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Joined
Sep 5, 2004
Posts
113
Lately I have found myself very curious about the innards of the Cessna 152 that I rent. This is a plane that I fly all the time, solo, and yet I can not look at it and envision what is inside. How are the ailerons attatched to the wings? How are they moved? Why do I always check those little pins? I am looking for a very in depth description of the plane, and pictures and diagrams and the like too. Can you offer any insights?
 
I'm not Avbug, but might I suggest getting to know the mechanic that works on the aircraft. When not busy most would be happy to show you what's all inside or at least point you to the maintenance manual with all the pictures and diagrams.


Skeezer
 
Cutlass1287 said:
Lately I have found myself very curious about the innards of the Cessna 152 that I rent. This is a plane that I fly all the time, solo, and yet I can not look at it and envision what is inside. How are the ailerons attatched to the wings? How are they moved? Why do I always check those little pins? I am looking for a very in depth description of the plane, and pictures and diagrams and the like too. Can you offer any insights?
A C152 is constructed exactly like the starship Enterprise. When you push the throttle (little red knob) forward to the firewall you are releasing more Dilitium Crystals into the Dilitium Crystal burner. Make sure you have at least 1 hours supply of Dilitium Crystals before you fly 1 hour.
 
I like cake doughnuts because they were ordained by God for the use of man, just like black licorice. This information is found throughout ancient chaldaec, aramic, and hebrew records; the bible is chock full of it. The Koran is full of it (literally). Much of the tao of zen buddhism revolves around the study of the doughnut in it's utter simplicity and form. Manna. Doughnut. Donut. Whaghmatanga. Pnudot. Whatever you want to call it. In concert with black licorice, which was given to the Hebrews as a treat, and to the ancient egyptians to promote the runs long enough to let the acclimated Hebrews to escape, it has been ordained for the use and enjoyment of man (and woman, with man's permission, but that is the subject for another very long, hotly contested post).

One looking for the particular construction and workings of an aircraft should look to the manufacturers maintenance publications. Pilot handbooks are idiot books; manufacturers (and mechanics) view pilots as idiots, and write manuals, color gages, and produce cockpit indications accordingly. Meaningful information regarding systems and their function is seldom found in pilot handbooks; pilots who desire to know their aircraft know to go to the manufacturer maintenance publications.

For service and repair, look in the aicraft maintenance handbook. For information on the specific construction, working, and repair of the the structure or subsystems, look in the Structure and Repair manual (SRM) for that aircraft. For a breakdown on parts and their relationship, go to the Illustrated Parts Bulletin (IPB).

On the 152, you can see what holds the ailerons on, by standing beneath the wing and looking up while the aileron is raised. Piano hinge. The ailerons are acutated by a pushrod, which extends forward at aileron midspan to a bellcrank that is moved by direct cables from the aircraft yoke assembly.

During the next 100 hour inspection at the place where you rent, ask the shop if you can help assist during the inspection itself. Set aside a day or so and plan on sore wrists from moving lots of screws. You'll get to open up the airframe and see what lies beneath.
 
avbug said:
I like cake doughnuts because they were ordained by God for the use of man, just like black licorice. This information is found throughout ancient chaldaec, aramic, and hebrew records; the bible is chock full of it. The Koran is full of it (literally). Much of the tao of zen buddhism revolves around the study of the doughnut in it's utter simplicity and form. Manna. Doughnut. Donut. Whaghmatanga. Pnudot. Whatever you want to call it. In concert with black licorice, which was given to the Hebrews as a treat, and to the ancient egyptians to promote the runs long enough to let the acclimated Hebrews to escape, it has been ordained for the use and enjoyment of man (and woman, with man's permission, but that is the subject for another very long, hotly contested post).

One looking for the particular construction and workings of an aircraft should look to the manufacturers maintenance publications. Pilot handbooks are idiot books; manufacturers (and mechanics) view pilots as idiots, and write manuals, color gages, and produce cockpit indications accordingly. Meaningful information regarding systems and their function is seldom found in pilot handbooks; pilots who desire to know their aircraft know to go to the manufacturer maintenance publications.

For service and repair, look in the aicraft maintenance handbook. For information on the specific construction, working, and repair of the the structure or subsystems, look in the Structure and Repair manual (SRM) for that aircraft. For a breakdown on parts and their relationship, go to the Illustrated Parts Bulletin (IPB).

On the 152, you can see what holds the ailerons on, by standing beneath the wing and looking up while the aileron is raised. Piano hinge. The ailerons are acutated by a pushrod, which extends forward at aileron midspan to a bellcrank that is moved by direct cables from the aircraft yoke assembly.

During the next 100 hour inspection at the place where you rent, ask the shop if you can help assist during the inspection itself. Set aside a day or so and plan on sore wrists from moving lots of screws. You'll get to open up the airframe and see what lies beneath.
Thanks for your informative reply Avbug- I knew I could expect such from you; thats why I put your name right in the title. Not to be a dummy, but what is a bellcrank?
 
Avbug:

You have not even touched on the subject of snag lists that mechanics get from pilots...I could write a book on that subject alone.



Cat Driver
 
manufacturers (and mechanics) view pilots as idiots, and write manuals, color gages, and produce cockpit indications accordingly.
Every mechanic that read your post is laughing, even if they do fly airplanes. Every pilot is going "huh?"

Fly SAFE!
Jedi Nein
 
Squawks and snag lists. Where to begin? Pilots who report oil pressure low...check the oil and there isn't any reachable by the dipstick. You mean that aircraft engines use up oil? (they thought that was just in cars). Generator appears off. Find drive belt missing. (That one, I found the belt before the pilot reported it, and asked how his right generator was doing. He said fine. I showed him the belt, and asked how long it had been since he looked at the voltmeter. He got angry).

One brilliant crowd that squawked the beacon switch; each time they turned on the master and turned on the beacon, the left engine started turning. The shocker wasn't the fact that this happened, but that the operators felt the aircraft was okay, if they could just get it to stop doing that. The household wiring used in place of aircraft wiring didn't bother them.

Or finding corrosion next to the outflow valve on a Sabre 60. I showed it to the operator, and he told me to put the panel back on and forget it. His reasoning, for putting that panel back in place without treating the deep intergranular corrosion, was that the airplane would be sold soon, six months or a year. Then it might be someone else's problem. What if it fails under pressure? Let's hope that doesn't happen. So says the owner.

How about the crew on a C-130. One career military, a lot of time in Hercs. Another a military mechanic (the FE), with C-130 experience. A really brain dead F/O, with no particular maintenance or flight experience, but a big mouth. Called to squawk that their "propeller is leaking." Big pool on the ground under the #2 engine. Draining into the intake.

We flew three mechanics with parts and tools directly to the airplane. We started a semitractor rig with a spare engine and propeller assembly on it's way.

The Herc had ample tools and equipment on board, and a full set of ladders to do field-expedient maintenance. Our mechanic arrived on scene, took a 16' ladder out of the back of the airplane, and set it up on the inboard side of the #2 engine. He climbed up, removed the screws holding down the hatch for the pressurized sump. Under that hatch is a little hinged lid commonly called the "toilet bowl" lid, because that's what it looks like. It's set in place and secured with a pin. Leave the pin off, and the pressurized propeller fluid sump blows the hinged lid off, and performs it's own overservice; it pumps fluid all over.

The mechanic put in the pin, which was out, having been left out by the crew that was too lazy to climb up the ladder themselves and put it in place. He then put away the ladder, got in the airplane in which he arrived, and went home.

Thousands of dollars wasted, some 12 people inconvenienced half way across the country, the airplane down for a day, an engine stuck on the highway in transit, and the shop without their personnel, because three brightsparks couldn't be bothered to put the pin in themselves, or check it. Don't want to get dirty, now. And these experienced C-130 personnel, one of whom was a mechanic. All with full tool sets, training, and parts.

Engine ran rough and quit. Happens, when out of fuel.

Engine ran rough and quit. Happens, when running rich at high density altitudes; plugs fouled such that no electrode of ground visible through the glazing.

Engine ran for a moment and then quit very suddenly, then turned easily by hand. Happens when pilot hydraulic locks lower cylinders, busts rods by pulling through by hand, then cranks. Wonders why it's smoking and shaking and pranging so badly. Or the guy that decided to pull his propellers through by winding a rope around the prop hub and attaching the other end to his pickup truck...
 
One individual brought me his Cessna 140, and wanted an electrical upgrade. He had already dismantled the electrical system and removed the wiring, and couldn't remember how it went back together.

When asked what was wrong, I can't count the number of times that pilots have said something like, "It was making a funny sound." "It was doing something wierd." "It didn't seem right."

Recently a lightening strike that the pilot didn't report. Burns through the wings, propeller, radome, nacelles, and other places. His only squawks were minor interior trim issues; apparently the holes burned through the airplane (the pictures taken on scene with a digital camera clearly show daylight through the wing) didn't bother him too much.

Recently another pilot complained that his FMS kept tracking four miles off course in the heading mode, on autopilot.

One pilot squawked a voltage annunciator light on the airplane; he aborted a takeoff. I climbed into the airplane with him and noted that while applying takeoff power, both engines rolled back in RPM substantially while torque was increasing, then took off unevenly and very roughly. He wasn't interestedin the engine rollbacks; thought it was fine, but was very upset about the voltage.

One of my favorites occured one afternoon while I was kicked back in a small town terminal, doing nothing. A navajo reported in,and when he landed, I noticed that his left engine was feathered. He managed, after considerable effort, to turn around and taxi on to the ramp. The pilot climbed out, along with 13 people...like a clown car, except a piper navajo. The pilot approached, asking for maintenance assistance.

He indicated that he felt he'd had an oil leak, and had shut down his engine. He had just had two overhauled engines put on board, and the first flight was with paying passengers (the ones on board), when this occured. He had been at a canyon airport and drifted down to land at this rural field about the same time he ran out of range and altitude, luckily for him.

The engine had a hole in it. The mechanic who performed the work was notified. He wanted to know if we could tell the cause. Why, yes. The rod end had fallen off, and the rod had beat it's way through the engine case, and then the oil left through the hole in the case. Can you see the rod end, he wanted to know. Why, yes. It's down there. Why did it come off, he asked. It came off because apparently the end bolts fell out; they're lying at the bottom of the engine, visible wth the rod end, through the hole in the case. Why?

He reasoned that we ought to be able to put the cap back on, patch the hole, fill the engine with oil, and ferry it somewhere.

We hung up. Shortly thereafter, the mechanic left the country. The financial owners of the airplane called some time later, and asked me to go run the engine from time to time until they figured out what to do with the airplane. I obliged them. During the run, the brakes failed, the airplane lurched, and actually straightened out the S hooks on the tie down chains. The airplane got carted away a year later.

I recently reviewed a pilot training manual for a turboprop in which the pilot is directed to "lean the mixture above five thousand feet."

To say nothing of the things that get left in engines, left behind in safety critical areas, and fixed by pilots who think they're mechanics. One pilot told me he'd tightened the forward lower engine cowl attach bolts on a King Air, but that the nutplates must be stripped. He'd tightened them as much as he could, but they just kept slipping. I had to use a cheater baron a wrench just to remove two of them; my torque wrench didn't go high enough to measure their value. Apparently the tighter, the better.

Or another guy who used wire nuts to secure pieces of electrical cord from a household lamp, that was used to do the wiring behind his instrument panel.

Or the folks at a drop zone who asked me to do some work on their Cessna 180. Their pilot reported that the aileron trim was off just a little. It was out of annual, so rather than flying it, I began by checking the rigging agains the manufacturer maintenance manual. With the ailerons symmetrical, I noticed that the control yoke was turned half way left. I asked if this was normal in flight, and the pilot said no, normally it's turned all the way left, 90 degrees. I asked him how he made turns to the left. He didn't...make all turns to the right, and it's okay. Anything you can do to even it up a little, doc?

One pilot sqawked a gear unsafe light, but kept flying the airplane. On jacks, the gear was so loose in it's trunion that the trunion bracket and gear assembly moved independently from the wing; it was hanging on by several broken, and twisted undersized attach bolts. On another airplane the pilot(s) reported a popping noise each time they applied flaps in the pattern...but kept flying the airplane anyway. Turned out the spar was completely cracked through in three places. The popping noise was the spar grinding as it's position changed under an aerodynamic load.

We flew three avionics techs to a different C-130 once, to handle insurmountable avionics problems; terrible com. Turned out that a little re-education of the crew on how to use their volume control fixed everything.

I was in the process of doing work on a glider one night, and became tired. I placarded the glider as unairworthy, noted that none of the interior was attached or bolted in, set all the parts in the cockpit, secured the airplane, and flew home. I came back the next morning to find the sailplane gone. When the owner landed, back from giving some flight instruction, he saw me and chuckled. You're going to laugh when you see what I did. He had put everything back in place, setting it there unsecured, and went flying. The seat, and everything else in that cockpit was just sitting there, unattached. He thought that was funny.

Another pilot who espoused shutting off the mixture on student's while flying, called to report that he couldn't get the engine started. I flew to his location and found the mixture cable pulled out enough to interrupt fuel, and siezed in that position. Luckily it had happened on the ground, because had he done his trick in flight, he wouldn't have been able to restore power.

A write up for a fuel leak. Three to five gallons a minute. I found the person who made the writeup, and enquired as to how they knew that was the rate of leakage. "Because we put a bucket underneath it and it filled up in a minute."

Fair enough. But they couldn't duplicate it, and decided to go flying anyway. I put an end to that, and grounded the airplane. It took three hours of trying to duplicate it, but I did get it to leak, and it did leak a LOT. I found that the fuel feed line to the pressure carburetor had been fabricated using aeroquip hose and automotive air conditioning fittings...which didn't fit. I refabricated all the aircraft fuel lines properly and installed them myself. No more leaks.

And on it goes. I just love writeups like "radio doesn't work." Or
"Engine sounds funny." These tell me absolutely nothing, and make the person executing the writeup look like an idiot.

I really like the folks who never write anything up. "That thing is supposed to be missing fastners...they make them 150% stronger than necessary...you can afford to lose a few. Let's just bend it back, good as new. Gotta love it.
 
I have heard that if you are muslim that allah will fill the fluids for you and you never have to check. I think that is one reason they go through so many C-130's. ;)
 
Avbug -

Have you ever met another pilot/mechanic that was as smart as you? I truly believe you think you haven't.
You are incredibly arrogant.:( I realize you may have had some experiences (obviously) with some real idiots but does that mean you always have to talk down to everyone when you post. EVERY post you write is like that.
 
Swass said:
Avbug -

Have you ever met another pilot/mechanic that was as smart as you? I truly believe you think you haven't.
You are incredibly arrogant.:( I realize you may have had some experiences (obviously) with some real idiots but does that mean you always have to talk down to everyone when you post. EVERY post you write is like that.
And this is why I specifically requested that AvBug reply to my question- to avoided pointless, dimwitted replies such as this one. I asked Avbug a question, and he spent a great deal of time answering it for me. Most people I know charge for that type of thing.
 
Cutlass1287 said:
And this is why I specifically requested that AvBug reply to my question- to avoided pointless, dimwitted replies such as this one. I asked Avbug a question, and he spent a great deal of time answering it for me. Most people I know charge for that type of thing.
Are you saying that Avbug has a Swassier Swass than Swass does?
 
Cutlass1287 said:
And this is why I specifically requested that AvBug reply to my question- to avoided pointless, dimwitted replies such as this one. I asked Avbug a question, and he spent a great deal of time answering it for me. Most people I know charge for that type of thing.
His initial answer to your question was outstanding. He obviously has a tremendous amout of experience and knowledge to draw on.

Then you asked "but what is a bellcrank?" and he elected to skip your question in favor of a comment about squawks and snag lists with a 20,000 character rant about how stupid pilots can be. I think that's the part Swass might object to.


:(




.
 
My favourite is this one.

I had been training some "Pilots" ? for an outfit that were starting up a fish haul with four C117's, well it did not take long to figure out that I was not skilled enough to teach that group and quickly got the hell out.

The engines on a couple of the airplanes leaked so much oil that the pilots did not need a map to fly home, they just followed the oil trail back to home base.

One night I get a call from their new mechanic asking me for advice, he said the pilots were stuck way up north with one of the machines and the problem was when they accelerated for take off the oil pressure light came on just as the tail was going up, so they aborted and called in their problem.



I said the thing is out of oil...no said my friend both pilots are positive it is full of oil....



Two days later the mechanic phoned me from way up north and said, you were right the engine had so little oil left in it the pickup went dry on take off and on went the oil pressure light....of course as I suspected the pilots had been checking the oil by just pulling it out, looking at it and putting it back in right after shutting it down....without wiping it off first.

You just gotta love some of these guys.

Cat Driver
 
Ya gotta love folks like swass and tonyc. I spend my time attempting to contribute something, and these two jokers spend their time attacking posters.

Mostly me.

A belcrank is an angled piece of metal that acts as a directional hinge to transfer motion of a control rod around a bend. Picture a bomerang with a hole at the middle, and a pencil stuck through the hole. Push on one tip of the boomerang away from you, the other tip moves toward you. By using this device, one can change the angle and leverage of control rods, move control surfaces, do just about anything, mechanically. They may be used to change direction, to gain or lose mechanical advantage, etc.

Not all pilots are idiots, tony. Never the less, you work very hard to at least keep the pool open. Keep up the good work, you're doing a fine job.

When a radial engine quits dripping, it's out of oil. I used to spend a lot of time trying to change that, but no matter how many hours one puts in, an hour of operation changes it back to the way it was. O-rings harden, set, things shift, hoses and seals deteriorate, and things leak again. Lots of places to leak.
 
avbug said:
Not all pilots are idiots, tony. Never the less, you work very hard to at least keep the pool open. Keep up the good work, you're doing a fine job.
I didn't say all pilots are idiots. In fact, I didn't say anything ABOUT pilots being idiots. That must have been you.

It's "nevertheless," one word.

I have the audacity to challenge your pomposity, and that makes me an idiot?

Shucks, I was hoping you'd call me a brightspark again.

:rolleyes:




You know, it's a real shame. With the wealth of knowledge and vast experience you have to draw on, you could stand to be a nicer guy.
 
Give it a rest.. Correcting spelling? WTF? avbug has the experience, credentials, knowledge, accomplishments, etc, to come across however he wants to come across. Most all respect him, I being one of them... You don't like him? Block him, simple solution to a simple problem.

3 5 0
 
350DRIVER said:
avbug has the experience, credentials, knowledge, accomplishments, etc, to come across however he wants to come across.
That would be like me claiming I have the intelligence, education and credentials to correct spelling, punctuation, and grammar and "come across howere I want to come across." That's asinine. Nobody would tolerate it from me, nobody wants it from you, and Avbug is no exception.

Notice I wasn't the first to notice, or even the first to dare speak up on this thread.


Like the signature line says . . .
 
Don't belive AVBUG, the wings are held on with wingnails as are the ailerons. Just ask any A&P they will show you what one looks like.
 
trip said:
Don't belive AVBUG, the wings are held on with wingnails as are the ailerons. Just ask any A&P they will show you what one looks like.
Not wingnuts?

I would suggest that at your field there's probably a mechanic who, if you ask, will let you work for free. Look around, try to make some connections... start by assisting them with one of your club/FBO's airplanes and mention that you'd like to gain experience. I've been doing that one day a week while I'm finishing up my A&P. You will learn a lot, especially if it's a flight school... student pilots find the weirdest stuff to break :)
 
Like the sign says...

55.00 an hour if you let me work.

65.00 an hour if you watch me work.

100.00 an hour if you help me work.


So, tony, tell me. Do you contribute anything, or spend your time attacking other posters? Do you ever actually just respond and have input, or can you not post unless there is someone else to undo? Seems that at least you can be better than swass, brightspark.
 
avbug said:
Another pilot who espoused shutting off the mixture on student's while flying, called to report that he couldn't get the engine started. I flew to his location and found the mixture cable pulled out enough to interrupt fuel, and siezed in that position. Luckily it had happened on the ground, because had he done his trick in flight, he wouldn't have been able to restore power.
The quote below was taken from a thread on simulated engine failures
avbug said:
Again, quite incorrect. It does not address every component of dealing with an inflight engine failure. Realistic creation of the engine failure has not been addressed by pulling the throttle, and it must be. Mixture killing is appropriate. Most of the time I do this I then restore the power by pulling the throttle to idle and pushing in the mixture, after the student has properly dealt with the emergency, but not until the student has properly dealt with it. At that point, it is a descent at idle (or zero thrust, as appropriate). However, if I am unsuccessful at restoring power, it's not particularly significant, as I never pull the power unless I have assured that a successful landing can be executed. That may be over a road, field, beach, whatever will make a suitable landing site...even a nice long hard dry runway.
Note, the black bold was added by me. Now, I have great respect for Avbug's knowledge and experience. I think he knows a lot more than I. However, this makes him extraordinailry condescending. My question for him now is: Do you still proclaim that pulling the mixture is appropriate, or is it "Luckily it had happened on the ground, because had he done his trick in flight, he wouldn't have been able to restore power."?
 
U of I Tweak

Oh, Lordy, you're tweaking the Avbug. When I did that he promised me pictures. Haven't gotten them yet though. <g>
 
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