Timothy’s statement is much appreciated, in particular having briefed for a circle to land, not going missed when he went visual and making a spur of the moment decision to continue straight in with a tailwind component. Understanding the error in judgment from the first hand is invaluable, and hopefully re in forces the need to stick to the original briefing/plan when planning an approach.
The METARS suggest a 10 knot tailwind component, before applying the 150% safety factor. This may be more of a factor than whether a CDFA was used or not. In the UK at least, IR examiners today expect to see a CDFA employed for non precision approaches.
To me this seems like failure to follow set procedures, caused by fatigue and possibly stress. The rest is just a question of luck. What’s there to learn from this other than when you push it, you’d better have the luck on your side? Just for the record, in my opinion Timothy was more lucky than unlucky here.
Rwy20 wrote:
I actually asked my instructor if you could set up the G1000 in a way that it would display you a virtual glidepath to any point in space. He said yes, but I won’t show you, because that is dangerous. I still think it would be safer to use your WAAS GPS in a way that allows to fly any approach as CDFA with advisory glidepath (as long as you respect step-down fixes and MDAs), but then I have very few real IFR experience. What is your take on this, and does anyone know how to do this on a G1000?
Getting a virtual glidepath to a point in space is the standard VNAV function and certainly neither dangerous nor a secret – it’s all in the G1000 manual.
Making an approach this way is a different matter. I figured out how to do it eventually. You can’t use the predefined overlay approaches – instead you have to set up everything manually. You set up a track from the FAF to the runway threshold in the flight plan. If there is no predefined waypoint at the threshold, you have to create a user waypoint. Next you set up VNAV to the threshold with the appropriate threshold crossing altitude and the appropriate FPA. Then you follow the VNAV path advisory on the PFD.
I’ve tried it in VMC and it works, but I would be very reluctant to do it for real, mainly because of the great risk of making a mistake in the setup (particularly if you have to program a user waypoint). Also, you can only set the threshold crossing altitude to even 100’s of feet, you don’t get any missed approach guidance (unless you yourself program that, too, in the flight plan), and you would have to manually set the CDI scaling to 0.3 NM (LNAV).
Hi Timothy, so sorry to hear only yesterday about the end of Lizzy, but relieved that you and all were not hurt! Your ex G-Lizz co-owner, Mark.
Interesting.
It’s happened to me, with a better outcome. Start the go around at MDA and you then get sight of the PAPIs and proceed to land uneventfully. Albeit on an LDA of 1,000 metres plus. The SPECI shows there was sufficient visibility that the approach ban did not apply – and I think most would agree the approach ban is a good practice also on private flights.
The current practice of CDFA (continuous descent final approach) for non precision approaches is an improvement in safety practice, and surprised (possibly not so surprised) that the Accident Board didn’t take an opportunity to mention this. Recently minted IR holders would therefore have gone around automatically.
It’s an impulse probably not many of us would stand up against at least some of the time. See the lights, let’s go! Changing decisions on the spur of the moment. Perhaps opening yourself up to the possibility of overlooking something in the haste… like a 10 kt tailwind…?
Is it me, or is landing on 600m with 3% slope at both ends, with an Aztec something that requires careful consideration?
He still had the option to go-around all the way until touchdown…?
4,300 hours ATPL … I guess it can happen to anyone of us!
It was mentioned that he was using a “derived DA” of MDA + 30ft so presumably this was flown as a CDFA and the go around was commenced normally, it was merely the decision to revert from a GA to a landing that seemed to cause the bother – not that a ‘dive and drive’ was flown since as far as I can read it wasn’t. (apologies if I’ve misunderstood your point, Robert).
I would imagine that if you have made multiple visits to the airfield in the past then that might also be a factor
