Ask The Pilot

[jb747]

I‘ll add a little about the procedures that caused all of this a bit later.

Mentour's video, called the pilot of QF1 was a 'management' pilot. He was actually from training; a senior check captain. So, whilst he still did a fair bit in the aircraft, it was often with trainees, so he was often watching, not so much doing. He would also have been in the sim a lot.

Actual management pilots are people like the Chief and Deputy Chief pilots, as well as the various fleet and base managers. They spend varying amounts of time in the aircraft, but I doubt that it would even be a third of what is done by the line pilots. One of the consequences of this, is that it often removes them from seeing the outcomes of their decisions on a day to day basis. And, of course, it leaves them out of practice. If you look at major incidents, all around the world, management pilots have a disproportionate share.

There were many paths that led to QF1.

Firstly was the decision to make flap 25, the 'standard' flap setting. Boeing gives you two possible settings for landing, (25 & 30) but their standard is 30. As best I recall, this part of things was driven by the fact that using F25 required less power on the approach, and so made less noise. It also used very slightly less fuel. Some airports are extremely noise sensitive, and also charge extra for more noise. But, there is a drawback to having less drag on approach. The aircraft is less speed stable. It doesn't respond as quickly to minor excursions. Plus as the engines are at a slightly lower setting, they are also slightly less responsive on acceleration, and a greater power change is required to get the aircraft to decelerate. None of this is especially difficult, and if anything, it didn't feel all that different in behaviour to the 767 when using F30. Another point to note was that many of the management people of the time had flown the 767, so they didn't find the aircraft's behaviour to be as unsettling as did the majority of the 747 people, who had only flown the 747.

The second part of the equation related to the carbon brakes. The previous normal, of full reverse, full flap, and braking as needed, actually resulted in very little braking on most landings. The brakes never warmed up, and apparently this caused excessive brake wear. They actually wear less if they are used much more solidly. So, the higher approach speed of F25, wasn't really considered an issue, as it could lead to better brake wear. And yes, that sounds strange...

The next scene involves reverse thrust. There are a number of things at play here, but apparently the leading item was that full reverse was causing vibration on the leading edge flaps, and that was giving flap track wear. Idle reverse got around this. So, firstly it was a saving due reduced maintenance. Next was another small fuel saving, in the order of about 25 kgs per engine. Not much per flight, but it would add up across a fleet. Reverse thrust provides very little 'reverse' thrust, but it does kill off the residual forward thrust that an engine produces, and in most landings removing that forward thrust component is it's major contribution. Little is not none, though, and it does contribute, especially at higher speeds. One other thing that reverse thrust does, that was not considered at all in this, was that it has the effect of blasting the water off the runway, and so making it somewhat less wet for the tyres, and so makes the braking more effective. On a wet runway, that becomes its major contribution.

So, now we've saved some dollars, but come up with a procedure that destabilises the aircraft on approach, gives a higher landing speed, and a somewhat greater tendency to float, and we're reducing the use of one of the braking systems. As you might imagine, there was some push back about this, with many Captains refusing outright to use the procedure, whilst others used it selectively. I'm told that there was quite a file of letters written to management about this, but basically anyone who objected was written off as 'resistant to change'. It was pushed so heavily in the sims that anyone who didn't use it was marked down for 'procedures', and some of the newer FOs have never seen the aircraft operated at full reverse and full flap, so it was effectively trained out of them as even being an option.

There would have been very little issue with this if it had simply been an option, to be considered when conditions suited.

Anyway, the scene was set, and it led to what was very much a management own goal.

 

[jb747]

So, was anything learnt, or did they do a NASA, and behave for a few years, before going back to old tricks? I think it's fair to say that they learnt for a while. But, mostly what was learnt was that you don't make things compulsory, 'cos then there will be major blowback when things go wrong. If you make it optional, on the other hand.... Sadly, I think much of this behaviour is driven by the fact that the people who come up with these ideas get bonuses for them. If I were a regulator I'd be seriously interested in the way these payments can distort management decision making.

Where are we now (or where were we when I retired)? Well, the use of less the full flap has made a reappearance, as has the use of idle reverse. It was not mandated, but it was recorded, and they'd come out with an iPad app which showed your use of these procedures, by airport, and in comparison with the other pilots. This app was also used as an attempt at low level intimidation with regard to fuel orders. There were even newspaper/net articles about this wonderful bit of software that was designed to help pilots. In reality it did no such thing, but I gather it was worth a large bonus to a number of people.

Something new was the shutting down of engines when taxiing in. No huge downsides to this, as long as you think it through. But it was recorded for the app too.

All of this led to what seemed to be three groups, especially with regard to the fuel ordering. There were the blokes in the middle, who took what they always had, and who saw the app for what it was. Then there was a group that included what I'd describe as the usual suspects, who took as little fuel as possible, and so looked really good on the graph. And then there was another group, who figured that carriage of the most was the winning position.

There was something quite enjoyable in offloading cargo to get an extra 8 tonnes of fuel, whilst on a route check with one of the zero fuel men. He almost had a heart attack then, but it was a gift from above when I later needed every one of those 8 tonnes to avoid a diversion in unforecast thunderstorms. Or sitting in a holding pattern, with plenty of time still available to me, whilst listening to another zero man as he has to divert 'cos he gave himself no margin.

So, I guess I'll finish this with a management tale. The bloke rarely flies, but decides to do Sydney - LA. Arrives early in the morning, when the runway in use is almost alway 24R. It's the shortest, but more than adequate. Briefs that he's going to use Flap 3 (one stage less than full on an Airbus), and idle reverse. Also that he's going to shut down the outboard engines when taxiing in. FO, who does this flight a lot, points out that nobody else does any this, and that there is likely to be a tailwind at this time of day. Also that the tailwind limit is 10 knots with F3, instead of 15 with full. Having said his piece, he then watches management as they squeak inside the tailwind limit, float, and then require lots of braking. As the outboards don't have reverse, he's able to shut them down on the taxi in. Arriving at the gate, he has an uphill, tight 90º turn to do, and with only two engines, there isn't sufficient power, so the aircraft slows to a stop in the turn. A lot of power is now needed to get it going again, and that has to be coordinate with the ground to ensure nobody is behind.

Did they learn....?

 

[Mattg]

Mentour's video, called the pilot of QF1 was a 'management' pilot. He was actually from training; a senior check captain. So, whilst he still did a fair bit in the aircraft, it was often with trainees, so he was often watching, not so much doing. He would also have been in the sim a lot.

Actual management pilots are people like the Chief and Deputy Chief pilots, as well as the various fleet and base managers. They spend varying amounts of time in the aircraft, but I doubt that it would even be a third of what is done by the line pilots. One of the consequences of this, is that it often removes them from seeing the outcomes of their decisions on a day to day basis. And, of course, it leaves them out of practice. If you look at major incidents, all around the world, management pilots have a disproportionate share.

There were many paths that led to QF1.

Firstly was the decision to make flap 25, the 'standard' flap setting. Boeing gives you two possible settings for landing, (25 & 30) but their standard is 30. As best I recall, this part of things was driven by the fact that using F25 required less power on the approach, and so made less noise. It also used very slightly less fuel. Some airports are extremely noise sensitive, and also charge extra for more noise. But, there is a drawback to having less drag on approach. The aircraft is less speed stable. It doesn't respond as quickly to minor excursions. Plus as the engines are at a slightly lower setting, they are also slightly less responsive on acceleration, and a greater power change is required to get the aircraft to decelerate. None of this is especially difficult, and if anything, it didn't feel all that different in behaviour to the 767 when using F30. Another point to note was that many of the management people of the time had flown the 767, so they didn't find the aircraft's behaviour to be as unsettling as did the majority of the 747 people, who had only flown the 747.

The second part of the equation related to the carbon brakes. The previous normal, of full reverse, full flap, and braking as needed, actually resulted in very little braking on most landings. The brakes never warmed up, and apparently this caused excessive brake wear. They actually wear less if they are used much more solidly. So, the higher approach speed of F25, wasn't really considered an issue, as it could lead to better brake wear. And yes, that sounds strange...

The next scene involves reverse thrust. There are a number of things at play here, but apparently the leading item was that full reverse was causing vibration on the leading edge flaps, and that was giving flap track wear. Idle reverse got around this. So, firstly it was a saving due reduced maintenance. Next was another small fuel saving, in the order of about 25 kgs per engine. Not much per flight, but it would add up across a fleet. Reverse thrust provides very little 'reverse' thrust, but it does kill off the residual forward thrust that an engine produces, and in most landings removing that forward thrust component is it's major contribution. Little is not none, though, and it does contribute, especially at higher speeds. One other thing that reverse thrust does, that was not considered at all in this, was that it has the effect of blasting the water off the runway, and so making it somewhat less wet for the tyres, and so makes the braking more effective. On a wet runway, that becomes its major contribution.

So, now we've saved some dollars, but come up with a procedure that destabilises the aircraft on approach, gives a higher landing speed, and a somewhat greater tendency to float, and we're reducing the use of one of the braking systems. As you might imagine, there was some push back about this, with many Captains refusing outright to use the procedure, whilst others used it selectively. I'm told that there was quite a file of letters written to management about this, but basically anyone who objected was written off as 'resistant to change'. It was pushed so heavily in the sims that anyone who didn't use it was marked down for 'procedures', and some of the newer FOs have never seen the aircraft operated at full reverse and full flap, so it was effectively trained out of them as even being an option.

There would have been very little issue with this if it had simply been an option, to be considered when conditions suited.

Anyway, the scene was set, and it led to what was very much a management own goal.

I wonder if anyone has calculated how much money the airline saved with the "flaps 25" landing procedure, and compared it to the cost of rebuilding a damaged 747?

 

[JohnM]

Mentour's video, called the pilot of QF1 was a 'management' pilot. He was actually from training; a senior check captain. So, whilst he still did a fair bit in the aircraft, it was often with trainees, so he was often watching, not so much doing. He would also have been in the sim a lot.

Actual management pilots are people like the Chief and Deputy Chief pilots, as well as the various fleet and base managers. They spend varying amounts of time in the aircraft, but I doubt that it would even be a third of what is done by the line pilots. One of the consequences of this, is that it often removes them from seeing the outcomes of their decisions on a day to day basis. And, of course, it leaves them out of practice. If you look at major incidents, all around the world, management pilots have a disproportionate share.

There were many paths that led to QF1.

Firstly was the decision to make flap 25, the 'standard' flap setting. Boeing gives you two possible settings for landing, (25 & 30) but their standard is 30. As best I recall, this part of things was driven by the fact that using F25 required less power on the approach, and so made less noise. It also used very slightly less fuel. Some airports are extremely noise sensitive, and also charge extra for more noise. But, there is a drawback to having less drag on approach. The aircraft is less speed stable. It doesn't respond as quickly to minor excursions. Plus as the engines are at a slightly lower setting, they are also slightly less responsive on acceleration, and a greater power change is required to get the aircraft to decelerate. None of this is especially difficult, and if anything, it didn't feel all that different in behaviour to the 767 when using F30. Another point to note was that many of the management people of the time had flown the 767, so they didn't find the aircraft's behaviour to be as unsettling as did the majority of the 747 people, who had only flown the 747.

The second part of the equation related to the carbon brakes. The previous normal, of full reverse, full flap, and braking as needed, actually resulted in very little braking on most landings. The brakes never warmed up, and apparently this caused excessive brake wear. They actually wear less if they are used much more solidly. So, the higher approach speed of F25, wasn't really considered an issue, as it could lead to better brake wear. And yes, that sounds strange...

The next scene involves reverse thrust. There are a number of things at play here, but apparently the leading item was that full reverse was causing vibration on the leading edge flaps, and that was giving flap track wear. Idle reverse got around this. So, firstly it was a saving due reduced maintenance. Next was another small fuel saving, in the order of about 25 kgs per engine. Not much per flight, but it would add up across a fleet. Reverse thrust provides very little 'reverse' thrust, but it does kill off the residual forward thrust that an engine produces, and in most landings removing that forward thrust component is it's major contribution. Little is not none, though, and it does contribute, especially at higher speeds. One other thing that reverse thrust does, that was not considered at all in this, was that it has the effect of blasting the water off the runway, and so making it somewhat less wet for the tyres, and so makes the braking more effective. On a wet runway, that becomes its major contribution.

So, now we've saved some dollars, but come up with a procedure that destabilises the aircraft on approach, gives a higher landing speed, and a somewhat greater tendency to float, and we're reducing the use of one of the braking systems. As you might imagine, there was some push back about this, with many Captains refusing outright to use the procedure, whilst others used it selectively. I'm told that there was quite a file of letters written to management about this, but basically anyone who objected was written off as 'resistant to change'. It was pushed so heavily in the sims that anyone who didn't use it was marked down for 'procedures', and some of the newer FOs have never seen the aircraft operated at full reverse and full flap, so it was effectively trained out of them as even being an option.

There would have been very little issue with this if it had simply been an option, to be considered when conditions suited.

Anyway, the scene was set, and it led to what was very much a management own goal.

On the face of it, it would seem to the amateur observer that the actions of missing de-throttling engine 1, and failing to implement reverse thrust, suggests a degree of panic by the flying pilots.

Is that an unreasonable impression?

Were the pilots in any way censured? Or was it recognised that a confluence of procedures led to this outcome in a particular set of circumstances by otherwise good piloting?

The other thing that I thought was unusual and not explained, unless I missed it, was why the approach angle and speed increased, the Captain mentioned it to the FO, but seemingly no correction was applied.

Was the SO merely a passive observer in the event?

 

[jb747]

I wonder if anyone has calculated how much money the airline saved with the "flaps 25" landing procedure, and compared it to the cost of rebuilding a damaged 747?

1%, but I'm sure it got someone some bonuses.

On the face of it, it would seem to the amateur observer that the actions of missing de-throttling engine 1, and failing to implement reverse thrust, suggests a degree of panic by the flying pilots.

Is that an unreasonable impression?

By not actually taking over, the captain committed the cardinal sin of splitting the flying. So who's job is reverse now...

I'll have to look at the full report again, but I don't think the lever was left at the TO/GA position. As I recall, it was reduced, but not quite all the way. There is an inhibit on spoilers if 1 or 3 are not completely at idle.

Were the pilots in any way censured? Or was it recognised that a confluence of procedures led to this outcome in a particular set of circumstances by otherwise good piloting?

I don't know about personal outcomes. The captain was no longer an SCC, but I don't know by whose choice. It was not good piloting, from either seat. Perhaps harsh, but true. Nevertheless, they were set up, so any repercussions would have had to fall on management as well.

The other thing that I thought was unusual and not explained, unless I missed it, was why the approach angle and speed increased, the Captain mentioned it to the FO, but seemingly no correction was applied.

He got slightly high, but wasn't aggressive enough in chasing it. The 747 has an extremely strong ground effect, which you start to notice from about 300', so a slight pitch and power decrease were always going to be needed. I disliked what he did from back when he disconnected the autopilot. I was always anti 'practicing' in other than good conditions. As a general rule I found that those who made comments about disconnecting to get practice were not very good in the first place, and were often weak with their management of the automatics.

Was the SO merely a passive observer in the event?

Basically. There's limits to what he can see and do.

 

[Quickstatus]

the reason is that the engines have a minimum time at idle before we can shut them down

And brakes?

 

[jb747]

And brakes?

The brakes continue to heat up for quite some time after landing. It was never much of an issue in the 747, but the 380 used to get very hot. Hundreds of degrees C. For that reason, when we parked we rarely left the park brake set, releasing it as soon as the engineers had some chocks in place. For most transits, they had to use conditioned air to cool them down. Dubai was the most problematic, as they wanted you off the runway at a quite early exit, so you couldn’t just go for a leisurely roll down the runway. On the other hand, they were quick to hook up the cold air from the terminal.

The brakes don’t heat up whilst taxiing, unless you’ve got a really bad technique. Riding the brakes will put heat into them.

It’s worth remembering that the 380s were generally landing at weights that were near to, or even exceeded, the 747s max take off weight. The fact that the brakes stopped it so well was impressive.

 

[flyingfan]

Thanks as always for extremely informative answers JB Been trying to think of something to talk about other than you know what.

Also appreciate the background on QF1 - up to now the reports I've read about it reduced the factors right down to banality.

 

[harvyk]

How often do airways and waypoints change their name?

The reason why I think that they change their name is I have some old navidata, which shows L521 (SYD - AKL) as going WALTZ ESKEL LUNBI, but if I look at the same route on sky vector it seems to show WALTZ LEGAN LUNBI

(Both LEGAN and ESKEL are located at S 36.5236 E 163 )

And this might be going more into airways management than something a pilot might care about, but under the assumption that they do change, do you know the reasons why?

 

[harvyk]

For long haul ops, how much freight are you likely to have loaded on an average flight both from Australia and to Australia?
Do you care how much of that is pax baggage vs actual freight or do you simply get given a weight?

 

[jb747]

How often do airways and waypoints change their name?

The reason why I think that they change their name is I have some old navidata, which shows L521 (SYD - AKL) as going WALTZ ESKEL LUNBI, but if I look at the same route on sky vector it seems to show WALTZ LEGAN LUNBI

(Both LEGAN and ESKEL are located at S 36.5236 E 163 )

And this might be going more into airways management than something a pilot might care about, but under the assumption that they do change, do you know the reasons why?

Can't help you with that one. I've noticed the occasional change, but never really wondered about it.

For long haul ops, how much freight are you likely to have loaded on an average flight both from Australia and to Australia?
Do you care how much of that is pax baggage vs actual freight or do you simply get given a weight?

We simply get a zero fuel weight. There's no need for any more, unless we're doing a manual load sheet, and I don't think I've done one of those in about 25 years.

If I really wanted some weight off, to make space for fuel, I'd tell them how much I wanted, and it was up to load control to work out where it came from. They tended to start with the staff passengers....

 

[jb747]

Something that was a common event is the application of an MEL, that has some form of limitation. In itself there's nothing wrong with this. But, sometimes they really were not thought out terribly well. The example that comes to mind is that of a brake that has been locked out. That means that a wheel is unbraked, and so will not be stopped by the braking system during retraction. A light application of the brakes is an automatic function during gear retraction. If a brake is locked out, then there was a limitation that required the gear to be left extended for 2 minutes after takeoff, to allow the gear to run down.

But, the problem with this is that it's effectively a 'gear down' dispatch for the first couple of minutes, and basically invalidates all of the normal terrain clearance plans. And remember that all departures must plan for the case of an engine failure. So, there's another chart giving weight equivalences for this sort of departure, which works by giving you weight reductions necessary to get acceptable performance.

Flying around Australia, terrain clearance on departure isn't normally an issue. But out of somewhere like Hong Kong it has to be carefully looked at. The problem comes when someone in Oz applies that MEL, without realising that at the next airport it won't be acceptable. This happened to me once in HK, and I was a tad cranky with the captain who accepted it in Oz. He was right, Jack, but I wasn't. We worked out that we needed to offload everyone, and everything, and even then would have to make a fuel stop. That wasn't going to work, so we ended up with a couple of hours delay as the engineers actually had to fix the issue....which would have been a lot easier before it left Oz.

 

[Saab34]

In crosswind landings, I note the gear can shift sideways across the ground. Is this bad for the gear?

Ie the 11 second mark.

JB why does the drift get worse also, the longer someone decides to continue the float and not give the approach away? I was watching a A380 landing and they flared early, kept with it, floated and floated, yet the drift was just deteriorating as each second passed. Was extremely messy once the gear hit they deck as they tried to them find the centreline, which didn’t seem to happen.

 

[Rangalad]

FWIW This is page 787

 

[jb747]

In crosswind landings, I note the gear can shift sideways across the ground. Is this bad for the gear?

Ie the 11 second mark.

That first landing is pretty solid. He never really flares, he starts to, but that only has the effect of slamming the wheels down harder (the wheels are behind the point that the aircraft rotates around). So, basically he needed to flare earlier.

Touching down before he meant to also meant that he did nothing about reducing the crosswind drift. Airbus has a limit of 5º at touchdown, reducing if the landing is anything other than smooth.

Boeing (767and 747) are much more tolerant of drift at touchdown, allowing the aircraft to land with all of the drift intact right up to the aircraft crosswind limit. This is actually their recommended technique on wet runways, though very few pilots do so intentionally. Especially in the 747, this was a surprisingly smooth technique, as the geometry of the landing gear tended to pull the aircraft straight, and you really didn't have to rudder it around to a great degree. I only ever tried it once in the 767, as an experiment in Brisbane, on a day when I had two landings there in 38 knots of crosswind. There was no real difference (between all drift and none)...they were equally uncomfortable in the conditions.

JB why does the drift get worse also, the longer someone decides to continue the float and not give the approach away? I was watching a A380 landing and they flared early, kept with it, floated and floated, yet the drift was just deteriorating as each second passed. Was extremely messy once the gear hit they deck as they tried to them find the centreline, which didn’t seem to happen.

Nobody chooses to float...it just means they've got things wrong, and they're either waiting for the aircraft to find the ground, or waiting for the engines to spool back up again, so that they can go around. There's a couple of videos on youtube where the extended float is all about the engines, not about wanting to land.

In the flare, you've got a couple of things to do. Firstly you have to reduce the sink rate to something acceptable. That does not mean you have to chase greasers. There are a number of landings in the video you referenced where the flare knocks the sink rate down, and then the aircraft is allowed to immediately land. That was my normal method.

But, if there's a crosswind, you also need to do something about the drift. So, you need to smoothly put in rudder, in the last moments before touchdown, to align the aircraft with the runway. As you do this, the aircraft will immediately start drifting downwind, so the idea is for it to happen as late as possible. In some aircraft you can put a little bit of bank in to counter the drift. But, if you take out the drift, and it doesn’t immediately land (i.e. floats), then the wind will be carrying you towards the edge of the runway. Fixing that now gets messy.

There's a couple of pretty amazing A380 videos around, showing very poor arrivals.

 

[Saab34]

Thanks JB I found this one. Assuming it was the FO would you takeover during this rollout to correct it?

I don’t think these guys ever found the centreline.

 

[JohnM]

Thanks JB I found this one. Assuming it was the FO would you takeover during this rollout to correct it?

I don’t think these guys ever found the centreline.

It's crazy, isn't it?

I'm debating whether to ask my mate in PER who retired as an EK A380 Check Captain about three years ago whether he was driving.

Maybe not...

But I'm sure he can tell me the story when I choose my moment.

 

[jb747]

Like so much of aviation, it gets easier, the further you are from the coughpit. There are two issues with this video, though one is probably a consequence of the other. The flare is too late, so he hits the ground without any real attempt to correct the drift, and then over corrects for it once he touches down.

I don’t know whether it’s true or not, but supposedly the pilot doing the landing was on conversion.

There’s something interesting happening before the flare. If you back up so that you watch the approach you can see that the aircraft is yawing around. As it approaches the runway, there’s quite a lot of activity from the lower part of the rudder. That‘s the FBW system at work. It’s detecting the lateral wind gusts as sideslip, and it’s very actively working to get rid of it. That’s why there aren’t constant bank changes as the pilot corrects drift for the wind gusts; the FBW is doing it for him. Feels weird when you first see it, but it does make life easier. For most of us anyway.

 

[tgh]

leads to…. how much conflict arrives when the pilot inputs and the computer inputs do not sync.
In the above clip , given jb's comments about the aircraft trying to help.. one has to wonder if they were not (in sync)
Of course the long lens compression makes it all look more spectacular

 

[JohnM]

Repeating what my mate has told me as best as an amateur can:

He confirms that the pilot in the left seat was on his first line sector on the A380, upgrading. So "The first time actually really flying a stick with his left hand." is how he put it.

The company's immediate action was to blame the pilot. Both the Captain under training and the training Captain were pulled off the roster. "Usual airline gut reaction: blame the pilot."

It wasn't until the engineer responsible for the quick-access recorder analysis did an analysis and noted the exceptional wind-shifts because it did appear that the pilot had completely over-controlled with the rudder in the flare but in fact there were massive wind shifts in less than half a second, and that's what caused it. So "Both guys' skins were saved."

The company did change its training policy so that the training Captain had to fly the first sector and the pilot under training had to observe the first landing.