Ryanair GPWS @ Bergerac
In this particular procedure, how would you know when are you safe to descent towards the NDB?
If that's the case the answer is two things:
1. Correct downwind timing.
2. Only leave platform altitude when established inbound.
From a human factors point of view this is an interesting one. There obviously was a RNAV approach available because the controller offered it. Not having the plate is the tricky bit as with one it would clearly have been the safest option. Nobody wants to hold their hand up and say they are incompetent to fly an NDB, but raw data in a 737 it is far from a regular procedure. A bit of finger trouble in the FMC with a under confident FO and it is surprising that so few of these incidents occur. In the good old, bad old days I suspect some people would have accepted the RNAV approach programmed it in the box (or as an ILS overlay) and without a chart used the NDB minimum. Given the cloud base it would not have been an issue. I am not for a moment suggesting this is the right thing to do. But a weak crew with a lack of situational awareness would have been better off than trying to fly this in vertical speed and heading select. Building a distance ring around the runway at 7 miles or suchlike would also have helped with determining distance to height. I strongly suspect that the ILS out of service was only properly understood just before top of descent and that with a bit more notice they would have been better prepared.
"Mildly" Eccentric Stardriver
Wiggy: plus one. Seems you are the only one on here who knows how to fly an NDB. The worst bit to me, apart from being badly positioned, is that when the EGPWS went off, they were already 400' BELOW the beacon crossing height. Retires to box, awaiting comments.
I'm with wiggy - established inbound means you must be within 5degs of the bearing, if my memory is correct. If not, you don't descend, you go round the pattern and try again.
What you’re missing is the fact that an NDB approach in 2015, in an NG could be flown using more than one method, depending on the Ops Spec and equipment (and we haven’t even started on IAN yet).
BTW - An NDB app would be flown in HDG mode - If you’d run out of ideas, or you’re a masochist or stuck in 1970. LNAV is also an option with the ADF being monitored. You can’t “confirm with LNAV”, it’s a mode. And you can’t have both at once. You can confirm your lateral track, which is what I assume you meant.
Cheers
I'm sure you're right...my comment ( if you're indirectly talking to me) was a generic one to address the concerns of those who seemed concerned or bemused by the lack of a electronically defined descent point or similar on the paperwork for what is by current standards a somewhat minimalistic procedure.
I don't disagree with you that in reality these days you'd up the automation a notch or two or three..even on something like the relatively steam driven "sans IANS" T7 you'd at least try find a suitable overlay or use runway extension and track in LNAV if you could, but have the needles displayed to confirm lateral tracking (you'd still need to know when it was legit to begin the descent down the slope though
).
I don't disagree with you that in reality these days you'd up the automation a notch or two or three..even on something like the relatively steam driven "sans IANS" T7 you'd at least try find a suitable overlay or use runway extension and track in LNAV if you could, but have the needles displayed to confirm lateral tracking (you'd still need to know when it was legit to begin the descent down the slope though
).
Last edited by wiggy; 2nd Jul 2020 at 23:00.
I have vague memories of an Airtours 767 in Orlando diverting because the ILS was out and they said they were not allowed to fly NDB approaches any more. This must have been around 20 years ago. I remember being shocked at the time. But now that NDBs are being removed, GPS has resulted in NDB approaches being well on the way to becoming like Consol and other old navigation systems just a memory. You don't even have to fly an ILS on the EASA single engine instrument rating test, GPS approaches will do. This may be keeping up with the times, but I was still surprised.
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To help me understand, those of you that are suggesting an RNAV approach do you mean an RNAV approach to a particular standard such as RNAV/RNP1 or RNP APCH? If so, is it not a requirement that the approach in the database matches the plate, and how can you check that without the plate? I'm aware that you can 'gash up' an RNAV approach based on manual waypoint entries and an NDB plate because that is what we used to do 40 years ago, but I thought that sort of practice was long ago banned! Genuine question, as I have never flown to modern PBN standards.
Good question Alex and what I was sort of alluding to a few posts back. Without the plate you can’t cross check waypoint sequencing and height restrictions so it doesn’t seem unreasonable not to fly the RNP approach. The investigation states that DME not available, so the NDB Z not available, which only leaves the NDB Y.
There’s no reason why LNAV couldn’t be used (backed up by raw data and taken over by Hdg Sel if required) but the error was the early descent below platform.
The big save was response to the GPWS warning. We’re doing EGPWS in our current sim sequence and a big discussion area is ‘can you imagine how difficult it would be to have to ditch the SA you thought you had and carry out the manoeuvre? And then to have to rebuild that SA prior to having another go. And then to have to prep and fly the return flight knowing that there will be awkward conversations to come.’
There’s no reason why LNAV couldn’t be used (backed up by raw data and taken over by Hdg Sel if required) but the error was the early descent below platform.
The big save was response to the GPWS warning. We’re doing EGPWS in our current sim sequence and a big discussion area is ‘can you imagine how difficult it would be to have to ditch the SA you thought you had and carry out the manoeuvre? And then to have to rebuild that SA prior to having another go. And then to have to prep and fly the return flight knowing that there will be awkward conversations to come.’
I think we are all on the same page that you can't do it without the chart (which is why I said in the good old bad old days). My company very clearly introduced guidelines about fifteen years ago about what you could and could not do. In the dim and distant past I remember flying into a new airfield that was not in the database (although I did have the charts). As it was the inaugural flight we needed some common sense and an explicit authorisation from the chief pilot to avoid red faces all round. We then merrily flew self constructed NDB approaches for several days before someone managed to update the database. Fortunately it was good weather and I had an excellent copilot later one of our checkers. Reminds me of the old line 'be nice to your co-pilot one day he might be your checker'. In this case they seem to have rushed the preparation, the pilot flying had some finger trouble with the FMC and when it started to go wrong I would not be surprised if they were both heads down trying to work out what was wrong with the FMS and nobody was really flying the aircraft as it descended in vertical speed, before the GPWS saved the day.
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For such an error, both pilots should have had their IRs immediately suspended and made to pass another 'initial issue' flight again. The situation seems to have been saved by the terrain warning. What could have happened had that system been unavailable is beyond imagination.
Last edited by Philoctetes; 6th Jul 2020 at 14:45.
The Crew would be expected to pull the CVR CV immediately after shutting down (which renders the aircraft AOG until until a reset is authorised) and file an ASR as soon as practicable. Standard procedure in order to comply with EASA requirements would be for the airline to take both pilots off the line and then conduct a safety investigation followed by a training package appropriate to the event. I doubt very much that this crew operated the return sector and even if they did - if authorised by the Chief Pilot, they would not have flown again without a thorough debrief of the event, then a simulator check and a line check.
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On another note, they do bring up that the crew reported established on the final leg, eventhough they weren't.
Am I the only one who find that rather "normal", that you'd call "established" to ATC before you actually are... hence not really a problem in the current situation?
And technically, ATC would've seen it on his monitor, and discarded it for the same reason I just did. If I understand there actually is surveillance coverage, which is based on the MSAW alert the approach controller got. I really hope they fix the coordination issue with the MSAW alert, there was a reason it became mandatory to alert aircraft to MSAW many years ago.
And the French BEA to use english in their reports...
Am I the only one who find that rather "normal", that you'd call "established" to ATC before you actually are... hence not really a problem in the current situation?
And technically, ATC would've seen it on his monitor, and discarded it for the same reason I just did. If I understand there actually is surveillance coverage, which is based on the MSAW alert the approach controller got. I really hope they fix the coordination issue with the MSAW alert, there was a reason it became mandatory to alert aircraft to MSAW many years ago.
And the French BEA to use english in their reports...
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For such an error, both pilots should have had their IRs immediately suspended and made to pass another 'initial issue' flight again. The situation seems to have been saved by the terrain warning. What could have happened had that system been unavailable is beyond imagination.
You seem to have a tenuous grasp of post incident protocols. Are you a pilot ?
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For such an error, both pilots should have had their IRs immediately suspended and made to pass another 'initial issue' flight again. The situation seems to have been saved by the terrain warning. What could have happened had that system been unavailable is beyond imagination.
That really is nonsense. You evidently don't understand how the professionals within the industry operate.
I suppose some of the problems in flying a raw data approach when much/all of your day-to-day operation involves radar vectors to an ILS or some kind of PBN approach, are not that you can’t do it or don’t know how, it’s the difference in preparation, execution, familiarity and workload.
RNAV: Load approach into FMC(s), check, brief, set up MCP, altimetry, FMAs, RNP/ANP, progressive config, etc. Much button pressing and checking of automation which has deviation alerts but 99.9% of the time does it all pretty well.
Raw data: Brief, tune/ident navaid, procedural, timing, tracking, altitudes, full config, descent rates, more tracking, etc. Hands-on with the aeroplane - no alerts or warnings that you’re not doing it right until the EGPWS gets involved.
At first glance, they did bits out of both lists but omitted some of the more important items.
RNAV: Load approach into FMC(s), check, brief, set up MCP, altimetry, FMAs, RNP/ANP, progressive config, etc. Much button pressing and checking of automation which has deviation alerts but 99.9% of the time does it all pretty well.
Raw data: Brief, tune/ident navaid, procedural, timing, tracking, altitudes, full config, descent rates, more tracking, etc. Hands-on with the aeroplane - no alerts or warnings that you’re not doing it right until the EGPWS gets involved.
At first glance, they did bits out of both lists but omitted some of the more important items.