undertaker Posted October 20, 2019 Posted October 20, 2019 Usually I extend the maneuver flaps using the DLC & maneuver flap command aft thumbwheel on the control stick during approach. When extending the gear the flaps retract suddenly without further command und I lose lift. Is this correct behavior of the flap system?
*Aquila* Posted October 20, 2019 Posted October 20, 2019 It is. Gears down, you need to use the landing flaps and the DLC. In this configuration, the thumbwheel will control the DLC. NB: when gear is up and you're not using the landing flaps, it's not the DLC you use with the thumbwheel. It's the maneuver flaps.
undertaker Posted October 20, 2019 Author Posted October 20, 2019 Yeah, I agree with you. I did not express myself clearly. It has nothing to do with DLC. I don´t use it in that case. Issue in short: when the maneuver flaps are extended, they will be retracted automatically when gear lever goes down. That´s a bit strange. Why would you want the aircraft to retract the maneuver flaps after lowering the gear at low speed?
*Aquila* Posted October 20, 2019 Posted October 20, 2019 That´s a bit strange. Why would you want the aircraft to retract the maneuver flaps after lowering the gear at low speed? 1) Because the flaps mode associated with the gear down is landing flaps, which is obviously not compatible with maneuvering flaps 2) Because you're gonna need the DLC, which shares the same command as the maneuvering flaps For those reasons, the plane won't let you chose. If you fly by the book, the operations order is: 1) Under 280 kts, wing sweep mode AUTO and confirm 20 degrees 2) Under 250 kts,gear down 3) Under 225 kts, landing flaps down 4) Activate DLC Between 1) and 2), it's possible that the maneuvering flaps are automatically working. As you saw, they won't anymore after 2).
lunaticfringe Posted October 20, 2019 Posted October 20, 2019 Maneuver flaps active when the flap handle is lowered for landing can damage the flap system outright. The reason you separate the process behind the boat is to make sure you're below 8 units of AoA (combination of speed plus gear drag with wings fully unswept), thus causing the CADC to automatically retract them before you pull the handle down. Similarly, my recollection of conversations on the subject for "dropping the Big Boys" in a grovel is that you command the maneuver flap override with the DLC rotator to close them, then pull the flap handle.
undertaker Posted October 21, 2019 Author Posted October 21, 2019 Sweet, now I got it. Thanks for the explanation guys. :thumbup:
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