crj 200 climb performance
Thread Starter
Joined: May 2009
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From: Uganda
crj 200 climb performance
The crj 200 is not the best at getting up to altitude..but with higher than standard temp say isa +17 is it efficient to climb at speeds less than 250kts to attain altitude much quicker?
Joined: Mar 2006
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From: Ormond Beach
ISA+17, ouch! I don't think climbing at 210 will help you all that much. Firstly, at higher weights 210 may be a tad too slow for comfort, secondly, rather than gaining much climb performance you'll probably just hurt your groundspeed.
If you're flying ship 7011, tell her hello for me. Oh, and I left my pen in there, too.
If you're flying ship 7011, tell her hello for me. Oh, and I left my pen in there, too.
Thread Starter
Joined: May 2009
Posts: 12
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From: Uganda
if then 210 kts is rather not productive and thus will not fly a sustain climb passed Fl250 they why certify it for Fl 410.
looks like with a paltry 8000lbs...its not meant for high altitude say past Fl 350. but I reckon there is a way to make it efficient within its meagre firepower
looks like with a paltry 8000lbs...its not meant for high altitude say past Fl 350. but I reckon there is a way to make it efficient within its meagre firepower
Joined: Mar 2006
Posts: 13
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From: Ormond Beach
Indeed. Keep in mind also that certification numbers presume a brand new airplane, brand new engines, test pilots at the controls etc. At ISA + 17, I doubt you'll see anything much above FL310 at normal weights.
Joined: Apr 2013
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From: everywhere
This report contains all you need to know about climbing the CRJ to FL410:
http://www.ntsb.gov/doclib/reports/2007/AAR0701.pdf
http://www.ntsb.gov/doclib/reports/2007/AAR0701.pdf
Joined: Sep 2002
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From: Hampshire
Climb Performance
In simple terms climb performance for shallow climb angles is calculated as follows:
Rate of Climb = [(thrust - drag) x TAS)]/weight
where TAS and ROC have the same units of speed (kt, m/s, fps, or whatever you choose)
or, put another way, approximates to:
TAS x [ (thrust/weight) - (drag/lift) ]
You set the best lift/drag ratio by flying at the speed for minimum drag. This will vary slightly with weight but does not change with thrust. Therefore the "best climb speed" is what it is. You fly it and you get the best climb rate because you have the best available L/D ratio. If you increase speed to try to get a better climb rate, the drag increases and thus you don't get the gain in climb rate you might expect.
The biggest factor in the equation is Thrust/Weight ratio. If you are at MTOW and it is hot outside (ISA + 17) then with the best will in the world your T/W ratio will be poor, so your climb rate will be low. To get a better rate all you can do is take off at a lower weight. Even the best pilot in the world will be constrained by the equations above.
The only way you could get around this, would be to do a series of diving accelerations, each interspersed with zoom climbs, converting speed to height in several steps. It can be more efficient but I expect ATC might have something to say about it in busy airspace!
Rate of Climb = [(thrust - drag) x TAS)]/weight
where TAS and ROC have the same units of speed (kt, m/s, fps, or whatever you choose)
or, put another way, approximates to:
TAS x [ (thrust/weight) - (drag/lift) ]
You set the best lift/drag ratio by flying at the speed for minimum drag. This will vary slightly with weight but does not change with thrust. Therefore the "best climb speed" is what it is. You fly it and you get the best climb rate because you have the best available L/D ratio. If you increase speed to try to get a better climb rate, the drag increases and thus you don't get the gain in climb rate you might expect.
The biggest factor in the equation is Thrust/Weight ratio. If you are at MTOW and it is hot outside (ISA + 17) then with the best will in the world your T/W ratio will be poor, so your climb rate will be low. To get a better rate all you can do is take off at a lower weight. Even the best pilot in the world will be constrained by the equations above.
The only way you could get around this, would be to do a series of diving accelerations, each interspersed with zoom climbs, converting speed to height in several steps. It can be more efficient but I expect ATC might have something to say about it in busy airspace!
