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?