Am I the only one who still thinks we should teach students to time from FAF to MAP?

[DB6]

IO540: First Non-Precision GPS Approach Introduced in the UK | CAA News | CAA

[Lookforshooter]

'Children of the Magenta': Need I say more?

[tbavprof]

What's the criteria for the new UK GPS approach if you get a RAIM alarm FAF inbound? No timing? Sorry, we've had "overlay" approaches for years. Brief the approach that the overlay is based on as a back-up to GPS failure, with appropriate monitoring and decisioning points (including time, MAP, and MDA). Same as you would on an ILS with loss of glideslope switching to localizer only.

Doesn't anyone do an off-airport NDB approach? How can you not time?

[bookworm]

Doesn't anyone do an off-airport NDB approach?

Not really. The classic set-up before DME became widespread was to have an NDB sitting at the OM for the ILS, and hence in the absence of the ILS, the approach of choice was an NDB approach based on timing from a beacon 5 miles off-airport.

In the UK over the last 30 years, ILSs have been paired with DMEs -- I can't think of one that's not. Rather than maintaining an NDB at the OM at each end, NDBs have been moved on-airport, and the approach used is an NDB/DME approach to that on-airport aid. I can't think of an airport in the UK with an off-airport NDB. I just looked at Norwich, which I haven't been to for years, but used to have an ILS with markers, an LOM and no DME. That has moved its LOM on airport and had a DME for years. In Germany, timing is not even authorised as a method of locating the MAPt for any NPA I've seen.

Moreover for commercial air transport, anything other than a constant angle NPA using a distance indication has become unacceptable. Losing that distance indication is an event that must trigger a go-around.

So the discipline of starting the watch at the FAF helps you in the case where both the DME and the GPS decide to fail, there's no radar and the beacon itself does not provide a convenient MAPt. For an ILS, add the condition that the glideslope also decided to fail. In the modern European environment, it's getting to the stage where the value is not worth the cost of the workload and break in the scan to start the watch.

[SNS3Guppy]

An ILS with a compass locator is not an NDB approach. An NDB approach involves an approach based on an NDB as the primary navaid.

There are more approaches in teh world than what is found in the UK...and there are a great many NDB approaches still in use out there.

[tbavprof]

Thanks, Guppy. Don't think I've ever tried (or even want to) use an LOM for an NDB approach. I had another couple of questions based on the response.

Rather than maintaining an NDB at the OM at each end, NDBs have been moved on-airport, and the approach used is an NDB/DME approach.

I have to admit, I've never run into an NDB/DME approach. Or, at least one that required a DME for MAP identification.

but used to have an ILS with markers, an LOM and no DME. That has moved its LOM on airport and had a DME for years.

Pardon my ignorance again, but how do you move an outer marker onto the airport?

And what was the LOM doing out there before? Some ILS approaches I've flown use it as an IAF, but inbound on the localizer it's the place to start the clock in case glideslope is lost, since FAF is glideslope intercept established on the localizer inbound.

The little flashing blue light and beeping also seem to make a convenient point for the hand-off from approach to tower.

[bookworm]

I have to admit, I've never run into an NDB/DME approach. Or, at least one that required a DME for MAP identification.

Difficult to find an NDB approach that's not paired with DME in many parts of Europe. If the MAPt is not defined by DME, it will usually be at the beacon.

but used to have an ILS with markers, an LOM and no DME. That has moved its LOM on airport and had a DME for years.

Pardon my ignorance again, but how do you move an outer marker onto the airport?

I'm sorry I expressed that badly. The Locator (NDB) part of the LOM was moved on airfield. The markers were decomissioned, since the DME defines an equivalent location.

Here are the approaches:
ILS 27

NDB(L)/DME 27

The equivalent has happened at virtually every UK airport that used to have an off-airport NDB.

[bookworm]

An ILS with a compass locator is not an NDB approach. An NDB approach involves an approach based on an NDB as the primary navaid.

Of course it does. And when the ILS is off, that's exactly what you have, an NDB approach based on the (obviously off-airport) locator. The vast majority of off-airport NDB approaches in the UK were based on such locators. The demise of the ILS with LOM means that there are none (or almost none, I haven't searched exhaustively) left.

There are more approaches in teh world than what is found in the UK...and there are a great many NDB approaches still in use out there.

True enough. But in the environment I fly in, the off-airport timed NDB approach is dying out, and I think it's appropriate to teach students the skills they're likely to need in the environment they'll fly in. If the OP is flying in a different environment, the training need may be different.

[SNS3Guppy]

Of course it does. And when the ILS is off, that's exactly what you have, an NDB approach based on the (obviously off-airport) locator. The vast majority of off-airport NDB approaches in the UK were based on such locators. The demise of the ILS with LOM means that there are none (or almost none, I haven't searched exhaustively) left.

Actually, no. You're talking about two different approaches, and indeed, two different kinds of approaches.

If the locator for a given approach is also used to form an NDB approach, then so be it...but an ILS approach with a compass locator is an ILS approach. It is not an NDB approach.

If the compass locator is then used as the basis of a stand-alone NDB approach, then that is an NDB approach.

When one undertakes an ILS with inoperative components, one may have different minima based on those components, such as a higher MDA for a glideslope inoperative. However, if one has neither a localizer or a glideslope, one isn't flying an ILS approach. If one has only a compass locator, one isn't flying the published ILS. One will be flying something else...a published NDB approach, perhaps...or one won't be flying the approach at all.

But in the environment I fly in, the off-airport timed NDB approach is dying out, and I think it's appropriate to teach students the skills they're likely to need in the environment they'll fly in. If the OP is flying in a different environment, the training need may be different.

One should not pick and choose the skills which one teaches when molding an IFR pilot. The ability to understand an NDB approach is really the basis for understanding any approach. When I fly an approach using an RMI, I fly the same techniques and method regardless of whether the approach is predicated on an NDB or a VOR. Timing is applicable, and should be performed whether or not one has DME. It's a valuable habit and practice to time turns, holds, and approaches regardless of whether the timing is necessary for that particular turn, hold, or approach.

Understanding the relationship of one's position to the course and to the navaid is crucial, and applicable, whether one uses a RMI or not, and whether one flies a timed approach or not. We're talking about basic skills that need to be taught to, and understood by all pilots intending to undertake instrument flight...even those who are children of the magenta line.

[what next]

Hello!

We're talking about basic skills that need to be taught to, and understood by all pilots intending to undertake instrument flight...even those who are children of the magenta line.

So let's hope Mr. "JAA" or "JAR-FCL" or whatever his name may be is following this discussion! As in IFR instructor for a commercial flight training organisation within JAA country I have to teach according to our government-agency-approved syllabus and training plan. This plan does not include timing other than for flying holding patterns. But I don't think that our trainees are bad pilots who lack fundamental flying skills. And their employers obviously don't think that either.

I find it amazing that after 100+ years of human flight such fundamental differences regarding the same thing still exist! Earlier this year I spent a couple of weeks in the United States for a type-rating and was not allowed to share sim-sessions with an Americal colleague because of the differences in FAA and JAA syllabi concerning non-precision approaches. Instead, each of us was given a "right seater" (all of them TRIs!) for every training session... Maybe it's time we find worldwide consensus regarding these issues.

Greetings, Max

[SNS3Guppy]

Max,

No law exists which states you must teach to the minimum standard. Keep that in mind.

Simply because you are not required by law to teach fundamental skills and proper practices, doesn't mean that you should refrain from doing so.

[bookworm]

If the locator for a given approach is also used to form an NDB approach, then so be it...but an ILS approach with a compass locator is an ILS approach. It is not an NDB approach.

If the compass locator is then used as the basis of a stand-alone NDB approach, then that is an NDB approach.

Exactly. Read what I wrote once again.

"The classic set-up before DME became widespread was to have an NDB sitting at the OM for the ILS, and hence in the absence of the ILS, the approach of choice was an NDB approach based on timing from a beacon 5 miles off-airport."

NDBs do not, generally, fall from the sky into convenient locations to create a straight-in off-airport-NDB approach. They are placed there for a reason. I explained that reason, and further, the reason why such NDBs, and the approaches associated with them are being decomissioned, at least in western Europe.

One should not pick and choose the skills which one teaches when molding an IFR pilot.

I have a lot of sympathy for that argument. However there comes a time when the requirements to train for the modern environment outweigh the need for those skills that have fallen into disuse. Would you teach A-N range tracking? At one time, it was highly relevant to the IFR pilot.

[SNS3Guppy]

A ridiculous comparison.

The AN range is no longer in use.

The clock still works just as it always did, and still has applicability to basic navigation skills...including flying an approach.

Timing one's fuel, timing one's turns, timing one's hold, and timing one's approach is still very much a useful, appropriate thing to teach and to practice in instrument flight.

[Lookforshooter]

Anyone in here hoping that the GPS will always work, hasn't seen one go out on them right before an approach...very interesting to see the moving map flip around...stand alone GPS approaches always made me nervous..(Hollister Airport, USA)...with no colocation of an NDB, VOR...ect ect, hoping RAIM was working...ect...and of course we can talk about a corrupt database in the FMS or GPS...that said...call me 'old school'...when passing an instrument ride meant nailing your airspeed, and knowing the head or tailwind, ergo proper groundspeed, so when you time ran out on a non precision approach, you were actualy close or over the airport...but not past...needless to say...any instructor or pilot that can't, won't, or doesn't consider doing a timed approach, is yet another pilot that is simply relying on technology to save the day, rather then pilot skills....on that note...open up your Jepps and find NDB after NDB approach, or a LOC approach with no DME, or Backcourse..no collocated VORS to tell you when to miss, ect ect...the world becomes pretty boring only landing at big airports with all the goodies...there is a whole world of airports out there with minimal nav aids....and on that note...while I fly jets for a living with all the goodies..I am currently getting my com/inst helo...and guess what? Had to brush off the lapboard and clock...because the helicopter doesn't have DME/GPS/FMS, ect ect.....

[SNS3Guppy]

You're currently working on your helicopter ratings, huh? Your previous screen-names professed to be a highly experienced helicopter pilot. Of course, you really blew that one day by asking on the helicopter forum if there were any "real helicopter pilots who could..."

[Lookforshooter]

Guppy...just shut up...I am dual rated in planes and helos, with single pilot exemptions in 6 Citation models...I also hop in and out of some larger jets as SIC..happy? Gosh I would luv to meet up with you in the cafeteria at Simuflite...that would be an interesting conversation. It would never happen...you need a PC to hide behind.

[SNS3Guppy]

Dual rated, are you? You recently told us you're a helicopter student pilot in Torrance, California (USA). Imagine that.

You've asked before if there are any "real helicopter pilots" who can answer a question for you...strong intimation that you are NOT.

You hop in and out of "some of the larger jets" as a SIC? Really? Which ones? Obviously not the LR60...you posted on that recently and had no idea what you were talking about...and couldn't cite the source of your imagined data.

A single pilot exemption in six different citations? How impressive...nearly like being single pilot in six different single engine cessna's...not much faster, either. Which ones, then? You're not one of those hair-on-fire guys that's got the only single pilot exemption in the Citation X, are you? Or perhaps you invented the Citation III? Tell us about flex in the Lear, again. When you're on that microsoft flight simulator, you can be single pilot all you want...but here it doesn't really count, you see.

...just shut up...

What do you suppose you might say if you were more than 14 years old, and a professional?

Gosh I would luv to meet up with you in the cafeteria at Simuflite...

Only possible if you actually were to go to Simuflite. No need for that while you're flitting around in your microsoft flight simulator.

[Dan Winterland]

Now now!

Back to the original topic, I think there's a little confusion as to what an 'overlay' approch is. In a modern airliner, if the GPS fails on the approach, you don't suddenly lose your position. Different installations use different position updating mechanisms. I've flown 4 types with GPS updated Inertial Reference Systems (IRSs) and they all did it differently, but this is how the A320 works - which is pretty typical.

The IRSs give a position to the Flight Management Guidance Computers (FMGCs). The IRS position is constantly updated by the two Multi Mode Receivers (MMRs). Each MMR has a VOR, an ILS, several DMEs and a GPS. An NDB is optional but doesn't update the IRS position. The IRS 'blends' this information to give a best position based on the quality of the position information. The pilots get an indication of the quality in the form of an Actual Nav Postion error and where the information is coming from - Invariably the GPSs as they're the most accurate. The pilots must verify the accuracy of the fix prior to an approach. Just seeing 'GPS Primary - Accuracy High' on the progress page is sufficient according to our SOPs.

If a Non Precision Approach is flown, the FMGC will navigate from waypoint to waypoint from it's database. If the approach is in the database, then the waypoints will exist. If you lose the GPS, all that will happen is that the annotation 'GPS Primary' will dissappear, but you will still get the IRS position which will now be updating from radio nav aids if available and still probably be 'Accuracy High'. If not, the position will take a long time to become too inaccurate to use - if ever.

However, we still have to have the NPA raw data displayed unless it's a GPS approach (which we can do at the TERPS arifields in our network) when we must verify that both MMRs are receiving a valid GPS signal.

We do have a couple of airfields in our route system which have non overlayed NPAs, but these don't have waypoints and therefore don't appear in the FMGC database. We're not prohibited from flying them, but we would never chose to fly one if there is an approach in the database we could use. In a commercial operation, there is just no justification in increasing the risks.

Incidently, on the Nav Display, time to the next waypoint is dispayed - so we do have automatic timing. And on the Airbus aircraft, you can press the APCH button on the AP control panel as you would on an ILS and the aircraft will fly the NPA as if it were an ILS - and very accurately too.

I noted the remark about 'children of the magenta' - this system breeds them. But in modern commercial operations, safety is the main concern and this way of doing things is certainly very safe. My company's network has a lot of NPAs into difficult airfields with poor weather and terrain. Kathmandu is one of them. I wouldn't like to be using any other system.



And still no need to time!

[Lookforshooter]

There is a philosophy to flying that I learned that came from a Type A approach to operating a plane. It goes like this...you take off, you lose an engine, deal with it...you lose some radios, deal with it, you lose presurization, deal with it...and so on...until your a dark aircraft at night, no power, no electrical, gliding to the field...there is no excuse to crash a plane. The worst that should happen is you become a glider to an off airport landing. Flash forward to how people are taught instruments today..when a pilot I know, CFII, did a trip with me to a Britney Spears concert...he got the ILS into Tacoma, followed the needles down(they didn't move) to a point where I asked him what he was doing...he looked around, then you saw the look on his face, utter disgust. He hadn't put in the actual ILS frequency, and checked auraly for the code. Since we were partialy IMC and I was using some goodies on my side of the plane, we were ok...Dinner was....aukward...he knew he would have flown it down, of course, and killed everyone. Sobering. He had a thousand hours and taught at Hillsboro Aviation in Oregon. He told me that they could use the GPS moving maps to do holds, ILS's ect...that was thier situational awareness, and they didn't have to time anything. I had dimmed the GPS display on his approach. He flies an Astra SP, because he is buds with the boss's son. Children of the Magenta came from a video presented to the instuctors at Simuflite..and basicaly documents all these pilots leaning on GPSs/FMS and moving maps to tell them where they are. Even questioning the veracity of timing approaches illustrates how endemic and dangerously shallow instrument skills have become. I am told at school that making a pilot, hand fly using 'raw data' ...meaning just ILS needless and no other goodies is considered an emergency procedure.

[tbavprof]

Even questioning the veracity of timing approaches illustrates how endemic and dangerously shallow instrument skills have become. I am told at school that making a pilot, hand fly using 'raw data' ...meaning just ILS needless and no other goodies is considered an emergency procedure.

That is truly frightening, especially knowing the theory behind that training is to put folks up front of huge, fast-moving aircraft as quickly as possible.

Look4, is there are copy of that movie you mentioned publicly available?