Controlling Aircraft with Failed Flight Control Surfaces

kontiki

kontiki

Cleared for Takeoff
Joined
May 30, 2011
Messages
1,122
Display Name
Display name:
Kontiki
A couple weeks back, an aileron cable broke in the PA28 I've been training in (for another student).

In general, any body know where to find good info on procedures for dealing with in-flight failure of control surfaces?

Thanks,
 
kontiki said:
A couple weeks back, an aileron cable broke in the PA28 I've been training in (for another student).

In general, any body know where to find good info on procedures for dealing with in-flight failure of control surfaces?

Thanks,
Click to expand...

I have a DVD set from Barry Schiff called "Proficient Flying".

In Vol.1, he deals with Control System Failures. I Don't recall if ailerons were covered. I remember him demonstrating flying with loss of elevator control by using trim and power.

He even took off and landed hands off to prove it can be done (which meant No ailerons). I'll have to look at them again. Very good set, I might add.
 
Last edited:
If the ailerons go, use the rudder. If the rudder goes, use ailerons. If the elevator goes, use trim and power.

The important thing is to stay calm. Declare an emergency and take straight in approach to the biggest runway you can find. Just remember that many pilots fly so poorly, you'd think they had a broken rudder or aileron cable.
 
dell30rb said:
Just remember that many pilots fly so poorly, you'd think they had a broken rudder or aileron cable.
Click to expand...
Darn, you were watching? I thought I was doing my touch & gos early enough this morning that no one saw. :rolleyes2:

Actually I'll ad that to my "to-do list"... see if I can develop decent technique for flying with any one control surface failed. To be honest, flying aircraft as old as a lot of us do, I'm more afraid of a broken cable than an engine failure. Justifiably so? I dunno, probably not.
 
Depends on the cable, and the weather. Either aileron or rudder failure, I'll take over an engine failure. Vfr conditions, I'd take an engine failure over elevator. Low imc, I'd rather lose the elevator.
 
kontiki said:
A couple weeks back, an aileron cable broke in the PA28 I've been training in (for another student).

In general, any body know where to find good info on procedures for dealing with in-flight failure of control surfaces?

Thanks,
Click to expand...

First things first. Stop renting from that outfit. Find a school that maintains its airplanes. There is no excuse whatever for an aileron cable (or any other part of the control systems) to reach the point of failure. They'll be fraying for a long time before they break, and in this case nobody was watching anything inside that airplane.

Dan
 
dell30rb said:
If the ailerons go, use the rudder. If the rudder goes, use ailerons. If the elevator goes, use trim and power.
Click to expand...
I have read a report once about a Mooney guy who had ailerons jammed hard by a flashlight, forgotten during maintenance. He managed to land just using rudder although the ailerons jammed off-neutral. Did not even cartwheel it, just slid off runway.
 
Dan Thomas said:
First things first. Stop renting from that outfit. Find a school that maintains its airplanes. There is no excuse whatever for an aileron cable (or any other part of the control systems) to reach the point of failure. They'll be fraying for a long time before they break, and in this case nobody was watching anything inside that airplane.

Dan
Click to expand...

:yeahthat:

Sure sounds like there's an IA involved who has been signing off 100 hour inspections without looking. If it's a true "out of the blue" failure I'd want to know why. Is the aircraft already back flying? Was it down a while for an investigation?
 
The tricky one is jammed elevator -- you have to use trim backwards to control pitch (trim in the normally-nose-down direction to pitch up, and vice versa).
 
kontiki said:
A couple weeks back, an aileron cable broke in the PA28 I've been training in (for another student).

In general, any body know where to find good info on procedures for dealing with in-flight failure of control surfaces?

Thanks,
Click to expand...

Rudder covers for aileron failure pretty well, trim can help you out on pitch; most of the time the reality is you have to think about it and figure it out when it happens.

When you try things with other things broke, loose and/or floppy when it's for real, try to keep your inputs as small as possible, especially in roll with dead ailerons since you'll reach a point of divergent stability in most all planes.

All your modern airplanes are designed to be positively stable; i.e. they'll return to their trimmed, straight, and level state after a minor upset.
 
Just received an inspection requirement for Pipers dealing with control cable turnbuckles. IIRC it was for cracks in the attachment of the cable to the turn buckle. Could explain why frayed cables weren't noted on past inspections.
 
Graueradler said:
Just received an inspection requirement for Pipers dealing with control cable turnbuckles. IIRC it was for cracks in the attachment of the cable to the turn buckle. Could explain why frayed cables weren't noted on past inspections.
Click to expand...

Many outfits ignore Service Bulletins and Service Letters. This often results in governments issuing ADs to force the owner to look at things. If it's true that Piper had to issue that sort of inspection requirement, there will almost certainly be an AD on it soon.


Dan
 
Ron Levy said:
The tricky one is jammed elevator -- you have to use trim backwards to control pitch (trim in the normally-nose-down direction to pitch up, and vice versa).
Click to expand...

Except in a Super Cub, Cessna 180/185, Mooney, or others that trim the horizontal stabilizer or whole tail.
 
Ron Levy said:
The tricky one is jammed elevator -- you have to use trim backwards to control pitch (trim in the normally-nose-down direction to pitch up, and vice versa).
Click to expand...
Unless you're flying something that tilts the tail for trim (e.g. Mooney) in which case you'd trim in the normal direction. Or if your trim is an adjustable spring/bungee the trim will have no effect with a jammed elevator.
 
kontiki said:
A couple weeks back, an aileron cable broke in the PA28 I've been training in (for another student).

In general, any body know where to find good info on procedures for dealing with in-flight failure of control surfaces?

Thanks,
Click to expand...

NTSB 830.5 (a)(1) requires immediate notification for control failure. I'm sure that was done.

We had an aileron cable seperate, pulled through the crimped end.
Pilot had RC experience with pitch and rudder control, attempted no turns and landed straight ahead in the desert, blew a couple of tires in the scrub.

IA that had installed the cable got a letter in his FAA folder for failure to follow accepted practices for the installation. He failed to use the proper inspection tool for the fitting.
 
There's an AOPA article from a year or so back about a pilot (in a 182 I think) who had I think a failure of his yoke and was stuck with only power, trim and rudder after some maintenance. He did crash land it at a backcountry USFS strip if my memory serves and and walked away. He tells how he navigated the canyons in the Idaho wilderness. Good read.
 
Thanks for all the useful info. I'll have to think about some of responses and I'll take a look at the Barry Schiff DVDs.

I also appreciate the reminder on NTSB 830.(a)(1). Honestly, it hadn't occurred to me.

I was at the field, flying a different airplane when other pilots brought it in with the aileron problem. I said aileron broke in the OP for simplicity.

It was a Sunday morning, there were just a couple instructors and students there that day. I did go out and verify the ailerons were "slack,"
no resistance to movement and lifting one didn't affect the other.

The person that brought it back claimed the cable broke. Having worked in aircraft maintenance for years, I did recognize she probably had no idea what actually occurred, and that no one would until they could open it up and look at it.

I was skeptical that a control cable simply broke. I've done some rigging, albeit years ago. I did the Nico press sleeve stuff in A&P school a zillion years ago. I've also been involved in making replacement cables in the hangar years ago (maybe for 727, BAC 111, or DC8 aircraft).

There, when you swagged a fitting on (using hydraulic power pack, driving a set of dies), you did a dimensional test (with GO-NOGO Gage) followed up with a tension test. I recall we used a load cell and hydraulic powerpack rig to apply (from memory) over 100% of rated strength (details long forgotten).

I now believe human memory may work like a garage. If you stuff too much stuff in it, you can't find half of it when you need it.

In any case, I was skeptical a steel aileron cable just broke, but haven't talked to anyone that would know the details. Gosh, I haven't pulled a rag along a cable in years. I believe the people working on these airplanes do good work though.

I work in an airline engineering department now, I used to be in maintenance. When you're in maintenance, you get used to people only bringing you broken airplanes.

It's not a matter of if a device will fail, just when (and whats available for redundancy when it does). So, I'm not so put off by a couple of maintenance problems, that airplane flies a lot. It's a trainer, It's going to break. I am looking forward to getting one of my own and keeping it "nice".

Again, thanks for all the useful info.
 
Last edited:
I think I posted about it before, but I've had a situation where my ailerons were locked up solid, and I managed to get back on the ground with rudder only steering, via a very wide, sweeping turn and a straight-in to a runway that was not the active at the time.
 
You must log in or register to reply here.
Back
Top