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-   -   What's the point of a QUJ? (https://www.pprune.org/questions/85360-whats-point-quj.html)

GoneWest 24th Mar 2003 02:42

What's the point of a QUJ?
 
Was reading the magically gripping book "CAP413" recently.

In the section on VHF Direction Finding, it suggested that I could call a "homer station" and ask for a QDM, QDR, QTE or a QUJ.

QDM: Magnetic heading to steer from where I am at the moment, to where I want to go (assuming no wind drift). Easy - use compass and D.I.

QDR: Magnetic bearing of aircraft from a station. Like a VOR radial, ya mean. Part of the info needed to work out where I am.

QTE: True bearing of aircraft from a station. Use protractor or plotter, based on lines of lat. and long. Also part of the material needed to work out where I am.

QUJ: True heading to steer from where I am at the moment, to get to where I want to go (assuming no wind drift).

True heading? I don't have anything in the aircraft that lets me fly a true heading - what do I do with a QUJ? (apart from apply variation to it whilst wishing that I'd asked for a QDM).

Bumz_Rush 24th Mar 2003 07:14

QUJ/QDM
 
Unless I am very much mistaken, in the old days, before transsistors, and circa valves and nuvistors, the QUJ was the military equivelent of a QDM. As to why I also have no idea, perhaps a mil bod will know the answer.

oxford blue 24th Mar 2003 10:27

In the RAF of old, it was common practice to have a professional directional consultant as part of the crew - the navigator. He still survives on many, but not all, RAF flight decks.

It was normal, when using a slaved gyro compass in those days, for this gentleman to set the variation into the Master Indicator and update it as the aircraft crossed each isogonal. This meant that the SGC, although sensing magnetic heading, actually displayed True Heading.

He also usually had the latest wind already plotted on his CRP-5 (or military equivalent) or could get the drift off the Doppler. Therefore, since the compass read in True, on getting a QUJ, he could give an instant True Heading to fly for a homing to the pilot.

I don't think people use QUJs much these days.

Captain Stable 24th Mar 2003 12:09

GW, you've actually misquoted the meaning of QUJ - or CAP413 does.

It's precise meaning is

QUJ
Question form:-
Will you indicate the TRUE track to reach you (or ...)?

Answer form:-
The TRUE track to reach me (or ...) is ... degrees at ... hours.
- nothing about heading or wind drift. I suspect that CAP413 is trying to explain it and, in the process, obscuring matters. Doncha love civil servants? :D

Spitoon 24th Mar 2003 16:20

FWIW you won't find many homer stations in the UK these days anyway!


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