Altimeter setting

On Jan 28, 10:55*am, Martin Gregorie
wrote:
On Sat, 28 Jan 2012 01:04:14 -0800, Bill *Palmer wrote:
There of course, is *no prohibition against having two altimeters. One
set to QNH (field elevation) the other set to QFE (zero on the ground).
This is *how American Airlines operated for decades. QFE is also the
standard in Russia and China.

The Chinese must have some pretty special altimeters if this applies to
all their airfields, including those in Tibet: Bangda airport in eastern
Tibet is at 14,219 feet AMSL.

Bangda has an 18,000 ft (5500m) runway and, I gather, needs it. I've
heard that the pilots must be on oxygen for takeoff and landing.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

There's no need for any of this in soaring. XCSoar (what I use) and
all other GPS-map gizmos do a very good job of reporting AGL height
given a good 3D gps input and will (among other things) report an
estimated arrival height over any navpoint. We beat this to death.
The "AGL" altimeter guys had not a single compelling argument. They
lost.

-Evan Ludeman / T8

On Sat, 28 Jan 2012 08:12:34 -0800, T8 wrote:

On Jan 28, 10:55Â*am, Martin Gregorie
wrote:
On Sat, 28 Jan 2012 01:04:14 -0800, Bill Â*Palmer wrote:
There of course, is Â*no prohibition against having two altimeters.
One set to QNH (field elevation) the other set to QFE (zero on the
ground).
This is Â*how American Airlines operated for decades. QFE is also the
standard in Russia and China.

The Chinese must have some pretty special altimeters if this applies to
all their airfields, including those in Tibet: Bangda airport in
eastern Tibet is at 14,219 feet AMSL.

Bangda has an 18,000 ft (5500m) runway and, I gather, needs it. I've
heard that the pilots must be on oxygen for takeoff and landing.

--
martin@ Â* | Martin Gregorie gregorie. | Essex, UK org Â* Â* Â* |

There's no need for any of this in soaring. XCSoar (what I use) and all
other GPS-map gizmos do a very good job of reporting AGL height given a
good 3D gps input and will (among other things) report an estimated
arrival height over any navpoint. We beat this to death. The "AGL"
altimeter guys had not a single compelling argument. They lost.

I'm not supporting or dismissing the use of QFE settings (though its what
I was taught), just pointing out the impossibility of setting a standard
altimeter to QFE for every airfield in areas that the Chinese say are
part of China.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Jan 28, 11:31*am, Martin Gregorie
wrote:
On Sat, 28 Jan 2012 08:12:34 -0800, T8 wrote:
On Jan 28, 10:55*am, Martin Gregorie
wrote:
On Sat, 28 Jan 2012 01:04:14 -0800, Bill *Palmer wrote:
There of course, is *no prohibition against having two altimeters.
One set to QNH (field elevation) the other set to QFE (zero on the
ground).
This is *how American Airlines operated for decades. QFE is also the
standard in Russia and China.

The Chinese must have some pretty special altimeters if this applies to
all their airfields, including those in Tibet: Bangda airport in
eastern Tibet is at 14,219 feet AMSL.

Bangda has an 18,000 ft (5500m) runway and, I gather, needs it. I've
heard that the pilots must be on oxygen for takeoff and landing.

--
martin@ * | Martin Gregorie gregorie. | Essex, UK org * * * |

There's no need for any of this in soaring. *XCSoar (what I use) and all
other GPS-map gizmos do a very good job of reporting AGL height given a
good 3D gps input and will (among other things) report an estimated
arrival height over any navpoint. *We beat this to death. The "AGL"
altimeter guys had not a single compelling argument. They lost.

I'm not supporting or dismissing the use of QFE settings (though its what
I was taught), just pointing out the impossibility of setting a standard
altimeter to QFE for every airfield in areas that the Chinese say are
part of China.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

Got that. Not intending to pick on you Martin. FWIW, I was taught
QFE too. One of only two obvious defects in my otherwise excellent
primary instruction. The other was poor checklist discipline (augh,
how did that happen? that's another thread).

QFE is so wrong in so many ways... it's amazing to me that this keeps
popping up. I really don't give a fig about certain well known
friends of mine that insist on doing this despite the inevitable
communication problems "Xray Lima, say altitude" / "I'd rather not,
thanks" (:-)), but if there are still instructors teaching students
QFE, they really need to be taken to the woodshed and this needs to be
stopped.

-Evan Ludeman / T8

On Sat, 28 Jan 2012 09:16:27 -0800, T8 wrote:

QFE is so wrong in so many ways... it's amazing to me that this keeps
popping up. I really don't give a fig about certain well known friends
of mine that insist on doing this despite the inevitable communication
problems "Xray Lima, say altitude" / "I'd rather not, thanks" (:-)),
but if there are still instructors teaching students QFE, they really
need to be taken to the woodshed and this needs to be stopped.


Understood.

FWIW I carry two altimeters, a standard mechanical one and my SDI C4 vario
which is also an altimeter. I normally set the mechanical to QFE and the
C4 to 1013mb. This works well since my local airspace designations are
split roughly 50:50 between height AGL and flight levels with a slight
excess of AGL.

We're taught to ignore the altimeter in the circuit in favour of looking
out the window because this is all that works for a field landing, just
as all UK glider landings are effectively short-field landings for the
same reason. Further, very few glider fields share with GA so what the
altimeter has to say around the airfield is unimportant: its interesting
to see how high the winch launch was and if you're well above winch
height if you want to cross the field but that's about it.



--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |