MLS Testing

[EX FTE]

Anyone know of any advisory circulars on certification testing of MLS approaches?

Looked in FAA & Transport Canada websites - nothing! AC25-7A section for MLS says 'reserved'

Looked on Edwards AFB test site and their library didnt help.

Looked on manufactuer websites and only get TSO references.

Any help gratefully received!

Many thanks

[forget]

I believe the FAA has abandoned the idea of MLS.

[EX FTE]

FAA still recognise it as a future navigation aid. From personal experience a few years ago teh following facilities definately exist under FAA control:
1. Moses Lake Washington
2. Boise Idaho
3. Savannah Georgia
4. Bellingham washington

There are a number of other facilities in the US and I believe that Amsterdam-Schipol also has one. Also from a recent article Heathrow has now been commissioned with 4 MLS with CATIIIb target clearance. Options on 27 other installations have been placed with THALES by UK NATS.



I know that MLS is a minority system but some customers still specify it for their aircraft - hence my search for info.

If I get any info I will post it here for posterity!Link to AIN article (http://www.ainonline.com/issues/01_02/01_02_collinsprovespg67.html)

[ICT_SLB]

We looked into fitting their then-standard MLS on a USAF proposal aircraft (CFIN) about 10 years ago so this is from possibly faulty memory.

The system was a Bendix MLS-21A and contained labels on the 429 output that gave you all the data needed to characterise the MLS beam (Azimuth, Elevation, safe sector angle or whatever) at least there was no addditional gear needed for flight inspection like you need for ILS or TACAN.

Such is the characteristics of MLS, you can do the beam checks from the ground if you need to - the only real "flight "portion is verifying the clearance angles to the local topography and I guess you could do that from the sectional as well.

My memory of the installation flight check was just carry out an approach with max allowable glide path followed by a go around & just verifying that there was no drop-outs plus repeats if curving or offset azimuth approaches are required. This will be entirely dependent on good siting of the MLS antennas on the aircraft so that direct line of sight is never lost between the two forward (upper & lower) and rear ones and the ground MLS.

[gnss]

Are you looking for guidance on approval of the aircraft receiver installation or of the ground equipment flight inspection? I guess its the former if you were looking for AC's but just in case guidance on the latter is in ICAO Doc 8071 The Manual on the Testing of Radio Navigation Aids.

Regards,

gnss

[EX FTE]

GNSS:
yes - looking for material on approval of aircraft installations.

ICT_SLB:
How are you old chap? Think we know each other and share a mutual Aberdonian friend! We may also be seeing each other again soon as a change of employment beckons!

[Iron City]

Believe the information you need is in TSO C-104. It can be downloaded from the FAA at [url]http://av-info.faa.gov/. On this page look at the index of TSOs and find TSO C104.

This would work for US reg aircraft. If not an N reg would have to work that out with local CAA.

If you can not get the document out come up again on PPRUNE and I will EMAIL you the whole thing as a Word document.