Wednesday, 16 November 2005 06:24
Hi Captain Lim,
I have a question on elevators. There have been a lot of questions on engine failure after V1 (safety speed) and so on. I have a scenario where the elevators fail during takeoff. I know the control surfaces are checked for proper working during the taxi.
As the aircraft starts its takeoff run, crosses V1 and reaches the Vr (rotate speed), the pilot pulls the control column to rotate the nose up. The elevators fail to work (due to mechanical/electrical failure, etc) and the pilot have no warning till that point of the malfunction. The engines are on full thrust but the aircraft is not airborne yet.
What action can be taken? Does the simulator have any such scenario?
The scenario you have mentioned is very remote in modern aircraft and I have not come across such an event being programmed in the simulator that I have flown. I have known of a few cases of elevator failures but they did not occur during the take off at after V1.
Below are two examples of elevator-related accidents in the US:
The first one involved a McDonnell Douglas DC-8 in February 16, 2000. It crashed into an automobile salvage yard shortly after takeoff while attempting to return to Sacramento Airport, California, for an emergency landing. The two pilots and a flight engineer on board this cargo flight were killed and the airplane was destroyed. The NTSB (National Transportation Safety Board) attributes the probable cause of the accident to a loss of pitch control resulting from the disconnection of the right elevator control tab.
The second one happened in on January 8, 2003 where an Air Midwest Beechcraft crashed shortly after takeoff from the runway at Charlotte, North Carolina. The 2 flight crewmembers and 19 passengers aboard the airplane were killed and the impact forces and a post crash fire destroyed the airplane. The NTSB determines that the probable cause of this accident was the airplane's loss of pitch control (elevator) during the takeoff.
In the above two cases, there were nothing the pilots could do to save the day as they were already airborne.
However, on one case that I know of where the control cable failed, the pilot (a personal friend of mine) was able to land the Twin Otter safely with the use of throttles to control the pitch (power on - pitch up, power reduce - pitch down) and the trim control to move the elevators.
Yes, there is a drill in the scenario that you have just created - loss of elevator control after V1. Well, you abort the take off! (Reduce thrust, select speed brakes, reverse thrust and maximum braking). This is the only exception against the normal philosophy that one should never abort after V1. Aborting a take off after the safety speed does come with some risks but it is the only safe course of action left!