QGH approaches are controller-interpreted versions of the above, where the controller interprets your changes in QDR (bearing from the station) and passes headings to fly,
A small correction (if memory serves). RAF style QGHs (or CDTC - Controlled Descent Through Cloud) were/are? based on Controller interpretation of
QDMs (Magnetic Bearing
to the Station) and not QDRs. The headings to fly were passed as 'Steers', and took into account forecast winds aloft.
Possible variations, depending on Aircraft/Station equipment:-
i) QGH to Visual
ii) QGH to SRA (Surveillance Radar Approach)
iii) QGH to PAR (Precision Approach Radar)
v) QGH to ILS.
The advantage of items (i) to (iii) is that all the aircraft requires is a serviceable radio - many military aircraft in the past had little else in the way of aids to navigation.
Pilots could also select a number of other options:-
a) No Compass/No Gyro QGH
b) Flame-Out QGH (See BEag's post)
c) Speechless QGH (microphone failure) - by Transmitting Carrier Wave Only
d) Any Combination of the above!
Happy Days!