CRJ Question...

[NJA Capt]

I have been following several threads here about CRJ ops up to FL410. From many of the RJ pilots descriptions, the CRJ sounds severely anemic at the higher flight levels. Does the CRJ's FMS unit not have a performance page that lists planned crz alt + maximum altitude possible for current weight/temp/ projected speed??

 

[wscrj]

Nope. Charts in the performance section (all assuming NEW engines and wingtips that haven't been rammed 13 times) is about it for us. There is a page listing the planned cruise altitude, which will predict fuel burn info assuming you fly the profile, but nothing telling you how high you can get.

And before I get jumped on, I will say that if you select an altitude that the performance section deems too high, a unable cruz alt message will appear...but that's it.

 

[Erlanger]

There are flip charts called Max Safe/Optimum Altitude Table that tell you what your max altitude is for a given temp and weight.

Examples from the charts;

Only two ways to make it to 41,000'; you would need a temp of ISA+5 degrees C or less and a weight of 39,000 lbs. or less. For a weight of 41,000 lbs. you would need a temp of ISA or less.

 

[katanabob]

Our max operating chart is mixed in with the speed cards and (supposedly) tells you what the max altitude is you can hold a 500 fpm climb to. They're incredibly optimistic, to say the least.

 

[Russ]

Try the alternate crz alt

I've had it tell me no at times.

 

[Twotter76]

The box will tell you if you try and input an altitude that is too high but you must be in predicted mode and you must enter the OAT (or deviation from standard, I forget which) in the perf init section. If you give an altitude which it deems to be too high you will get the "UNABLE CRZ ALT" message. However I do not know the crtieria that it uses to define what too high would be.

On a side note our charts show the max altitude attainable at a given weight and temp but they are extremely pessimistic. I am sure that every companies charts will vary significantly.

 

[DirkkDiggler]

On a side note our charts show the max altitude attainable at a given weight and temp but they are extremely pessimistic. I am sure that every companies charts will vary significantly.

You sound like you don't respect the company charts very much. They are intentionally pessimistic so you have a greater margin for error. That doesn't mean you should ignore the company charts because you think you're smarter than the folks who put that information together. This is why pilots get in trouble. Fly the aircraft the way your company wants you to fly it and you won't get in as much trouble. You also don't have to think as much which is a bonus.