Ask The Pilot

[GoneMissed]

This one's been bugging me for a while...

In regards to MEL/SYD-UAE flights, why do some route via Singapore/Malaysia/India/UAE and some route Perth/Maldives/UAE. I've noticed it's very mixed every day across all carriers, I found it odd that they were weaving through all parts of Asia enroute, traffic was heavy whilst the Maldives route was completely clear and it's a very direct route requiring little deviation.

The other night Etihad (MEL-AUH) and Emirates left right with each other, both A380s. Etihad flew Perth/Maldives/UAE and Emirates went way up north and went via Singapore/Malaysia and mid India. There appeared to be a lot of track deviations as they went through Asia which I assumed would just slow things down.

Thanks!

This is also a good question for dispatchers/flight planners. Aeroplanes fly along routes which are basically a set of highways in the sky. When airlines flight plan they must do so to have the aircraft following this fixed-route network - for example one cannot flight plan from Melbourne to Alice Springs direct, you must fly via a series of highways which may not be the most efficient way of getting there. I'm not a pilot, however do publish the flex tracks to/from the middle-east and south east Asia. The system is called AUSOTS (Australian Organised Track Structure).

Qantas and Emirates propose their tracks for the day to us (I work for Airservices in the national ops centre), we review them against a set of ATC constraints, edit them, then publish (in a nutshell). Tracks are published via NOTAM and AFTN (basically a messaging service to the airlines). Virgin also propose the only domestic flex track city pair, Brisbane-Perth.

As jb747 said, we publish the tracks in order to take advantage of the jet stream for inbound aircraft, and devise a track minimising the impact of the jet stream for outbound aircraft. We look very carefully at weather and get frequent briefings from the BOM guys. Thunderstorm activity, turbulence, tropical lows/cyclones and volcanic ash are what we pay a lot of attention to. It is not uncommon to receive a track proposal from an airline dispatcher who has clearly not paid any attention to weather, and will punch a track through an area of forecast frequent thunderstorm activity for example. Quite often the proposals we receive will have the track going straight over the top of active military airspace also. The most important considerations for us are publishing a flex track that has minimal impact on ATC workload and safety. Only once I have configured the track with this in mind will I put my attention towards how I can shorten track miles or position the track with regards to taking advantage of the winds. Even if the winds are the same as the previous day, all it takes is for Defence to activate one or two military restricted areas and some development of thunderstorm activity somewhere else to completely change the profile of the track.

Once we have published the flex track, the dispatchers at the airliners compare it to the their company routes and make their decision. Sometimes we can publish very similar tracks for days, other times it varies quite strongly. It is a fun job as it as a very direct impact on ATC who we speak with frequently, and it is cool to come home and later check there are a bunch of A380s and 777s along this flex track you created and published much earlier in the day.

You can see some more info here - https://www.airservicesaustralia.com/ausots/ausotstoday.asp - it has a picture of the previous days tracks and contains all of the TDMs, so you can see what the messages that get published look like.

 

[JessicaTam]

To be honest we provide enough genuine mistakes that have to be managed....

But, they do have pilots drop dead every now and then, mostly at very inconvenient times. My last death was in the middle of rotate at Hong Kong yesterday. FO carried on, playing both roles. I miraculously recovered to do the overweight landing, but in the real world he would have just done the same.

There have been some specific exercises to show the aircraft reaction to some mistakes. Retraction of the flap, instead of the gear, just after take off was looked late last year. As the flap starts to retract, the angle of attack increases, and the system stops the retraction. Quite impressive, as it just flew away with only a slightly degraded climb gradient.

The sessions are not random. Instructors need to remain within a fairly tight script to ensure that the standardisation of the training programmes works. Nevertheless, there are enough permutations, that no two sessions are quite alike. Yesterday, our instructor wanted to give us a comms failure (which is quite difficult in an aircraft with so many different means of communications), and he found a method he hadn't tried before....and it stopped us in our tracks, in that there was no cure, and it wasn't totally unrealistic.

Would a scenario producing an outcome like that be forwarded to Airbus to develop a workaround?

 

[mjt57]

our instructor wanted to give us a comms failure (which is quite difficult in an aircraft with so many different means of communications), and he found a method he hadn't tried before....and it stopped us in our tracks, in that there was no cure, and it wasn't totally unrealistic.

A "no win" situation? Ala the Kobayashi Maru...

 

[petercr]

JB, saw one of your colleagues driving what appeared to be the late-running QF9 from the top of the London Eye a few hours ago, looked pretty spectacular...

 

[jb747]

Would a scenario producing an outcome like that be forwarded to Airbus to develop a workaround?

Not in this case, though procedural questions go between the operators and makers all of the time. The only way there could be a workaround (for this), would be to add more equipment. It took a triple unrelated failure for the result he wanted...same item of equipment, but with three units and no commonality. Real world, there would be virtually no chance of duplicating it.

I put a question in to our management the other day, concerning a fuel management issue. They'll ask Airbus, and in a few months, I might get an answer. In that case, it may be a procedural addition one of the checklists, alternatively, they'll come back with a no and a reason why.

Some years ago, I found an issue with the 767. I passed it on to our technical rep (who I'm sure didn't believe me), but he then passed it to Boeing. They looked at it, and the very next day, a red bulletin was released. They'd found that it really existed, was repeatable, potentially dangerous, and existed across the entire fleet of glass coughpit aircraft. A red bulletin is effectively a warning from the maker, and something that is fixed ASAP.

 

[jb747]

A "no win" situation? Ala the Kobayashi Maru...

He wanted a communications failure, to force us to fly the no radio procedure at London, Heathrow. The aircraft has so many means of communications, that you can transmit on...and even more listen on, that it's not all that realistic. Anyway, you'd be at low level, pull out your phone and ring someone. By failing the comms control boxes (RMPs), he could get the failure to happen with 3 items, not 7 plus.

 

[jb747]

JB, saw one of your colleagues driving what appeared to be the late-running QF9 from the top of the London Eye a few hours ago, looked pretty spectacular...

Well, if you see the 1 on Wednesday, wave. I've just received a timing update, so it's going to be about 3 hours late (for whatever reason).

 

[Flying Fox]

Some years ago, I found an issue with the 767. I passed it on to our technical rep (who I'm sure didn't believe me), but he then passed it to Boeing. They looked at it, and the very next day, a red bulletin was released. They'd found that it really existed, was repeatable, potentially dangerous, and existed across the entire fleet of glass coughpit aircraft. A red bulletin is effectively a warning from the maker, and something that is fixed ASAP.

Nice work by everyone involved.

So what was the rectification and how long did it take to roll-out across the fleet?

 

[mjt57]

Some years ago, I found an issue with the 767. I passed it on to our technical rep (who I'm sure didn't believe me), but he then passed it to Boeing. They looked at it, and the very next day, a red bulletin was released. They'd found that it really existed, was repeatable, potentially dangerous, and existed across the entire fleet of glass coughpit aircraft. A red bulletin is effectively a warning from the maker, and something that is fixed ASAP.

Ah just like car manufacturers, always ready to respond to driver complaints, like my Jeep, for example...

 

[petercr]

Well, if you see the 1 on Wednesday, wave. I've just received a timing update, so it's going to be about 3 hours late (for whatever reason).

Thanks JB, if I do see you on Wed, I'll wave but be a bit concerned as you would be well off track unless you were landing at RAF Dishforth (in North Yorkshire)

 

[Quickstatus]

How do pilots detect whether adjacent lightning actually stuck the aircraft? Is there an indicator of sorts?

 

[jb747]

Nice work by everyone involved.

So what was the rectification and how long did it take to roll-out across the fleet?

I don't recall how long it took for new software to appear. I think it was in the next scheduled update, so probably a few months. The fix would have to be developed, and then tested in all of the types and variants, so a bit of work to it.

The actual issue was that I'd found a way to make the aircraft fly through the altitude set on the MCP (the mode control panel) with the autopilot engaged. There should have been no occasions on which it would go through the altitude limit set on that panel. The FMC can contain more restrictive limits, but the MCP should have the final say. I was actually surprised that nobody else had found it, but I guess people who had seen it before assumed they'd made an error, and just moved on. I had a bunch of domestic sectors, and was, after a couple of experiments, able to repeat the issue every time.

Looking at my log book, and I see that the flight I discovered it on was in April 1994. Fast forward to about 2006, and a subsequent software update brought the error back. And it had to be removed again.

 

[jb747]

How do pilots detect whether adjacent lightning actually stuck the aircraft? Is there an indicator of sorts?

There's no solid indication....unless the lights go out. Just write up a suspected strike, and leave it to the engineers. So, even if you weren't actually hit, it will take them a while to do the inspection. Mostly they'll find a static wick or two missing, and perhaps a scorch mark on any stainless steel components.

Just recalled a flight on which there was no doubt...probably the first time I was ever hit too. In an A4G, off the coast near Nowra, towing a target for the ships. It was out on about 20,000' of steel cable. I didn't think I was anywhere near the cell, but all that cable must have been an invitation. Hit the aircraft, ripped down the cable, and lovely display of sparks from the target. I never saw what actually happened to it, because when I tried to recover it, it started to misbehave, and I eventually hauled about 19,000' of cable in and then cut it loose.

 

[Melburnian1]

Well, if you see the 1 on Wednesday, wave. I've just received a timing update, so it's going to be about 3 hours late (for whatever reason).

The sole reason I am answering this (an honour usually fo our aviators, or our new and most informative contributor from Airservices Australia) is that one of the aforesaid asked this.

Here is what I posted in the QF delays/ cancellations forum:

The Tuesday 11 April delay for the 1550 hours QF1 ex SYD has now extended to a predicted 2030 hours departure tonight, four hours and 40 minutes late, which confirms that it will be formed by the delayed QF12 that should come in at around 1835 tonight. Predicated upon some gains in gate-to-gate times and a reduced time on the ground in DXB, QF suggests that eventual LHR arrival will be three hours 35 minutes late at 1030 on Wednesday 12's morning.

 

[clazman]

Watched a video on how aircraft fly ten dynamic routes between Europe and North America.

Canadian air services publish the changing routes daily, the idea behind these routes is to counter no radar, aircraft also work with increased separation

Does this concept exist over the pacific?

 

[por930]

Watched a video on how aircraft fly ten dynamic routes between Europe and North America.

Canadian air services publish the changing routes daily, the idea behind these routes is to counter no radar, aircraft also work with increased separation

Does this concept exist over the pacific?

"Pacific Organised Track System (PACOTS) tracks are daily high altitude pacific routes between eastern Asia and the western coast of North-America. Eastward tracks are named numerically (1,2,3...). Similarly, westward tracks are named incrementally from the beginning of the alphabet (A,B,C...). Daily updates for each direction allow for routing around weather systems and tracking of favourable tailwinds to improve efficiency".

 

[Flying Fox]

For some reason on my last flight (B737) I really noticed the announcement about ensure that you take your allocated seat for take-off due to balance of the aircraft. Same said again when landing.

From a pilot, is this true?

If true, more of an issue on a large A380 vs a smaller B737?

I have heard that its only done to make identification of pax easier in the event of a crash.

Thanks

 

[jb747]

For some reason on my last flight (B737) I really noticed the announcement about ensure that you take your allocated seat for take-off due to balance of the aircraft. Same said again when landing.

From a pilot, is this true?

If true, more of an issue on a large A380 vs a smaller B737?

I have heard that its only done to make identification of pax easier in the event of a crash.

Weight and balance issues are most certainly real, and they are calculated based upon individual seat loadings.

 

[Captain Halliday]

How common is turbulence as a cause of a stick shaker activation?

 

[moa999]

I assume that relates to the QF29 VH-OJU stick shaker report. Thread in Open Discussion