Autoland qs need answers urgently

[tonymmho]

1) In triple autopilot system has an ILS receiver failure on lacaliser approach : (a) Aircraft continue to autoland (b) Autoland is discontinue and GA is initiated (c) revert to cat II.
2) If during autoland system has an ILS receiver failure Before Alert Height, the scenario: (a) Continue Autoland (b) Autoland is discontinue and GA is initiated (c) revert to Cat II
3) If during autoland system has an ILS receiver failure After Alert Height, the scenario : (a) Revert to Cat II (b) GA is initiated (c) Autoland continue with no failure annunciated.

Thanks in advanced.

[Alex Whittingham]

The ILS receiver failure is not the primary warning you would act on, on the A320 for instance an ILS receiver failure would give rise to an AUTOLAND warning light, and you would react to that.

Q1. You can't do an autoland on a localiser only approach. No correct answer
Q2. As far as I can tell there are two possibly correct answers. The Boeing procedure for a failure before alert height is to downgrade to a lower autoland status with higher decision height, the Airbus procedure is to go-around.
Q3. You would continue with the failure annunciated. No correct answer.

I'd be interested to know where the questions came from, that might give us a better possibility of answering them. I'd also welcome inputs from others, Keith?

[Alex Whittingham]

After a bit more research, the Airbus view is:

Alert height is a height defined for CAT III operations with a fail-operational landing system.

Above AH, a go-around must be initiated if a failure* affects the fail-op landing system (* list as per AFM)

Below AH, the approach will be continued (except if the AUTOLAND warning is triggered).

The AH is evaluated during a/c certification. Operators are free to select AH lower than the one given in AFM but not a higher value.

and, as the ILS receiver failure would set off the AUTOLAND warning, the correct answer - on an Airbus - to Q3 would be to Go-around.

[potkettleblack]

You summed it up quite well. From the Airbus FCTM any failure down to the AH will involve a go around. A failure of any aircraft equipment or ground equipment below AH does not in itself necessitate a go around depending on the nature of the failure and may involve a quick command decision. However, as you pointed out if the AUTOLAND light comes on then its a go around in anycase.

As an aside if a failure occurs above a 1000ft then usually the crew will deal with the problem (clear ecam items etc) and if necessary set a higher minima (say due to the aircraft downgrading itself from CAT 3 to CAT 2 or 1) and rebrief accordingly (calls, approach lights to be seen etc). Failures below a 1000ft by their nature will invariably involve a go around as the workload will be to high and your to close to the ground to safely deal with them. As per the FCTM 02.150. This of course is Airbus recommended SOP's and the company ops manual will need to be consulted for detailed advice but that is how we do it in our outfit. Of course nothing precludes good airmanship at the end of the day.

[tonymmho]

Autoland Qs

Thanks for the inputs. Qs gathered from EASA Part 66 Module 13 paper. Bit confuse what I read from the course note that autoland failure Below AH will not have warning annunciation and autoland continue?? Pls enlighten me in this statement. Gathered from the input it does has autoland warning light. Confuse indeed
Thanks again.