Under normal circumstances Autoland's require 3x A's, namely:
- Aircraft is capable and airworthy to do it and the weather's is in-limits for the aircraft type.
- Airport is capable of providing a CAT II / IIIa/b approach (with all that that entails).
- Aircrew is capable, i.e. trained and in-check to do it.
Anyone of those not in place and the autoland game is up.
BUT... when the fuel's running out (
i.e. it's not normal circumstances), the Commander is granted authority to throw the rule book out of the proverbial window and do whatever needs to be done.
Looking at the METAR's (
for Luknow & Delhi... which all reported Cb's / TSRA and knowing the general pandemonium that can cause for the airports in that vicinity, i.e. everybody charging about trying to find somewhere to land) there's also maybe a question to be asked about their initial fuel planning and judgement thereof (
i.e. from initially taking barely enough for Dehli, wherein they should be well aware that when Delhi's got Wx issues - and your primary alternate too - you need to be generous with tankering), i.e. they seemingly had loaded only 20-30 minutes of extra fuel (
which they used when holding for Delhi, which somewhat proves my previous point about generous tankering required for Delhi when the Wx there is ****) before proceeding to their primary alternate, arriving there with only a smidgen more than 'Final Reserve' (
then, having thrown away their 1st approach into Lucknow, declaring a Mayday because of their now parlous fuel state) and then trying to divert to some place else... well, you couldn't make it up.
And I highly suspect that, during their no doubt panicked attempt to divert to some place else (
with barely ½ ton of fuel remaining in each wing) ATC then helped them out by providing a sudden 'improvement' in the Wx in Lucknow.
Imho, they should have declared their Mayday much sooner (
which immediately has the effect of throwing the rule book out the window) and landed in Lucknow on the first attempt (
or broke off, circled around pronto, and done it again); with Final Reserve fuel remaining (
or bloody close to it) even if the tailwind was a tadge too much and / or the visibility was a tadge below system limits? well "oh dear, how sad, never mind". It's called airmanship. This debacle smacks of a complete lack of judgement, as well as blind obeisance to the rules at the expense of common sense, i.e. it's symptomatic of the sort of folks who would follow the rule book into a mountainside.