Engine Failure in Flight and the Restart

With height beneath you an engine failure becomes a problem with time in it. The order of priorities is fixed: fly first, glide towards somewhere usable, and only then try to work out what happened.

At a glance

• Airspeed, step 168 KIAS

Priorities, in order

What matters most is that somebody goes on flying the aeroplane, with best glide speed established as quickly as possible. While gliding towards a suitable landing area an effort should be made to identify the cause, and if time permits a restart should be attempted.

The restart procedure

Steps 1 to 5 are memory items — known by heart, in order.

Engine Failure During Flight (Restart Procedures)

1. Airspeed — 68 KIAS.

2. Fuel Shutoff Valve — ON, pushed fully in.

3. Fuel Selector Valve — BOTH.

4. Auxiliary Fuel Pump Switch — ON.

5. Mixture — RICH, if restart has not occurred.

6. Ignition Switch — BOTH, or START if the propeller is stopped.

7. Auxiliary Fuel Pump Switch — OFF.

Read the memory items as one idea: get fuel to the engine. Shutoff valve open, both tanks selected, auxiliary pump running, mixture rich. Four of the five most common causes of a stoppage in flight are answered by those four switches.

Two notes that change the procedure

NOTE — A windmilling propeller will restart the engine automatically within a few seconds. If the propeller has stopped, which is possible at low speeds, turn the ignition switch to START, advance the throttle slowly from idle, and lean the mixture from full rich as required for smooth operation.

NOTE — A fuel flow indication that collapses to zero at once points to a failed engine-driven pump: put the auxiliary fuel pump switch back to ON.

The second note is the reason step 7 exists at all. Turning the auxiliary pump off is the normal last step, but it is also the test: if fuel flow collapses the moment you switch it off, the engine-driven pump has failed and the auxiliary pump is now the only thing feeding the engine.

Check yourself

• In what order does the handbook rank flying, diagnosing and restarting?

• What is the first step of the restart procedure, and what speed does it call for?

• Which steps of the restart are memory items, and what do they have in common?

• What should you do if the propeller has stopped rather than windmilling?

• What does a fuel flow indication dropping to zero at step 7 tell you, and what is the response?

Study aid — always fly your aircraft's current AFM/POH.