CRJ-100/-200 Automatic Power Reserve

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11-24-2009 | 06:08 AM

#21

krisma

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Joined: Oct 2008

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From: The one that holds the thingy that moves the doo-hickie, and keeps the other thing from falling down

Quote:

Originally Posted by rickair7777

Probably have to ask bombardier on that, but I doubt it would be designed to be able to physically add much more than is required for APR...otherwise you create a potential to destroy the engine during an APR event.

The following is for the purposes of education and no knowledge of current revisions is implied.

"3. Operation
A. With the APR system armed, if the N1 fan speed decreases to 67.6 percent or lower on one of the two engines, the control amplifiers will receive a signal to schedule a fan speed increase for the remaining engine. The speed of the engine, at the usual takeoff N1 speed, will increase by approximately 2.3 percent and the engine that has the N1 drop, will revert to N2 mode and will not follow N1 commands. (For description of N1 and N2, refer to 73-20-00).
NOTE: The APR does not change or cancel the thrust reverser lever inputs to the main fuel control. It is also possible to move the throttle levers and get power settings higher than the usual (non-APR) takeoff thrust.
B. With higher than usual takeoff thrust settings, followed by a loss of power on one engine, the serviceable engine will have a higher turbine temperature (ITT) The data concentrator units (DCU) will change the ITT red line from 900°C to 928°." -bombardier crj-200 aircraft maintenance manual

11-27-2009 | 05:05 PM

#22

atlmsl

Gets Weekends Off

Joined: Dec 2007

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From: ATL

After takeoff tonight the APR engaged on both engines without reason. I wasn't timing it but we discussed when it finally disengaged and seemed as if it disengaged right at the 5 minute mark where APR is normally disarmed after takeoff. Both engines responded to power lever movements. Maintenance said to continue and it would be deferred after landing. It wasn't really an issue.