Engine Start Malfunctions

Question 1

Hot Start

Answer 1

If the engine experiences unusual difficulty accelerating during start, a hot start may occur. There won’t be enough airflow to cool the initial combustion of fuel within the engine. Acceptable temperature and time limits are published within individual aircraft flight manuals to prevent engine damage.

Question 2

No Starter Cutout

Answer 2

According to the FAA, a no starter cutout condition exists when the start selector remains in the start position or the engine start valve is open when commanded closed. Since the starter is intended only to operate at low speeds for a few minutes at a time, the starter may fail completely (burst) and cause further engine damage if the starter does not cut out.

Question 3

Tailpipe Fire

Answer 3

fuel may puddle in the turbine casings and exhaust during start-up or shutdown, and then ignite. This can result in a highly-visible jet of flame out of the back of the engine, which may be tens of feet long.

There may be no indication of an anomaly to the flight crew until the cabin crew, ground crew, or control tower draws attention to the problem. They are likely to describe it as an “Engine Fire,” but a tailpipe fire will NOT result in a fire warning on the flight deck.

Question 4

No Light-Off

Answer 4

When fuel flow is introduced and engine light-off has not occurred in a proper timeframe, fuel may begin building up in the engine. If light-off DOES occur, this could result in a damaging fire or hot start.

Question 5

Hung Start

Answer 5

A hung start occurs when the engine lights off normally but doesn’t accelerate to idle RPM. This is usually the result of insufficient power to the engine from the starter.