The mighty RV-4 has manual flaps. Clever design with a simple aluminum bar connected to the flaps that locks into the side of the pilot's seat. There are some small, beveled blocks on the seat that hold the handle up (and keep flaps down) when the flaps are deployed. After a while (about 2000 hours, including lots of flap use for flight test), the bevel on the flaps 40 detent was pretty worn down. Warning, there is a bit of sporty language in the video:
https://youtu.be/R8VIUQTO-XU
It may be one of the few airplanes that has manual flaps and a flap position sensor. That sensor is part of the AOA system. If you have an AOA system, it's important that the system has an accurate calibration for each flap setting. If you watch the video closely, you'll see how the system responds when the flaps retract with a "bang" (momentary slow tone during the AOA excursion or "spike") The initial pitch-up is caused by the pitch trim change when the flaps retract uber fast. If you watch the "indexer" (military slang for the visual AOA display), you'll see that the trend indicator responds to the event (as well as the % lift indication), but it happens fast. Real fast. The tone does a better job of conveying the "slow" condition to the pilot.
Fly safe,
Vac
https://youtu.be/R8VIUQTO-XU
It may be one of the few airplanes that has manual flaps and a flap position sensor. That sensor is part of the AOA system. If you have an AOA system, it's important that the system has an accurate calibration for each flap setting. If you watch the video closely, you'll see how the system responds when the flaps retract with a "bang" (momentary slow tone during the AOA excursion or "spike") The initial pitch-up is caused by the pitch trim change when the flaps retract uber fast. If you watch the "indexer" (military slang for the visual AOA display), you'll see that the trend indicator responds to the event (as well as the % lift indication), but it happens fast. Real fast. The tone does a better job of conveying the "slow" condition to the pilot.
Fly safe,
Vac
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