Ask The Pilot

[jb747]

So why did OQB land at a speed usually associated with a heavy aircraft?.

What did I say normally happens on downwind?

 

[Quickstatus]

You are describing "downwind" as the part of the airfield traffic pattern heading away from the airport which then turns to base then final??
So flaps 1 at downwind and then 2 for base then 3, 4 for final.

So flaps could not be deployed to 2 for base so minima speed had to be higher than if flaps 2,3,4 were deployed...

So flaps issue....

 

[jb747]

And all from a careful study of FR, with the guessing removed. As it turns out, that big wing makes it a pretty benign event, even if the brakes get a bit hot.

 

[Quickstatus]

What was the manufacturer's reason for overengineering the wing?. Planning for the future supersizing the fuselage but sacrificing fuel economy in the present?

An oversized wing means lower takeoff and landing speed. Maybe incidents like this may not be as "benign" if the wing was smaller. Would QF32 OQA have been able to land with a smaller wing?

thanks for the insights!

 

[jb747]

What was the manufacturer's reason for overengineering the wing?. Planning for the future supersizing the fuselage but sacrificing fuel economy in the present?

It's a wing that could handle a bigger aircraft. I've heard over 600 tonnes mentioned. But, whilst it has weight of it's own to carry around, a bigger wing won't necessarily hurt fuel consumption. In fact, it's likely to be the opposite, with both wing area and aspect ratio being positives.

An oversized wing means lower takeoff and landing speed. Maybe incidents like this may not be as "benign" if the wing was smaller. Would QF32 OQA have been able to land with a smaller wing?

At the design stage, you can look at all of the possible outcomes with the various wing sizes. If you have a smaller wing, and higher approach speeds, you'll almost certainly have increased brake issues, probably lower performance from many runways, and nastier behaviour with some failures...which means you might need to engineer in more ways to recover from those failures, which may itself increase weight and complexity. Overall a big wing is good.

On approach QF 32 wasn't in all that bad a place. A single engine out isn't hard to handle, especially if the autopilot is still available (which it was, for part of the approach). The damage to the leading edge had resulted in the SLAT SYS 1 & 2 failing, which does increase the approach speed, but to a lesser extent than flap issues (though not anywhere near as much as you might expect). The combination of problems was beyond the software's ability to compute a sensible answer. Their biggest issue was one that they couldn't know about until after landing, with one complete gear truck not having any braking.

 

[Quickstatus]

Thanks for the insights! JB747

 

[ChrisGibbs]

So flaps issue....

Not sure if this is related however a number of years ago when QF were still doing the LHR-SIN-SYD sectors with the A380's I was on NBW (OQA) on approach into Sydney. We were lining up on a long final for 34L and we pulled out of the approach and went off the coast for around 10-15 minutes then re-joined the circuit on base for a right circuit onto 34L. Apparently as the flaps were being extended an asymmetric condition was created and the flaps locked into position to ensure the asymmetric condition didn't get any worse. From what the Captain said this issue cannot be fixed in flight and needs to be fixed on the ground. I noticed the approach was appreciably faster and somewhat flatter than usual....

 

[mjt57]

Not sure if this is related however a number of years ago when QF were still doing the LHR-SIN-SYD sectors with the A380's I was on NBW (OQA) on approach into Sydney. We were lining up on a long final for 34L and we pulled out of the approach and went off the coast for around 10-15 minutes then re-joined the circuit on base for a right circuit onto 34L. Apparently as the flaps were being extended an asymmetric condition was created and the flaps locked into position to ensure the asymmetric condition didn't get any worse. From what the Captain said this issue cannot be fixed in flight and needs to be fixed on the ground. I noticed the approach was appreciably faster and somewhat flatter than usual....

How were you able to work all this out from a passenger's seat???

 

[ChrisGibbs]

How were you able to work all this out from a passenger's seat???

As we pulled into the gate the Captain gave a PA that was way more articulate and detailed than I previously gave where he explained what had happened and why the lengthy manoeuvring for landing. As a passenger you generally get a sense of when things are different than normal. For example you can generally hear when flap or gear is being is being extended at a particular phase of an approach. I agree IAS is hard / impossible to ascertain from a passenger perspective but for some reason I do remember the angle of the approach seemed to be flatter and the relative speed of the approach faster than normal.

 

[jb747]

Not sure if this is related however a number of years ago when QF were still doing the LHR-SIN-SYD sectors with the A380's I was on NBW (OQA) on approach into Sydney. We were lining up on a long final for 34L and we pulled out of the approach and went off the coast for around 10-15 minutes then re-joined the circuit on base for a right circuit onto 34L. Apparently as the flaps were being extended an asymmetric condition was created and the flaps locked into position to ensure the asymmetric condition didn't get any worse. From what the Captain said this issue cannot be fixed in flight and needs to be fixed on the ground. I noticed the approach was appreciably faster and somewhat flatter than usual....

If the asymmetry system stops the flaps, the flaps (or slats) will remain locked at their current position. It can only be fixed on the ground.

It will involve increased airspeed on the approach. The amount varies with the degree of flap that was out when the lock occurred. If the trip happened with flap 1 or more, the increase is less than 10 knots. No trailing edge bumps it up by about 20-25.

Pitch attitude on the approach is higher (about 5º instead of 2.5º). Power is lower (because of the reduced drag). But, the approach is not 'flatter'. It's exactly the same 3º as usual (i.e. the ILS glidesplope angle).

 

[RAM]

It gets pretty messy, and shows the folly of only having one decent runway.

Crosswind limit (including gusts) for the 380 on take off is 35 knots. Crosswind limits will reduce if it's wet.

To use the shorter runway, you'd look at the performance with the worst wind (which would have been about 20 knots, i.e. the least wind). That gives a performance limit of about 550 tonnes. MTOW is 569 tonnes. Normally the weight on those flights (QF11) is low enough that you'd be able to use 25, but you'd need that wind to hang in there. If it were dropping below 20 knots, or swinging around, you'd not be able to guaranteed getting the needed performance. The Dubai flight is much closer to the max weight.

The decision to carry limited fuel would need to be made very early, well before the crew get involved. The aircraft are normally pre-fuelled to about 80% of the expected load as soon as they land. For a splash and dash that would be way too much.

Beyond that though, you now run into some interesting crew flight time limitations.

If a flight has issue (medical or anything else), the crew may extend the allowed duty. But, if the company decides to make a tech stop, it then becomes a planned operation, and the times have to fit the non extended limits...which they won't. So, if you really had to do this, you'd basically need to place a replacement crew at your landing point, and they could not have started their duty on the same day in Sydney...you'd need to have done it the previous day. Time travel would be useful.

The issue with the RWY25 is also to do with those high rise towers directly in line with the run way for takeoffs to the west using it.

In the information out out before the 'emergency upgrades' were done a few years back to extend them the Airport Community Forum/Committee where given out a presentation stating that A380s would NEVER take off from the E/W runway regardless of the extensions being done.

Here's the media release on the completion...
Runway Safety | Major Development Plans | Planning | Community Environment and Planning | Corporate | Sydney Airport
Approved Major Development Plan

The Minister approved the MDP for the extension of the runway safety area at the western end of the east-west runway on 15 August 2008. As part of the Minister’s approval, 22 stringent Conditions of Ministerial Approval were issued relating to the construction project.


Airservices Australia prepared a few page doc about the safety issues from a heavily laden taking off from it and suffering an engine loss. During the presentation the air traffic controller joked about what guests at the offending hotel would do in response to a question on 'About high rise do you mean the hotel on Grand Parade. Shouldn't be there anyway."

And the rest is history.

Not long after they were finished I couldn't believe my eyes as I watched a Q A380 come in directly over the top of our house. So I rang up Airservices Australia and asked for the plot for that flight and all other A380 landings or take-offs after the ATC mentioned that there had been unannounced tests being carried out in violation of the operating agreement. The first 4 test flights taking off/landing on the E/W were done with SQ A380s, then the Q tests began.

No public announcement ever made as far as I know. So much for 'undertakings' and 'guarantees'.

Strangely enough, the A380 is much louder than a 737-800 landing over us. It also is louder than the B747-400 although the spin is that with the newer engines it is quieter.

 

[jb747]

The issue with the RWY25 is also to do with those high rise towers directly in line with the run way for takeoffs to the west using it.

I don't know which towers you are talking about. I can't find anything that I see as a problem on google.

In the information out out before the 'emergency upgrades' were done a few years back to extend them the Airport Community Forum/Committee where given out a presentation stating that A380s would NEVER take off from the E/W runway regardless of the extensions being done.

I wonder how they worked that out. Another person who has never heard of crosswind.

Airservices Australia prepared a few page doc about the safety issues from a heavily laden taking off from it and suffering an engine loss. During the presentation the air traffic controller joked about what guests at the offending hotel would do in response to a question on 'About high rise do you mean the hotel on Grand Parade. Shouldn't be there anyway."

Well I'd certainly agree with him if he's referring to hotels in line with 16L. I'm sure they were permitted by the council in an outright attempt to spoil the use of the runway.

Not long after they were finished I couldn't believe my eyes as I watched a Q A380 come in directly over the top of our house. So I rang up Airservices Australia and asked for the plot for that flight and all other A380 landings or take-offs after the ATC mentioned that there had been unannounced tests being carried out in violation of the operating agreement. The first 4 test flights taking off/landing on the E/W were done with SQ A380s, then the Q tests began.

I very much doubt that either airline did 'test' flights to the runway. They'll just crunch the numbers and survey the obstacles. Beyond that, no testing is needed.

Strangely enough, the A380 is much louder than a 737-800 landing over us. It also is louder than the B747-400 although the spin is that with the newer engines it is quieter.

I'm not surprised that it's louder than a 737. I doubt that it's louder than a 747. I used to have a flat on the extended centreline of 34, and 380s were far less noisy.

At any weight that an A380 is likely to use 07/25, it would climb away at around 1,000 fpm, even with an engine out. Its EO performance is way better than a 747.

 

[jb747]

For anyone travelling over the next week, I'm flying...

MEL-DXB QF9 1/6
DXB-LHR QF1 4/6
LHR-DXB QF10 6/6
DXB-LHR QF10 9/6

 

[Quickstatus]

Hi JB747,

Do radars that pilots use on aircraft give a vertical profile and is it displayed so you could not only avoid weather by going left or right but above or under it?. Traditionally lay people like us envisage a radar profile only in the horizontal plane.

The seat arrangements in the coughpit of the A380 compared with the width of the aircraft at the nose section suggests a significant space between the pilot seat and the sides. How are these spaces used?

 

[jb747]

Do radars that pilots use on aircraft give a vertical profile and is it displayed so you could not only avoid weather by going left or right but above or under it?. Traditionally lay people like us envisage a radar profile only in the horizontal plane.

The A380, and presumably the A350 and 787, shows a vertical cut of the weather, below the normal display. The standard display shows the cut only along the track, but we can manually slew the radar to look in a particular direction. Additionally, weather that the system assesses you as being above is also shown as 'hashed out' on the normal display once you're within about 40nm.

Climbing above weather is not normally a practical option. It can still be nasty above cells, even if they aren't showing radar returns (which really only see the moisture). Secondly, it takes time for ATC clearances to happen, and a lateral clearance is normally much easier to get than a vertical one.

In normal use the vertical information is used to help us decide on which track to take.

Here's a couple of examples.

The seat arrangements in the coughpit of the A380 compared with the width of the aircraft at the nose section suggests a significant space between the pilot seat and the sides. How are these spaces used?

The sides of the coughpit are quite a bit out of vertical. The side window is close enough that I can lean my head against it (if I try). There is space a bit lower though, that holds a bin that was once the repository for the Jeppesen charts. It now holds my bag. The oxygen mask, rubbish bin, cup holders, nose gear tiller and laptop are all there too. iPad sits at the base of the #2 windows.

 

[Awesom Andy]

For anyone travelling over the next week, I'm flying...

MEL-DXB QF9 1/6
DXB-LHR QF1 4/6
LHR-DXB QF10 6/6
DXB-LHR QF10 9/6

If there is a need, can the company send a pilot out to LHR again after the 3rd leg, or does the next flight need to be one heading back to AU?

 

[Quickstatus]

What are the bulbous things to the side of the thrust levers for. These coughpit seats do not seem to have arm rests?.

 

[jb747]

If there is a need, can the company send a pilot out to LHR again after the 3rd leg, or does the next flight need to be one heading back to AU?

You can be moved to another flight at any stage. The only restrictions are minimum slip, and maximum flight hour. In most cases, they'll move you forward by about 12 hours, but keep you headed in the same direction. Because we're often quite close to the 100 hour in 30 days limit, adding an extra 16 hours to a trip may mean you have to drop a subsequent sector, which could make the problem worse.

 

[por930]

For anyone travelling over the next week, I'm flying...

MEL-DXB QF9 1/6
DXB-LHR QF1 4/6
LHR-DXB QF10 6/6
DXB-LHR QF10 9/6

Almost jb, I am flying BNE-DXB EK433 1/6. But, as QF do not fly BNE-DXB, and a tad expensive to fly down to MEL, even though, I would have the pleasure of you up front....I am not a fan of these early flights. EK433 departs at 05:00, and it means I get a 02:00 drive to the airport(10 mins away). Do you guys get any early flight departures, or are your slots all at 'decent' times?

 

[jb747]

What are the bulbous things to the side of the thrust levers for. These coughpit seats do not seem to have arm rests?.

They are palm rests. There's a trackball on their forward face. The cursors are currently on the top left of the Captain's FMC (the yellow X), and the very top line of the FO's. They can be moved to the lower centre display, and NDs.

There are armrests on both sides of the seat. The outboard one is very adjustable, and has a scale on it so that pilots are able to set the rest to exactly the same position each time. That's important for control of the sidestick. The inner one just folds up out of the way, for access to the seat.