CRJ 200 climb performance in Summer

[Poahi]

Here's what I'm wondering. When it's hot and you're heavy, climbing out at 250 will get you to say FL200 in a hurry, but then the climb virtually stops and it seems like it takes forever to make it to cruise. At say, FL250, the deck angle is relatively high when you make the transition and I've had days where the aircraft never makes it cruise speed (desipte the charts saying otherwise). So what I'm curious about is whether or not the extra fuel burnt at lower altitides (and higher speed with lower deck angle), offsets 'hanging' at cruise at climb power for a half an hour. Does that extra 20 knots of initertia blast you through the doldrums or do you get it either way?

 

[DrewBlows]

OK, you can take it for what it's worth from a former CRJ instructor (one of the first in the USA), but it works very well.

Once you get to 10,000', nose it over to accelerate to 300-310 KIAS, then start climbing. As your altitude increases, try to maintain the highest possible IAS while maintaining at least a 500 FPM rate of climb. The idea is to climb a jet at the lowest possible deck angle to keep forward speed and increase economy. Also, when you get to your cruise altitude at the lower deck angle, you won't be "hanging" on the engines and unable to accelerate.

In the Whale, we use Vref + 100 to 110 for best angle of climb; Vref + 130-140 for best rate; Vref + 160-170 for best economy. It works as well in the CRJ, but not quite the same numbers, though.

Remember, the 500 FPM rule is only an ATC reporting requirement. A Part 25 jet is only required to be able to climb at cruise altitude at 300 FPM.

Please, please don't try to climb to your cruise altitude at best angle or best rate. You'll find that you likely will not get there because the best angle and best rate is a "temporary" rate for lower altitudes.

I have found that many who get into a jet for the first time have an unrealistic expectation of how a Transport Category Jet actually performs. Even the Whale peters out when it is heavy and hot. It's a rocket ship, even heavy, below FL180, but when we get on up there...it's 300 FPM sometimes.

Also, religiously check your cruise performance charts. Are you even legal to be where you are (FL wise)?

I learned from experience, if you use the climb techniue I described, you will beat the dispacthed fuel every time and you won't be pi**ing off guys behind you so badly.

Like I wrote, take it for what it's worth from an old dude.

That's interesting information. I've never flown the -200, but we used to climb at about 320/.80 in the CR7 (probably winter numbers, my memory isn't great) and it seemed to work well. The company came up with a 300/.77 profile and performance dies between about FL260 and FL300. They say do it that way, so I do, but we don't go as high as we used to and I suspect it costs us. On the other hand the descent profiles they gave us work pretty well (flight idle, cruise speed/290 KIAS).

The company profiles remind me of the profiles the company engineers gave Earnest K. Gahn's pilots in his book Fate is the Hunter. Everyone obeyed and barely made it to the destination until one brave soul used the old profiles and made it with plenty of fuel to spare.

 

[JettBoii]

I like big chi chi's. Nice avatar scang.

 

[Ganja60Heavy]

Man, it's bad. When I first started flying, I was like, whoa Captain, it's hard to keep this thing afloat! I think he knew what I meant, but I wanted to go faster so I dumped it over to about 200 per for a bit. Dude, it just wouldn't climb! Captain told me not to climb at that rate, but man, we gotta climb faster on hot days! How do you guys do it!?

Sounds like Captain is what's keeping you from crashin'....

 

[bertengineer]

There really is a reason the FMS displays

UNABLE CRZ ALT

 

[pilotdiscretion]

For some of you this is going to be the 'duh' statement of the year. For some of you this is going to be a wake up call.

Airplanes fly because of air flow over and under the wings.

Reduce the airflow and you reduce effectiveness of the wings. Keep the speed up between 280 and 310 and the airplane will keep climbing. It gets difficult and climbs very poorly between FL260 and FL280 due to atmospheric conditions and airplane design. Try to hold your speed between these altitudes and the airplane will perform better passing FL290.

Why do we let an ATC rule over ride aerodynamics? If the airplane needs to climb at 300 fpm why do we let the 500fpm notification rule put us in a position of high drag? ALPA should lobby to get this rule thrown out.

If you're departing a hub during a busy time please fly the company profile until you get some distance from the airport. When you get some distance from the departure corridor and are away from everyone else then you can slow down with out screwing the guys behind you.

 

[bluefishbeagle]

CRJ climb performance ha ha ha ha ha ha ha ha ha ha ha........ etc infinity. It doesn't have any what's to talk about.

 

[SuperPilot]

CRJ 200 = Climb Restricted Jet 200fpm

 

[N1VIBS]

Why do we let an ATC rule over ride aerodynamics? If the airplane needs to climb at 300 fpm why do we let the 500fpm notification rule put us in a position of high drag? ALPA should lobby to get this rule thrown out.

I don't think its a ATC rule that you have to climb at 500 fpm. The rule( As I understand it)is if you can't climb at least 500 fpm, you have to notify ATC. Right GCD?

 

[Sawmill]

OK, you can take it for what it's worth from a former CRJ instructor (one of the first in the USA), but it works very well.

Once you get to 10,000', nose it over to accelerate to 300-310 KIAS, then start climbing. As your altitude increases, try to maintain the highest possible IAS while maintaining at least a 500 FPM rate of climb. The idea is to climb a jet at the lowest possible deck angle to keep forward speed and increase economy. Also, when you get to your cruise altitude at the lower deck angle, you won't be "hanging" on the engines and unable to accelerate.

In the Whale, we use Vref + 100 to 110 for best angle of climb; Vref + 130-140 for best rate; Vref + 160-170 for best economy. It works as well in the CRJ, but not quite the same numbers, though.

Remember, the 500 FPM rule is only an ATC reporting requirement. A Part 25 jet is only required to be able to climb at cruise altitude at 300 FPM.

Please, please don't try to climb to your cruise altitude at best angle or best rate. You'll find that you likely will not get there because the best angle and best rate is a "temporary" rate for lower altitudes.

I have found that many who get into a jet for the first time have an unrealistic expectation of how a Transport Category Jet actually performs. Even the Whale peters out when it is heavy and hot. It's a rocket ship, even heavy, below FL180, but when we get on up there...it's 300 FPM sometimes.

Also, religiously check your cruise performance charts. Are you even legal to be where you are (FL wise)?

I learned from experience, if you use the climb techniue I described, you will beat the dispacthed fuel every time and you won't be pi**ing off guys behind you so badly.

Like I wrote, take it for what it's worth from an old dude.

Its refreshing to hear from someone who actually knows what they are talking about and not just wanting to "hear" themselves.

 

[Sawmill]

One question though: What if the CRJ 200 is on a giant treadmill?

 

[regionalcap]

Why do we let an ATC rule over ride aerodynamics? If the airplane needs to climb at 300 fpm why do we let the 500fpm notification rule put us in a position of high drag? ALPA should lobby to get this rule thrown out.

I don't think its a ATC rule that you have to climb at 500 fpm. The rule( As I understand it)is if you can't climb at least 500 fpm, you have to notify ATC. Right GCD?

Why would ALPA want that rule thrown out? It lets ATC know when we are barely climbing so they can plan accordingly. I think it is a good thing.

 

[sweptback]

There really is a reason the FMS displays

UNABLE CRZ ALT

As I understand, all that message means is that your TOC is past your TOD. I don't think it necessarily means that you can't reach your planned altitude, that's what the climb capability charts are for.

 

[Crzipilot]

Its refreshing to hear from someone who actually knows what they are talking about and not just wanting to "hear" themselves.

But the ones that needed to hear it, or read it, couldn't due to the shades on and ipods sticking in their ears..... Oh well...

 

[DGdaPilot]

As I understand, all that message means is that your TOC is past your TOD. I don't think it necessarily means that you can't reach your planned altitude, that's what the climb capability charts are for.

That's not correct...at least not on the -700. If you're too heavy for the altitude you pop in (like FL400 or 410), it'll give that message.

 

[GCD]

Climbing at 250 KIAS to planned cruise altitude is not a good technique, unless it is to a lower FL. Here's why.

FAR Part 25 cruise altitude requiremnts:

At such altitude that the airplane must be able to:

1. Maintain designed cruise speed at maximum cruise thrust;
2. Be able to have a 1.3G buffet margin;
3. Still have climb capability to climb at 300 FPM at max continuous thrust / climb thrust.

If you climb to a higher FL at 250 KIAS and cannot accelerate to designed cruise speed at max cruise thrust, you've screwed yourself out of that altitude. The only way you can get to cruise speed is to descend.

When you go through the higher FL's, you should be transitioning from KIAS to Mach climb, anyway.

Keeping the deck agle lower for the climb will keep your kenectic energy higher and it will also help your thrust available by keeping the engines at a lower angle. The key word is intake. If the engine's angle is steep, it doesn't have as much intake to produce thrust with.

 

[BoilerUP]

Climbing at 250 KIAS to planned cruise altitude is not a good technique, unless it is to a lower FL. Here's why.

FAR Part 25 cruise altitude requiremnts:

At such altitude that the airplane must be able to:

1. Maintain designed cruise speed at maximum cruise thrust;
2. Be able to have a 1.3G buffet margin;
3. Still have climb capability to climb at 300 FPM at max continuous thrust / climb thrust.

If you climb to a higher FL at 250 KIAS and cannot accelerate to designed cruise speed at max cruise thrust, you've screwed yourself out of that altitude. The only way you can get to cruise speed is to descend.

When you go through the higher FL's, you should be transitioning from KIAS to Mach climb, anyway.

Keeping the deck agle lower for the climb will keep your kenectic energy higher and it will also help your thrust available by keeping the engines at a lower angle. The key word is intake. If the engine's angle is steep, it doesn't have as much intake to produce thrust with.

I thought it was illegal for people to post honest-to-God informative posts on Flightinfo these days.

Nice work and thanks!

 

[GCD]

I always try to help or mentor others because I sure needed it, and got it. It's time for me to pay back.

 

[flynryan15]

One question though: What if the CRJ 200 is on a giant treadmill?

You sir are evil!!! But funny

 

[Poahi]

GCD,

Thanks. You've confirmed my suspicion.