737NG Variants - Reverse Thrust
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Joined: Mar 2005
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From: UK
737NG Variants - Reverse Thrust
Do all 4 variants of the 737NG produce the same amount of reverse thrust, or do the EEC limits vary?
For example; 737-800
2nd detent - approx. 74-76% N1
Max - approx. 82% N1
Are these values likely to be the same for the -600 -700 (putting aside any issues with rigging etc...)?
Many thanks!
For example; 737-800
2nd detent - approx. 74-76% N1
Max - approx. 82% N1
Are these values likely to be the same for the -600 -700 (putting aside any issues with rigging etc...)?
Many thanks!
Joined: Jul 2013
Aviation Qualifications: Non-Aircrew
Posts: 5,683
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From: Everett, WA
Disclaimer, I don't have any specific knowledge of the NG reverse thrust limits. That being said, I'd be rather surprised if the reverse thrust limits were different depending on the aircraft model.
For forward thrust on the 737, the max approved thrust rating is determined by the ability of the tail to counter the pitch up and yaw effects at max thrust settings - for example if you somehow used the same max TO thrust setting on a -600 as you have on a -900, you wouldn't be able to counter the resultant pitch-up forces with the shorter moment arm tail surfaces.
Those things don't normally apply in reverse - rather, max reverse is determined by the efficiency of the reverse thrust (as you increase power in reverse, the unreversed core thrust increases faster than the reversed fan thrust - at some point you actually get less effective reverse thrust as you increase N1) - as well as engine life/durability/reverser structure concerns, re-ingestions, and fuselage impingement considerations.
For forward thrust on the 737, the max approved thrust rating is determined by the ability of the tail to counter the pitch up and yaw effects at max thrust settings - for example if you somehow used the same max TO thrust setting on a -600 as you have on a -900, you wouldn't be able to counter the resultant pitch-up forces with the shorter moment arm tail surfaces.
Those things don't normally apply in reverse - rather, max reverse is determined by the efficiency of the reverse thrust (as you increase power in reverse, the unreversed core thrust increases faster than the reversed fan thrust - at some point you actually get less effective reverse thrust as you increase N1) - as well as engine life/durability/reverser structure concerns, re-ingestions, and fuselage impingement considerations.
