Vacuum, Venturi's, pumps, & wing leveling.

[zero.one.victor]

Just for fun,I checked out available suction at different speeds today. I have 2 venturi's,and a modern DG & AH.
Green on the suction gauge is 4-1/2" to 5-1/2". At normal cruise (114 mph),it pulls about 5-1/2". At high cruise (120),it pulls about 5-3/4". At about 80,it pulls about 4-1/4". All in the green. However,when I checked the suction gauge in the pattern, turning base at about 70,it was only pulling about 2-1/2", so it looks like it really starts dropping off fast below 80.
I've noticed the DG seems to be alive as soon as I break ground,but not so with the AH,it seems to take longer to spin up.

Eric

[GAHorn]

Hoog,could be that your airplane's not sitting level on the ground in the roll axia. That's the case with mine. Check it by measuring from the ground up to the wingtips,while parked on a level spot. Mine's off by a couple inches,if I recall. A friend had the same situation with his Cessna,he fixed it by moving a shim from the top of the gear leg to the bottom at the gearbox. It doen't take much "off" at the gearbox to make a big difference at the wingtip.

Eric

The correct method to fix this problem is to adjust gear-leg height with shims PN 0541105 (or common AN970 washers ) at the gear-leg attach bolt. This is done at the attach angle (PN 0713495-6) not the outer wedge. This is to be done if the wingtips vary more than 3 inches from the ground (relative to each other.)