Compass and ASI - legal requirement?

[FlyingForFun]

Sounds like a stupid question, but:

Is there any legal requirement to carry either a compass or an air speed indicator?

Several very experienced instructors I work with are all of the opinion that there is a legal requirement to carry certainly a compass, and probably an ASI too. But we've tried to find the appropriate legislation, and drawn a complete blank. It doesn't appear to be anywhere in Schedule 4, which is where I thought we'd find it, and a search of a soft copy of CAP393 for "compass" only finds the word in connection with compass swings.

If anyone could point us to the right place, we'd be very grateful (and slightly red-faced for not being able to find it ourselves!)

FFF
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[Tony Hirst]

Schedule 4 of the ANO

Edited to say, there does not appear to be a specific requirement, but I think this requirements captures it:
The equipment carried in an aircraft as being necessary for the airworthiness of the aircraft shall be taken into account in determining whether this Schedule is complied
and
with in respect of that aircraft.
Maps, charts, codes and other documents and navigational equipment necessary, in addition to any other equipment required under this Order, for the intended flight of the aircraft including any diversion which may reasonably be expected.In other words, if you can't navigate or something else says you need it, such as a flight manual, then it is captured here. But I would agree that it is a bit wooley!

[Fitter2]

Don't know definitively about things with fans on the front, but the flight manual of sailplanes has a required equipment list, typically ASI, Altimeter, compass, then if cloud flying turn and slip required, if aerobatics G-meter.

Flying without required equipment invalidates the CofA and insurance, therefore is a legal requirement.

I would be mildly surprised if the same didn't apply to aircraft requiring a noise generator to remain airborne.

[Brooklands]

I don't know about a legal requirement, but I believe that the PFA require an ASI, ALT and magnetic compass as a minimum. If you're fitting a glass cockpit they still require these as backup instruments.

Brooklands

[englishal]

Yes....

And in addition (VFR- IFR lists certain additional stuff) an oil pressure gauge and in an aeroplane with an air cooled engine, a means to determine the temperature of the oil, in a liquid cooled engine, a means to determine the temperature of the coolant, an altimeter, and if to be flown at night a landing light amongst other things.

[FlyingForFun]

But still not definitive legal reference.....

Englishal, as part of the same exercise that I'm doing, I'd also be interested to know the legal reference for the contents of your post. I don't dispute it, but I need references! Apart from a landing light for night flight (clearly stated in Schedule 4), I can't find any reference to any of the items you've listed - except a sensitive pressure altimeter, which is only listed as being required for IFR or night flight for non public transport.

FFF
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[Mark 1]

That's because it's part of type certification requirements.

For example, under CS-VLA:

CS-VLA 1303 Flight and navigation
instruments
The following are required flight and
navigational instruments:
(a) An airspeed indicator;
(b) An altimeter;
(c) A magnetic direction indicator.

So if the aircraft was certificated without any of those items on the TCDS, and there is no requirement under Schedule 4, then you don't 'need' them.

It may be the case that some very old aircraft weren't originally kitted out with many (if any) instruments, so may carry on that way.

Homebuilts and ex-mil won't have a TCDS so the permit issuing authority may specify anything that it considers appropriate.