Engine Starting System

Question 1

Assuming there are no faults, during an engine start at what percentage NG will the igniters commence operation?

Answer 1

8%

Question 2

At which condition will the Electronic Control Unit (ECU) automatically abort the start?

Answer 2

NG is less than 50% after 60 seconds (in the air)

NG is less than 50% after 30 seconds (on the ground)

PTIT exceeds 850°C during the starting

No light-off 10 seconds after fuel being enabled (effectively no kick in PTIT after 10 seconds of the green IGN appearing on the SMD)

Question 3

Which condition is required to automatically initiate an engine relight following an uncommanded engine shutdown, overspeed or flameout?

Answer 3

Switches - EMSS GI or FLY, Starter Master ON

Speeds - NP less than 107.2%, NG less than 100% but above 50%

Question 4

Under what condition would an engine automatic relight not occur, and a manual restart of the engine would have to be carried out?

Answer 4

NG is fallen below 50%