Biz Jets Flex or Derate Thrust settings
Thread Starter
Biz Jets Flex or Derate Thrust settings
A question I was asked today
Do midsize Bizjets, Citation X, Sovereign, Falcons, Challengers, Gulfstreams etc use reduced thrust (assumed temp and.or fixed derate) for light weight takeoffs.
In an aircraft doing 300 odd hrs a year, is their any benefit.
Im well versed in the advantages of flex and derate on the heavy iron but wasnt able to anwer the question re bizjets.
Do midsize Bizjets, Citation X, Sovereign, Falcons, Challengers, Gulfstreams etc use reduced thrust (assumed temp and.or fixed derate) for light weight takeoffs.
In an aircraft doing 300 odd hrs a year, is their any benefit.
Im well versed in the advantages of flex and derate on the heavy iron but wasnt able to anwer the question re bizjets.
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So does the GLEX. Useful, seeing as on many/most takeoffs we aren't up anywhere near MTOW and therefore rather over-powered. Procedure not used by many operators though, from what I gather.
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Citation Sovereign: no procedures available for that,
And I just love to depart with 1 dude in the back and 3000lbs of fuel, no baggs...that when the plane really performs...when 6000fpm climb won´t keep ya below 250KIAS...
Sometimes I wish we`d had an F-4 instead of the Cessna -> way more fun for me!
And I just love to depart with 1 dude in the back and 3000lbs of fuel, no baggs...that when the plane really performs...when 6000fpm climb won´t keep ya below 250KIAS...
Sometimes I wish we`d had an F-4 instead of the Cessna -> way more fun for me!
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We use Flex on the G550 wherever possible now. No reason not to. Gulfstream have published clear guidelines and the company encourage us to do so, but its entirely at our discretion.
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Citation Sovereign: no procedures available for that,
And I just love to depart with 1 dude in the back and 3000lbs of fuel, no baggs...that when the plane really performs...when 6000fpm climb won´t keep ya below 250KIAS...
Sometimes I wish we`d had an F-4 instead of the Cessna -> way more fun for me!
And I just love to depart with 1 dude in the back and 3000lbs of fuel, no baggs...that when the plane really performs...when 6000fpm climb won´t keep ya below 250KIAS...
Sometimes I wish we`d had an F-4 instead of the Cessna -> way more fun for me!
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The point of doing it on a corporate jet? Your on a long runway, light, by yourself, and you don't want to climb like an F16...sure I have done it in jets that will come off the ground in 1500 feet on a 10k runway. Now how many here fly by themselves with out pax back from maintenance?
Otherwise what's the point? You can't trend monitor your engines out to 30k like the airlines, a corporate jet engine is coming off in say 5k whether you baby it or not..so it's kinda stupid to be flying a 25 million dollar plane to the fence and pulling up because you think your saving on overhaul costs.
Honestly, this is the kinda crap that happens when you hire buddies and pals off the bottom of the resume pile...just puts lives at risk and our reputation suffers for it.
:
Otherwise what's the point? You can't trend monitor your engines out to 30k like the airlines, a corporate jet engine is coming off in say 5k whether you baby it or not..so it's kinda stupid to be flying a 25 million dollar plane to the fence and pulling up because you think your saving on overhaul costs.
Honestly, this is the kinda crap that happens when you hire buddies and pals off the bottom of the resume pile...just puts lives at risk and our reputation suffers for it.
:
Last edited by Sillypeoples; 4th Jul 2012 at 13:46.
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New business planes offer on condition maintenance for engines same as for airliners, for those i would guess that reducing makes sense. For those business jets that are derivates from airliners (BBJ, ACJ etc) it is a given anyway.
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so it's kinda stupid to be flying a 25 million dollar plane to the fence and pulling up because you think your saving on overhaul costs.
this is the kinda crap that happens when you hire buddies and pals off the bottom of the resume pile...just puts lives at risk and our reputation suffers for it.
You are getting too predictable 
Mutt
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Otherwise what's the point? You can't trend monitor your engines out to 30k like the airlines, a corporate jet engine is coming off in say 5k whether you baby it or not
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Emirates used flex at Melbourne some years ago IIRC and nearly caused the worst air disaster in Australian history.
Speaking of Australia, one airline, who had never had a haul loss decided it was beneficial not to use reverse thrust, even on a wet runway. They came to grief.
We all tend to be getting away from the basics in aviation today. When we did ab initio training, did we reduce the power on T/O?? Hell no. Then why do it now? Don't try and reinvent the wheel, as it has all been done before.
Risk management is the term they use today i believe. Then manage it.
K.I.S!!
Speaking of Australia, one airline, who had never had a haul loss decided it was beneficial not to use reverse thrust, even on a wet runway. They came to grief.
We all tend to be getting away from the basics in aviation today. When we did ab initio training, did we reduce the power on T/O?? Hell no. Then why do it now? Don't try and reinvent the wheel, as it has all been done before.
Risk management is the term they use today i believe. Then manage it.
K.I.S!!
Last edited by doubleu-anker; 5th Jul 2012 at 20:30.
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d-a, the problem at Melbourne was not the use of flex but the incorrect weight loaded into the FMC. The problem was rectified by judicious application of power which was almost too late but did finally get the beastie off the ground after causing some havoc with runway lights and aerials.
As for QF1, there were many other problems that led to that little overland excursion other than merely the use of reverse thrust or not. To that airlines credit they learned very quickly.
As for QF1, there were many other problems that led to that little overland excursion other than merely the use of reverse thrust or not. To that airlines credit they learned very quickly.
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"d-a, the problem at Melbourne was not the use of flex but the incorrect weight loaded into the FMC. The problem was rectified by judicious application of power which was almost too late but did finally get the beastie off the ground after causing some havoc with runway lights and aerials."
Put simply, reduced T/O power/Flex, was calculated, using the FMS.
"As for QF1, there were many other problems that led to that little overland excursion other than merely the use of reverse thrust or not. To that airlines credit they learned very quickly. ."
Correct. Management complicating things. Trying to save fuel etc., by not using full reverse, on a runway with poor braking. Asking for trouble. Look for trouble and you will find it.
K.I.S!!
Put simply, reduced T/O power/Flex, was calculated, using the FMS.
"As for QF1, there were many other problems that led to that little overland excursion other than merely the use of reverse thrust or not. To that airlines credit they learned very quickly. ."
Correct. Management complicating things. Trying to save fuel etc., by not using full reverse, on a runway with poor braking. Asking for trouble. Look for trouble and you will find it.
K.I.S!!
Last edited by doubleu-anker; 6th Jul 2012 at 10:47.
