Why is it that so many pilots seem to neglect to remove the control lock before takeoff? I just don’t get it. This is the one thing that’s 100% guaranteed to kill you in an aircraft.
Take, for example, this DeHavilland DH4 Caribou. In 1992, this aircraft was being used as a testbed for the Pratt & Whitney PT-6 turboprop conversion. The pilots failed to remove the control lock before a flight, with predictable results.
It is supposed to be physically impossible to advance the throttles with the lock on. But this aircraft was being modified and was operating in the restricted category. The throttle quadrant was not properly rigged to accommodate the throttle levers for the turbine engines. Three people were on board; two test pilots and an engineer.
These sorts of accidents are especially noteworthy when you consider that it took more than just a lazy preflight. The pilot(s) also had to ignore the control check, fail to see the lock installed, and neglect to put in any sort of crosswind correction during taxi. They’d also have to exhibit a general lack of checklist discipline. In fact, they’d have to basically not touch the controls at all until rotation.
For those of you who are not pilots, the control lock is usually painted red, very visible, and located in the cockpit right in front of the pilot.
(hat tip: John Pappas at Dreamflight)
Looks like a W and B issue to me..not a control lock isuse
The pilot was able to make a BIG elevator movement for rotation, but seemingly unable to make a nose down movement. Are you sure this was a control lock issue? I think I have to agree with Graeme, it sure looks like a weight & balance problem, perhaps a cargo shift?
With an elevator lock in place the aircraft will lift off at the right speed and begin climbing on full throttle. The pilot has no control. I am one of very few who have survived such an accident. Just before the point of stall I throttled back, thus bringing the nose down. As a result we hit the ground obliquely, injuring only me and co-pilot. This was in a DC3 taking off from Carpiquet airfield onOctober 24th 1944 Yes, it was pilot error, a reminder that familiararity breeds contempt.
I can’t imagine the sinking feeling you must have had upon realizing the flight controls were immobilized! The technique you describe illustrates the relationship between trim and airspeed. Amazingly quick thinking on your part to start flying the airplane with power.
It probably helped that the DC-3 was a relatively low performance aircraft compared to many of the airplanes flying today. Being built like a tank probably didn’t hurt either. Thanks for sharing your story!
I take no credit for an act of God controllling my hand.
For us none-pilots, can you explain what the control lock actually locks down? Is is sort of like on your car the steering wheel will lock when you are in ‘park?’
Joel: it’s more akin to one of those anti-theft steering wheel clubs in that it physically prevents the controls from being moved.
The control lock physically holds the flight controls in one place so that they are immovable. On some aircraft, it’s a pin that goes through the control column to keep it from moving.
The purpose of using a control lock is to prevent damage to the aileron, rudder, and elevator if the winds should kick up. Such winds could cause these control surfaces to “flutter” back and forth in the gusts, hitting the mechanical stops with enough force to cause damage to the control system.
There are many different types of control locks. Some go on the yoke or stick inside the cockpit, while others are external locks that are physically placed on the control surfaces.
An internal lock looks like what you’ll see at http://www.gustlock.com.
An external lock (in this case, for a rudder) looks like this.
Regarding the issue of whether this was a W&B problem or a control lock problem, I did some digging via Google and found an analysis of this accident by Bombardier Aerospace product safety manager James Donnelly. Here’s part of what he wrote:
I was only ever a student pilot, but everything I climbed into had control locks that could dismay Godzilla. Even finding the ignitions while being hit in the face with all those red aluminum flags and nylon streamers was difficult. The only thing missing from the locks was a red barbed-wire barrier between the pilot and the seat. Not a bad system. As one of my instructors made her students memorize, ‘90% of the problems a pilot encounters in the air, he chose to take into the air with him’.
In my case the cockpit check was hurried while taxying out for take-off – the reason for the hurry is not important. – Malcolm
Lost BUSHMASTER 2000 trimotor (think FORD) in Fullerton, Ca. Sep. 2004 to a FULLY left tied rudder ground gust lock.
Boeing, rocket scientist CFI, ATP, PIC survived.
It’s on Utube.
POGO (40s cartoon character) said, “WE HAVE MET THE ENEMY AND HE IS US.”
I remember that accident well. I wonder how many control lock related accidents there have been over the past century. The total number would probably be quite surprising.
you’ve already seen my comments. Only Divine guidance directed me to throttle back before the stall, thus dropping the nose. The ensuing crash didn’t kill anybody.
So can you explan how how HOW on earth do pilots forget to shut off all the locks, or the gust lock, when its 100 percent sure that they and everyone else in the plane will die in a plane crash if they don’t do that??? How?
Bad attitude, bad training, bad habits.
Any one can be the root cause to any accident.
There is no cure we want to live with in a free culture.
Lost my Bushmaster Trimotor in Fullerton, Ca.
2004 to just this.
R BUD Fuchs CFI,ATP,A&P
DC3 TO B767
Bud, I had the good fortune to have flown on your Trimotor, twice. Both flights out of Long Beach Airport. I organized a Trimotor flight with fellow BA mechanics, very memorable!
Charles