Using Trim to Climb?

SkyChaser

SkyChaser

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SkyChaser
I was reading the thread in Aviation Mishaps that has turned into a discussion about the seat sliding back on takeoff, and got to thinking about what to do if that happened. I always try to rock the seat backwards and forwards a couple of times when I'm buckling up, but I like having game plans for what to do in as many situations as possible.

So, I'm taking off. The seat starts sliding back. I can't reach the glare shield and I let go of the yoke because I'm not about to stall myself. I'm short, so there's a good chance I may not be able to reach the yoke at full seat back. If this was an airplane with a trim wheel, would it be possible to use that to maintain a climb to a safe height where you could level off and move the seat (or switch seats!)? Or would not being able to use rudder on climbout cause too much of a problem?

I know, weird question. :D
 
At takeoff trim, the airplane should gently climb on its own anyway. The problem with the seat sliding back is the pilot instinctively pulls back on the yoke and stalls the airplane. The solution is to just let go and let the airplane fly itself. One thing I always show my students is that the airplane actually flies better without the pilot.
 
I don't think it's likely you can reach the trim wheel if you can't reach the yoke.

Don't forget about the weight shift when the seat and its occupant slide rearward and create an aft CG. Particularly with a heavy pilot the plane is likely to pitch upward even if the pilot lets go of the yoke, making it even harder if not impossible to correct by pulling on anything in front of you, i.e. you need to pull the seat "uphill". I hope I never have the need to deal with this, but I think the best option might be to use your feet to push the yoke forward and hope you can make adjustments from there.

It might be interesting to put a crew member in the right seat, climb to altitude and simulate the event by sliding the pilot seat and occupant fully rearward, with the copilot assuming control. I say "interesting" because an the actual event would be very dependent on actual loading of the aircraft, including weights of the occupants.
 
Instead of thinking how to fly with the seat back, I'd think about how to move the seat, or reach the controls with it back. You can do that on the ground. Slide the seat all the way back with your seatbelt on. Can you reach the yoke or rudder pedals? If not can you slide yourself forward in the seat? Can you use the door handle or something else as a grab to slide the seat forward?

Rare event, but having an idea of what to do before it happens is a good exercise.
 
Add a supplemental seat lock. It’s second nature for every Cessna pilot I know.

My wife’s seat has slid back twice. The passenger is less likely to properly engage the seat pins so it make sense to add secondary locks on the right seat, too.

Cessna locking reels work great.
 
I agree with both Skychaser and Midwestpa.

The plane in takeoff trim will climb after rotation, but the weight shift aft will steepen the climb. Working the trim wheel to get a better rate and angle is a wise move. If the plane is stable, whether turning slowly due to torque, you are safe.

Opening the window gives a safe place to grab to pull yourself forward.

Take your time, formulate a complete plan on getting forward without contact with the yoke. As Skychaser points out, if solo, climbing into the right seat is a good option. Fasten your seat belt before flying the plane when you are in that seat, unless the plane has done something unusual.

Then return and land to straighten out the left seat issues, double checking all check list items, and LOOKING at every control moved. Mirror image moving engine controls is sometimes done on first time flight from the right side. Pulling the carb heat on with the mixture knob produces silence, I personally did that. Solution, if doing something and the result is not what you want, undo it :). Good landing.
 
dbahn said:
I don't think it's likely you can reach the trim wheel if you can't reach the yoke.
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Wouldn't that depend on the location of the trim wheel, Dave? Sure, in a Cessna you'd have a problem reaching the trim but, for example, the PA28 and Mooney trim wheel is between the front seats and would be reachable even with the seat all the way back.

But there are other issues with the situation. A small movement of the trim wheel might be enough to overcome the CG change from the seat sliding back. But the seat all the way back also means lack of rudder control.
 
Stewartb said:
You guys have vivid imaginations. A solo pilot seat slide is nearly impossible to recover from. Prevention is the only action plan.
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Have you tried it at altitude?

I agree it is unlikely, mainly because not only does the pilot hold on to the yoke, the natural reaction is to pull on it to stop the slide back.

Maybe we need a handle like the F/A-18 for cat shots. One hand on the yoke (for us) and one hand on a handle to pull if the seat slides. :D
 
A lot depends on the plane, the configuration, the weight of the pilot, & how much the CG shifts. If you were doing a short field takeoff, you’d likely be sunk regardless. Older Cessnas used to have hand straps on the door frame pillar. Maybe we should bring those back. (It a think knotted rope attached to the panel).

it seems Cessnas are about the only planes with enough rail to make much difference, compounded by the trim wheel being on the panel.
 
midlifeflyer said:
Wouldn't that depend on the location of the trim wheel, Dave?
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Good point. I was thinking Cessnas because that's what I've flown most often.

Another consideration is that if the aircraft was loaded at or near gross weight and the CG was nearly full aft, the shifting of the pilot weight further aft could make recovery aerodynamically impossible. If the CG is nearly full forward, you'd have a better chance at it.
 
I would suggest that the fix be at the source of the problem ... design a proper seat rail with locks that actually work.

Stewartb's suggestion to add supplemental seat locks is a good one ...
 
Stewartb said:
You guys have vivid imaginations. A solo pilot seat slide is nearly impossible to recover from. Prevention is the only action plan.
Click to expand...

It's like y'all forget you can take the seat belt off.
 
Stewartb said:
You guys have vivid imaginations. A solo pilot seat slide is nearly impossible to recover from. Prevention is the only action plan.
Click to expand...
It happened to a friend of mine on takeoff, right after rotation, he was solo. He managed to recover, but I don't remember the details. It was years ago, in a rented 172.
 
Dana said:
It happened to a friend of mine on takeoff, right after rotation, he was solo. He managed to recover, but I don't remember the details. It was years ago, in a rented 172.
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I had the Cessna seat slide happen. Undid the belt, slid myself to the front edge of the seat. Got the plane leveled. Reset the seat. Made sure it was locked in. Buckle back up. The single track (get it?) mind of people never ceases to amaze me. Break the *** **** rules if you need to.
 
Daleandee said:
I would suggest that the fix be at the source of the problem ... design a proper seat rail with locks that actually work.

Stewartb's suggestion to add supplemental seat locks is a good one ...
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Cessna DID design a seat rail that actually works. It's in all the restart airplanes. It's a good system.

The Cessna supplemental lock works, but it is a real pain to get rigged so it works properly. I have installed many of those, and the control cable routing and adjustment is really critical. I have found some, installed by other shops, that didn't work much at all and had to be corrected. False insurance if it's not done right. The SK instructions are very detailed as to how it's to be set, and it takes time.

But the real problem in this whole discussion is maintenance of those rails and locks and seats. There is an AD, 2011-10-09, that superseded an AD from 1987 that dealt with Cessna seat rails and locks. Judging by what I regularly found in airplanes, neither of those ADs have been taken seriously by mechanics, and of course the seats might slide. Badly worn and/or cracked rails, lock pins too short, roller housings shot. Lock springs missing. Seat stops in the wrong places. Then I'd sometimes find other problems with the seats, like cracks or worn parts that could result in the seat back failing and falling back, with the same sort of effect as a sliding seat.

Maintenance matters, and so much "maintenance" is nothing more than a casual look. You can't properly do that AD without taking the seats out. The AD: https://wwwapps.tc.gc.ca/Saf-Sec-Sur/2/cawis-swimn/AD_dl.aspx?ad=2011-10-09&cn=US&ft=pdf
 
Stewartb said:
You guys have vivid imaginations. A solo pilot seat slide is nearly impossible to recover from. Prevention is the only action plan.
Click to expand...

Well, you could put your foot on the yoke and push. Legs are much, much stronger than arms.

I will point out that in a short body Mooney, this is never a concern.
 
Happened to me once in a Cessna 150. I had one hand on the yoke, the other on the throttle. When the seat slid back I immediately let go of the yoke, but instinctively tried to hold myself with the throttle...pulled the throttle to idle! I put both feet flat on the floor, slid the seat forward with force from my legs, pushed the throttle back in, then turned into the pattern to land. The seat pin completely quit. I bought the seat locks after that (it was my own Cessna).
 
bflynn said:
Well, you could put your foot on the yoke and push. Legs are much, much stronger than arms.

I will point out that in a short body Mooney, this is never a concern.
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Also an excellent suggestion!
 
totally related............in high school a buddy had a souped up car with holes in the floorboards so you could actually see the road underneath your feet, but also the seatback locking thingie was broken so he kept a basketball behind the seat so it wouldn't go all the way back. a basketball.....$2 at a garage sale....c'mon, people.......problem solved!
 
Great point Skychaser about the trim. Just letting go isn't necessarily the first thing that comes to mind for sure!

As I think about this, if I ever do get my own plane...or if I follow through with my idea for a retirement project of building a kit of some type....I'm making a mental note to add a sturdy handle up on the panel or someplace strategic. Could be helpful just generally as in adjusting the seats in normal operations, getting in and out, etc...

I still remember the fear I had that the little cushioned glare shield brow was going to rip right off and I was trying to be real careful to only pull just as hard as I needed to and no more!
 
eman1200 said:
totally related............in high school a buddy had a souped up car with holes in the floorboards so you could actually see the road underneath your feet, but also the seatback locking thingie was broken so he kept a basketball behind the seat so it wouldn't go all the way back. a basketball.....$2 at a garage sale....c'mon, people.......problem solved!
Click to expand...

Nice!!!
If you fill it with helium will you gain some useful load?
 
The seat sliding back and recovery could be a statistical enigma. There’s no form w/a check box and no one wants to walk into the FBO bragging they recovered from the seat sliding back, because the didn’t check it on pre-flight. Generally the only ones we hear about are the ones that end poorly.
 
Stewartb said:
You guys have vivid imaginations. A solo pilot seat slide is nearly impossible to recover from. Prevention is the only action plan.
Click to expand...
Happened to me twice. Non-event both times except for being startled. I have long arms and legs, so seat was pretty far back already. First time I thought I forgot to shut the lock, second got me to look at the rails. Repaired and all good now.
 
Maybe I am missing something but in a older Cessna if the seat were to slide all the way back would it lock or is it because the lock broke. If it didn't break and only just slid backwards you would need both hands: one under your left knee to release the seat and the other to help you pull so nothing is on the yoke.

On our first annual we had the floor belt installed in the skylane (part is free from Cessna/Textron) and labor was 1hr. Way better than that ridiculous extra pin.

I know some people have arm rests installed in 182's I would think that would be a great place to grab.

Our glare shield is so old it would probably rip right off.
 
my seat can’t slide back because I have it safety wired directly to the yoke.

95a47090dcfc47a23856a85199e89aa0.jpg
 
Sinistar said:
Maybe I am missing something but in a older Cessna if the seat were to slide all the way back would it lock or is it because the lock broke. If it didn't break and only just slid backwards you would need both hands: one under your left knee to release the seat and the other to help you pull so nothing is on the yoke.

On our first annual we had the floor belt installed in the skylane (part is free from Cessna/Textron) and labor was 1hr. Way better than that ridiculous extra pin.

I know some people have arm rests installed in 182's I would think that would be a great place to grab.

Our glare shield is so old it would probably rip right off.
Click to expand...

I think the big issue with the cessna seats was that the seats could easily come off the track if adjusted too far forward or aft. Then the seat can tip, or rock back. That's what happened in my case.... the seat tipped back...sorta like when a kid sits in a straight chair and leans back on the rear two legs...gets a little past the balance point and to the floor he goes before he knew what hit him. It wasn't so much about teh seat not latching into place.

Although.... sure seems to be a whole lot of reports of that happening here too. Seems to me there's a lot more reports from folks with the seat sliding back than there is like mine where it tipped. Hmmmm...I'm feeling very blessed right about now.
 
eman1200 said:
totally related............in high school a buddy had a souped up car with holes in the floorboards so you could actually see the road underneath your feet, but also the seatback locking thingie was broken so he kept a basketball behind the seat so it wouldn't go all the way back. a basketball.....$2 at a garage sale....c'mon, people.......problem solved!
Click to expand...

I was thinking a cooler of Bee…I mean soda would do the trick
 
This has never happened to me. I make it a habit to make sure the bar or lever is in it's place after I adjust a seat. This includes attempting to move the seat after adjusting. But it can still happen. I'd just let go (hopefully). I always try to stay in trim while flying. Especially on take off. I estimate where the trim should be for take off, then as soon as I am off the ground I adjust out stick force. I do it constantly as needed. I try not to spend more than a few seconds out of trim. I'm thinking this would buy me time to get things sorted should that seat slide. I hope I never find out.
 
PaulS said:
This has never happened to me. I make it a habit to make sure the bar or lever is in it's place after I adjust a seat. This includes attempting to move the seat after adjusting. But it can still happen. I
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A properly inspected and maintained seat, checked by the pilot for positive locking, will not slip. It can't. Sure, Cessna's design was inadequate, but those airplanes were never designed to last 40 or 60 years and 15,000 hours. Stuff wears out. Even their new design, robust as it is, will eventually wear and make trouble for some pilot.

Some pictures from AD 2011-10-09, which is legally MANDATORY:

upload_2022-10-14_7-57-42.png
Wear of the lock pin hole in the seat rail. I have found them easily beyond this.


upload_2022-10-14_7-58-36.png
Lock pin minimum engagement. I have found them less than this. I prefer much more than the .150", but the minimum will positively lock the seat.

Then there's the spring, or springs (depending on aircraft serial number) that keep the pin in that hole. Found them missing, stretched or corroded and ready to break. All the rest of the mechanism, including the lever, has to be in decent shape as well. The AD is exhaustive in this stuff.


upload_2022-10-14_8-1-10.png
Seat roller housing wear. Those tangs reach under the rail and keep the seat on it. Most of them are aluminum and they gall and wear, and sometimes a clumsy mechanic or owner can spread them apart by twisting the seat as its being removed, with a couple of housings still on the rail, so they're barely grabbing the edges of the rail. Like so:

upload_2022-10-14_8-2-55.png

These dimensions are legal limits, and for good reason. When seats slip, something is beyond those limits.
 
that's a great look at the rail and latching mechanism. Thanks for posting that!

as I mentioned earlier though, I think the bigger issue was more about the seat coming off the rail.... not as much about slipping position.

Is there another AD that required the installation of those little stops to limit travel so that it can't go forward or aft off the rail?

Slipping position is in my estimation very similarly bad, but perhaps not quite as bad...seems more likely to slide to the next adjust point and then lock....but when it comes out of the track you're going all the way to lay in the back seat...unless you're lucky enough to grab something.
 
SkyChaser said:
I was reading the thread in Aviation Mishaps that has turned into a discussion about the seat sliding back on takeoff, and got to thinking about what to do if that happened. I always try to rock the seat backwards and forwards a couple of times when I'm buckling up, but I like having game plans for what to do in as many situations as possible.

So, I'm taking off. The seat starts sliding back. I can't reach the glare shield and I let go of the yoke because I'm not about to stall myself. I'm short, so there's a good chance I may not be able to reach the yoke at full seat back. If this was an airplane with a trim wheel, would it be possible to use that to maintain a climb to a safe height where you could level off and move the seat (or switch seats!)? Or would not being able to use rudder on climbout cause too much of a problem?

I know, weird question. :D
Click to expand...
Seats sliding back up unexpectantly is usually caused by poor seat and/or seat track maintenance.
 
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