Apparently this happened more than 7 years ago, and if German investigators really have taken this long to write a report, I suspect that report would be of limited value today.
The crew of the 777 let the autopilot land. Runway status was CAT I (not CAT II/III) allowing departures which might block the localiser, and exactly that happened just before the 777 touched down, and then the autopilot lost directional control of the airplane. The crew was blamed and I guess the autopilot logic could have handled the situation better (immediate go-around), but I wonder if it is really according to ATC rules to allow the localiser in use to be blocked while an aircraft is on low final approach on an ILS using that localiser – in CAT I status?
Indeed it is, but the rules are prescribed from the other perspective. If you want to do a CAT III the Airport has to be in LVPs, for precisely this reason.
Just pasting the video from the article.
I had to go around On a CAT3 approach at EDI when a B757 missed an exit and had to taxi slowly to the next exit.
The disturbance to the LOC signal happened as the B757 turned off the runway, the rapid movement in the LOC indications was the reason for the autopilot to drop out and the GA to be carried out.
The approach might have technically been a CAT 3 with the RVR being 250/250/1500+ but it was shallow fog and the whole thing could be seen on the approach, after 10 min the return to the airfield was CAVOK but we did a faultless autoland to check the auto flight system was OK and give the maintenance crew the info required to re-certify the system following a failed autoland.
Is ATC required to warn landing aircraft in such cases?
I have heard the phrase “You may get a flag on the localiser” but do they have to say that?
Not during CAT I ops, except when the crew asked a CAT III for practice. Then we say: “sensitive area not protected”.
I wish I could show you some Localiser plots when we see such an event calibrating but the effect is significant. I’ll see if I can dig some out.
Some places with non-level runways also suffer. Abu Dhabi 31L is a classic – it has a dip near mid-point and anyone on a CAT III roll-out will notice some significant fishtailing as the aircraft passes the 7000ft to go point.
A minor thing, the article mentions the German “BRU” as investigator but means the Bundesstelle für Flugunfalluntersuchung (BFU).
Is it standard practice to tell the tower you’re doing an autoland? Then this would be a good old communications failure, as is so often the case.
Is it standard practice to tell the tower you’re doing an autoland? Then this would be a good old communications failure, as is so often the case.Quote
Yes it is.
The phrase is:
“Requesting Cat 2 training approach”
With that you are telling ATC that you are going to perform an AutoLand during better than CAT 2 weather. Critical areas will be protected.
With reference to the Asiana accident in SF, I think there is a lot of use of automation to land big jets on a regular basis, especially by Asian operators.
Most Western airline pilots I know of, would only use Autoland when it is really required (CAT 2/3). Heck. Landing is the best part of the flight.
