IFR equipment

[NotAnotherUsername]

I'm confused

I'm playing around with the idea of buying a share in something to get better availability (and prices!) than I can get with the places I rent from. Although I've only got a bog standard PPL at the moment, I'm planning on doing an IMC soon and want to be able to use it at least for getting back home if the weather turns a bit crappy after a weekend away.

So, I want something that'll allow me to come back IFR or 'VFR on top' to an instrument approach once I've got the IMC. So:

- What equipment does the aircraft have to have to be able to do this?

- If an aircraft is advertised as IFR equipped, what does that mean? That you can fly airways with an IR? Or just that its got VOR/DME/ADF?

- do I need FM immune radios to be able to legally fly in IMC?

[Chilli Monster]

What equipment does the aircraft have to have to be able to do this?

Only what you need to navigate by and do the approach. I've done that with one VOR and one ADF as the whole flight was outside CAS. Depends where you fly from and what flying you will be doing, especially with regard to the type of airspace you will be flying in.

If an aircraft is advertised as IFR equipped, what does that mean? That you can fly airways with an IR? Or just that its got VOR/DME/ADF?

It's an advert, treat it with caution - the person selling is trying to put his aircraft in the best possible light and those words 'IFR equipped' do that. Have a read of schedule 5 of the ANO and compare what that states you should have with what the aircraft has. That tells you the legal requirements for radio / nav equipment for the different types of flight in different types of airspace and is the benchmark you have to work to.

do I need FM immune radios to be able to legally fly in IMC?

No - you only need them to fly IFR inside controlled airspace. Shooting an approach with a non-FM immune ILS however could cause serious problems if a local radio station is transmitting on a frequency that could cause interference. That was the whole reason behind the FM immunity issue.

CM

[bookworm]

- What equipment does the aircraft have to have to be able to do this?

If you're intending to operate only outside controlled airspace, then not much from a legal standpoint. You need a turn and slip indicator and an altimeter.

From a practical standpoint, you want at least the basic instruments, at least one reliable radio, and whatever you need to fly the approaches at your usual haunt and alternate. I would suggest at minimum a VOR/ILS and ADF. I'd also suggest investing in a good handheld GPS, and test it in the aircraft.

To fly IFR in class D/E airspace you need VOR/ADF, transponder (C) and a COM radio. To fly in class A you need VOR/ADF/DME, transponder and a second altimeter.

- If an aircraft is advertised as IFR equipped, what does that mean? That you can fly airways with an IR? Or just that its got VOR/DME/ADF?

It means only what the owner intended it to mean, which could be as little as turn indicator and altimeter!

- do I need FM immune radios to be able to legally fly in IMC?

If you legally require a nav radio, then it must be FM immune.

[stiknruda]

I have no desire ever to fly in anything but day/vfr on permit aircraft but read this topic because of general interest and yet again am overwhelmed at the knowledge that Pprune allows us to share!

Thank you to all who make Pprune happen!

Stik

[Keef]

"IFR equipped" can mean anything, so is meaningless.

"Airways equipped" means it has a full set of IFR instrumentation and is useable for Class A IFR flight - assuming you have the rating for it.

If you plan to fly IFR in IMC with your IMC rating, then my advice would be to ignore the "you could get away with..." and go for something fully airways equipped.

To get me to fly in IMC, which I do often (including some today) I insist on 2 VORs (at least one with ILS), DME, transponder (with Mode C or Mode S), marker receiver, ADF, 2 COM sets (all FM immune), AH, DI, Turn Coordinator, 2 altimeters, and a clock. You might also want an IFR-approved GPS but that's sort-of optional although nice.

Yes, I've done IFR approaches with only an ADF and one VOR, and it's not a good idea.

If you're going to use an IFR-approved GPS, then plan to spend a LOT of time with it, getting to know how to drive it. At 2000 feet in filthy turbulence isn't the time to start trying to work out which button to press...

[NotAnotherUsername]

To paraphrase Stiknruda - what a clever bunch you are !!

Thanks - exactly what I was looking for. I'll brave the ANO - the fact its there would explain why I couldn't find anything on the CAA or JAA sites other than Min Equip Lists for A340's!

[BEagle]

These are the appropriate statements from AWN 84 which affect light aeroplanes flying without FM-immune NavComms:

a. 'UK registered aircraft of 5700 kg MTWA or less may continue to be operated under IFR with non-immune VHF communications receivers provided that the receivers are identified so as to alert flight crews to the potential risk of interference'

b. 'Where non-immune ILS localiser and VOR receivers remain installed, they must be identified to the flight crew and their use restricted to VFR operations'.

If someone tries to sell you a light ac without FM-immune VHF navigation receivers, walk away if you intend using the aeroplane under IFR! Don't underestimate the cost of upgrading non-immune systems; I had to upgrade 4 ac last year and it cost over £18 000!!

[bookworm]

But BEagle, you stopped before the good bit!

'NOTE: For aircraft of 5700 kg MTWA or less, an acceptable means of compliance is to placard and restrict non-immune receivers to operations permitted under the Restricted Approval Category LA Class 3 (see paragraph 5.4), irrespective of the approval category for that equipment.'

LA Class 3 equipment may be used for the 'facilitation' of any flight (IFR or VFR) outside controlled airspace.

Nevertheless, your point stands that anyone contemplating an aircraft for serious IFR would be nuts to pick one without FM immune equipment.

[A and C]

Remember that it is not just the radios that have to be "class 1" for IFR flight the indicators have to be approved to the "class 1" standard.

[englishal]

Shooting an approach with a non-FM immune ILS however could cause serious problems if a local radio station is transmitting on a frequency that could cause interference

Again, only in Britain it seems (and possibly Europe). Why do other countries, possibly with a more realistic view on GA, decide that the risk of RF interference is negligible, and therefore don't insist you spend £5,000 extra on 'FM immune' kit?.....and more to the point, why does the kit cost £5,000?

Cheers
EA

[NotAnotherUsername]

Ouch, BEagle, four and a half grand each !!!

How on earth do they get from a grand and a half for the radio box (from an ad for Harry Mendellson for some FM immune kit) to 4,500????

[foghorn]

It was promised that there would be cheap modifications to most models of NAV and COM radios available - what has happened to that? Most FM immunity upgrades that I've heard of have involved brand new expensive kit rather than a mod.

The biggest risk of FM interference is to ILS due to the 105-108MHz band now being available for commercial radio stations.

This may not be the official word from the CAA, but I have been informed by an avionics engineer that in Private category aircraft the CAA is happy with just 1 x FM immune VOR/ILS and no FM immune radios as long the Nav kit is suitably placarded... useful for people with seperate NAV and COM boxes.

Obviously I'm not condoning that one should not follow the regulations to the letter


cheers!
foggy.