FM Immunity in UK

[invalid entry]

Hi,
Wondered if anyone could help me here. As an IR holder of a non FM Immune a/c in the UK, am I correct in believing that I cannot conduct instrument approaches in IMC? Does this also apply to PAR approaches which use no navaids?
Thanks

[Stan Evil]

From a strictly legal point of view you must carry the nav kit listed in Schedule 5 of the ANO if you wish to fly in regulated airspace. So, if you fly in airspace where a VOR/ILS is required then it must be FM immune (for public transport you need 2 FM immune boxes). Outside regulated airspace there is no legal requirement to carry an FM immune VOR/ILS so you can fly a PAR/SRA/NDB approach anywhere you like as long as you meet the requirements of Schedule 5.

[Noggin]

Now if you read AIC 87/2000 Pink it also refers to the requirement for communications receivers to be FM imune so in theory, you cannot do a PAR either. It is of course total nonsense.

[rolling circle]

I don't know Noggin, read the AIC and get the real answer? That's a pretty radical idea!

http://www.ais.org.uk/Uk_aip/pdf/aic/4P007.pdf

Paragraph 3 makes it clear that equipment which does not comply with AN 84 must be placarded as such and can be used on VFR flights only. So, not only no approaches of any kind in IMC, no flying at all under IFR.

[Noggin]

The effects discribed in the AIC apply to receivers on adjacent frequencies and in close physical proximity to potential high power transmitters that can now be located up to 107.9MHz. These transmitters have always existed up to 104.9MHz without any significant problems.

This 3 MHz extension, now seems to threaten the entire aviation band, all 29 MHz of it. Have the laws of physics changed? We can accept interference on a 25Khz spaced receiver from 8.33 Khz spaced transmitters operating in the receiver passband, but the highly improbable interference from a source over 10 MHz away makes comms receivers obsolete.

Strange it does not apply to FAA certifed aircraft.

[Stan Evil]

Rolling Circle you're OTT on this one. You are implying that, if you do not have any VOR equipment fitted, you can fly in IMC but, if you have a non-immune VOR (even if you don't switch it on) you can't. This is obviously absurd. The ANO is the legal document, not the AIC.

With regard to comms immunity, GA have a waiver on FM immunity for comms equipment.

[A and C]

Noggin as you quite rightly point out the FAA has no requirment for FM immunity this is probably because the americans are smart enough and have enough space to not let commercial radio stations use the frequencys hard up to bottom of the navigation band.

So an FAA registered aircraft will be just as subject to disruption of navigation imformation as a european aircraft and so to fly IFR in europe FAA registered aircraft have to meet the FM immunity requirment.

In my view the aviation community should have objected more strongly at the first hint of this requirment to do this we must activly support AOPA and the PFA with letters to MP,s MEP,s and the press.
This has cost us all a great deal of money and should be a warning to us all that if we dont stand up for light aviation we will lose it........now rochester airfield is being eyed up by the local planing authority as a site for "development" now just how few of us are going to send a letter of objection to the planing authority.

[BEagle]

I understood from a chum that the original acceptance of increasing the ECAC Band II FM broadcasting spectrum was conditional upon there being a cheap method of ensuring that the aviation community would not suffer from expensive re-equipment requirements. Simple in-line filtering or something to that effect.
I'm at a bit of a loss to understand why, with normal CD, satellite radio, internet broadcasting, multiplexed digital FM, MP3, and now even satellite car radio being demo'd in the US we need more spectrum space for conventional Band II FM at all.
Blue Line - any comments to add?

[BlueLine]

The rather silly thing about all of this is that the decision to expand European FM Broadcasting was made at the World Radio Conference in 1978 almost 23 years ago. The improved specification for aviation receivers dates back to a similar time however, the majority of equipment in current use is based on a specification dating back to the 50s. One has to ask what have the avionics companies been doing for so long, all modern equipment should have met the required specification years ago. As for AOPA they have done little or nothing at all.
The original plan did of course assume that by now ILS would have been replaced by MLS.
Any potential problems could still be resolved by planning frequency allocations, not a very difficult task. As the predominance of FM transmitters in the US far exceeds the number in the UK and their proximity to airfields is considerably closer, I would have expected the problem there to be greater rather than less.

[BEagle]

BlueLine - in the CAA's Regulatory Impact Assessment which, of course, accompanied the decision to allow the increased access to Band II for commercial broadcasters, what estimate of the cost impact on GA resulting from this regulatory change was made?
They did conduct a RIA, didn't they........??

[Vigilant Driver]

Someone over on Mil Pilots said that AN84 does not apply to aircraft under 5700Kg.

Has anyone got AN84? All I've seen is that pink AIC and as Stan says it isn't the law!

Business as usual for us IMC Instructors on light aircraft then ?!?

[Noggin]

AN84 Version 5 dated 23 Oct 2000 says that aircraft under 5700 Kg do not have to be FM compliant on the Comms receiver. The Nav receivers are however required to be compliant for IFR flight in controlled airspace.

As the Comm/Nav equipment in most light aircraft is Class III anyway, it never has been legal for IFR flight in controlled airspace.