RJ Flaps poblem

[arff]

When the Canadair RJ has flaps problems (partially retracted and/or no flaps) the manufacturer recommends 8000 ft of runway for landing. Very often the pilots of RJ (with partial flaps) are using 5000 ft instead and are solliciting the brakes heavily leading to a hot brake situation. Why, with a 10000 ft runway, RJ's pilots when confronted with partial flaps do not use more runway ? Thanks.

[ronster]

Thrust reversers will help slowing down with minimal brakes usage.

[arff]

Thanks Ronster;

Often the flaps problem comes from hydraulic problems, do you know if the reversers will be affected by the hydraulic problem affecting the flaps, or if they are (the thrust reversers) on a different hydraulic system ?

[West Coast]

arff
Been awhile, forgive me if I am wrong but the flaps on the CRJ, at least the 100 and 200 series are completely electric, no hyd's involved.

[take_that]

West Coast is correct, the 100's & 200's have electrically operated and actuated flaps.

I'm not sure where the 8000' recommendation comes from. In the UK using our company QRH (which obviously is authorised by Bombardier) we consult a table to get the required landing distance. Below is a couple of examples

Max weight,10000' landing elevation (pressure altitude) with no thrust revrs = 7271' (the worst case)

Max weight, 0' landing elevation with no thrust revrs = 5470'

Average lndg wt, 10000' land elvtn & operative revrs = 5603'

Avg lndg wt, 0' land elvtn & operative revrs = 4444'


Should stress that the above examples are for a full flap failure i.e. flaps remain at 0. There are further decrements to the required landing distance if you manage to get flap 8, 20 or 30.

I have so far not come across any instances where the flaps & the reversers have failed in my company (we've had our fair share of full and partial flap failures!)

So to answer your original question the 'calculated' distance required depends on the stage at which the flaps have failed, the pressure altitude of the airfield, your landing weight and (in a bizarre circumstance) whether you have thrust reversers. Therefore, I should imagine that many of the RJ's you have seen after burnig off some fuel would probably only need 4000'. On top of this an nice healthy head wind would be a bonus but not taken into account.

Having a 10000' runway is nice but given the above facts your comment would be similar to every aircraft using the full 10000' with or without flap problems - to save on the brakes!

Hope that answers your question.