Airsupport

As someone mentioned before the wings aren't based on pressure but based on temp. That is why if you do the ice test when its warm you will get a green ice message instead of a caution because the sensor is warm. After taxiing for about 5 minutes the wing anti-ice status message will come on and stay on even when the thrust levers are at idle. The cowls are pressure based. Infact on taxi out with both systems on I will get cowl caution messages more than wing caution messages.

Aquapilot

They did not De-ice....contaminated wings......

winglet

Under the right conditions frost can form very rapidly even with a "clear" sky. Every regulation, procedure, policy, checklist item, etc. ever written has simply been a reaction to an accident or incident. In rare cases they are written by the lone proactive individual who senses a potential hazard.

I agree that many rules and/or regulations assume pilots don't have good judgement and seem like common sense but unfortunately "common sense isn't very common is it?".

FAA InFO Document 10/01/09
Identifying Small Amounts of Frost, Snow, Ice or Slush on Aircraft and the Effects on Aircraft Control and Performance


China Yunnan Airlines
Canadair CRJ200LR (CL-600-2B19)


Epps Air Service
Canadair Challenger 604 (CL-600-2B16)


Belavia
Canadair CRJ-100ER (CL-600-2B19)


Global Aviation
Canadair Challenger 601 (CL-600-2A12)


Jet Connection
Canadair Challenger 604 (CL-600-2B16)


Fort Aero
Canadair CRJ100SE (CL-600-2B19)



Take Care,

winglet

atlmsl

But that's my point. You can wait 5 minutes and deal with numerous caution messages or you can bump the power up at the end of the runway and get the advisory message in 30 seconds. It takes a lot longer with power at idle.

av8sean

The caution message will usually only come on once and then go away once the wings are a certain temp. You are probably thinking of the cowls, which are based on pressure. If I know it's going to be a shorter taxi I just hit the wings on with the cowls during the after start check, it usually only takes 2-3 minutes for them to reach their temperature even at idle thrust.

krisma

This is just to let you know that everyone was right as far as Eicas indication for wing anti-ice.

FOR REFERENCE ONLY!!!!

"30-12-00-00 WING ANTI-ICE CONTROL AND INDICATION - DESCRIPTION AND OPERATION

2. Component Details
H. Pressure Switches
(1) The pressure switches are located in the crossover duct on each side of the isolation valve. The pressure switches send a signal to the DCU's that will display a L WING A/ICE and/or a R WING A/ICE caution message on the primary page of the EICAS when:
(a) Wing anti-ice switch is selected to NORM or STBY, and
(b) The duct pressure decreases below a set value, and
(c) There is not-sufficient heat sensed on the applicable wing leading edge."

JetPipeOverht

Good info on that last post...Thank you

flyboyPH

Sounds a bit crazy but we have the same in our FOM. Must turn the wing anti-ice 5c even on a clear day. Sounds crazy but its because of the accident.

ExperimentalAB

Clarification: Many guys are thinking you must taxi with wings on...definately not the case, folks. The AD addresses the final taxi only. As you are approaching the runway, bring up the wings and thrust momentarily to bring them to temp. Don't overthink it LoL

trip

Sure is a lot of misunderstanding on this AD out there, shows it has not been throughly explained to the flight crews. The reason for the wing heat on final taxi is because of the real danger of flow separation on the 200 wing. Frost or clear ice is also the most likely contaminate to go unnoticed by flight crews. Turning on the wing heat prior to T/O should eliminate any chance of frost on the leading edge. Flow separation is something that the BBA engineers have been very concerned about since this model was introduced. Some of the old guys might remember when bugs on the leading edge where considered reason for concern on the 200. The engineers found that the first few inches aft of the L/E is where the separation will occur if it is going to happen, (leading edge gap sealant missing or sticking up sound familiar?) The comment was made that they would rather have the pilots turn on wing heat for final taxi than deice the entire wing and not turn on wing heat at final taxi- that is how strongly they feel about it.