single pilot ifr trip tonight

[name removed, since this isn't personal] writes:

Without knowing for sure, one of the possible factos for the Kennedy
accident [...]

I think that we need to create a new variation of Godwin's Law, for
aviation groups and lists, named in honour of John F. Kennedy Jr.:

John Jr's Law
-------------

As an aviation-related discussion grows longer, the probability of a
cautionary reference to John F. Kennedy Jr.'s fatal crash off
Martha's Vinyard on July 16, 1999 approaches one.


All the best,


David

Roy,

Oops! I remembered wrongly. Sorry!

--
Thomas Borchert (EDDH)

"David Megginson" wrote in message ...


John Jr's Law

Gee, my corollary was "When someone famous crashes and non-aviation oriented
people find out that you are a pilot, they're going to ask you about it."

I flew up to my family reunion in Mass. a few weeks after the JFKJr crash. I got
asked that every time I turned around.

Dan Truesdell wrote:
the few short
forays into the clouds lead me to investigate an electric AI. Although
we were only in the bumpy stuff for a few minutes at a time,

Now that the FAA has finally relented and allowed you to throw away your
turn coordinator and get a second AI I went and talked to my local
avionics shop about the RC Allen electric AI that I see advertised for
about $1800. They said don't bother as 90% of them come back because
they are so horribly built. They told me to get the reliability of a
vacuum AI it's gonna take about $4000.

Thanks for the heads-up on those. I was figuring on about $2K, but $4K
would mean asking the other 4 owners to kick in $1000 for an item that
they won't use. For a 172, it's probably just as good then to get a
manifold-driven backup vacuum. Too bad the electronic AI's are not
certified for IFR (the $1500 ones, not the $6000 ones.)

Newps wrote:


Dan Truesdell wrote:

the few short forays into the clouds lead me to investigate an
electric AI. Although we were only in the bumpy stuff for a few
minutes at a time,


Now that the FAA has finally relented and allowed you to throw away your
turn coordinator and get a second AI I went and talked to my local
avionics shop about the RC Allen electric AI that I see advertised for
about $1800. They said don't bother as 90% of them come back because
they are so horribly built. They told me to get the reliability of a
vacuum AI it's gonna take about $4000.



--
Remove "2PLANES" to reply.

Dan Truesdell wrote:
Thanks for the heads-up on those. I was figuring on about $2K, but $4K
would mean asking the other 4 owners to kick in $1000 for an item that
they won't use. For a 172, it's probably just as good then to get a
manifold-driven backup vacuum.

Consider the dual-rotor vacuum pump from http://www.aeroadvantage.com instead.

I've owned one of the manifold-driven backup vacuum systems, and it's marginally
OK, but I wouldn't buy one again. The shuttle valve gets stuck. It requires
pilot action to preflight test it, and to switch it on when you need it. The
vacuum it provides is limited. There is no provision for practicing with it (you
have to physically disconnect the vacuum pump), so you don't get proficient with
flying with the reduced vacuum and altered operational requirements. Under
most operational regimes, you will have to limit engine power in order to keep
the vacuum sucking.

By contrast, the dual-rotor pump failover is automatic, you get full vacuum
without interruption, just a panel annunciator to check during preflight and to
tell you one of the rotors has failed.

The cost is only slightly more than the manifold-dirven system.

Dave
Remove SHIRT to reply directly.

Dan Truesdell wrote:

Thanks for the heads-up on those. I was figuring on about $2K, but $4K
would mean asking the other 4 owners to kick in $1000 for an item that
they won't use. For a 172, it's probably just as good then to get a
manifold-driven backup vacuum. Too bad the electronic AI's are not
certified for IFR (the $1500 ones, not the $6000 ones.)

One of our club airplanes has something like this. But someone told me that
it works least well under full throttle...which means down low executing a
missed approach.

Was I told correctly? How serious is "least well"?

- Andrew

Roy Smith wrote in message ...
A friend of mine and me tried an experiement once. I put our Archer
into some unusual attitudes, and he recovered using just the synthetic
instruments on his handheld GPS (Garmin something-or-other, might have
been the 295 but I'm not sure). Conditions were night VFR, no
turbulence.

I haven't tried this yet, and I really should.

What I can say is that IME it's significantly easier to fly
a full approach partial panel at night with either my panel
moving map, or my handheld moving map, than it is with both
failed, and that this is not because it's easier to navigate
per se, but because it's easier to *keep the wings perfectly
level* in TB or chop by using the track info on either GPS
to hold a steady track. (Basically, I would hold that navigation
at its most fundamental is simply the ability to hold heading,
and that the ability to hold heading at its most fundamental
is simply the ability to keep the wings level).

Our CFI has absolutely no regard for the FAA's views on
which instruments to fail or how many *g* and we did this
very deliberatly as an emergency exercise, in order to learn
exactly how much info we extract from the moving maps and
the best setup to extract it from our particular equipment.

If he ignored pitch (let the trim take care of it)
and just used rudder to zero out rate of turn on the synthetic TC, he
did pretty well.

I don't have a "synthetic TC", but it sounds analogous to what
I learned to do in the way of zeroing the change on the track.

I'll have to see about trying it with unusual attitudes.

Best,
Sydney

Andrew Gideon wrote:

Dan Truesdell wrote:

For a 172, it's probably just as good then to get a
manifold-driven backup vacuum. Too bad the electronic AI's are not
certified for IFR (the $1500 ones, not the $6000 ones.)

One of our club airplanes has something like this. But someone told me that
it works least well under full throttle...which means down low executing a
missed approach.

Was I told correctly? How serious is "least well"?

That's exactly right. (From memory) the STC recommends you maintain at least 3.5
inches of vacuum to the gyros. That means the intake manifold pressure has to be
at least 3.5 inches less than the ambient pressure.

At sea level on a standard day, you will have to adjust your power to have a
manifold pressure no higher than (29.92 - 3.5) = 26.42 in Hg.

If you have a fixed prop and no manifold pressure gauge, you have to figure out
what that means for a throttle setting. There will be a calibration placard
giving maximum RPM for different pressure altitudes. At high pressure-altitudes
(low ambient pressure), you will need to reduce power correspondingly to
maintain the required vacuum to keep the gyros spinning.

Specifically, during a missed approach, you'll have to choose between keeping
the gyros spinning and having full power available.

My limited experience is that 3.5 inches is not enough for good reliable
instrument indications. That may be a function of which models of instruments
you have installed and how new the bearings are.

Of course, as I pointed out elsewhere in this thread, you don't get to practice
managing the vacuum under realistic conditions. Pulling out the knob on the
panel doesn't activate the system if you have a working vacuum pump. There is a
shuttle valve that selects the vacuum source that provides the most suck
(manifold or pump) when the panel control is activated.

Said shuttle valve is also a point of failure. You can check it on the ground
with the engine idling. At idle, the manifold will pull more vacuum than the
pump. I can count on the fingers of *no* hands the number of pilots I have ever
seen perform this check routinely.

At risk of beating a dead horse, get the dual-rotor pump from
http://www.aeroadvantage.com instead.

Seriously close to "not at all".
Your instruments want to see vacuum of about five inches Hg to operate.
I'm guessing they'll still function OK down to four inches Hg.
That means your manifold pressure would need to stay at least 4 inches
below ambient atmospheric pressure to keep your gyros up to speed.
That sacrifices a lot of climb power, for sure.
---JRC---

"Andrew Gideon" wrote in message =
online.com...
=20
One of our club airplanes has something like this. But someone told =
me that=20
it works least well under full throttle...which means down low =
executing a=20
missed approach.
=20
Was I told correctly? How serious is "least well"?
=20
- Andrew