What is a hung start characterized by?

• A. Low RPM and High EGT
• B. High RPM and Low EGT
• C. Low RPM and Low EGT
• D. No RPM change with stable EGT

Answer: (A)

Hung start is when the engine lights off but cannot spool up to normal idle speed. In this situation, combustion is occurring (so the exhaust gas temperature rises) while the rotor speed remains low and unable to accelerate. That combination—low RPM despite rising EGT—fits a hung start best, because you’re seeing ignition and heat without the expected rotor acceleration.

During a normal start, you’d expect RPM to rise as fuel flow is established and EGT climbs briefly before settling; here, the rotor speed stays low even though EGT is high, signaling a stuck or insufficiently fueled/unaccelerated start. If you encounter this, the typical response is to abort the start and investigate fuel control, ignition, or mechanical causes that are preventing acceleration.