X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Mon, 20 Nov 2006 11:26:24 -0500 Message-ID: X-Original-Return-Path: Received: from imo-d21.mx.aol.com ([205.188.144.207] verified) by logan.com (CommuniGate Pro SMTP 5.1.2) with ESMTP id 1585631 for lml@lancaironline.net; Mon, 20 Nov 2006 10:56:56 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.144.207; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-d21.mx.aol.com (mail_out_v38_r7.6.) id q.c25.8e6a4c7 (58808) for ; Mon, 20 Nov 2006 10:56:21 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Mon, 20 Nov 2006 10:56:21 EST Subject: Re: [LML] Electrical /Hydraulic system questions lancair 235/320 X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1164038181" X-Mailer: 9.0 Security Edition for Windows sub 5330 X-Spam-Flag: NO -------------------------------1164038181 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Randy, Flickering Lights The voltage regulator is certainly a possibility. How about a loose connection to your light dimming circuitry or a bad ground there? What alternator, regulator and battery are you using? Lo side pressure It is hard to imagine the low side fluid expanding since there is so little of it available when everything is sucked up. However, if the stops are, uh, not rigid, it is conceivable that the up side fluid pressure rise could push the piston further, maybe thru fluid expansion in the nose wheel well actuators that are heated by lower cowling air entering the well during flight. The ambient temperature rise in the main gear wells doesn't seem high enough to have much of an effect except that it isn't helping relieve any pressures. Maybe Chris has more useful information. Luckily your pressures are different enough that the dump valve relieves the lo side enough to allow the pump to come on. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) A man has got to know his limitations. In a message dated 11/20/2006 9:16:51 A.M. Central Standard Time, randylsnarr@yahoo.com writes: I haven't posted in a while as I have been busy flying and completing my interior. I will post a few pics when I am completed to keep the grinding, sanding crowd motivated. Anyway, I was flying recently near dark and I had the panel switch lights on. Can someone tell me why my lights flicker with the alternator on? When I turn the alternator off the flicker goes away. Is this just a bad voltage regulater or something else? Ironicly my wifes Lexus suv started doing the same thing. Maybe it is her fault! 2nd question. I have experienced the same issue as some have documented regarding the gear not coming down without recycling the dump valve. I flew on Friday and noticed something interesting. Here are the facts: Depart from PVU 50 deg f 4500 ft field elev cruised at 12.5 for 1.2 hrs to a warmer place decend to 4000 ft new atmosphere temp near 65 f I have gauges on the high and low side of the hyd system After take off they idicated low-0 and high-1300 or so. After decending to a warmer atmospheric conditions both the high and low side of the hydraulic system had significantly risen. low 400 psi and high 1700 psi. What happens in my case is the system pressure rises in cruise on the high and low side. The lower side exceeds the high pressure switch and the gear does not come down. I open the dump valve and then close it and the gear acts normally. My question relates the down side witht he gear up. It would seem to me that that side should always stay at 0 relieving pressure back to the resevoir in the pump. At first I thought I may have a leak somewhere allowing the pressure to sneak past the high side to the low side in cruise. I do not believe that is happening to me as both the high and low sides rise. Can someone give me some idea where to start? -------------------------------1164038181 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
 
Randy,
 
Flickering Lights
 
The voltage regulator is certainly a possibility.  How about a loo= se=20 connection to your light dimming circuitry or a bad ground there? = =20 What alternator, regulator and battery are you using?
 
Lo side pressure
 
It is hard to imagine the low side fluid expanding since there is so li= ttle=20 of it available when everything is sucked up.  However, if the stops ar= e,=20 uh, not rigid, it is conceivable that the up side fluid pressure=20 rise could push the piston further, maybe thru fluid expansion in the n= ose=20 wheel well actuators that are heated by lower cowling air entering= the=20 well during flight.  The ambient temperature rise in the main gear= =20 wells doesn't seem high enough to have much of an effect except that it isn'= t=20 helping relieve any pressures.  Maybe Chris has more useful=20 information.  Luckily your pressures are different enough that the dump= =20 valve relieves the lo side enough to allow the pump to come on.
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

A m= an=20 has got to know his limitations.
 
In a message dated 11/20/2006 9:16:51 A.M. Central Standard Time,=20 randylsnarr@yahoo.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I=20 haven't posted in a while as I have been busy flying
and completing my=20 interior.
I will post a few pics when I am completed to keep=20 the
grinding, sanding crowd motivated.

Anyway, I was flying rece= ntly=20 near dark and I had the
panel switch lights on. Can someone tell me why= =20 my
lights flicker with the alternator on?

When I turn the=20 alternator off the flicker goes away.
Is this just a bad voltage regula= ter=20 or something
else?
Ironicly my wifes Lexus suv started doing the=20 same
thing. Maybe it is her fault!

2nd question. I have experien= ced=20 the same issue as
some have documented regarding the gear not=20 coming
down without recycling the dump valve. I flew on
Friday and=20 noticed something interesting.

Here are the facts:

Depart f= rom=20 PVU
50 deg f
4500 ft field elev
cruised at 12.5 for 1.2 hrs to a=20 warmer place
decend to 4000 ft
new atmosphere temp near 65 f
I=20 have gauges on the high and low side of the hyd
system
After take of= f=20 they idicated low-0 and high-1300 or
so.
After decending to a warmer= =20 atmospheric conditions
both  the high and low side of the hydrauli= c=20 system
had significantly risen. low 400 psi and high=20 1700
psi.

What happens in my case is the system pressure risesin=20 cruise on the high and low side. The lower side
exceeds the high pressu= re=20 switch and the gear does not
come down. I open the dump valve and then=20 close it and
the gear acts normally.

My question relates the do= wn=20 side witht he gear up.
It would seem to me that that side should always= =20 stay
at 0 relieving pressure back to the resevoir in the
pump.
At=20 first I thought I may have a leak somewhere
allowing the pressure to sn= eak=20 past the high side to
the low side in cruise. I do not believe that=20 is
happening to me as both the high and low sides rise.

Can som= eone=20 give me some idea where to start?

 
 
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