max altitude deviation before bust?

"Robert Moore" wrote in message
. 6...

When is IFR traffic required to have separation from VFR?


When in Class B and Class C airspace.

Teacherjh wrote:

It's what I was taught. I think it's also in the PTS for instrument flight
(though I don't have one handy). I haven't found it in a printed reference.

PTS standards for straight and level flight (FAA-S-8081-4C) states
applicant maintains heading within 10 degrees, altitude within 100 feet
and airspeed within 10 knots.

Which really leads me to another question.

If I am assigned an altitude of 5000, does this allow me from 4900 to
5100 or does it mean that I stay within 4950 to 5050? I always took it
as no higher or lower then 50 feet of my assigned altitude.

Allen
(working on my instrument rating)

BTIZ wrote:
ATC radar's (at least they used to when I was working them) show you on
"assigned altitude" when you are within +/-200ft

No, ATC radar shows what your mode C reports.


... so if you are assigned
9000 it will say "90C"... if you are still climbing to that altitude it will
say 90 "up-arrow" 87, or 8700 climbing to 9000 assigned.

You've mixed up two differnt things that are going on. What you are
talking about is the center. The center tag will often have your
assigned altitude shown similar to the way your type aircraft is shown.
Your actual altitude will always be shown. This way other controllers
can see what each aircraft is assigned. In the TRACON we don't show
assigned altitudes in the data block because we are much smarter and
don't need that crutch. Actually it's because the assigned altitudes
are constantly changing so there's no point in doing that.



the "traffic alert" on the ATC system is geared to the 90C, if you are at
9300 it will show 90 "arrow" 93 and if there is a traffic conflict at 10,000
it will "alert" the controller.

Center only.



Then he may "bust you", but if it's a momentary deviation and no other
traffic is involved, the controller may query and ask your altitude to
verify that his read out is correct. If you say, level 90, Then he may offer
up a new altimeter setting to you, or just tell you that he sees 9300, as a
hint that he is watching, or that you need to get it looked at. If your
altimeter setting is not set to "local", his computer radar will
misinterpret the altitude ModeC information from your aircraft.

Never admit an altitude bust. Just get back to your assigned altitude.

A Lieberman wrote:



If I am assigned an altitude of 5000, does this allow me from 4900 to
5100 or does it mean that I stay within 4950 to 5050? I always took it
as no higher or lower then 50 feet of my assigned altitude.



No, just like when you are cleared on an airway you must maintain the
centerline of the airway.

A Lieberman wrote:

If I am assigned an altitude of 5000, does this allow me from 4900 to
5100 or does it mean that I stay within 4950 to 5050?

If you're assigned 5,000 and you're actually at 4,901, you're within 100' of
your assigned altitude.

George Patterson
Battle, n; A method of untying with the teeth a political knot that would
not yield to the tongue.

BTIZ wrote:

If your
altimeter setting is not set to "local", his computer radar will
misinterpret the altitude ModeC information from your aircraft.

It won't in most aircraft. The mode-C encoder used in small aircraft has it's own
little altimeter, and it's not affected by the altimeter setting you're using.
When the controller tells you the altimeter setting, he or she is telling you
that you are flying at the wrong altitude. They're going to give you the benefit
of the doubt and assume that you just set the altimeter incorrectly, but they
know it's really because you're a klutz.

George Patterson
Battle, n; A method of untying with the teeth a political knot that would
not yield to the tongue.

BTIZ wrote:

If your
altimeter setting is not set to "local", his computer radar will
misinterpret the altitude ModeC information from your aircraft.



Your mode C reports a 29.92 altitude to ATC. ATC adjusts your reported
altitude for the local altimeter setting. You have no way of affecting
what your mode C reports, other than actaully changing altitudes.

If your
altimeter setting is not set to "local", his computer radar will
misinterpret the altitude ModeC information from your aircraft.

No, if your altimiter setting is not set to local, the PILOT will misinterpret
his altitude and fly an incorrect altitude, which will be correctly shown to
ATC.

Jose

--
(for Email, make the obvious changes in my address)

"Newps" wrote in message
news:PXi7c.54180$Cb.838268@attbi_s51...




BTIZ wrote:

If your
altimeter setting is not set to "local", his computer radar will
misinterpret the altitude ModeC information from your aircraft.



Your mode C reports a 29.92 altitude to ATC. ATC adjusts your reported
altitude for the local altimeter setting. You have no way of affecting
what your mode C reports, other than actaully changing altitudes.

Interesting - in the UK flying IFR means setting 1013mb. 29.92 above the
transition altitude so the pilots altimeter reads the same as the ATC.

"S Green" wrote in message
...

Interesting - in the UK flying IFR means setting 1013mb. 29.92
above the transition altitude so the pilots altimeter reads the same
as the ATC.


In the US we set our altimeters to 29.92 when above the transition altitude
for IFR and VFR flight. We set them to the local altimeter setting for IFR
and VFR flight when below the transition altitude. In both cases the pilots
altimeter will read the same as the ATC readout.