Defective Flap Valve


Hello all
interestingly, while completing my IV-P operational testing (newly built) I was very pleased with the gear swing, and emerg gear extension.

However, when it came to the flap extension and retraction, it was stuck in the extended position and the flap position valve movement DID NOT change anything. Checking the hydraulic line to the actuator piston revealed NO FLOW of hydraulic fluid to the retraction side. Hmmm.

So inspecting the valve, I discovered that the block port providing pressure to the flap retraction is completely blocked. The aluminum valve block is not drilled out for that port. Further, with the flap valve in the down position, it connects with the gear-up port - UGH !

Not sure if they simply used the wrong valve block connected to the port block - but this is really bad!

There is no exploded diagram for the valve blocks in particular - but if anyone out there could help with this - I would really appreciate it. Lancair tech support has been non-responsive on this. My guess is that nobody there is familiar with this part and its defect. There are few builders out there so I am hoping someone could advise me.


rpastusek's picture



call me on this. I may be able to help??

Bob Pastusek

LOBO Secretary