[johnm]

GPS is a lot easier but it isn't the only way. As for declaring a PAN, were you really being serious johnm?

Yes I was, there's no way I'm trying to navigate IFR round the London TMA without a GPS or radar help!

[James Chan]

there's no way I'm trying to navigate IFR round the London TMA without a GPS or radar help!

johnm speaks wisdom. Anyone who thinks they can go around/under certain parts of the London TMA IFR without either is prone to get into trouble. I had written elsewhere that en-route CAS has been designed for +/-5nm tolerance. Outside CAS the tolerances can be as small as +/-1nm en-route, and a contributing factor to infringements.

Elsewhere if the classification of airspace permits a clearance then you should ask for one.
If you can't get one then I would avoid flying under any base level of CAS that would take you below MSA.

[ZOGman]

That's not right.

How do you interpenetrate this note - in uncontrolled airspace?

*Aircraft (except helicopters) at 140KIAS or less: clear of cloud with the surface in sight in a flight visibility of at least 1500 metres. Helicopters at a speed which, having regard to the visibilty is reasonable: clear of cloud with the surface in sight in a flight visibilty of at least 1500 metres

[low&slow]

I would interpret that note as the VMC minima pertaining to aircraft flying under VFR below 3000' amsl at less than 140 knots IAS in class F & G airspace. You can fly faster than 140 knots but visibility has to be better than 5km if you wish to fly VFR.

[Joe Dell]

Earls Colne/Wattisham- Humberside using Biggin, Clacton and Ottringham VORs? Only a few minutes more than direct. You could chuck Gamston in for good measure.

[Chilli Monster]

I don't know what's scarier - people trying to say VFR minima are applicable to IFR flights, or James insistence that you need GPS or Radar to circumnavigate the TMA? It wasn't that long ago some of us were navigating it using VOR's and NDB's because GPS units weren't "de rigeur".

[Keef]

Last time I did the "IFR circuit of London" I used VOR/DME and NDB: SND - BIG - OCK - radial/DME from OCK - WOD - DR from WOD to pick up radial from BNN - BNN - LAM - SND. I spoke to the various ATC units on the way round. That was a long time ago, and I'm not sure if all those are there now (G-UTSY gave up on NDBs soon after that), and anyway it's a lot easier with GPS

[Joe Dell]

"How do you interpenetrate"

Is that really a word Zog?

[Lefty]

If you are established on a track - based on GPS and / or VOR's then you will have worked out the drift that is affecting you.
You will have worked out your heading and groundspeed - and your heading and ETA at your next waypoint (even if that waypoint is in the middle of a "dead zone).

You should therefore be reasonably comfortable to keep going on that "known" heading - until the ETA time is reached - then assume that you are at the waypoint (then turn as per plan).

[Joe Dell]

The route I suggested has no 'deadzone' turns. I like things simple.

[ZOGman]

"How do you interpenetrate"

Is that really a word Zog?

Being Sidlexic - I obveusly carnt manage multitaskin

[ZOGman]

Let’s try this:

Flying below London TMA (2500ft) with a cloud base, generally, at 12-1500ft – vis 1000 mtrs.

Option 1 - Fly at 2200ft IMC in cloud.

Option 2 - Fly at 1000ft in sight of the surface.

Do any speed restrictions need to be complied with in either option, given p/x’s on board and an a/c capable of 220kts?

I’m learning here!

[Keef]

In your 220kias aeroplane, no. The speed limit is 250kias in both cases.

[Chilli Monster]

However, as you're still technically IMC in Option 2 (Visibility)then you're likely to fall foul of the "Minimum Height Rule".

Be sensible - get an IR, fly inside CAS at that speed.