CRJ-200 Wings before Cowls

[Lazy8]

Turning on wing anti-ice before cowls to prevent the blowout plugs from opening... At least that's how it was explained in ground training...

Is Pinnacle the only CRJ-200 operater that practices this? The more I think about it the more silly it would seem that Canadair built it to where you could not open the cowls before wings with power on the engines. Also, it takes time for the wing anti-ice to opening up, yet we flip right through the switches (wings/cowls) in under a second. What's the point?

Was talking with a SKYW captain and she said it's the first she ever heard of it.

Just curious who else does this and if there is any truth behind the method.

 

[G2T]

They are not the only operator to do this.

 

[siucavflight]

Turning on wing anti-ice before cowls to prevent the blowout plugs from opening... At least that's how it was explained in ground training...

Is Pinnacle the only CRJ-200 operater that practices this? The more I think about it the more silly it would seem that Canadair built it to where you could not open the cowls before wings with power on the engines. Also, it takes time for the wing anti-ice to opening up, yet we flip right through the switches (wings/cowls) in under a second. What's the point?

Was talking with a SKYW captain and she said it's the first she ever heard of it.

Just curious who else does this and if there is any truth behind the method.

I think that we found your problem.

 

[jehtplane]

I think that we found your problem.

That there is funny I don't care who you are

 

[McNugent]

ASA does it too

 

[rickair7777]

Turning on wing anti-ice before cowls to prevent the blowout plugs from opening... At least that's how it was explained in ground training...

Is Pinnacle the only CRJ-200 operater that practices this? The more I think about it the more silly it would seem that Canadair built it to where you could not open the cowls before wings with power on the engines. Also, it takes time for the wing anti-ice to opening up, yet we flip right through the switches (wings/cowls) in under a second. What's the point?

Was talking with a SKYW captain and she said it's the first she ever heard of it.

It is a valid technique, used by several airlines that I know of.

Skywest does not train or use this trick, they recommend a power reduction before selecting cowls. Skywest also doesn't seem to really care if you pop the relief valves...they just send Mx out and re-wire it closed (it takes about a minute). Another airline I worked for would bust your nads if you popped a relief valve.

 

[Rez O. Lewshun]

Many operators do this.... some actually reduce the thrust before turning on the wing to turn on the cowls then turn off the wing.... and reduce the thrust before turning on the wing when the wing is needed...

Also... one doesn't have to have an N2 value above the amber band if the wing is on...

<H1 style="MARGIN: 0in 0in 0pt">CF34-3 Flight Operations Notes

(Information for airline operators of CF34-3 engines. Published by GE Aircraft Engines Commercial Product Support.)

TO: All Canadair Regional (100/200) Jet Pilots No. 11 Revision 1

SUBJECT: Operation Below 78% N2 in Icing Conditions Date: 14 APR 1998


The CRJ EICAS N2 gage displays an amber/ yellow band below 78% N2 whenever the wing anti-ice protection system is activated. If N2 is reduced below 78%, it is annunciated as a caution by turning the pointer and display digits amber/yellow.

The threshold of 78% N2 was determined by Canadair in testing to show the level above which anti-icing was fully effective under all conditions up through “continuous maximum icing”. Thus at conditions that are less severe, the engine may be operated at settings below 78% N2.

If power settings below 78% are used, for aircraft operational considerations, monitor the CAS Amber Caution messages for L(R ) Wing Anti-Ice, or L(R ) Cowl Anti-Ice. The L(R ) Wing Anti-Ice message will illuminate if there is insufficient heat at the wing leading edge or if there is insufficient duct pressure. The L(R ) Cowl Anti-Ice message will illuminate if there is insufficient pressure in the engine inlet cowl anti-ice duct when the system is turned on.

Assuming that the ice protection system is functioning properly, operating below 78% N2 is acceptable as long as the Wing or Cowl Anti-Ice Caution messages do not annunciate. If this does occur, the recommendation is to advance engine thrust levers to greater than 78% N2 to allow higher bleed air pressure to raise the wing leading edge temperature above the sufficient heat level. This condition was simulated by Canadair in “Delayed TURN ON” tests where ice build up was cleared by activation of the system after a 30 second delay. Following a period of dwell at greater than 78% N2, the engines may be reset lower. If lower settings resulted in Wing or Cowl Anti-Ice messages to annunciate, a slightly higher setting (closer to 78% N2) should be used to decrease the probability of illuminating these messages.

Engine N1 vibrations may indicate the accretion of ice on the fan spinner in icing conditions over observed steady state levels. This secondary indication may be used as additional information regarding the severity of icing conditions and, therefore, be used to maintain higher N2 power settings.






In summary, the EICAS N2 amber/yellow indication band is a conservative range that is intended to provide a minimum power setting at which the ice protection system is fully effective in all icing conditions, and also allows an acceptable descent rate for the lowest weight aircraft while avoiding nuisance Anti-Ice caution messages. In the event that higher descent rates are needed, for operational reasons, lower power settings may be used if the severity of icing conditions permit. Proper system operation can be effectively monitored by using the Wing Anti-Ice and Cowl Anti-Ice messages to alert the pilot of insufficient heat to the wing leading edge or the cowl.


This recommendation has been jointly reviewed by Canadair and GE Aircraft Engines. Please contact us if there are any further questions regarding this subject.

</H1>

 

[skydraulic]

That there is funny I don't care who you are

And that there is one purdy avatar jehtplane!! what was this thread about again??

 

[cargoflyr69]

Chq does it that way too

 

[PCL_128]

It's usually only a problem at lower altitudes with climb power set. Once you get higher and the engine is producing less thrust, it's very unlikely that you'll blow a plug.

 

[AbOvo]

This was a problem at SkyWest about five years ago but they were able to reduce the number of blown plugs by changing the spec on the safety wire used on the plugs (probably why the SkyWest captain you talked to hadn't heard of it being a common problem). It's only five minutes to replace the blown plug if your company MX thinks far enough ahead to have some plugs already made up with new safety wire.

If you don't have any made up the mechanic needs to remove the plug assembly and re-safety it in place, more like a 15 to 20 minute job.

 

[jvrac]

Just do it the way your company tells you to do it. That way if a plug does blow, you can say "hey I did it the way you guys wanted me to". They can't fault you for following SOPs. It only takes a second to flip the wings on, then the cowls. Not that big of a deal.

 

[Lazy8]

Also... one doesn't have to have an N2 value above the amber band if the wing is on...

</H1>

Good to know! I've flown with a couple folks that do not realize that.

 

[Casper]

PSA also does it like this.

 

[skyaddict]

We did it at ACA/Independence too.

 

[Rez O. Lewshun]

We did it at ACA/Independence too.

You can discuss in detail

The details for the next gathering of former ACA/IDE employees has been
set:
> THURSDAY, January 31, 2008 - 5:00pm till they throw us out!
> Ned Devine's Irish Village (The STERLING location-not Reston)
> Additional details can be found on the Evite invitation that is linked
> below!
>
> Please help spread the word! Forward this message to friends and former
> coworkers, post info in crew rooms, and use the "invite other guests"
> feature in the invitation itself! I'm looking forward to another great
> event!
>

> Reunion Organizer / IAD CRJ FO
> [email protected]
703-867-8679

 

[bailout]

of course most 'tards simply turn the wings on then the cowls in rapid succession. Do they really think .25 sec time frame between turning the wings on and then the cowls actually gives the valves time to react,. NOT..

 

[Lazy8]

of course most 'tards simply turn the wings on then the cowls in rapid succession. Do they really think .25 sec time frame between turning the wings on and then the cowls actually gives the valves time to react,. NOT..

That's what I was trying to say. I don't see what the point is if you flip them all on in a rapid movement like that, but that's how everyone (that I've flown with) does it.

:erm:

 

[Rez O. Lewshun]

Well it bothers me to cuase it goes agains the way I was trained.. however, if it was that big of a deal then bomardier/ge would have stronger language..

It's kinda like using TR's with the nosewheel off the ground!