Effects of warm air masses
Thread Starter
Joined: May 2006
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From: australia
Effects of warm air masses
To all the smarties...
We (in a turbofan aircraft) fly into a region of warmer air. What are the effects on the flightpath and engine performance?
Is the following correct?
On the Engine side: Warmer air = less density = reduced thrust = EPR decrease?
On the flight side: For a given angle of attack lift will decrease so we need to increase thrust or we will descend?
Any thoughts?
Thanks
We (in a turbofan aircraft) fly into a region of warmer air. What are the effects on the flightpath and engine performance?
Is the following correct?
On the Engine side: Warmer air = less density = reduced thrust = EPR decrease?
On the flight side: For a given angle of attack lift will decrease so we need to increase thrust or we will descend?
Any thoughts?
Thanks
Joined: Feb 2005
Aviation Qualifications: ATPL
Posts: 1,427
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From: Correr es mi destino por no llevar papel
Your asumptions are correct for plane flying with manual throttles (set at constant position, too) and autopilot engaged in AoA hold mode (nonexistant AFAIK).
In everyday operation planes are flown with autothrottles engaged and autopilot in alt hold mode, so moving from cold to warm airmass will produce slight pitch-up to increase AoA and compensate for lost lift and slight throttle-up to compensate for bit of extra drag and bit of thrust loss. However, those effects are far from signifficant.
In everyday operation planes are flown with autothrottles engaged and autopilot in alt hold mode, so moving from cold to warm airmass will produce slight pitch-up to increase AoA and compensate for lost lift and slight throttle-up to compensate for bit of extra drag and bit of thrust loss. However, those effects are far from signifficant.
