Thanks for the prompt and full response, ATCO Two.
As you know, a SVFR clearance is only available in a Class D Zone in IMC or at night, and ATC are required to provide standard separation of 1000ft vertically or 3nm horizontally between SVFR flights, IFR flights, and SVFR and IFR flights.
I didn't know that. Is that from MATS Pt1? Being devious, if there's a little low cloud around it's not hard to accelerate past 140 KIAS and enter IMC
but of course that doesn't mitigate your difficulties in accommodating it.
And changing the type of clearance would have no impact on what would happen in the event of failure of a power unit anyway!
Quite. So it's daft that it changes the low flying rules too!
With singles as you know, the transit route is via the Lea Valley which takes aircraft clear of the Specified Area (built up area of Central London for those not in the know).
Well the Specified Area only relates to helicopters and doesn't, by a long stretch, constitute the limits of the "congested areas" of London, which a fixed wing has to glide clear of after a power plant failure.
even City Airport in an emergency - but don't use the PAPIs!
I would have thought they'd be pretty close to a light aircraft glide angle. Aren't they 6 degrees?