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Old 8th Apr 2012, 14:15
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Downwind.Maddl-Land
 
Join Date: Oct 2001
Location: Starring at an Airfield Near you
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As an ex-QGH (aka CDTC) endorsed Approach Controller – as I recall - the Safety Height (all approaches were on QFE remember ) ‘steps’ were:
Homing: Lowest High-level Quadrantal Flight Level (circa FL120 or thereabouts), Lowest Safe Quadrantal Flight Level (below FL120) or lowest procedure safety height (if starting below transition altitude).

Overhead – at least 2 no-bearings or very rapidly changing QDMs – then sending ‘Bloggs’ outbound on the required outbound track (+/- 15º ‘oversteer’ if track change was greater than 90º). Set QFE, NO DESCENT YET.

Outbound: Descent outbound to Intermediate Approach Height (IAH) could not be commenced until the outbound QDM was within +/- 60º of the outbound track. Then descent to IAH was initiated. Turn inbound was commenced at ½ Overhead height + 2,000ft (Hi level procedures) or timed (3 or 4 mins for lo-level procedures) when turn inbound to Final Approach Track (FAT) commenced. (For all old ATCO’s – ‘double any outbound QDM error and apply it in the same direction’ for the inbound steer!)

Inbound: Descent below IAH to Procedure Minima/Break-off Height (BOH - remember those???) could not commence until the aircraft was within +/- 15º of FAT. Once the aircraft reported at Procedure minima/BOH the aircraft had to be maintained within +/- 5º of the FAT, which could be tricky the closer you got in, if one hadn’t ‘sussed’ the wind.
I well remember the workload as a Stude at Shawbury when working one aircraft in the ‘DF Simulator’ phase! A tour at RAF Leeming when it was a real flying unit soon cured that; doing 4 QGHs at a time because the AR-1 was off the air (again!) soon got the CADF tube ‘talking’ to you. I even devised a ‘Triangular’ pattern QGH for RW 34 (based on the Shawbury RW 01 QGH procedure) that worked fine (even allowing for Dishforth’s Circuit) as a ‘DF to PAR’ to cater for when the AR-1 was off.

Job satisfaction: off the scale!

The Safety Lanes were the +/- 60º, +/- 15º & +/-5º sectors referred to above. Never, ever, heard the term Safety Path in all my 25+ yrs.

Last edited by Downwind.Maddl-Land; 8th Apr 2012 at 14:31.
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