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HUNG START�� - In gas turbine engines, a condition of normal light off but with rpm remaining at some low value rather than increasing to the normal idle rpm. This is often the result of insufficient power to the engine from the starter. In the event of a hung start, the engine should be shut down.


HOT START
- In gas turbine engines, a start which occurs with normal engine rotation, but exhaust temperature exceeds prescribed limits. This is usually caused by an excessively rich mixture in the combustor. The fuel to the engine must be terminated immediately to prevent engine damage.

TURBINE ENGINE HOT/HUNG START
A hot start is when the EGT exceeds the safe limit. Too much fuel entering the combustion chamber or insufficient turbine rpm causes hot starts. Any time an engine has a hot start, refer to the AFM, POH, or an appropriate maintenance manual for inspection requirements.

If the engine fails to accelerate to the proper speed after ignition or does not accelerate to idle rpm, a hung start has occurred. A hung start may also be called a false start. A hung start may be caused by an insufficient starting power source or fuel control malfunction.

5 comments

Unknown said... @ March 20, 2014 at 9:29 PM

who is the author?

Unknown said... @ March 11, 2020 at 5:22 AM

Good explain

Unknown said... @ August 27, 2020 at 11:37 PM

What is the difference of hung start and hot start?

DareDevilzz said... @ October 13, 2021 at 12:58 PM

^ from the definition looks like hot start has to do with exceeding engine starting temps due to enriched fuel, while hung start has to do with when an engine has started but fail to reach proper RPM to maintain idle due to insufficient starting power. Both seem to be a related phenomenon.

Anonymous said... @ December 15, 2021 at 9:44 AM

A hot start is due to too much fuel, and the engine temperature will increase rapidly even if engine RPM is accelerating normally.

A hung start occurs when the engine accelerates very slowly, or fails to accelerate to normal idle rpm. RPM stagnation can occur any time during the start cycle, depending on the cause. This is usually due to insufficient power to the starter, but could also be caused by excessive tailwinds, or snow collected in the intake area. Low RPM means low airflow through the engine. If the start is allowed to continue like this, it is very likely going to turn into a hot start.

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