IMC course - what type of approaches/navaids ?

[noblues]

I have been asked to teach an IMC on an owners own aircraft. Only snag is that it only has a VOR/ILS, no DME and no ADF.
Can I still do it ?

I feel being able to 'track a needle' is elementary for instrument work, but does the CAA stipulate the canditate for an IMC must show profeciency in an ADF ?

Is the AOPA 5hr instrument appreciation course still going these days ?

[Night Rider]

noblues,

The short answer is no. I think you can get away with not having DME, but you definitely need an ADF. The rules say you need to complete a non-precision approach, which in theory could be something like an SRA or VOR approach, but you certainly need to cover ADF tracking (and ideally let-downs)during the course. I personally would be very concerned if a candidate came to me for an IMC test having never used an ADF!!!

[Honest Frank]

I'm sure part of the test involves tracking to/from a facility whether it be NDB or VOR with a needle presentation, ie. RBI or an RMI.

[Noggin]

The original idea of the IMC rating was that you could do it with a range of different instrument fits. The minimum invisaged was a VOR and an ADF, you do not need ILS glideslope or DME. The lack of an ADF is likely to affect many new aircraft as ADF is no longer a standard fit. You might like to check CAP53 which is still the most up to date syllabus reference.

[ 05 August 2001: Message edited by: Noggin ]

['I' in the sky]

The IMC test calls for two approaches, 1 pilot interpreted and 1 controller interpreted.So far in my experience it has been taken that controller interpreted can mean radar vectors or an SRA, and pilot interpreted means a full procedural approach.Most full procedures use either an NDB as the IAF, or rely on a DME arc to avoid the need for vectors to the FAT. However there are are a handful of VOR approaches ( mostly in Scotland and Ireland) where you could do a fully pilot interpreted procedure without either ADF or DME.

[Noggin]

A careful read of CAP 53 indicates that ADF is not mandatory.

[ 06 August 2001: Message edited by: Noggin ]

[BEagle]

Concur with Noggin. Incidentally, if, after obtaining his IMC Rating, your friend is intending to use his VOR/ILS under IFR (not just in IMC), he will be observing AWN 84 with regard to FM-immunity requirements, won't he?

I wonder how many private GA pilots are still operating contrary to this expensive AWN??

[ 06 August 2001: Message edited by: BEagle ]

[noblues]

Thanks for all the replies.

BEagle - what exactly is FM-immunity ? and what does AWN stand for (airworthness notice ?).

I wouldn't feel I had taught a complete IMC without NDB tracking. In my experience its the one area most students have the greatest difficulty with and potentially the most badly used navaid in existance, despite its faults their the charts are still littered with the things. I noticed even LHR have put the HRW back on the plates again after trying to ditch it !

[BEagle]

Since 1 Jan 01, all use of VOR/ILS equipment under IFR in any category of UK airspace, including Class G, must comply with the improved immunity requirements of Airworthiness Notice No 84.

Non-immune equipment remaining in use must be placarded as such and its use restricted to VFR operations only. I have had to replace 4 NavComs plus associated work to comply with this AWN - total cost about £17K

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

[ 06 August 2001: Message edited by: BEagle ]

[RodgerF]

I am not sure whether you can carry out an ILS approach without DME unless some other cross check is available. Either you need radar ranges or markers to ensure that the correct glideslope has been intercepted.
Also without DME it is much more difficult to judge the correct descent rate to set up.

[Julian]

ILS is a prescision approach, your fixes will be given on the approach plate. You dont need DME as you are following the slope down to minimums and then you will go missed, if you lose the GS then you are no longer precision approach. Descent rate for a 3' slope is approx. 500'/minute @ 100Kts - ie a PA28, etc.

[CaptAirProx]

StickMan, ILS does need some sort of cross check during the approach. It has to be a marker, NDB, DME, or radar ranges. Take the Bournemouth ILS for example. It has an ILS/DME for both runways, no outer marker and no NDB on the approach centreline. Im sure it says in the notes "Without DME radar ranges by ATC mandatory". This is due to the fact you would have no way of knowing whether you had picked up the correct glideslope on the approach. Years ago most airports had NDB/markers on the approach to each runway for that reason. Since DME came along the NDB's have been removed and placed on the airfield purely for the procedure and holding. I am no specialist so stand corrected if I am wrong.