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Date: Mon, 20 Feb 2012 07:58:13 -0500
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From: Lorn H Olsen <lorn@dynacomm.us>
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Subject: Re:320/360 Hydraulic Pressure Switch
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Angier,

If you are flying and the gear doesn't come down, opening the dump valve =
for a fraction of a second and then closing it, fixes the problem.

On a climb out your switch would work but the problem only occurs when =
there is at least a 50=B0F temperature raise. Why not just land and open =
a fitting? To see if you are going to have a problem on the ground, just =
open and then close the dump valve. The pump should run. If it doesn't, =
you will have to open a fitting to relieve the pressure. You could also =
install pressure gauges and just look at them.

The pressure gauges are probably the 1st extra item that should be =
installed.

The problem with all of the above solutions is that they can require a =
pilot's time at the worst possible moment.

None of the above solutions would have stopped me from having a gear up =
landing. At the OM, on an IFR approach, I put the gear lever down. It =
was very turbulent. I was busy keeping the dirty side down. At 500' I =
was crabbed 45=B0. The wind was 6kts on the ground. I just didn't notice =
that both switches were open.

Wolfgang's pressure switch closer would have saved my bacon.

Lorn

> From: "Greenbacks, UnLtd." <N4ZQ@VERIZON.NET>
> Date: February 17, 2012 1:07:36 PM EST
>=20
> Seems to me the simplest and least expensive option would be to =
install a momentary on switch in the cockpit to override and close the =
open pressure switches.
>=20
> Just my 2 cents.
>=20
> Angier Ames
> N3ZQ


--
Lorn H. 'Feathers' Olsen, MAA, ASMEL, ASES, Comm, Inst
DynaComm, Corp., 248-345-0500, mailto:lorn@dynacomm.us
LNC2, FB90/92, O-320-D1F, 1,800 hrs, N31161, Y47, SE Michigan