Ask The Pilot

[Quickstatus]

how much time did that 3 tonne margin equate to?

 

[Mr Pumblechook]

Would appreciate an Aviators’ perspective on the OneSky project - integration of military and civilian ATC

Imagine connecting a 1980s Nintendo console in Melbourne to a garden shovel in Darwin and then programming them so that pressing A on the Nintendo makes the shovel dig a 1 m deep hole while throwing the shovel like a javelin makes Mario run forwards and you'll see how ATC works today - the two systems can't talk properly so we use human operators and lots of rules to bridge the technology divide, then we interact as little as possible).

The airlines always want more access to military airspace so the aim of the project is excellent - if you combine civil and military ATC systems then it's easier for the civil and military ATCs to share but clearly it's not going as planned.

 

[iRobbo]

What happens in the US where the amount of both civil and military traffic would massively dwarf that in the roughly similar land area of Australia?

Not sure, never had a look. I did talk to a US controller who was in Australia for Recategorisation of Wake Turbulence meetings and he stated their system modifications get put out to tender and there were 3-4 companies that bid for the work. That doesn’t happen here. The US does also have airspace with more ‘relaxed’ rules than we have here, maybe part of it.

 

[jb747]

how much time did that 3 tonne margin equate to?

That's about 16 minutes. But bear in mind that that was the margin above what I needed for a full diversion to Muscat.

 

[Quickstatus]

The declared fuel emergency of 200kg.
Seems to me that’s running on fumes. I know in general measuring equipment can be inaccurate when measuring at the extreme of the measuring range.

In your aircraft is there a point at which displayed fuel is inaccurate?. I understand if displayed fuel is this the aircraft should have already been on the ground.

 

[jb747]

The declared fuel emergency of 200kg.
Seems to me that’s running on fumes. I know in general measuring equipment can be inaccurate when measuring at the extreme of the measuring range.

When he declared his emergency, what he actually said was that if he had to fly the arrival, he'd be landing with 200 kgs. By not flying the arrival, and taking as direct a route as possible, he would have landed with more, though how much more is hard to work out. I'd guess at about 1,000 kgs. That's still an extreme figure. I don't understand how he got so low, as even if the airport he was using for his diversion calculations was suddenly snatched away from him, he still should have been planning to get to the end of the runway with:
a) Fuel to fly from present position to the start of the approach, plus 10%
b) Fuel to fly the approach
c) 30 minutes holding
plus
d) Fuel to go around and fly to the alternate
c) Fuel to fly the approach there

By my maths, he was somewhere around 6-7 tonnes short of what he should have had. Which really means he should have made the decision to divert much earlier, and probably should never have joined the holding pattern at all.

In your aircraft is there a point at which displayed fuel is inaccurate?

It would be interesting to know the actual inaccuracy. The tolerance is catered for by the min fuel at the end of the runway, which is a regulatory requirement of 30 minutes.

We monitor the fuel in a couple of ways. One by looking at what the fuel system says, but also by comparing the recorded fuel burn with the start fuel. Any divergence from the planned fuel, that we can't explain (by different altitude or wind to the plan) will also cause us to delve into the system. Generally, the difference peaks at around 1-1.5 tonnes in the middle of the flight, but then they close up again, mostly being close to equal at low fuel states. I'd take that as meaning that the system has been tweaked to ensure as much accuracy as possible at low fuel states.

I understand if displayed fuel is this the aircraft should have already been on the ground.

If the weather had been nice, he should have been on the ground with about 3 tonnes. As it wasn't, then he should have carried about 6-9 tonnes over the fence (depending upon which alternate you use). The numbers just don't make that much sense, so something else has happened to confuse the issue. Basically, he should have landed in Muscat as he passed by....

 

[Quickstatus]

Hopefully the system is tweaked to ensure displayed fuel is always less than actual usable fuel

Can your aircraft use all displayed fuel before symptoms of fuel starvation?
Or if displayed fuel is zero, how much usable fuel is still available?.

I understand this may be a moot question as it implies that flight is no longer guaranteed

 

[jb747]

Hopefully the system is tweaked to ensure displayed fuel is always less than actual usable fuel.

No. It's not like a car, where people drive right down to empty, and then a bit further. We need to know the exact weight for any of the performance calculations.

Can your aircraft use all displayed fuel before symptoms of fuel starvation?

Probably not. The fuel is in multiple tanks. At very low levels, it would be spread across four tanks. You'd have all of the crossfeeds open, but the distribution wouldn't be totally even, so you'd end up with engines dropping out at slightly different times. I'll try very hard not to test that theory.

There would be some fuel in the lines, but only seconds worth.

Or if displayed fuel is zero, how much usable fuel is still available?

Zero. Actually there'd be no displayed fuel, 'cos it would already have gone very quiet. The only aircraft that I have any knowledge of that was run out of fuel, was a Macchi. It had 2,400 lbs of fuel capacity, and the engine snuffed at 2,410 lbs used.

I understand this may be a moot question as it implies that flight is no longer guaranteed

Flight would be guaranteed....it's just that range would be 3 miles per thousand feet of altitude.

 

[Quickstatus]

Have a look at this Flightradar24.com - Live flight tracker! If the link doesn't work correctly, look at the flight on 4/12/17.

The pertinent time is 01:25Z.

You can draw your own conclusions.

Seems like the solution is to go to EWR
Emirates adds Dubai – Newark nonstop service from June 2018

Using 777.
Is LGA (though a domestic airport only) a 777 alternate?

 

[jb747]

Seems like the solution is to go to EWR
Emirates adds Dubai – Newark nonstop service from June 2018

Using 777.
Will they still use JFK as an alternate or does using the 777 instead of A380 open up LGA as an alternate?

Who knows...it's not what I'd consider a solution to not being able to fly a visual sector of an approach.

Is LGA 777 capable? Mostly, when it turns to poo there you'll be sent to airports quite some distance away, so I'm not sure they'd even be able to use JFK as the alternate.

Dubai right now...

That's looking in the direction of Dubai World, so the fog may not be at Dubai itself (yet).

 

[Quickstatus]

Very nice photo

It’s unfortunate that at lower altitudes such as on approaches, there is usually some turbulence interfering with photography from flight deck. Have you found a Solution?

 

[jb747]

It’s unfortunate that at lower altitudes such as on approaches, there is usually some turbulence interfering with photography from flight deck. Have you found a Solution?

I haven't done much of it lately, but I've got the gear with me now, so I should have a look on the way home.

The biggest issue I find is that it's very hard to get a totally rigid location within the coughpit. Many times I've tried to get a shot that shows the coughpit clearly, whilst letting the outside lights streak, but the aircraft vibrations tend to make seemingly rigid locations less so. Getting night shots from the aircraft is possible, but the machines are not totally inert in the sky. Not only are they constantly making small corrections that we can see, but the FBW systems have constant motions, which tend to show up as tiny sine waves on images.

I've been trying to get a decent image of St Elmo's on the windscreen for years, but the good displays never coincide with the days I have the camera.

 

[Saab34]

I saw this the other day and found it strange. A330 landed MEL 16, deployed engine reverses as per normal then closed once slowed down, then deployed again for about 5 seconds then closed again. I have never seen it deployed twice? Any ideas? Hey were rolling through to J so hardly needed a second time.

 

[jb747]

I saw this the other day and found it strange. A330 landed MEL 16, deployed engine reverses as per normal then closed once slowed down, then deployed again for about 5 seconds then closed again. I have never seen it deployed twice? Any ideas? Hey were rolling through to J so hardly needed a second time.

Still on the runway?

I've seen cases where an engine doesn't indicate that it's totally out of reverse, and the engineers normally fix this by cycling the engine in and out again. On the engines that I'm familiar with, they don't want the pilots to do that, as there's a way of damaging the reverser system if the fault is real and not just indication, but that may not be the case for all engines.

I've only had it happen once, and we just shut the engine down, and left it in reverse.

 

[defurax]

Isolated airports are handled in a couple of ways. One is to have an arbitrary additional holding fuel (90 minutes or so) on top of any normal requirements. The regulator would have to decide whether that was acceptable. Having a look at the docs for IPC shows that the Chileans limit the number of aircraft that could potentially be using it, by ensuring that no aircraft has passed the point of no return, if there is another closer to the island...they risk one aircraft at a time. Carrying enough fuel to return to your start point, or in fact, ANY point, simply may not be possible. Contrary to popular opinion, in fine weather, most aircraft do not have enough fuel to go very far when landing. Aircraft landing at Melbourne might be able to get to Avalon, but unless forced by the weather, will not be able to go to Adelaide/Sydney/Canberra.

Last time I was in Papeete I met an elderly couple who were flying around the world and Easter Island was their next destination. The following day I looked at the LAN flight path from PPT to IPC and it showed that the aircraft flew near IPC but actually landed at SCL. I'll never know what the Captain told the PAX when leaving PPT, but I imagine that the plan could have been to see if weather would improve at IPC while en route and continue to SCL if not.
My question is, considering the amount of fuel that would have to be carried to fly all the way to SCL from PPT is that a realistic scenario or the landing at IPC would have been "heavy" and requiring inspection for possible damage? The LAN flight is operated by a Dreamliner.

 

[Saab34]

Still on the runway?

I've seen cases where an engine doesn't indicate that it's totally out of reverse, and the engineers normally fix this by cycling the engine in and out again. On the engines that I'm familiar with, they don't want the pilots to do that, as there's a way of damaging the reverser system if the fault is real and not just indication, but that may not be the case for all engines.

I've only had it happen once, and we just shut the engine down, and left it in reverse.

Yes still on the runway.

I YouTubed the situation, what’s interesting is I found the SAME carrier in question doing the same thing a few months ago on the same runway. Weird

 

[jb747]

Last time I was in Papeete I met an elderly couple who were flying around the world and Easter Island was their next destination. The following day I looked at the LAN flight path from PPT to IPC and it showed that the aircraft flew near IPC but actually landed at SCL. I'll never know what the Captain told the PAX when leaving PPT, but I imagine that the plan could have been to see if weather would improve at IPC while en route and continue to SCL if not.
My question is, considering the amount of fuel that would have to be carried to fly all the way to SCL from PPT is that a realistic scenario or the landing at IPC would have been "heavy" and requiring inspection for possible damage? The LAN flight is operated by a Dreamliner.

I would not be surprised if carrying the mainland alternate were not the norm on that operation. In round figures, it's a 2,000 mile diversion. A 787 would not have had landing weight issues with that.

The biggest issue with 'heavy' landings is not the weight. It's the sink rate, combined with any lateral motion.

 

[jb747]

I YouTubed the situation, what’s interesting is I found the SAME carrier in question doing the same thing a few months ago on the same runway.

Ok..don't understand. There's no reason to do it that I can think of. At low speeds it's not going to save the brakes at all (and that's a reverse of the cost equation anyway).

 

[mjt57]

JB, while browsing Whirlpool yesterday, I found that thread on pilot shortages. I started reading it. Then discovered what appears to be a familiar username.

A lot of the comments dismayed me, particularly those guys who seem to think that learning basic skills and retaining them is a waste of time, given the technology in a modern glass coughpit.

I don’t know if any of them fly or if they do, if they are airline pilots, but if they are, I would have to guess that they are with the LCC type of airlines, and ones to avoid.

 

[jb747]

JB, while browsing Whirlpool yesterday, I found that thread on pilot shortages. I started reading it. Then discovered what appears to be a familiar username.

A lot of the comments dismayed me, particularly those guys who seem to think that learning basic skills and retaining them is a waste of time, given the technology in a modern glass coughpit.

I don’t know if any of them fly or if they do, if they are airline pilots, but if they are, I would have to guess that they are with the LCC type of airlines, and ones to avoid.

Threads like that one amuse me. A classic case of not knowing what they don't know.

The thread took a turn onto the need for visual navigation training, on the basis that 99.9% of flying is done using GPS, so why spend so much time looking out the window, learning to navigate by reading ground features. By the same token, I could ask why not train using the autopilot, as that's also how we fly most of the time. It's about having the absolute basics so well understood that they'll remain with you for the rest of your life...not about getting one or two nav flights more or less right.

It struck me as a desire to dumb down the job as much as possible, 'cos then they'd be able to do it.

Of late, we've seen a number of accidents in which pilots have been unable to fly an aircraft after failures that actually leave them with a flyable aircraft. AF447 is being mentioned in the news again, as if the loss of pitot heat was the cause of that accident. It wasn't. That aircraft would have flown perfectly well, if a) it had been left at about 2.5º nose up, and about 85% N1 (or whatever the power setting was as the issue started) and b) if the person flying it, had realised that in no world is full aft stick a recovery from anything. Basics...not there.