Dennis wrote:

I know this might not work in a Lancair IV, but in my Legacy, I do an alternate gear extension test in flight, using gravity and the gas shocks, to confirm that I get three down and locked.  If it works, I don't think there is any need to remove the gas shock and test it.


Dennis,
As designed by Lancair, the IV/IV-P mains will "free fall" to a trail position when the "up" pressure is removed from the gear retraction cylinder. They will not fully extend and lock down because they have to move forward against the airstream. Because of the design, there is no reasonable way to attach a gas strut to assist this, although some folks have devised various alternative "automatic" extension systems. The Lancair solution was to mount an emergency pump between the front seats to pump the mains down. Works well in all situations except some broken/leaking hydraulic line emergency situations. The reservoir even has a pick up for the emergency pump that is lower in the tank so there is some fluid left after the electric pump starts sucking air. The IV/IV-P nose gear is extended by a gas strut just like the Legacy, and should extend and lock down any time the "up" pressure is removed from the nose gear retraction cylinder. Part of the recommended condition inspection is a flight test to confirm that it will extend at or above 120 KIAS when the hydraulic pressure is depleted--(and that you can also pump the mains down and locked). My nose gear will extend and lock down reliably at 140 KIAS so I have not removed and tested it with a bathroom scale as recommended, but I'm thinking that this year is probably time to do so...

My two cents...

Bob