The commercial pilot reported that the accident flight was the first flight following maintenance, which included the installation of right-seat rudder pedals with brake controls.
He added that, during a preflight inspection of the Piper PA-28R-180, he actuated the ailerons, however he did not verify which direction the control yoke moved.
He again checked the flight control movement before takeoff, but did not verify which direction the aileron moved when he moved the control yoke.
During the takeoff sequence, as the airplane became airborne, it immediately entered an uncommanded left roll. He attempted to correct for the roll, however he was unable to do so. He reduced the engine power.
The airplane then hit the ground near San Jose, California, and came to rest upright on an adjacent runway.
Post-accident examination of the airplane revealed that, when the control yoke was rotated for input of right aileron, the right aileron moved down, and the left aileron moved up, which is opposite of what would be expected.
Examination of the aileron cables revealed that they remained attached to the “T” bar aileron control chains. However, the right aileron control cable was attached to the left aileron control chain, and the left aileron control cable was attached to the right aileron control chain, meaning the cables were connected backward.
The cables were oriented such that they crossed underneath the flap handle and center console area.
The two mechanics who performed the maintenance on the airplane reported that they had disconnected the aileron control cables to facilitate the installation of the rudder pedals and brake controls. After completing the maintenance, they checked the flight control cable tension and aileron movement, however they did not observe which direction the control yoke moved when the aileron was moved.
It is likely that the mechanics attached the aileron control cables backward during the reassembly of the aileron control system, which resulted in roll control that was opposite of that commanded by the pilot.
Probable cause: Maintenance personnel’s incorrect installation of the aileron control cables and subsequent failure to verify proper aileron functionality following the maintenance, which resulted in roll control that was opposite of that commanded by the pilot, and the pilot’s inadequate preflight inspection, during which he did not verify that the aileron movement matched the control yoke input.
NTSB Identification: WPR17LA164
This July 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Glad I don’t work for that FBO!!!
Obviously the mechanic performing his work did not do the operational checks required after disconnecting cables. Which would be a deflection check to ensure that the control surface gets its desired travel. From my experience piper is pretty thorough with their service manuals. The pilot is also at fault also as the checklist states to ensure the flight controls are free and correct.
Years of training !!!
“It is LIKELY that the mechanics attached the aileron control cables backward……………”? I’d say it is pretty darn certain that they attached the cables backward.
Obviously the pilot should have checked for proper movement, but he also should have known that any time any maintenance has been done is when an extra careful preflight should be done.
My mantra when checking the controls is “STICK LEFT, LEFT UP RIGHT DOWN, STICK RIGHT, RIGHT UP LEFT DOWN”.
Piper apparently was still doing the same thing they did 50 years ago. The turn buckles should be manufactured with reverse threads for each side cable. This prevents attaching them incorrectly. I have seen the same results on PA 22’s, J3’s and amateur built aircraft. Of course if you cross the cables somewhere else in the routing you can still screw it up. The additional pedal modification is a great safety improvement on the Comanche and Cherokee. My ole time instructor (ag pilot too) had this happen to him and he realized what had happened after T.O. he said he locked his knees under the control wheel and used the pedals to skid his way around the pattern to a normal landing.
Hold the left side of the yoke with your left hand, with your thumb pointing up.
Turn the yoke to the right, your thumb points to the up aileron.
Turn the yoke to the left, your thumb points to the up aileron.
Actually, it doesn’t matter which hand you use, this still works. I was taught this a long time ago and it is part of every pre-flight.
My own pre-flight aileron-check is: “PULL ‘EM DOWN.”
When you move the stick full right, you “Pull” the left aileron DOWN.
When you move the stick full left, you “Pull” the right aileron DOWN.
If the controls have accidentally been reversed, it would appear that you’re “Pushing” the ailerons down.
As I test-fly a variety of different light aircraft (mostly antiques, homebuilts, and ultralights), making this simple check part of my pre-flight has never let me down (over the past 52 years & 140+ aircraft).
Murphy’s law
Yes – quite the perfect storm – mechanic who didn’t check followed by a pilot who didn’t check. The preflight should always include manually moving the controls while looking at the control wheel movement in the cockpit. As we know from other reports, any of the controls can function in reverse after servicing mistakes, so the proper elevator, rudder, and trim control movements should also be verified 100% of the time.
Control cables don’t get rerigged between flights UNLESS maintenance is done so we tend to get complacent about which way they move when we wiggle them around in the run up area. The way to combat this is to THINK each time you check for “controls for free and PROPER movement”, “Left wing up, Right wing down” and actually visualize the movement of air over the surface to determine if the wing will move in the direction it should. Down=up, Up=down.
WOW, this is quite rare for a mechanic to miss-rig and aircraft. Digital photos of an area to be worked on makes a great reference. Also, why not tag the cable and the other connection with ‘left’ and right’ ?
Then there is very little chance of miss-connecting the cables.!
A complaint should be filed with the FAA and NTSB that this mechanic allow the aircraft to be returned to service this way.
Lastly, as part of the pre-flight is to check that the controls are ‘free and CORRECT’…oops.!