Ask The Pilot

[mjt57]

A shame you can't force it to always display in real units of measurement that people can understand - knots, feet, and nautical miles .

How is this information displayed, if not in knots, feet, etc.?

Or do they use those meaningless units of measurement that the media uses when describing something. eg. "currently flying at 300 football fields above the ground at 8 times the freeway speed limit and we're using 1 Olympic swimming pool of fuel every hour..."

 

[flychrisfly]

No ice is allowed on the upper surfaces. Will that amount be a problem? Almost certainly not. But, it should have been removed.

Is there anyway for a pilot to know if ice is present when it's not easily visible from the coughpit or from the ground, as I imagine this ice was?

 

[AVC]

On that note, how much of the wing/engines is/are visible from the flight deck?

 

[simongr]

How is this information displayed, if not in knots, feet, etc.?

Or do they use those meaningless units of measurement that the media uses when describing something. eg. "currently flying at 300 football fields above the ground at 8 times the freeway speed limit and we're using 1 Olympic swimming pool of fuel every hour..."

Actually that's not a bad idea - using measurements to which people can relate.

Saying something like "we are going about 700 miles per hour which is like driving Melbourne to Sydney in an hour" is more relatable than "we are traveling at 400 knots"

 

[Fruitcake]

How is this information displayed, if not in knots, feet, etc.?

It switches between metric and imperial. Personally knowing the aircraft is at "35,000 feet" is a lot more intuitive than reading "10,668m" and I don't like having to wait thirty seconds to read the numbers in my preferred units of measurement . Luckily my smartphone can usually get a GPS lock when sitting in a window seat .

 

[Boris spatsky]

Is there anyway for a pilot to know if ice is present when it's not easily visible from the coughpit or from the ground, as I imagine this ice was?

Some modern aircraft have ice detectors - in simple terms, it's a probe that vibrates in flight, and when it gets iced up, it vibrates less - this then triggers the alert to the pilot. There can be multiple alert levels depending on the intensity of the icing. I am not sure whether Airbus have these - jb will have to answer that. This alert can then also be linked to the aircraft de-ice/anti-ice system; the issue being that some of these systems can be fairly sensitive and set off even when icing isn't present.

The best way to detect ice is normally to look at the wipers - they seem to ice up first in my experience.

 

[Boris spatsky]

On that note, how much of the wing/engines is/are visible from the flight deck?

Depends on the aircraft type of course, but not a lot in most cases. The best view tends to be from the cabin, if you are looking for something specific.

 

[wafliron]

That basically makes no sense at all. Are you talking about long haul 380 flights? The aircraft can't even get to FL420 until almost the end of the flight, and it's very rarely worth doing.

Hmm, now I'm confused. The two flights in question were SYD-HKG (QF) and JFK-FRA (SQ) - so not what I'd personally call true "long haul" (not sure if there's a technical definition of "long haul" or not though!), but not "short" either (although I guess JFK-FRA is pretty short for an A380 route).

My memory definitely says that we were at FL420 (or at least FL4x0) quite early in the SYD-HKG flight, but if that's impossible then I guess it's wrong. I'll also put aside the SQ flight as I wasn't paying that close attention, but on the SYD-HKG flight I'm sure that we started out high (even if not FL420) and gradually descended over the course of the flight though - I say "sure" because I noticed we were higher than I expected ("expected" in a very loose sense, given I'm not a pilot nor aircraft engineer!) after completing the initial climb, and kept an eye on our altitude over the duration of the flight because it intrigued me.

Is there no good reason why a flight might start high and gradually descend, even if it's unusual? Or could the IFE altitude data possibly have been wrong somehow (seems unlikely based on your other recent answers about the data source for this though)?

The biggest noise change is caused by extension of the landing gear. It's especially noisy whilst the gear doors are open.

You've got to be careful not to read too much into isolated pitch changes. You really don't know exactly what the pilots are seeing, or doing, and changes can happen for all sorts of reasons. Assuming the aircraft is established on the ILS glideslope, the autothrust will almost certainly be in SPEED mode, so that when the gear is extended the power will pretty well instantly react to the increased drag. But, at around the same time the gear is going out, the later stages of flap are also being selected, and so decelerations will also be happening. Pitch changes on the glideslope are only about corrections to stay on the slope, they aren't to correct IAS. Different speeds and flap settings will all require different pitch attitudes to maintain that stable 3 degree slope, so the required attitude is a moving target.

We aren't always on the ILS miles out either. It's quite common to intercept it 1,500-2,000 feet, so pitch changes prior to that could simply be related to ATC cleared altitudes.

Thanks for the info. The noise-nosedown-noseup pattern I asked about seemed to be identical on all four flights, so I had thought it was something "specific" that the pilots / flight computer were doing during the landing sequence. Based on what you've said I guess it must've just been a coincidence - that it just felt identical to me.

 

[mjt57]

.


The sims feel very real. So real that the first time you fly an aircraft now, it will have passengers, whereas when I did my 747 Classic and 767 training, we took empty aircraft and flew many circuits at Avalon a

I remember, around 1985-86, driving from Geelong back to Melbourne watching a 747 taking off from Avalon (presumably), doing a turn then landing again.

It looked spectacular as we were probably a kay away from it and the aircraft looked like it was floating.

I had to be reminded by my passengers to keep an eye on the road...

 

[jb747]

Is there anyway for a pilot to know if ice is present when it's not easily visible from the coughpit or from the ground, as I imagine this ice was?

Ice is something you should be looking for in the preflight.

In flight, in the big aircraft we normally can't see it at all. The 380 has a small probe on the centre of the windscreen which picks it up. We turn engine icing on based upon the conditions..basically in cloud and temperature less than 10 degrees C. There is very little airframe deicing on the A380 (basically one small panel on the slats). The 747 has leading edge flap deicing, but it very rarely ever needs to be used.

Vision...you can see the outboard engines in the 747, but you can't see any part of the aircraft in the 380.

 

[jb747]

Is there no good reason why a flight might start high and gradually descend, even if it's unusual? Or could the IFE altitude data possibly have been wrong somehow (seems unlikely based on your other recent answers about the data source for this though)?

There is no reason for a stepped descent. On the other hand, there are reasons to descend. ATC may not be able to give you the altitudes that you want due to other traffic. Wind could be sufficiently bad at altitude that it's worth descending, or perhaps it turns out to be smoother down lower. Sometimes it's even a viable method of passing another aircraft....

On the flight to HK from Sydney, the aircraft would weigh about 480 tonnes at take off. Max altitude that you could reasonably use would be F360, with the step to F380 happening at 450 tonnes. At 450t, max usable altitude would be FL380. The step to FL400 would happen at about 405t. FL420 wouldn't become available until around the time you were starting the descent.

 

[jb747]

I remember, around 1985-86, driving from Geelong back to Melbourne watching a 747 taking off from Avalon (presumably), doing a turn then landing again.

It looked spectacular as we were probably a kay away from it and the aircraft looked like it was floating.

I had to be reminded by my passengers to keep an eye on the road...

That was good fun. Especially when we did low level circuits.....A circuit at a few hundred feet in a 747 is just as spectacular from the inside as it is on the outside.

 

[Bjet]

Hello Pilot,

I would love to ask you about strange inflight experience when we arrived in Brisbane.

When we were going to approach soon (5 sec before touch down), I could feel the strong wind pushed our plane down and I thought that the pilots may abort landing but they didn't. I could also feel that the pilots forced our plane down and hit the runways so hard (with sway from side to side and again). The pax and I were pushed by the force and I could hear that some pax were yelling very loudly cos the pilots pressed the pedal soo hard in order to try to slow our plane to down immediately. We were all shocked and little frightened. It was my first time to feel that - that was the hardest landing I have ever had.

The weather looked fine and normal. It's not cos of crosswind... I am positive sure that the wind might come from up there.

Also... Why the pilots refused to abort landing? I know we were delayed (30 mins late) and pilots didn't want to waste their time to turn around. Am I right?

Thanks

 

[wafliron]

There is no reason for a stepped descent. On the other hand, there are reasons to descend. ATC may not be able to give you the altitudes that you want due to other traffic. Wind could be sufficiently bad at altitude that it's worth descending, or perhaps it turns out to be smoother down lower. Sometimes it's even a viable method of passing another aircraft....

On the flight to HK from Sydney, the aircraft would weigh about 480 tonnes at take off. Max altitude that you could reasonably use would be F360, with the step to F380 happening at 450 tonnes. At 450t, max usable altitude would be FL380. The step to FL400 would happen at about 405t. FL420 wouldn't become available until around the time you were starting the descent.

Thanks for the extra info. I guess I shall remain somewhat confused about what was going on WRT altitude on this flight - even if I'm a little less confused than before

 

[markis10]

Hello Pilot,

I would love to ask you about strange inflight experience when we arrived in Brisbane.

When we were going to approach soon (5 sec before touch down), I could feel the strong wind pressed plane down and I thought that the pilots may abort landing but they didn't. I could also feel that the pilots forced our plane down and hit the runways so hard (with sway from side to side and again). The pax and I were pushed by the force and I could hear that some pax were yelling very loudly cos the pilots pressed the pedal soo hard in order to try to slow our plane to down immediately. We were all shocked and little frightened. It was my first time to feel that - that was the hardest landing I have ever had.

The weather looked fine and normal. It's not cos of crosswind... I am positive sure that the wind might come from up there.

Also... Why the pilots refused to abort landing? I know we were delayed (30 mins late) and pilots didn't want to waste their time to turn around. Am I right?

Thanks

A hard landing is not necessarily a bad landing, the fact you mention sway from side to side suggests some crosswind component buts its more than likely the landing was always going to be safe, hence no go round. Pilots who put schedule before safety don't last long. What a passenger thinks is a good landing may vary significantly from the coughpit opinion.

 

[jb747]

When we were going to approach soon (5 sec before touch down), I could feel the strong wind pressed plane down and I thought that the pilots may abort landing but they didn't. I could also feel that the pilots forced our plane down and hit the runways so hard (with sway from side to side and again). The pax and I were pushed by the force and I could hear that some pax were yelling very loudly cos the pilots pressed the pedal soo hard in order to try to slow our plane to down immediately. We were all shocked and little frightened. It was my first time to feel that - that was the hardest landing I have ever had.

The weather looked fine and normal. It's not cos of crosswind... I am positive sure that the wind might come from up there.

Also... Why the pilots refused to abort landing? I know we were delayed (30 mins late) and pilots didn't want to waste their time to turn around. Am I right?

Perceptions of what is happening in the cabin often bear little relationship to what the pilots are seeing. The occupants of the cabin are subject to all sorts of illusions, which they aren't even aware of.

Rudder use would indicate crosswind, either on the ground on on the approach. It does not slow the aircraft down.

I expect that your version of a hard landing, and mine, are two very different animals. Passengers are lulled into thinking that smooth landings are desirable and normal. Not really the case at all, and there are many occasions on which a firm landing (with all drift intact) and lots of heavy rudder use after touchdown is actually the best outcome.

I'm sure the pilots did not go around because they saw no need to. They wouldn't care at all about the aircraft being late.

 

[Sprucegoose]

Thanks for the extra info. I guess I shall remain somewhat confused about what was going on WRT altitude on this flight - even if I'm a little less confused than before

JB is saying by the time you could get to 42000 feet it would be time to descend. An illogical sequence one would suggest.

 

[Bjet]

ok thanks mate. It makes sense.

For pilot...do u prefer to land roughly or smoothly?

 

[mjt57]

JB, found this on another forum.

TU-154 RA-85563 Almost Crash! (subtitles) - YouTube


I think it's Russian. A/C had problems with flight stability. Care to speculate as to the cause?

 

[jb747]

ok thanks mate. It makes sense.

For pilot...do u prefer to land roughly or smoothly?

It varies. Smooth, on a calm, dry day, is nice. But smooth, is, as often as not, associated with long floating flares, which is bad. I guess it's the 767 (and ex Navy) pilot in me, but I'd much prefer a solid landing that is exactly on the aim point, with the energy vector straight down the runway. Solid isn't hard though...

Smooth on a wet day is bad, and it's often not all that desirable on a windy day either.