max altitude deviation before bust?

[Magnus]

I thought it was +/- 200 feet before you've violated if you are flying
IFR, but someone just told me it's a 100 feet, which seems a little
steep considering they use 1000 feet separations.

[Teacherjh]

It's +/-100 feet, which is a total range for 200 ft.

Jose

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

[Richard Hertz]

Why do you say "a little steep?" Clearly if you understand what is going on
there would not be a question. (assuming US/FAA)

vfr traffic 500 feet above/below
altimeter error allowed - 75 feet.
deviation of 100 feet
deviation of VFR traffic - 100 ft

Add up those errors and you have only 150 ft of separation



"Magnus" > wrote in message
...
> I thought it was +/- 200 feet before you've violated if you are flying
> IFR, but someone just told me it's a 100 feet, which seems a little
> steep considering they use 1000 feet separations.
>

[Capt.Doug]

>"Teacherjh" wrote in message > It's +/-100 feet, which is a total range for
>200 ft.

I was taught that it was +/- 300 feet and you violated seperation standards
with another IFR target. What is your reference?

D.

[Magnus]

Where can you read about the +/- 100 feet, I couldn't find it in the far-aim.


On 2004-03-20 21:44:58 -0500, "Richard Hertz"
> said:

> Why do you say "a little steep?" Clearly if you understand what is going on
> there would not be a question. (assuming US/FAA)
>
> vfr traffic 500 feet above/below
> altimeter error allowed - 75 feet.
> deviation of 100 feet
> deviation of VFR traffic - 100 ft
>
> Add up those errors and you have only 150 ft of separation

[Steven P. McNicoll]

"Magnus" > wrote in message
...
>
> I thought it was +/- 200 feet before you've violated if you are flying
> IFR, but someone just told me it's a 100 feet, which seems a little
> steep considering they use 1000 feet separations.
>

Depends what you mean by "violated". If your Mode C altitude is within 200
feet of your reported altitude you're considered to be on altitude.

[Teacherjh]

>>
>"Teacherjh" wrote in message
> It's +/-100 feet, which is a total range for
>200 ft. [for IFR flight tolerances]

I was taught that it was +/- 300 feet and you violated seperation standards
with another IFR target. What is your reference?
<<

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.

Jose

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

[Robert Moore]

"Richard Hertz" wrote
> Add up those errors and you have only 150 ft of separation

When is IFR traffic required to have separation from VFR?

Bob Moore

[Magnus]

That's exactly what I'm talking about. My understanding was that if you
have been cleared to maintain 3000 feet, and you dip down for example
past 2800' then it's a violation. A friend heard that it's actually 100
feet, which would incur a violation passing 2900 feet going by my
previous example.

Is there some reliable source of information where this info can be found?

On 2004-03-20 22:16:00 -0500, "Steven P. McNicoll"
> said:

>
> Depends what you mean by "violated". If your Mode C altitude is within 200
> feet of your reported altitude you're considered to be on altitude.

[BTIZ]

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

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.

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.

All controllers verify altitude readouts on the radar display on initial
contact, whether you call in, "out of 8500 for 9000" or, "level 9000", he
compares to what he sees on his data. If you do not offer up an altitude, or
in the case of an "IFR pickup" in the air, he will ask altitude leaving or
verify alt so he can compare his data.

BT

"Magnus" > wrote in message
...
> I thought it was +/- 200 feet before you've violated if you are flying
> IFR, but someone just told me it's a 100 feet, which seems a little
> steep considering they use 1000 feet separations.
>

[Steven P. McNicoll]

"Robert Moore" > wrote in message
. 6...
>
> When is IFR traffic required to have separation from VFR?
>

When in Class B and Class C airspace.

[A Lieberman]

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)

[Newps]

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.

[Newps]

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.

[G.R. Patterson III]

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.

[G.R. Patterson III]

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.

[Newps]

>
> 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.

[Teacherjh]

> 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)

[S Green]

"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.

[Steven P. McNicoll]

"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.

[C J Campbell]

"BTIZ" > wrote in message
news:rK87c.20095$Nj.6945@fed1read01...
If your
> altimeter setting is not set to "local", his computer radar will
> misinterpret the altitude ModeC information from your aircraft.
>

The controller has no way of reading your altimeter, no matter what setting
you have in it. The only thing he can read is the mode C of your
transponder. That is always set to 29.92.

[Richard Hertz]

There is none for vfr traffic - but supposedly vfr traffic should be flying
on the 500 ft intervals.


"Magnus" > wrote in message
...
> Where can you read about the +/- 100 feet, I couldn't find it in the
far-aim.
>
>
> On 2004-03-20 21:44:58 -0500, "Richard Hertz"
> > said:
>
> > Why do you say "a little steep?" Clearly if you understand what is
going on
> > there would not be a question. (assuming US/FAA)
> >
> > vfr traffic 500 feet above/below
> > altimeter error allowed - 75 feet.
> > deviation of 100 feet
> > deviation of VFR traffic - 100 ft
> >
> > Add up those errors and you have only 150 ft of separation
>

[Richard Hertz]

When you don't want to crash into them.

"Robert Moore" > wrote in message
. 6...
> "Richard Hertz" wrote
> > Add up those errors and you have only 150 ft of separation
>
> When is IFR traffic required to have separation from VFR?
>
> Bob Moore

[BTIZ]

Newps.. thanx for the "difference update".. between center and tracon..
please note my "statement of experience" in the first line of the posting...
granted I did not add that it was well over 20years ago when "shrimp boats"
were still around for when the computers failed..

you do know what those are ... don't you?

BT

"Newps" > wrote in message
news:Hxi7c.54106$Cb.837732@attbi_s51...
>
>
> 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
>

[BTIZ]

"Teacherjh" > wrote in message
...
> > 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)

Thank you Jose...

BT

[Newps]

BTIZ wrote:
> Newps.. thanx for the "difference update".. between center and tracon..
> please note my "statement of experience" in the first line of the posting...
> granted I did not add that it was well over 20years ago when "shrimp boats"
> were still around for when the computers failed..
>
> you do know what those are ... don't you?

I heard about 'em. Never actually seen them.

[Capt.Doug]

>"Teacherjh" wrote in message > 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.

For a practical exam, I agree with you. The original post asked about
violations in the text. I was thinking enforcement actions, not practical
tests.

D.

[Peter Duniho]

"Richard Hertz" > wrote in message
et...
> There is none for vfr traffic - but supposedly vfr traffic should be
flying
> on the 500 ft intervals.

When in cruise flight, above 3000' AGL. Doesn't sound like that would have
applied in this particular case.

[Andrew Sarangan]

I've had situations where my mode C was malfunctiong and reporting an
altitude outside of the accepted range for IFR. In such cases, ATC
verified what altitude I was maintaining and asked me to turn the
altitude encoder.


"Steven P. McNicoll" > wrote in message et>...
> "Magnus" > wrote in message
> ...
> >
> > I thought it was +/- 200 feet before you've violated if you are flying
> > IFR, but someone just told me it's a 100 feet, which seems a little
> > steep considering they use 1000 feet separations.
> >
>
> Depends what you mean by "violated". If your Mode C altitude is within 200
> feet of your reported altitude you're considered to be on altitude.

[Bob Gardner]

FAA Order 2150.3a, Compliance and Enforcement Program, in section
"Compliance/Enforcement Bulletin 86-1," says

"ACTION: Until further notice, a computer detected altitude deviation of 500
feet or less, where no near midair collision resulted, should normally be
addressed by means of administrative action, unless a prior altitude
deviation occurred within 2 years of the date of the subject altitude
deviation or other aggravating circumstances require initiation of legal
enforcement action. In determining whether a violation is "aggravated," all
circumstances surrounding the incident (e.g., whether the deviation was
deliberate or inadvertent, the hazard to safety, etc.) shall be considered."

In searching my Summit Aviation CD-ROM, I found the figure "300 feet" only
in reference to oceanic airspace and RSVM (Reduced Vertical Separation
Minimum), which applies above flight level 290.

Bob Gardner


"Magnus" > wrote in message
...
> I thought it was +/- 200 feet before you've violated if you are flying
> IFR, but someone just told me it's a 100 feet, which seems a little
> steep considering they use 1000 feet separations.
>

[Robert Moore]

"Bob Gardner" wrote
> In searching my Summit Aviation CD-ROM, I found the figure "300 feet"
> only in reference to oceanic airspace and RSVM (Reduced Vertical
> Separation Minimum), which applies above flight level 290.

In the Boeing jets that I flew, the altitude alerting system was
set to trigger an alarm when the aircraft deviated 300' from the
set altitude.

Bob Moore