Hey fellow flyers! I’m new to this forum and also a new aircraft owner. When I talked to an A&P before I got the plane he informed me that the lh seat bracket would probably not pass inspection this year. Just wondering if any of y’all have had to address this AD yet, and if so, what’s your advice? Any info will be greatly appreciated.
1966 Cessna 150F pilot seat AD
- Thread starter KY Flyer
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howdy
Are we talking about the roller tangs? If you're not able to bend it back into an acceptable gap, you'll have to replace it (possibly with a used part). There's no other way around it.
Dan Thomas
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"Seat bracket" really doesn't tell us anything. There are many places on a Cessna seat that can wear out or crack. Maybe the mechanic said "seat track" instead? Would make more sense. They're aluminum and the locking pins chomp away at the top rail around the pin holes when people don't lift the release lever far enough to get the pin clear of the track bedore they move the seat. There are dimensional limits to the wear around those holes and the amount that the pin sits down in that hole.
The tracks aren't that expensive from McFarlane. The cost is more in the labor to replace it.
There are other places to check that aren't mentioned in the AD. The 150's seat back adjustment uses a couple of cams on a shaft that runs through small steel tabs welded to the seat bottom frame. Those tabs crack. If the affair failed on takeoff, you'd flop right back into the baggage compartment, and the automatic reaction is to pull yourself back up. You end up pulling the yoke all the way back and the airplane stalls and crashes. See? Little things matter, even if they're not mentioned in the AD. The entire seat assembly needs a close look.
Cessna engineers never designed that system to last 50 years and 10,000 hours carrying 250-pound people. It's very light and we often expect far too much of it.
The tracks aren't that expensive from McFarlane. The cost is more in the labor to replace it.
There are other places to check that aren't mentioned in the AD. The 150's seat back adjustment uses a couple of cams on a shaft that runs through small steel tabs welded to the seat bottom frame. Those tabs crack. If the affair failed on takeoff, you'd flop right back into the baggage compartment, and the automatic reaction is to pull yourself back up. You end up pulling the yoke all the way back and the airplane stalls and crashes. See? Little things matter, even if they're not mentioned in the AD. The entire seat assembly needs a close look.
Cessna engineers never designed that system to last 50 years and 10,000 hours carrying 250-pound people. It's very light and we often expect far too much of it.
Dan Thomas
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Yup. It's at http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/144A3898BF71041A8625788F004B5DF2?OpenDocument
A Cessna seat lock failure resulted in General Aviation's largest lawsuit in history. A 185 on floats crahsed when the pilot's seat slid back on takeoff. The court awarded $450 million. Must be 20 years ago. Textron is probably still appealing it. There was obviously some lousy maintenance somewhere. The original AD was 87-20-03R2. The current AD superseded it and added more requirments.
cgrab
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You should go to the AD website and read all the AD's for your plane, engine, and appliances. Check them all to see that the one time ones were done and are in the logbooks and record those that are recurring like the seat and seat rail AD. Then look up "secondary seat restraint" and see if you can get one installed in your plane. They will prevent the seat from sliding back in a seat failure.
Actually it was $480 Million and it isn't being litigated anymore. Cessna and the parties settled for an amount rumored to be $41MM. Note only $80MM of the original award was compensatory. The other $400MM was punitive damages that weren't likely to stand up on appeal anyhow.
The sad truth is, despite assertions by the plaintiff and their "attorney," it likely wasn't the seat rails but the pilot's own hamhanded flying an inexperience int he plane that caused the crash. The NTSB found both front seats in the same position.
mtuomi
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I'm still wondering why this AD applies to the 150. Unless you are 4 foot nothing, if the seat slides all the way back, it's not a big deal.
I was going to post something similar. How does a seat or seat rail get worn out in a 150? It’s always in the aft most hole and rarely moves.
No idea, but one of ours got worn out several months ago to the point where the seat would slide back if you put very much pressure on the seat back. That little handle to adjust the seat position somehow wouldn’t stay down all the way, so it allowed the whole seat to move backward along the rail with little pressure. All in all, not much of a problem, but it became annoying having to readjust, if you decided to readjust your body.
Someone made the comment during the AD rulemaking that the FAA dismissed it saying "short people."
Tom-D
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The tracks crack, the roller seize, the holes wear.
Dan Thomas
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If they didn't apply it to the 150, some four-footer would crash and they'd get sued.
I think the point was that most of us don't even use the stops on the 150. I have the thing slid all the way back until it hits the end. But, as I said, this was discussed in the rulemaking. The FAA says "short people need the stop"
Dan Thomas
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Yup, and the roller housing tangs get worn and/or bent and the housing can come right off the track. Bad deal.
Dan Thomas
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Thanks for the update. Hadn't seen that.
Dan Thomas
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Doesn't apply to the 150. There's no room under that seat. You can barely get at the fixed seat stops as it is, to get the seat out. Installation of that kit doesn't eliminate the AD, either.
The SB for the secondary stop: https://www.google.com/url?sa=t&rct...?as_id=31366&usg=AOvVaw2SV__AxqHpZVDhDIkbf7xF
Tom-D
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Your's is the track most likely to fail.
Every track that I have changed had 1 hole that would not meet the criteria of the AD, Why? that is where the pilot always set the seat.
Matthew Rogers
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I fly my 150 with the seat quite far forward. I am 5’10”, and just like it that way.
SkyDog58
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Btw, for you owners who want a quick and simple way to check your pin holes, a 27/64 drill bit makes a good no-go gauge. It’s just a tad bit bigger than the .42” that you are allowed. So if it goes in a hole, the hole is definitely too large.
Lachlan
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Yeah, it’s always best if you have to work at it a little. If it goes in with out hitting the sides it’s definitely a no-go.
I’m not tall, and I like to pin my seat a couple clicks forward in my 150. I like using my feet for the pedals instead of my whole leg, I can see out really well that way, and I feel like I’m more connected to the airplane. I can see how anyone 6’ or taller would sit further back, though, and get the same thing out of it that my spot does for me. I also like a snug harness, and sitting forward allows me to reach everything on the whole panel easily.
Gerhardt
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It's been years, but I had that happen on a 150 owned in a partnership. It was like the seat was sitting on ice, and on takeoff...back I go. That was a near catastrophe.
I worked with the guy who replaced it. Always looking over his shoulder, picking his brain. Nice guy and he seemed to appreciate the company. He showed me what happened, why, etc. Tom was right on spot with his comments.
I worked with the guy who replaced it. Always looking over his shoulder, picking his brain. Nice guy and he seemed to appreciate the company. He showed me what happened, why, etc. Tom was right on spot with his comments.
Ravioli
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As an aside, you knew about this in the pre buy and didn't get it addressed before purchase? I hope you deducted for it in your purchase offer.
Dan Thomas
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It's more complex that that. From the AD:
If you can get the drill bit into the hole, the hole is WAY too big. That's why McFarlane sells a tool like this:
https://www.mcfarlaneaviation.com/media/documents/drawing-tool103-seat-rail-wear-gauge.pdf
The bottom of the hole doesn't wear. The pin engagement has to be at least .150 inches, and that's about the thickness of the top flange. Not much. The hole wears with a taper, leading to pin pop-out. This is what a worn rail looks like:
In fact, some seats right from the factory had less than .150" pin engagement. The tiny roll pin on the lock pin that stops the pin travel wasn't located properly. I've found that pin left out as a means of getting full engagement. The 180 and 185 airplanes seemed to be bad for this.
There must be 20 different seat designs. At least. That SB210-174B addresses the general groupings, but not the part number specifics.
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Ghery
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That's why I have 4.1 hours in a 150 (from back in my student pilot days, many moons ago) and will never increase that number. I'd run the seat all the way back (if it wasn't there already) and I'd still hit the bottom of the panel with my knees when going for the brakes. But, I'm not 4 foot nothing.
That said, get it checked and replace the bad parts if necessary.
SkyDog58
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You are absolutely correct. I was just providing a very crude way for the typical pilot to do a quick check so they could at least know if they had a real bad one or not. I wouldn't expect a pilot to buy the gauge or to get out any sort of measuring tools. I also wasn't suggesting that they use the drill bit for AD compliance.
And, therein lies the "gotcha". If the seat roller tangs don't pass the "go, no go" gauge test, you have a problem. The tangs of the seat frame assembly are not designed to be replaced, and when you start that search for serviceable salvage, good luck. Serviceable 150 seat frames are very difficult to locate. The salvage community is aware, and charge you accordingly. Even have been known to try to pawn off non-serviceable seat frames for the almighty buck.
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Until the pilot pulls on the yoke to right him/herself.
Mtns2Skies
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Rant incoming (Not just at you Rob)
Not sure what it is with PoA folks in particular assuming that EVERY purchase is a textbook call trade-a-plane, negotiate, pre-buy, negotiate, buy, sale of an aircraft. This is an aging fleet and to expect that every problem be taken care of by the previous owner is just ludicrous. The market doesn't support that way of thinking anymore. Many planes are sold as-is, some are such hot commodities that they have to be bought ASAP, some are barn/ramp finds, some are inherited aircraft. To be up on your high horse and spout "prebuy should have caught this prebuy should have that" will just leave you with no airplane at all. If you take ANY of your average GA fleet, replace the things that are aging or "should" be replaced then you'd negotiate every airplane down to about nothing... which is just preposterous. You're not buying a new aircraft, it's going to have problems, it's okay to ask about those problems WITHOUT snide and snarky comments about your pre-buy. PoA thinks you need to disassemble the aircraft down to atoms every pre-buy.
Even IF a good pre-buy does happen, mistakes can be made and small things can be overlooked i.e like seat rails. They don't cost that much and quite frankly in my pre-buy I was more worried about corrosion and engine health than I was the small things.
It's like the people that barn-find planes and expect it to have a brand new engine, and beautiful panel, it's just BS. They're old airplanes... they're going to need work regardless of the conditions of which it was bought. Let the OP ask his question.
/rant over
@KY Flyer welcome to the board... It can be sporty.
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Dan Thomas
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Some good points there. However, the seat rails and locks are an AD, not something that might be overlooked more often. The governments take ADs extremely seriously; in Canada we can't even get a ferry permit if an AD is outstanding. Besides, seat rails and locks are right there, easily seen, and can hardly be missed unless the prospective buyer gives the mechanic some ridiculously low time limit for the inspection, in which case he should have just bought the airplane without any prebuy at all.
And yes, the fleet is old. Cessna and the other manufacturers never dreamed that these things would still be flying 50 and 60 and 70 years after they were built. And as new airplanes get more and more expensive, the fleet will continue to get older yet. And as parts and labor go up, the condition of old airplanes will get much worse.