VMC ROLL OVER

UNCONTROLLED FLIGHT INTO TERRAIN: VELOCITY MINIMUM CONTROLLABLEROLLOVER

This accident is confined to multi engine aircraft only where the sudden loss of thrust during takeoff causes a large thrust differential between the two power plants.

The continued thrust from one side as compared to the drag associated with the failed opposite engine causes a turning moment that is normally quite pronounced. The net effect is that the aircraft performs what appears to be a low-level acrobatic maneuver and typically impacts the earth almost inverted and about thirty degrees off of runway heading.

Numerous recent crashes in both Hawaii and Texas have spotlighted the deadly rollover effect where the crash site was located in a very small area (near vertical impact) just off the runway.

Vmc training is often inadequate, not recent, or not taught correctly in preventing the fatal outcome. The most pronounced effect of the sudden loss of power occurs immediately after takeoff and during a high angle of attack.

On some aircraft, the two-engine climb angle can be as high as 18 degrees.

Most training facilities train pilots for what they consider to be the worst case scenario or loss of power during the act of rotation. In that case the pilot is easily able to control the craft by raising the nose up to a target pitch specific to that aircraft and those conditions.

Oftentimes this is the only maneuver that training is provided for. In real life, the actual engine failure occurs at around 300 feet while climbing and the pitch has already been established at a very high (normal) angle.

A pilot that is trained to raise the nose up to target pitch in time of crisis will often pull aft on the yoke during the engine failure when the correct action is actually to push down to the same target pitch.

A single engine pitch should be established that maintains Vyse by adjusting pitch and completing the memory items. Quickly establishing proper pitch appropriate to the loss of thrust offers enough airflow over the vertical stab and rudder to make the aircraft controllable.

Flight below Vmc (red arc) will normally cause the Vmc roll over effect. Being ready to immediately establish proper pitch and even the acceptance of the loss of some altitude are all possible during this precarious maneuver.

If it becomes obvious that the rollover is beginning, the pilot should consider closing the opposite throttle in order to equalize the thrust differential immediately.

SOLUTION: 

If you fly multi engine aircraft, this is one that you have got to train for and be ready for. Constant preparation and pre takeoff rehearsal are critical for quick action during the loss of thrust on takeoff in any multi engine plane. Get with a MEI or consider simulator training that can review these fundamentals often.

SAMPLE ACCIDENT REPORT: 

The National Transportation Safety Board determines the probable cause(s) of this accident to be: The failure of both the pilot and the certified flight instructor to ensure that the left fuel selector was in the on position for takeoff and their failure to follow the proper procedures when the left engine lost power shortly after takeoff, resulting in an in-flight loss of control. Accident Number: ERA11FA054.

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}
>