cfischer

+1 what good would it do ... ?

chavala

Xyzzy

Yes, and hw you communicate that can be important... https://en.wikipedia.org/wiki/Avianca_Flight_52

docbert

IMHO, it depends on the reason for the mayday call.

If it's a mayday call because their fuel levels are getting close to their legal minimum, which means that before too long they potentially won't have sufficient fuel to make it to their alternate airport in the event of a problem (likely Canberra or Newcastle, but possible Melbourne or Brisbane), then I'd say no. In this case they have simply called Mayday to get the attention they need - priority for landing, etc. The odds of an incident during landing are probably exactly the same as any other normal landing, at most ever so slightly increased (due to, say, the pilots being slightly more likely to avoid a go-around if one is needed), so the benefit of the cabin knowing is zero.

If it's a mayday because there's a problem with the plane, then I'd say there IS a benefit of the cabin being aware, and thus slightly more ready to react in case of an emergency. This is the situation where a reminder of the brace position, a double-check of seatbelts, etc, would be in order.

The fact that Sydney Airport apparently decided to treat it as a full-on emergency is just most likely their by-the-book response for such an incident (and not a bad excuse for some real-life training!) - and probably not because anyone truly expected there to be an issue during landing. (Presuming that it was simply a legal minimum fuel issue, and not something more).

Interestingly, over the past few week the route for this flight has been very north on some days. Whilst this could just be due to the weather conditions en-route, it could also be due to them aiming more towards BNE (which is a few hundred miles closer to LAX than SYD) and then once they confirm they have sufficient fuel focusing on SYD. I've seen this style of route before when fog is forecast in SYD - if the fog is bad they are pretty much on route for BNE and land there instead, otherwise they continue on to SYD. It's a much shorter route than getting close to SYD and then having to divert.

transportprof

I wonder if with the plans for the new western Sydney airport, they'll never upgrade the instrument landing capabilities at SYD?

It's another reason that I tend to fly into MEL on United. They can do Cat III landings there, if needed.

TA

The better question I think would be what about their flight planning and fuel load caused the fuel reserve level to be breached?

Kacee

I wouldn't want to know about a mayday call, which alerts ATC to a problem. I would want to know if there was a need to brace or take some other sort of measure to protect myself, and expect the crew would instruct pax to do that if it became necessary (and if they had time).

Those are two entirely different things.

docbert

Listening to the LiveATC recordings it seems that the actual mayday call (and thus the reason for it) wasn't actually recorded, but best I can work out it occurred at least 50 minutes before landing (5:53am Sydney time, or possibly earlier). They were given a slightly more direct route and avoided any circling (eg, QF12 on the same route had to do two loops over the ocean). They were also offered the option of going to Williamtown (Newcastle) at time when they were 135 miles away from it, but declined it. Otherwise appears to have been 100% routine and uneventful landing.

They also reported that they were at the "fuel economy" speed of mach 0.80.

Edit: slight correction - they declared mayday at 5:47am Sydney time. The recording only captured part of the ATC side and none of the pilot side of the conversation, but ATC clearly says "United 839, Roger Mayday". They then ask the usual questions - people on board (239 restated by ATC), fuel endurance and dangerous cargo, but the response isn't captured.

Mwenenzi

Was an interview on the midday TV news with someone from the Aust Civil Aviation Safety Authority. He stated had less than 40 minutes of fuel left. So guessing at 50 minutes out they made the commitment to land at SYD.

skywardhunter

That is so ironic... the United States is the only country in the world where the word "mayday" is not in use, an rather the phraseology "declare an emergency" or similar must be used. Similarly "roger" is commonly used in the US, but rarely elsewhere other than in naval or military applications, general ICAO phraseology dictates "copy" or "affirm" or similar, so when I first heard this story I immediately was surprised that the US (presumably) pilots on the US airlines used the correct "mayday" call rather than declaring an emergency. Now it is ironic that in the response the ATC used the non-standard "roger"...

Sorry, bit of a ATC-nerd tangent

(More ATC Fun: one should say affirm, not affirmative, as the latter could be confused with negative, the number three is pronounced tree (as well as 9 being niner, which is more commonly known) and, at least in SA where I hold a PPL, the phrase "repeat" is to be avoided as in military speak it means fire again, instead one should use "say again")

HNLbasedFlyer

What is weird to me - there are so many places to land after you pass Hawaii if fuel is really an issue......

Steve M

It's the Captain's discretion, but my understanding and belief is that in such a situation, an announcement to passengers is warranted in such a situation, if only to the effect of "You may see emergency equipment meeting our aircraft upon landing. No need to worry - they are there out of an abundance of caution" rather than leaving passengers wonder why fire trucks with their emergency lights on are pacing the aircraft on the adjacent taxiway.

cesco.g

So, they had 90 minutes worth of fuel left at the time they made the decision to land at SYD?

Kacee

Yeah I'd like to know before landing, but there's no need to tell the pax when you're still an hour out. Which is when the mayday was called here.

markis10