maintenance.

(2) A pilot may not perform preventive maintenance on aircraft used under Parts 121, 127, or 135, even when the pilot owns the aircraft.

c. Persons authorized to perform preventive maintenance. In addition to those persons listed in paragraph 4a of this AC, Section 43.3(g) authorizes the holder of a pilot certificate issued under Part 61 to perform preventive maintenance. Section 43.7 limits the privilege to persons holding at least a private pilot certificate and Section 43.5 prohibits operation of the aircraft unless approved for return to service. Further, pilots may only approve for return to service preventive maintenance which they themselves have accomplished.

d. Applicable performance standards.

(1) FAR 43.13 requires preventive maintenance to be done using methods, techniques, and practices acceptable to the Administrator. These are normally set forth in the manufacturer's maintenance manuals; however, some may be found in ACs published by the FAA.

(2) FAR 43.13 requires the use of the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. This means that the proper tools and test apparatus must be used. Normally these are listed as part of any FAA-approved manufacturer's maintenance literature.

(3) FAR 43.13 also requires that any special equipment recommended by the manufacturer or its equivalent must be used in a manner acceptable to the Administrator. This provision is more directly applicable to maintenance than preventive maintenance. However, it may come into play. Therefore, owners and pilots should be aware of it.

(4) Additionally, Section 43.13 requires that the work performed and the materials used are to be such as to ensure that, when the work is finished, the item worked on is at least equal to its original condition. Caution must be exercised because some functions which appear to be simple tasks may, in fact, be quite complicated. Care should be taken to ensure that the manufacturer's instructions are understood, the function is within the individual's capability, within the definition of preventive maintenance, and that it is listed in paragraph (c) of Appendix A of Part 43.

e. Recording preventive maintenance. Preventive maintenance must be recorded in accordance with Section 43.9 of FAR Part 43. This is done by entering in the maintenance record, of the item worked on, the following:

(1) "A description (or reference to data acceptable to the Administrator) of the work performed." This should indicate what was done and how it was done. This is normally quite simple for preventive maintenance; however, if the description is extensive, reference to documents containing that description is acceptable. These may be manufacturer's manuals, ACs, or other documents or references containing data acceptable to the Administrator. If documents other than types which are in common use are referenced, the document should be made a part of the maintenance record, as required by Section 43.9(a)(1).

(2) "The date of completion of the work performed." This is self explanatory and is the date on which the entry is made, as required by Section 43.9(a)(2).

(3) The kind of airman certificate exercised. When preventive maintenance is performed as authorized in Section 43.3(g), the certificate may be indicated in any manner which would be clear to the reader. For example: PP, CP, or ATP might be used to indicate private, commercial, or airline transport pilot, respectively. The certificate number is that number displayed on the certificate being exercised. Affixing a signature to the entry, which describes the work accomplished, constitutes approval for return to service, as required by Section 43.9(a)(4).

NOTE: Since owners/pilots are not authorized to approve work accomplished by others, Section 43.9(a)(3) is not applicable when preventive maintenance is performed by the holder of a pilot's certificate. The holder of the pilot's certificate doing the work is the only person who can sign the approval for return to service.

 

[ackattacker]

I have stopped reading. You've gone over the top.

The point is not that you're wrong, you're not. The problem is you're an A$$. I'm guessing this is not the first time someone has said that to you. The poster asked a simple question. He walked into an FBO, after presumably flying in on a normal GA or small jet type aircraft, presumably with normal aircraft type tires. You know, the kind with valve stems sticking out of them where you can get to 'em.

He asked the FBO if he could fill his tires with nitrogen. They said that using the nitrogen required a mechanic. He now asks the board "hey, is this right or are they feeding me a line of BS? Is there something in the regs which specifically prohibits me (a pilot) from filling these tires with nitrogen (as opposed to air)?"

I answered that no, the regs don't make a differentiation between filling a tire with air and filling it with nitrogen. The FBO is feeding you a line of BS, because the regs don't in general require a mechanic to fill a tire. In fact, the regs don't actually mention filling a tire at all. That is the end of story, all a normal person needs to know.

I *incorrectly* stated that it would be an item of preventative maintenance. In fact, as you have (eventually) pointed out, it is not *normally* an item of preventative maintenance, although it could be if it involved some more complex steps. Normally, filling a tire does not even make it the level of "preventative maintenance".

Your response to my post was both condescending and confusing. You brought transport category aircraft into it, approved maintenance programs, and a bunch of discussion about all the detailed technical knowledge you need to perform a full-on inspection and repair of a wheel assembly. Your first post strongly implied that a mechanic was *normally* required to fill a tire with either air or nitrogen, which I naturally took issue with.

Let me ask you a question: If someone asks you a simple question, say "is the sky blue", is the answer "yes"? Or is a 15 page rambling discussion about how the sky may or may not be blue depending upon your altitude and whether or not a volcano in Indonesia just erupted?

If I answer "yes, the sky is blue" does that mean that I'm too stupid to possibly understand all the technical ramifications of Rayleigh scattering and atmospheric science?

 

[ackattacker]

According to you, plenty of certificated mechanics die from this action...

Too me, even one mechanic dying from adding nitrogen to wheel is "plenty" to illustrate the point that it can be dangerous if done improperly. I don't think that's a skewed perspective. You wouldn't either if you were the one with your arms blown off.

You are so argumentative that you didn't even realize that I introduced it in support of your point that some items of maintenance should be done by qualified and trained individuals even if the regulations permit otherwise. You actually accused me of making it up.

 

[mtrv]

Well-----------

Thank god, that I'm legal to put nitrogen in my airplanes tires; and the fact that I have nitrogen tanks along with gauges to regulate the pressure; and have been using nitrogen for business purpose's at least 30 years or so.

I feel good!

 

[The_Russian]

The point is not that you're wrong, you're not. The problem is you're an A$$.

Avbug and A-Squared. One in the same?

 

[avbug]

The poster asked a simple question. He walked into an FBO, after presumably flying in on a normal GA or small jet type aircraft, presumably with normal aircraft type tires. You know, the kind with valve stems sticking out of them where you can get to 'em.

He asked the FBO if he could fill his tires with nitrogen. They said that using the nitrogen required a mechanic. He now asks the board "hey, is this right or are they feeding me a line of BS? Is there something in the regs which specifically prohibits me (a pilot) from filling these tires with nitrogen (as opposed to air)?"

I answered that no, the regs don't make a differentiation between filling a tire with air and filling it with nitrogen. The FBO is feeding you a line of BS, because the regs don't in general require a mechanic to fill a tire. In fact, the regs don't actually mention filling a tire at all. That is the end of story, all a normal person needs to know.

I *incorrectly* stated that it would be an item of preventative maintenance. In fact, as you have (eventually) pointed out, it is not *normally* an item of preventative maintenance, although it could be if it involved some more complex steps. Normally, filling a tire does not even make it the level of "preventative maintenance".

The truth is that filling a tire might be nothing, or may be a very big deal. Aircraft wheel assemblies are not car tires, and require special handling and attention. I did reply (#28) early to the post; numerous posters got carried away on incorrect points and information, missing the legalities, reasons, and purpose of nitrogen. You got carried away on multiple incorrect tangents regarding legalities of various forms of maintenance, and repeatedly attempted to defend your uninformed positions. Had you not been so bent on opening your mouth and appearing the fool, the thread would have been considerably shorter.

The regulations, advisory circulars, airworthiness directives, and approved data for numerous aircraft applications do make a difference, and do specify the use of nitrogen. You answered incorrectly when you stated that the regulations do not specify the use of nitrogen. As we have shown, numerous references are required to understand the regulation properly. Part 43 requires that work be done in accordance with approved data, and if an approved manufacturer maintenance manual or other aproved technical data dictates the use of nitrogen, then the regulation per Part 43 requires the use of nitrogen. Likewise an AD, or even an advisory circular, as required per Part 39 and Part 43 respectively, often serve this same purpose. We have seen that for some aircraft, the certification regulations themselves require the use of nitrogen...and we have seen in the same regulation the reason thereof.

Ultimately, even in your most basic point, your reply you have just cited, you were wrong...and can't even admit that much. I'm not particularly concerned that you wise up...clearly you either can't, or won't. However, I'm concerned that someone may be foolish enough to listen to you, and thereby get themselves, or their student, or even an unwitting third party, in trouble.

So yes, the regulations do frequently address not only what goes in the wheel assy, but how it's done, pressures, torques, inspection proceedures, practices and techniques, and standards for completion...right down to the percentage of oxygen that may be inside the tube or tire. This regulatory information may be in the Code of Federal Regulations, or any publication required to be used by the CFR...including AC's (eg, AC 43.13, etc) AD's, Service Bulletins, Manufacturers approved maintenance publications or instructions for continued airworthiness, and so forth.

You should take some time and get more familiar with Part 43...you're just as beholden to it as any certificated mechanic, and held to the same standard.

The original poster requested nitrogen from the FBO. The FBO advised that a mechanic was required to put in the nitrogen. Most likely the FBO isn't going to allow an unknown person not employed by the FBO to use their nitrogen; I wouldn't either. Liability is a big concern. The FBO may have a policy regarding the use of their nitrogen equipment by uncertificated persons or persons not employed and trained by the FBO to use that equipment. The equipment may belong to a maintenance contractor that only allows their mechanics to use it. The counter personnel may have been using their best guess. No information there has been provided, so we really can't say. The FBO may have been quite right with respect to their insurance, policy, or even with respect to the operation intended...bottom line is that it's their nitrogen, it's their equipment, it's their call.

You brought transport category aircraft into it, approved maintenance programs, and a bunch of discussion about all the detailed technical knowledge you need to perform a full-on inspection and repair of a wheel assembly. Your first post strongly implied that a mechanic was *normally* required to fill a tire with either air or nitrogen, which I naturally took issue with.

*With which I naturally took issue.* But as you like it.

Transport category aircraft because you adamantly insisted that no regulation requires the use of nitrogen in an aircraft tire. I cited a regulation that does.

Approved maintenance documents because the regulations require all work to be done in accordance with approved data (that pesky Part 43, again), which means that the regulation requires the use of nitrogen where the manufacturer approved data calls for it.

A discussion regarding inspection of wheel assemblies because any time you service that tire or wheel, it should be closely inspected...something you may not do on your car, but should certainly do on your aircraft...and cited points regarding which you were clearly not aware. Further, as you introduced the topic of pilots performing owner maintenance in accordance with Appendix A of Part 43, I addressed the reasons why your points were wrong...including a frequent need to perform advanced technical inspections of wheel assemblies when doing something as simple as changing a tire.

Each point discussed only because you brought it up.

And no, the sky is not blue. At some altitudes it may appear so, under certain circumstances...but you can get the technicalities from those energetic souls here that managed to go to school in their youth.

You've concluded post after post challenging me to prove you wrong...it's not challenge as you're wrong virtually all the time. You spend your time thinking up stupid questions and answers, and upon your invitation, so long as I've nothing better to do, I'll spend spare time explaining why you're wrong. Again. And again. And again. Have a ball.

 

[avbug]

Avbug and A-Squared. One in the same?

Now, there's an original idea.

No, not even close.

 

[ackattacker]

You answered incorrectly when you stated that the regulations do not specify the use of nitrogen.

I never stated any such thing. I stated the regulations don't differentiate between who is authorized to fill a tire with air and who is authorized to fill a tire with nitrogen. I never claimed the regulations fail to specify when one or the other is required, yet you seem to feel that was my point? Presumably the poster who wanted to fill his tires with nitrogen wanted to do so because it was required for his aircraft.

The original poster requested nitrogen from the FBO. The FBO advised that a mechanic was required to put in the nitrogen. Most likely the FBO isn't going to allow an unknown person not employed by the FBO to use their nitrogen; I wouldn't either. Liability is a big concern. The FBO may have a policy regarding the use of their nitrogen equipment by uncertificated persons or persons not employed and trained by the FBO to use that equipment. The equipment may belong to a maintenance contractor that only allows their mechanics to use it. The counter personnel may have been using their best guess. No information there has been provided, so we really can't say. The FBO may have been quite right with respect to their insurance, policy, or even with respect to the operation intended...bottom line is that it's their nitrogen, it's their equipment, it's their call.

A point which I made much more succinctly in my first post when I said "the nitrogen equipment is typically under the control of mechanics and they don't want you touching their stuff".

Transport category aircraft because you adamantly insisted that no regulation requires the use of nitrogen in an aircraft tire. I cited a regulation that does.

A never insisted any such thing adamantly or otherwise. That would be pretty stupid of me to argue, I agree. Where did I say that? It's easy to argue endlessly when you are writing both sides.

And no, the sky is not blue. At some altitudes it may appear so, under certain circumstances...but you can get the technicalities from those energetic souls here that managed to go to school in their youth.

Well, there you go. You did answer my question. I didn't ask if the sky was blue. I asked if you would give some sort of ridiculously technical, borish answer to such a simple yes/no question. The answer is that you would.