Airway Crossing

[Speedbird744]

I'm planning an IFR flight off airways, from Enstone direct Isles of Scilly.
The question of airway crossing comes to mind at Bridgewater Bay. I'll be cruising at FL40, seeing as the base of N864 starts at FL55, is there a requirement for me to fly at right angles until clear of the airway?
I'm not in Class A at that height, or within the airway.

My other plan is from Enstone direct Swansea direct Isles of Scilly.
Now is there any requirement for me to cross any airways so long as I stay beneath them? In this case it is FL75, and FL165. So according to the quadrantal rule, I'll be at FL60. And clear of problems?

Thanks

[FlyingForFun]

Speedbird,

You are outside controlled airspace, so you can fly wherever you like. The airway a few hundred feet above you shouldn't affect your flight at all.

There are two times you need to fly at right angles to an airway, and they both relate to VFR flight (i.e. not relevant to your IFR flight). The first is to cross the base of an airway. If N864 starts at FL55, and you are VFR at FL55, you may cross the airway at right angles. (This rule seems a little silly to me - surely much easier to fly at 5400 on 1013mb and not worry about the airway? But that's the rule, anyway.)

The second time you must fly at right angles to the airway is if you are flying in VMC and you want to fly through the airway (e.g. in the case of N864 at FL65). To do this, though you need to file a flight-plan (you can do this in flight) and request permission. More importantly, though, you must have a valid Instrument Rating.

IFR in IMC, neither of these options is available to you, so you can safely ignore them. Enjoy your flight!

FFF
-------------

[Speedbird744]

Thanks FFF, cleared that one up!

[sycamore]

Speedy, I would check the base level of N864 around BCN, if you go that way as my chart shows F55, with lowest use at FL60. Also, remember that if you are IFR, you may end up IMC, and your Min .Safe FL, for your track may require you to be at FL60, or higher depending on the QNH.
Remember, there are Danger areas off the NW coast of Devon/CW, up to FL100, if you track direct SW.-SI.

[flower]

A couple of other pointers to watch out for.
Danger area 119 is often active up to 5000ft and of course you need to be above 2000ft going over the Nuclear power station at Hinkley point.
The base of the airway N864 raises at EXMOR to FL65.
We descend and climb aircraft outside the Airways into and out of Cardiff, Bristol and Exeter there so I would recommend you are speaking to one of the LARs units in that area.
It may make it sound very complex but it isn't really and as long as you are in contact with Cardiff, Bristol or Yeovilton LARS they will be able to tell you the status of D119.