ENGINE FAILURE — MEP(A)

A twin engine airplane has two engines. What happens if one engine fails?

Engine failure in a ‘light twin engine aircraft’ — an airplane with two engines with MTOW of less than 7,500 kg.

FLY THE AIRPLANE FIRST!

With one of our two engines failing, we will have to take asymmetric thrust into consideration. Asymmetric thrust is a condition that exists when the net centre of thrust of a MEP (Multi Engine Piston) airplane is laterally displaced from the net centre of drag.

We will also have to take into account the following three V speeds;

• Vmcg,
• Vmca &
• Vyse.

VMCG

Vmcg is the minimum airspeed at which an aircraft is directionally controllable with one engine inoperative while on the ground.

This is significant when an engine fails during the takeoff run.

VMCA

Vmca is the minimum airspeed at which directional control can be maintained;

• at max Gross Weight
• with Centre of Gravity max aft
• at sea level
• with Flaps in T/O position
• with Gear retracted
• with the Operating Engine at max power
• with the Critical Engine failed and windmilling
• with max bank 5º toward the live engine

VYSE

Vyse is our best rate of climb airspeed with a single operating engine in a light twin. The speed that provides the ‘most altitude gain per unit of time’ after engine failure.

In the unfortunate event that one of our engines fail, the other engine should carry us safely to the nearest suitable airfield. It is a documented fact that, during an engine failure on takeoff, the margins for error are very small.

Identification of the failed engine should be rapid and accurate. Its propeller must subsequently be feathered whilst simultaneously sticking to Vyse, marked by the ‘Blue Line’ on the analogue Airspeed Indicator.

The landing gear should be retracted to reduce drag and flaps should be raised in stages. If these tasks are performed correctly, and in a timely manner, we may experience no loss of altitude and in favourable circumstances perhaps even a positive rate of climb.

I did my MEP(A) training in a Tecnam P2006T. Following is the procedure for engine failure that was taught to me:

1. All levers fully forward!
2. Gear up! Flaps up!
3. Identify! (dead leg, dead engine)
4. Verify! (pump L/R throttle 3 times to verify no change)
5. Feather! (L/R propeller)
6. Secure the failed engine.
7. Restart engine (if appropriate)