Hdg True/Mag?

[Oxford1G]

If i was to have a compass failure, would ATC with their systems, be able to tell me what either my true or magnatic heading was, in order to allow me to fly an approach, and or take radar headings?

Thanks

[BDiONU]

As an ex D&D controller I've had several of these for real (as well as dozens of practice ones!).
If your compass is U/S what difference does it make what heading you fly, you're only interested in pointing in the right direction, as are ATC.
ATC will use what they see on the radar and (in my experience) will use the No Compass No Gyro procedure. Although it does seem that civil pilots are not familiar with this, so.....
"Adopt the No Compass No Gyro procedure, make all turns rate 1 (thats 3 deg per second), start and stop turns on the executive word NOW!"
With a standard rate 1 turn you can time turns, i.e. 30 deg = 10 seconds (stopwatches supplied! ) but its generally been my experience that its best to just watch the aircraft turn, taking into account the lag on radar (about 30 degrees).

[Whipping Boy's SATCO]

For what its worth, the radar displays magnetic track. However, T3C5 is correct, if you don't have a compass, what use is it for you to know your hdg/track.

[Hippy]

I think T3C5 & SATCO are well under-selling themselves. The procedure is tought to all mil ATCO's, not sure about civil?, and is accurate enough to conduct an SRA, so easily accurate for vectors to an ILS. The stopwatch and timing are done by ATC by the way, should there be any cofusion, so I should imagine the hardest bit for the pilot is flying straight. Any comments from aircrew?

Hippy.

[professor yaffle]

no compass/no gyro is taught to civvies - least it was to me not that long ago

prof

[Oxford1G]

Chaps and Chapess,

Thankyou for your comments.

Consider the following:

On some aircraft types, you have two independent compass systems, so what happens when both compass systems show different headings? I know that you have a standby compass (E2B), but this is only a guide, in fact all three systems may show different headings.

I understand the no gyro no compass procedure, but the thrust of my question was about obtaining information from ATC, if they could supply me with an accurate magnetic heading, then i would be able so see which compass system, if any was accurate.

It is possible that radar may not be able to provide you with a SRA/PAR, and you may need to fly an NBD approach.

Thanks

[Hippy]

...no, we can't tell you what your heading is by radar observation. We don't know exactly what winds you are experiencing or how much rudder trim you have on. We can tell you your true track pretty accurately, using electronic measurement. We could tell roughly what your heading is, based on current knowledge. By that I mean that ATC will have a pretty good idea of what the wind is doing from experience of observed track relative to headings given to previous aircraft in the area, but we can't assume to know your heading.

Hippy.

[youngskywalker]

Dear me! c'mon boys, every Pilot with an instrument rating knows what a timed turn is and a rate one! Christ, that is taught at basic PPL training! Controllers are not the only ones who spend 18 months at college in Bournemouth you know!!:)

[Hippy]

mmmmmm, chilling out you need to be, youngskywalker.

Nothing in Oxford's first post suggested he had an instrument rating. He asked if we could tell his heading using 'our systems' - true/magnetic/compass/whatever is irrelevant, just wanted to know if we could tell him his heading so that he could take vectors using a suspect compass. The origional replies were made using assumtions of the pilots knowledge taken from the naivety of the query. Once Oxford clarified the question a more appropriate reply was given. I trust, youngskywalker, that you show a little more equanimity on the R/T?

[BDiONU]

Not all pilots appear to know what a rate 1 turn is. I have in my hot sticky mitt a letter of approbation from CAA's Safety Regulation Group from an incident I handled on 11th August 1994 where the pilot had not the faintest idea about No Compass No Gyro nor rate 1 turns!
This person had 'made a gross error in synchronising his direction indicator with the magentic compass which resulted in approximately 50 deg of track deviation'. Had taken off from Belfast Harbour and thought he was South of IOM, but I found him (using 7700) North of IOM, in fact flying along the coast of Wigtonshire. When told to turn he done about 180 deg in 2 radar sweeps! Eeekk!

[vector4fun]

In the U.S., at least in the Terminal environment, our Radar maps and the Compass rose surrounding the scope are oriented to Magnetic. As others have said, I can tell your magnetic Track pretty closely, your actual heading may depend on a number of things.

As for a no-gyro surveilance (radar) approach, we use the terms "standard rate turn" for 3 deg/sec. After you're pretty well established on the inbound track, we'll ask that you make "half standard rate" turns.

Also in the U.S., published radar approaches are fast becoming scarce. I've done hundreds, but not one in the last three years. In not too many years, there's a good chance you might get a controller who's never done a real one.....

:eek:

[matspart3]

We have to do a NCNG SRA as part of our TRUCE (Training for Unusual oCcurences and Emergencies) at least once every 13 months, although one of our schools does them as part of the limited/partial panel phase of the IR fairly regularly.