Vacuum pressure

[Peter MacPherson]

At what rpm do people see their vacuum pressure drop below an acceptable
level(3.2?).
I also have a standby vac with a low vac pressure red warning light. When I
reduce power
to 1200-1300 rpm the vac pressure drops off and the red light comes on. I
thought in the
past the pressure would hold until around 1000 rpm. Does this seem to be
working properly?

TIA,
Pete

[Karl Treier]

Most of the 172R's I have flown don't show Vacuum in the green below 1200
rpm.

[G.R. Patterson III]

Peter MacPherson wrote:
>
> At what rpm do people see their vacuum pressure drop below an acceptable
> level(3.2?).
> I also have a standby vac with a low vac pressure red warning light. When I
> reduce power
> to 1200-1300 rpm the vac pressure drops off and the red light comes on. I
> thought in the
> past the pressure would hold until around 1000 rpm. Does this seem to be
> working properly?

That's about the same as my Maule ('cept I don't have a warning light).

George Patterson
None of us is as dumb as all of us.

[Louis L. Perley III]

"Peter MacPherson" > wrote in message
news:Dqluc.14569$3x.7535@attbi_s54...
> At what rpm do people see their vacuum pressure drop below an acceptable
> level(3.2?).
> I also have a standby vac with a low vac pressure red warning light. When
I
> reduce power
> to 1200-1300 rpm the vac pressure drops off and the red light comes on. I
> thought in the
> past the pressure would hold until around 1000 rpm. Does this seem to be
> working properly?
>
> TIA,
> Pete

I don't get into the green on my C152 until I'm at 1200 RPM or so, but
some of the 172's at the local flight school will hold 5 at 1000 RPM just
fine.

--
Louis L. Perley III
N46000