| Lancairains,
The below only applies to the IV which has the main gear retract into the fuselage. Lancairs which retract more conventionally into the wing should not do this...... so everybody is right.
In order to get the IV mains over center the aircraft needs to lift up more than a foot which cannot be accomplished with the hydraulics alone. Only with a IV, it is safer to leave the mains on the ground when working with the nose gear only. Just be sure to restore the hydraulic pressure before setting the nose down.
Just wanted to be sure the non IV wing retract owners didn't try this.
Jack Morgan On Jun 13, 2013, at 6:00 AM, Lancair Mailing List wrote: Subject: Fwd: nose gear check
Date: June 12, 2013 3:11:45 PM EDT
Oops. Got my up and down backwards. Once you have the latch released move the gear lever to up with the small reservoir and avoid moving the lever all the way down until you are through checking things out. As long as you move the lever all down and bring the system to full pressure you will insure the main down locks are secure when you set the nose back down again.
Keep in mind that the nose gear needs full pressure to insure it is locked down.
Jack Morgan Begin forwarded message: Subject: nose gear check
Date: June 12, 2013 8:56:17 AM EDT
Hi Ralf, I have often done this and see no problem. I hang a "box of rocks" (Lancair part number 120099008-00-a.... just kidding) from the tail tie down. Just add large rocks until the airplane sits back on the box (over 100 lbs of rocks). I then have a friend blow gently into the pitot to release the gear lever and move it part way. Turn the master off or pull the pump breaker and move the gear lever to full down if you have the standard hydraulic reservoir. There is not enough capacity with the standard reservoir to put significant pressure on the main cylinders. You can cycle the nose gear up and down without moving the gear lever all the way up to lock it. I suggest using the master to control the hydraulic pump since repeated cycling of the pump breaker will eventually fail it.
If you have the large reservoir, discharge it by moving the gear lever partially up and down until it is depleted and then use the pump as above.
With the weight of the rocks and the airplane there is considerable weight on the mains. I believe this set up is preferable to lifting the nose as it gives extra insurance that the mains can't move. I have never let the full hydraulic pressure come up so don't know if the mains can actually lift the airplane and collapse. Perhaps others have experience here and can comment. It is easy to partially retract the nose by cycling the master and therefore the pump. You can then manually move the nose gear up to check the door clearance and closure. Release one door so you can see what is going on with the other door when moving the wheel up into the tunnel.
Hope this helps.
Jack Morgan
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