DME and the ILS

[nakuru flyer]

In order to fly a published ILS/DME a servicable DME is required. Is this true? cAN a GPS be substituted? Where does the glass cockpit sit with this scenario? Thanks in advance for any comments.

[S-Works]

If the plate states that a DME is required, then a DME is required. Glass cockpit aircraft in Europe carry DME to be legal.

[avionimc]

DME not necessarily required in the RNP world (e.g., new Cirrus aircraft do not have a DME). TRUE/FALSE

(LOC DME are included in IFR GPS databases).



Check this AOPA information dating back to 1998:Effective July 16, 1998, pilots may substitute IFR-certified GPS receivers for DME and ADF avionics for all operations except NDB approaches without a GPS overlay. GPS can be used in lieu of DME and ADF on all localizer-type approaches as well as VOR/DME approaches, including when charted NDB or DME transmitters are temporarily out of service. It also clarifies that IFR GPS satisfies the requirement for DME at and above Flight Level 240 specified in FAR 91.205(e). This approval represents a major step toward removing the need to retain DME or ADF in our cockpits for any reason.Note: Air carrier operators should consult their operations specifications and their principal operations inspector for approval.

Requirements

As with most operational capabilities, there are minimum requirements that must be met in order to take advantage of their benefits in a safe manner. When using GPS in lieu of DME and ADF for the purposes stated above:

The receiver must be certified for IFR operations and be installed and approved in accordance with FAA guidelines.
When using GPS course guidance; i.e., navigating to/from an NDB or locator outer marker (LOM), the course deviation indicator (CDI) must be set to 1 nm or terminal sensitivity.
The required integrity for these operations must be provided by at least en-route receiver autonomous integrity monitoring (RAIM), or an equivalent method. Although currently not available, Wide Area Augmentation System (WAAS) receivers will also be eligible for the substitution.
Pilots must conduct GPS operations within the guidelines contained in the aircraft flight manual supplement or approved operations manual.
The DME, ADF, or intersection names or identifiers must be retrieved from the database, and pilots must ensure that data is current in accordance with the aircraft flight manual supplement or approved operations manual.Caution: Pilots should be extremely careful to ensure that correct distance measurements are used when utilizing this interim method. It is strongly recommended that pilots review distances for stepdown points during preflight preparation.


Note: Pilots should exercise caution when selecting the appropriate DME and NDB/LOM locations to avoid erroneous distance information.

source: http://www.aopa.org/whatsnew/air_traffic/gps_in_lieu.html (http://www.aopa.org/whatsnew/air_traffic/gps_in_lieu.html)

[avionimc]

And,

FAA AC 90-94 - Guidelines for using Global Positioning System Equipment for IFR En Route and Terminal Operations and for Nonprecision Instrument Approaches in the U.S. National Airspace System (Cancelled)
Date Cancelled January 23, 2009/Date Issued December 14, 1994/Responsible Office AFS-820

AC90-94part1.pdf (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%2090-94/$FILE/AC90-94part1.pdf) (PDF)
AC90-94part2.pdf (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%2090-94/$FILE/AC90-94part2.pdf) (PDF)
Replaced By AC 90-105 AC 90-105 - Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System - Document Information (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/74457)

[lasseb]

I think it depends on the "local" CAA.
In DK you need a DME to have a plane IFR certified, and it was not until 6 month ago that you also required an ADF to have it IFR certified.
So all cirrus a/c that wants to fly IFR have a DME fittet regardless of the RNP of the GPS.

It is still a requirement that a plane certified for IFR schoolflight must have ADF.

[Stan Evil]

In the UK you cannot substitute GPS for NDB or DME. The requirements for various types of flight and operation are laid out in Schedule 5 of the UK ANO 2009. For example, to fly IFR in CAS you need a transponder, ADF, VOR and DME. To make an approach using a published procedure (ie in the AIP) you need the aids prescribed on the plate. Some approaches allow the substitution of range info from ATC in place of DME.

[SNS3Guppy]

In order to fly a published ILS/DME a servicable DME is required. Is this true? cAN a GPS be substituted? Where does the glass cockpit sit with this scenario?

This depends on the country and the regulations governing the operation in question. The answer is yes, and no.

GPS can be substituted for DME, as well as ADF, but not in all jurisdictions or locations.

[BillieBob]

Given that the OP is based in the UK, I think we can take that as a 'No', then.

[IO540]

The UK has no GPS substitution option at all.

A few years ago I was wading through the national AIPs and found Switzerland (which had a similar "ADF for all IFR in CAS" requirement to the UK) allowed an IFR GPS to substitute for an ADF, but it still required an ADF to fly an NDB approach.

Regarding having to legally carry a DME to fly an ILS/DME approach, can anybody find the ANO reference for that? I seem to recall some ambiguity around this bit, when in Class G. In Class D+ it is a done deal since you have to carry a DME for all IFR in CAS anyway :)

Obviously practically one should have a DME but I think the legal case for carrying the "implied equipment" (e.g. carrying an ADF to fly an NDB approach) is less than clear cut in Class G airfields.

[Islander2]

In Class D+ it is a done deal since you have to carry a DME for all IFR in CAS anyway http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif
Not true for G-reg non-public-transport aircraft in Class D or Class E, IO540. Schedule 5 of the ANO refers.

[IO540]

I stand corrected, though that makes my case even better.

Probably helps to explain why no Cirrus owner has been done for no-DME or no-ADF.

[Islander2]

Probably helps to explain why no Cirrus owner has been done for no-DME or no-ADF.

Except, bizarrely, carriage of ADF is still currently required in all classes of CAS for G-reg non-public transport (unless agreed otherwise by the appropriate ATCU before commencement of flight).

[IO540]

The other thing is that, IIRC, a DME is required for IFR practically everywhere (a UK exception notwithstanding) so not having it doesn't help, because almost nobody in this context will be limiting themselves to the UK.

[belowradar]

Probably helps to explain why no Cirrus owner has been done for no-DME or no-ADF

CAA would look a bit daft prosecuting a pilot of a Technically advanced aircraft for not having an ADF (just a personal opinion)

"Well Mlud, I had twin gps, vor, synthetic vision blah blah blah ....."

Analogy - proseduted for using a PC instead of a typewriter

I know the technicalities and risks etc but I know which I would rather have

[avionimc]

Well said Below Radar.

In thirty years of flying in four continents I only flew two NDB approaches, one at BIRK, the other at LSGC, both in the 1980s.

Now, for the law abiding ADF aficionados, in the 21st century there still may be a very small probability that someone would have to fly a NDB approach (despite the fact that they are being decommissioned all over the world).

Let's assume the NDB approach is the only option, it is night IMC with lots of wind, blowing snow (but at or above minimums) and you have your entire family on board.

Would you rather fly the approach with your state of the art KR87 ADF (purchased on eBay because most reputable avionics shops do not sell ADFs any longer), or with a GNS430 or G600?

For my part, I'll fly it exclusively with the GNS430, same for a DME arc. If your local CAA does not like it, then they will have to take a walk and think about another way to slow down GA.

No wonder many aircraft owners all over Europe change their registration to N (and the ADF is not the reason).

PS. Installing an ADF or a DME in a new generation aircraft, where there is no panel space for it will most likely reduce its resale value.

[SNS3Guppy]

Given that the OP is based in the UK, I think we can take that as a 'No', then.

Never assume. In any given week, I may fly in ten or fifteen different countries, often several in a day. I don't presume to guess what the poster asks, unless he so specifies. Some may feel that the flying world revolves around their corner of earth, but it simply isn't so.

In thirty years of flying in four continents I only flew two NDB approaches, one at BIRK, the other at LSGC, both in the 1980s.


I maintain currency in NDB operations and make full use of the RMI on a regular basis using both VOR's, LOM's, and NDB's, on an international basis.

[avionimc]

LOMs and NDBs are being decommissioned, worldwide. Go figure!:rolleyes:

[SNS3Guppy]

A lot of NDB's are still in use world wide...go figure.