Ask The Pilot

[jb747]

Narita can be a very challenging spot to land, as it always seems to be windy, with that wind often very gusty and largely crosswind. Most power changes on approach are of a short duration, and small magnitude, so you don't notice them. Large power increases on finals are generally a response to gusty conditions, with power being pushed up (and down) as required to keep the indicated airspeed on target. That could be done by either the auto throttle (if engaged), or manually.

Have a look on youtube for "narita crosswind landing".

 

[PJ747]

I'm a bit late to the party with this one, but here goes..
Flew on 93 9 MEL-DXB late November (around the 19th or 20th or so). Flew across the Bite, over WA and left the western coastline somewhere south of Broome by memory. From the time we got across the Bite and back over mainland Aus until just before landing in DXB, we were in constant choppy turbulance (not enough to leave the seatbelt sign on - in fact there was only once that it did come on during cruise that i'm aware of, but felt like driving down a dirt country road), with only a couple minutes here and there of smoother air throughout the flight. Similar, but not quite as prolonged turbulance was experienced on the next leg with EK to AMS. Having never experiences a flight with such prolonged turbulance, is it just that time of year where it is that bad or would there have been other weather related issues around that would be a more likely cause?
The flight home a week before Christmas was much closer to my normal experience with small amounts of turbulance here and there.

 

[Altair]

I wonder if some SIM sessions for that particular approach, would be a good idea for all of their pilots. QF wouldn't let you operate that sector unless you'd done the sim session. But, if airlines send you there, without specific training, and the approach contains a bit of a trap, then the result we've just seen is only a matter of time. Firing the one group in the company who are least likely to make that mistake again, is also counter productive. Recall too, that similar happened at Moscow only a few weeks beforehand. I'd be looking that their overall culture, and their fatigue situation.

I spoke to an EK pilot (ex RNZAF A4, CX and then EK 777), 8 years ago, and this came up. He said that EK did not do this for crew flying into any specific airport, nor could crew request a practice during a sim session as they are too busy.
The DBX - JFK route was the one he hated most due to flying into JFK at night after a long sector and made much more difficult in poor weather. Also comments about poor rostering that could see two very fatiguing sectors back to back and other conditions that increased fatigue. Of course he said he wold continue to fly EK, he liked the life in Dubai and his wife was an aviation doctor for EK as well.

 

[mikenz]

Does prolonged turbulence have much of an effect on fuel consumption?

 

[jb747]

I'm a bit late to the party with this one, but here goes..
Flew on 93 MEL-DXB late November (around the 19th or 20th or so). Flew across the Bite, over WA and left the western coastline somewhere south of Broome by memory. From the time we got across the Bite and back over mainland Aus until just before landing in DXB, we were in constant choppy turbulance (not enough to leave the seatbelt sign on - in fact there was only once that it did come on during cruise that i'm aware of, but felt like driving down a dirt country road), with only a couple minutes here and there of smoother air throughout the flight. Similar, but not quite as prolonged turbulance was experienced on the next leg with EK to AMS. Having never experiences a flight with such prolonged turbulance, is it just that time of year where it is that bad or would there have been other weather related issues around that would be a more likely cause?
The flight home a week before Christmas was much closer to my normal experience with small amounts of turbulance here and there.

I do hope you weren't on the 93!

Routes are chosen to make the most of the prevailing winds. Sometimes that means you can find areas with lots of mixing going on, that that annoying light chop. Generally it doesn't last all that long, otherwise we'll have a look at different levels to see if we can get out of it. Mostly that means descending, which will have a negative affect on the fuel consumption.

The routes between Hawaii and the USA are almost always choppy, but recently on a flight from LA to Melbourne the chop didn't let up for close enough to 10 hours. Made for a very long flight. Very unusual though.

 

[jb747]

Does prolonged turbulence have much of an effect on fuel consumption?

It can...if the turbulence is sufficient to cause the aircraft to constantly gain and lose a few knots, you'll lose because the auto thrust will be chasing the correct speed....the engines will be spooling up and down by a few percent, which is less efficient than having a stable speed/power. You'll lose even more if you have to move off the optimum altitude to get away from the bumps.

Going around weather adds to the track miles you've flown, so that costs fuel too.

On long range sectors with tight fuel loadings, it can make the difference between getting to destination or diverting.

 

[PJ747]

I do hope you weren't on the 93!

Routes are chosen to make the most of the prevailing winds. Sometimes that means you can find areas with lots of mixing going on, that that annoying light chop. Generally it doesn't last all that long, otherwise we'll have a look at different levels to see if we can get out of it. Mostly that means descending, which will have a negative affect on the fuel consumption.

The routes between Hawaii and the USA are almost always choppy, but recently on a flight from LA to Melbourne the chop didn't let up for close enough to 10 hours. Made for a very long flight. Very unusual though.

Indeed, my bad! QF 9 of course (no idea why I had that brain fart!)
Thanks though! After around 12hrs of the constant chop, it was quite nice to get back on the ground, even only for an hour or two! So likely then the other available levels were facing similar choppy turbulance so it would have been decided to stay put and deal with it I imagine.

 

[Quickstatus]

On long range sectors with tight fuel loadings, it can make the difference between getting to destination or diverting.

A hint re PER-LHR?

 

[Quickstatus]

Would appreciate an aviator comment on the centre of gravity for the AA A321 with the transcontinental seating arrangement

 

[jb747]

A hint re PER-LHR?

Anecdotally, the westbound flight will be very tight...but that’s just the rumour mill. Turbulence won’t be the issue, but failure to get desired levels, and any weather requirements at destination will be.

 

[jb747]

Would appreciate an aviator comment on the centre of gravity for the AA A321 with the transcontinental seating arrangement

I don’t think we have any 320 experts. What’s the problem?

 

[Quickstatus]

I don’t think we have any 320 experts. What’s the problem?

The aircraft is configured to sit 10 passengers forward of wing, 20 passengers over the wing, and 76 behind wing.
So maybe 4.5 tons ((76-10)*80kg) net behind the wing?.
With no fuel tank in horizontal stabiliser, payload (additional to passengers) forward of wings need to be similarly biased to the front?

 

[jb747]

Ok, I found a seating diagram. Nice if you happen to be up front, but economy looks pretty horrible.

From what I can find, the A321 actually has a forward CofG problem anyway. It's basically nose heavy to start with.

In designing the seating configuration, they would have considered all of the possible loadings. It's certainly possible that some would be deemed unacceptable, and seating allocations managed to control that. Cargo, baggage, seat allocation, and fuel loadings would be considered at the loading stage. When the load sheet is issued, not only does it have to keep the start CofG within limits, but it must do so for the entire flight. The CofG moves, generally forward, as fuel is consumed.

A slightly aft CofG is more efficient, but can lead to controllability and issues at rotate.

Some interesting data here: http://www.caac.gov.cn/ZTZL/RDZT/XJSYY/201511/P020151126413571677121.pdf

 

[Boognoss]

Roster time....

Leftover from the current roster...
02/12 QF93
03/12 QF94

09/12 QF93
10/12 QF94

And the new...

23/12 QF93
24/12 QF94

01/01 QF93
02/01 QF94

08/01 QF93
09/01 QF94

23/01 QF9 MEL-DXB
26/01 QF9 DXB-LHR
28/01 QF2 LHR-DXB
31/01 QF10 DXB-MEL

Long time listener, first time caller. Thanks for this great thread.

I’ll be on your QF2 on 28/1

 

[jb747]

Long time listener, first time caller. Thanks for this great thread.

I’ll be on your QF2 on 28/1

Send up a business card, or tell the cabin crew.

 

[Quickstatus]

You comments re thunderstorms being more difficult to deal with compared to fog and QF going back to SIN....

VH-OJH after the repair - was it “as good as new?”

 

[jb747]

You comments re thunderstorms being more difficult to deal with compared to fog and QF going back to SIN....

Fog is just procedural. It's nice and smooth. Just do an auto land. Thunderstorms are rough, nasty, and potentially dangerous. Give me smooth any day.

VH-OJH after the repair - was it “as good as new?”

OJH, K, and for that matter, Nancy, were all as good as new when they came back. H was interesting, as it was actually 'straighter' than most of the others. Before the engine event, Nancy was prone to software glitches, and they seemed to be banished in her time out.

I spoke to the engineers involved in repairing K. Things were not patched. Everything, frames and stringers included, was taken back to a manufacturing junction, and then new parts inserted...so there was no panel beating, just new parts. I didn't speak to people who did the other repairs, but I expect exactly the same methods would have been used.

 

[Himeno]

OJH, K, and for that matter, Nancy, were all as good as new when they came back.

Just to make sure I've got this right...
OJH: QF1 BKK runway overshoot into golf course
OJK: QF30 ex-HKG O2 bottle failure, depressurization and land in MNL
Nancy/OQA: QF32 ex SIN uncontained engine failure

 

[Quickstatus]

What do you mean H was straighter?. Did you notice this with aircraft characteristics inflight?

 

[jb747]

When you start flying training, from the very first flight, it's bashed into you that the aircraft should be kept in trim during any steady state flight. The big aircraft will automatically trim themselves in pitch, but not in the other two axes. With the autopilot engaged, they simply put in a slight control input to negate roll and yaw issues. But, it's quite possible the overall effect will be a slightly increased drag and fuel flow.

When the aircraft is in trim, you can let go of the controls, and it basically sits where you left it (as long as the speed and power don't change).

In the 767/747 we used to disconnect the autopilot every now and then, and just check the trim. Aircraft that are a little bit bent (which is most of them) will normally need a slightly different roll trim setting at different speeds.

The A380 has no roll trim that the pilots can access. Normally it just sorts out it's own act. But, in the case of a reversion to alternate law, the ailerons may move to their physical neutral position, instead of the position with neutral effect. The upshot of this is that there are some scenarios in which the autopilots won't work, and you also cannot get the aircraft correctly trimmed in roll. Pitch and yaw are still available.