new Cessna Seat track AD

[Tom-D]

Ah... so you could bolt the seat to the floor and climb over it to get in, and the FAA would still think an inspection was needed.

Yup, sounds like the agency we've all come to know and love...

I feel safer already.

The only seat track AD you will ever see is the one the company lawyers asked for when they try to sell parts.

You use words like Safety, Emergency, or Hazard to flight, when you ask for an AD and the FAA will rubber stamp the request, because they go with the idea you know your product better than they do.

Cessna did this when they got sued over a seat slippage accident in a C-185.
Precision Airmotive did this when they screwed up the Marvel carb.

 

[Skylane81E]

The only seat track AD you will ever see is the one the company lawyers asked for when they try to sell parts.

You use words like Safety, Emergency, or Hazard to flight, when you ask for an AD and the FAA will rubber stamp the request, because they go with the idea you know your product better than they do.

Cessna did this when they got sued over a seat slippage accident in a C-185.
Precision Airmotive did this when they screwed up the Marvel carb.

Gee and I thought Hartzel and Piper were the only ones

 

[Tom-D]

Gee and I thought Hartzel and Piper were the only ones

the list is long, and my typing is slow.

 

[Skylane81E]

the list is long, and my typing is slow.

 

[Stewartb]

Thread resurrection.

A couple of years ago I had a seat pin break in my C-180. Anyone care to guess what happened as a result?

Most of you think the seat slid, right? Wrong. The seat was jammed in the most forward position. For me that means I slide the seat forward until the seat cushion stops against the forward door post. That makes exiting the airplane difficult!

Here are some pictures to help understand the issues. First is a new MacFarlane seat rail. See the wear? That was after one flight. That may help put the lock hole wear issue into perspective. With the seat removed you can see the tangs that hold the seat on the rail. Some seat failures have come from the seat coming off the rails. That's the area of interest. If the tangs let go the pin comes out and the seat tips back/slides back. Notice the guide fixture for the pin. The lower couple of inches of the pin is straight. If it breaks it breaks on a bend above and that fixture maintains the pin-rail engagement. Pretty clever. Finally you can see the pin engaged and not engaged. Pilots slide their seats and sometimes it feels secure when the pin isn't engaged. THAT's the primary issue that leads to the sliding seat and subsequent full pull on the yoke. Bad news.

 

[Stewartb]

Part 2. The first pic shows the typical Cessna rail stop. Properly installed this will prevent the seat from sliding all the way back. Problem is many of us remove them. When my wife's seat slid the second time I had the rear seats out. Her seat slid back until the tangs came to the removal slot that you see and she went tumbling back from there. The next picture shows an Aero Stop. It's nothing more than a seat jammer that we slide up and lock in place. The problem is you have to remember to do it and in an emergency you have to remember to undo it. It sounds simple but it isn't the ideal solution. The ideal solution may not exist but the Cessna locking reel seat locks is the best thing I know of. It's a passive solution. The pilot doesn't have to do anything to lock or unlock it. The reels mount to seat structure and are locked from extending unless the seat adjust lever is lifted. They are not inertia reels that require motion to activate. They're fail-safe locked all the time unless the seat is intentionally moved. They aren't the easiest things to adjust but when it's right they work great. No seat slide or seat tip will happen with the locking reel working properly. Cessna has provided the reel for the pilot seat for free for many years. You can see that I use one on both seats. One seat safety is half a solution.

 

[Tom-D]

My problems with Cessna is, they never came out with a permanent solution to the problem to make the AD go away.
the 150 has this AD and every one who flys one puts the seat all the way back, who can it fail in that position?

But the original AD was written in blood. and cost Cessna 13 million bucks as a result of a 185 crash killing two.

An updated seat rail, and a new latch and make it go away,??? but no just keep inspecting every year, or 100 hours.

all I ever see is elongated holes and cracks in the rail.

 

[denverpilot]

Just a note: Cessna will pay for the reel on the pilot's side. They will not pay for the reel on the passenger side.

Tell passengers to never ever grab for the yoke and hope their reptile brain still doesn't do it subconsciously if they're headed for the back seat.

 

[denverpilot]

P.S. We are getting a little closer to the AD limits on our pilot side seat track every year.

Mechanic thinks maybe next year we will have to buy the McFarlane STC'd ones because of cracking, not the micrometer measurements.

The Cessna tracks are a significantly poorer design from a cheaper era.

Passenger side will probably last another ten years, it's in much better shape.

The big question for us is whether to bother doing the pax side to make them match. I don't think we care. The Cessna one will probably be over there a long long time.

 

[Stewartb]

My problems with Cessna is, they never came out with a permanent solution to the problem to make the AD go away.
the 150 has this AD and every one who flys one puts the seat all the way back, who can it fail in that position?

But the original AD was written in blood. and cost Cessna 13 million bucks as a result of a 185 crash killing two.

An updated seat rail, and a new latch and make it go away,??? but no just keep inspecting every year, or 100 hours.

all I ever see is elongated holes and cracks in the rail.

What would it cost we owners if the FAA required a wholesale change of seat and rail that would have to comply with current Part 23 certification standards? Do you think owners would complain? I would! The problem with our old seat tracks has been long identified and is well managed with appropriate maintenance and the locking reels. The AD is not a burden on mechanic or owner. That photo of the new seat rail is in my plane from the last annual. No big deal.

 

[Tom-D]

What would it cost we owners if the FAA required a wholesale change of seat and rail that would have to comply with current Part 23 certification standards? Do you think owners would complain? I would! The problem with our old seat tracks has been long identified and is well managed with appropriate maintenance and the locking reels. The AD is not a burden on mechanic or owner. That photo of the new seat rail is in my plane from the last annual. No big deal.

When your rails wear out wouldn't you upgrade to a better track?

 

[Stewartb]

Since you asked? I get along fine with the products and prescribed maintenance that we have now. I hear guys complain about seat tracks and locking reels and frankly I don't agree with their complaints. I appreciate that my seat's security has improved through the years.

 

[bnt83]

That secondary seat stop just sheet metal screwed to the seat frame? Really?

(Post #45 picture #3)


I've heard the secondary stop cables aren't very durable or inexpensive to replace to the point an owner I know is ready to remove the thing altogether.


I still find it odd that no service bulletin or AD ever replaced the seat latch spring with something stronger.

 

[Stewartb]

The sheet metal you see in that photo is a piece of scrap that's there to attach a fire extinguisher. On the articulating pilot seat the reel is attached to the seat's cross tube with two adel clamps. You can see the tube and clamps behind the fire extinguisher in this photo but the reel is hidden from view. When a Cessna Service Center does a reel installation they do a compete seat condition inspection and replace rollers and shims as required. They took no exception to the fire extinguisher being mounted there. The earliest locking reels had a cable installation problem that frayed some cables. They quickly came out with a solution and provided replacement cables. That's the only locking reel service problem I'm aware of.

The installation on the non-articulating co-pilot seat is different but I can't find a picture of it.

 

[Pedals2Paddles]

We just had one rail replaced and the reel installed on ours. I love the reel. That seat isn't going anywhere. Does anyone know what the cost is to have one installed on the right seat since it isn't free?

 

[denverpilot]

We just had one rail replaced and the reel installed on ours. I love the reel. That seat isn't going anywhere. Does anyone know what the cost is to have one installed on the right seat since it isn't free?

In think our shop said $500 or so installed.

 

[Henning]

What would it cost we owners if the FAA required a wholesale change of seat and rail that would have to comply with current Part 23 certification standards? Do you think owners would complain? I would! The problem with our old seat tracks has been long identified and is well managed with appropriate maintenance and the locking reels. The AD is not a burden on mechanic or owner. That photo of the new seat rail is in my plane from the last annual. No big deal.

I bet the rail cracking issue could be cured with some bushings.

 

[Tom-D]

I bet the rail cracking issue could be cured with some bushings.

how?..

 

[Henning]

how?..

Drill and insert Nibral bushings. The rails are cracking at the latching pin hole right?

 

[Tom-D]

Drill and insert Nibral bushings. The rails are cracking at the latching pin hole right?

no,,,there is no repair for a cracked seat rail, other than replacement. see the AD / SB for the cracks we are referring to.

 

[denverpilot]

The only fix is to stop using the lightest portion of the rail as a weight bearing surface when the thing flexes under weight of the seat.

It's a really dumb design. Even a non-engineer can easily see the McFarlane STC'ed replacement is way WAY better. More metal where it counts.

 

[Henning]

Would putting a high density plastic runner underneath it could help?

 

[denverpilot]

Would putting a high density plastic runner underneath it could help?

It'd have to go inside. It's a u-channel. Kinda. Maybe a hollow "t-channel" would be a better description without photos. Might help but there's better designs that have already gone through the (onerous) STC process.

Like Tom said, read the AD. There's photos in it. Really obvious when you see it and then look at a photo of the McFarlane replacement.

 

[Henning]

It'd have to go inside. It's a u-channel. Kinda. Maybe a hollow "t-channel" would be a better description without photos. Might help but there's better designs that have already gone through the (onerous) STC process.

Like Tom said, read the AD. There's photos in it. Really obvious when you see it and then look at a photo of the McFarlane replacement.

Well, I looked at the AD and Pics and I think a good bit of the problem is the foundation. A 1/4" Delrin strip as a 'rail bed' may be helpful.

 

[Stewartb]

MacFarlane rails are PMA replacement parts. They are not STCd. They are a little bulkier but not much. They may last a little longer than Cessna rails but they do not solve the problems of hole wear and cracking. The track that was replaced in my Cessna a few months ago was a MacFarlane.

Bushings would make cracking worse. A plastic strip wouldn't do anything. As it is the tracks have reasonable service life and are easy to replace. Why guys complain about it is beyond me. They fly 50 year old airplane's and grumble that a high wear part like a seat track shouldn't have to be replaced. Crazy.

http://www.mcfarlane-aviation.com/Products/?PartNumber=MC0511240-15&

 

[bnt83]

Rail cracking due to overweight pilots/passengers?




Quick question to all you Cessna drivers, how many rails have both the inboard and outboards drilled for the seat stop pins?

My 1968 Cessna 177 only has one stop pin per seat and only one rail per seat drilled for them.

The 1977 Cessna 177B has two stop pins per seat and both, (all 4 rails) rails are drilled...

It looks to me like the same lone puny spring on the 1968 is used to hold the two pins in the track on the 1977.

Last I checked, all my seats on the 1968 have provisions to add a seat stop pin. No new stop pins were available and the solid tracks would have to be replaced with drilled ones to accept the additional pins.

I'm a bit surprised that no one has come out with an AMOC to plug worn out holes. If you can't use those holes there would be no danger of the stop pin slipping out of them. I think a guy could come up with an aluminum plug and glue it on via EA9309.3NA adhesive or something. Then you could replace the track later when/if it cracks or more holes wear out.

 

[bnt83]

As it is the tracks have reasonable service life and are easy to replace. Why guys complain about it is beyond me. They fly 50 year old airplane's and grumble that a high wear part like a seat track shouldn't have to be replaced. Crazy.

Some tracks are easier to replace than others. On the 177 it sucks.

It all adds up. A 37 year old 177B I know could really use a set of wing tips, a new plastic panel overlay, a new nose wheel fairing, a new outboard seat track, a new center overhead plastic trim piece and I'm sure about another $10m in plastic crap.

 

[jnmeade]

I just fly a Piper.

I was right seat in a Piper Geronimo (Apache) making the take-off on my CFI-ME checkride when the seat unlatched and slid back. I lifted my hands up and said "your airplane". After I got the seat forward, latched and took control again he asked, "has that ever happened before?" "No, officer," I replied. I passed the checkride.

 

[Monte]

Some tracks are easier to replace than others. On the 177 it sucks.

Yes, I replaced all four seat rails in my 177RG. There are over 300 fasteners of three different types and about 6 or 8 lengths. Working under supervision of my A&P, I had almost 50 hours into that job. Removing the old ones without damaging them was as difficult as installing the new ones.

The McFarlane rails I bought are way beefier than the original stock rails in my '73 177RG.

All four rails cost me over $1100. These are definitely not 172 seat rails!

I'm glad that nasty job is behind me.

Monte