Time Delay & Engine Spool Up Time
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Time Delay & Engine Spool Up Time
Hi,
It seems that some aircraft are fitted with time delay that keeps engine spooled up on touchdown.
Is this time delay a basic item on all airliners (Boeing, Airbus…)?
What’s the purpose of this time delay?
Feedback appreciated.
Regards
It seems that some aircraft are fitted with time delay that keeps engine spooled up on touchdown.
Is this time delay a basic item on all airliners (Boeing, Airbus…)?
What’s the purpose of this time delay?
Feedback appreciated.
Regards
Actually there wasn't a time delay on the aircraft I flew - flight idle mode was entered in the air when the gear was lowered and changed to the lower rpm of ground idle when the undercarriage weight on oleo micro switches closed.
My first jet aircraft took around 13 secs for the engines to fully spool up.
My first jet aircraft took around 13 secs for the engines to fully spool up.
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My first jet aircraft took around 13 secs for the engines to fully spool up.
You could nearly go out to lunch waiting for spool-up...
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Hello,
Thanks for your responses.
This time delay may increase landing distance especially if the reverses are not used or dispatched inop.
Wondering if the crew are required to use the thrust reversers once the main landing gears touch the ground (nose gear is airborne)?
Also wondering if this time delay works also in case RTO?
Feedback appreciated.
Regards
Thanks for your responses.
This time delay may increase landing distance especially if the reverses are not used or dispatched inop.
Wondering if the crew are required to use the thrust reversers once the main landing gears touch the ground (nose gear is airborne)?
Also wondering if this time delay works also in case RTO?
Feedback appreciated.
Regards
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As far as I'm aware, as it's normal system operation, the resulting landing distance is the normal when not using the reversers, see the performance tables.
Once the mains are planted, you can start the selection process for the reversers, whilst you are smoothly lowering the nose, then throttle the reversers at that time, that's very efficient use of the system.
BTW...the 737NG also has a backup system where if there is a fault preventing the EEC sensing of the engine anti-ice system or flap landing positions, the engines will go into Approach Idle at 15,000 feet AMSL on the descent.
As far as an RTO is concerned, since the weight remains on the wheels throughout, the EEC keeps the engines at minimum ground idle (normal ground idle setting).
EW73
Once the mains are planted, you can start the selection process for the reversers, whilst you are smoothly lowering the nose, then throttle the reversers at that time, that's very efficient use of the system.
BTW...the 737NG also has a backup system where if there is a fault preventing the EEC sensing of the engine anti-ice system or flap landing positions, the engines will go into Approach Idle at 15,000 feet AMSL on the descent.
As far as an RTO is concerned, since the weight remains on the wheels throughout, the EEC keeps the engines at minimum ground idle (normal ground idle setting).
EW73
Last edited by EW73; 10th Feb 2011 at 09:05.
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As far as an RTO is concerned, since the weight remains on the wheels throughout, the EEC keeps the engines at minimum ground idle (normal ground idle setting)