Ask The Pilot

[jb747]

Is idle reverse still used if the runway is "contaminated" (in Syd i guess that would be wet but LHR i guess would include snow/ice) or are you required to use "maximum braking"? If so, would that preclude curfew "fringe" landings (if you know the runway is wet)?

Landings within the shoulder period include requirements for a particular runway and idle reverse. If you can't comply (due tailwind or anything else), then you are not permitted to land, and will either need to hold until normal procedures are resumed, or divert.

A wet runway is not considered contaminated. The manuals include various charts that are used to define the levels of contamination. It the runway is wet you'll enter that into the performance calculation...in most cases it will still permit landing with idle reverse. Tailwinds are much more likely to be limiting with regard to curfew.

Use of maximum brake settings is extremely rare.

 

[jb747]

Assuming the speed brakes are armed at what point in the sequence above are the speed brakes automatically deployed? wrt QF30 where you lost control of the starboard aileron did you also lose use of the Speed Brakes and if so how did that impact the landing (if at all).

The spoilers are armed just after selection of "gear down". They automatically deploy with weight on the main wheels and thrust levers at idle. They will also deploy, even if not armed, when reverse thrust is selected to the interlock.

On QF30 the starboard aileron cables were cut, so there was no path for roll commands to get from the coughpit to the control surfaces. The controls themselves were powered as normal. Landing spoilers are deployed by a different command route, so they worked normally. The actual surfaces can vary too. All spoilers are deployed fully for landing, but only some for roll control. And a different subset and amount of deflection for speed brake.

 

[Skyring]

Places that are sensitive, like London, have automatic noise monitor stations, a bit like speed cameras on the road, and in a similar manner the bill comes through to the company.

…and they forward it to the pilot?

I imagine that these fines, to be effective, aren't token amounts.

 

[jb747]

…and they forward it to the pilot?

I imagine that these fines, to be effective, aren't token amounts.

To the company. Though I guess you might get a phone call to ask about it. It's one of the reasons why departures from London have mandated autopilot use. At least that way you can blame George for any tracking error. I have no idea of the amounts, though from what I've heard, at some times of the day a perfectly legal departure may still be pinged, so it's not really trying to stop anything...just another tax.

 

[PJ747]

With regards to radio protocol, is there a reason for the lack of use of 'over' and 'out' in the airline industry? Is it simply to reduce the amount of radio chatter/length of radio conversations?
In the railways, management have a tendency to get somewhat upset if we don't use "correct radio protocol" by using 'over' and 'out' (among other things).

 

[jb747]

With regards to radio protocol, is there a reason for the lack of use of 'over' and 'out' in the airline industry? Is it simply to reduce the amount of radio chatter/length of radio conversations?
In the railways, management have a tendency to get somewhat upset if we don't use "correct radio protocol" by using 'over' and 'out' (among other things).

"Over" etc, simply isn't necessary on VHF or UHF communications, that are themselves constrained to standard phases. They may have a place in poor quality HF comms, but even then are rarely used or needed. They are not standard.

 

[D747]

We know what can happen when a cabin loses pressure, but can the opposite happen? Can the pressure in the cabin be too high? Can it be difficult to release the pressure?

 

[jb747]

We know what can happen when a cabin loses pressure, but can the opposite happen? Can the pressure in the cabin be too high? Can it be difficult to release the pressure?

If you sealed an aircraft and kept pumping air in, without pressure management, you'd end up with exactly the same thing as happens with a balloon. The structure would eventually fail. https://www.youtube.com/watch?v=rpGF3dVdj14

To prevent that, aircraft have overpressure relief doors that open to dump the pressure if it goes (roughly) .5 psi over the maximum. These are mechanical, so not subject to any electrical glitches. As an aside, they were both open on QF30.

 

[Boris spatsky]

We know what can happen when a cabin loses pressure, but can the opposite happen? Can the pressure in the cabin be too high? Can it be difficult to release the pressure?

We did this in the sim recently. Cabin altitude warning due to slow but steady depressurisation. You go on oxygen and try to manually control the cabin by closing the outflow valve. It didn't work, so we conducted an emergency descent. In the descent, the pressure controller (which was malfunctioning) drove the valve fully closed. So when i looked at it at 10000 feet after levelling off, it was off scale below zero. This didn't make any sense at the time as i knew we couldn't control the outflow valve manually. We had maximum differential though. What i eventually worked out was that the pressure controller had come back online and had driven the valve closed, thereby pumping air into the cabin and descending the cabin altitude to below sea level.

We manually climbed the cabin and conducted an emergency landing. Never seen that one before and took some effort to identify exactly what we had (i initially thought the cabin altitude gauge had failed as i was not expecting a sub zero cabin at that point.)

It was a pretty interesting sim scenario.

 

[mjt57]

As an aside, they were both open on QF30.

How did that happen if the aircraft suffered decompression?

 

[jb747]

How did that happen if the aircraft suffered decompression?

Decompression was the result, not the cause.

When the oxygen bottle exploded, there were multiple damage causing events. Most of the bottle was blasted up through the floor, and did the damage seen on the passenger deck. In the meantime, down in the hold, we've got a bubble of oxygen that's suddenly no longer contained. It expanded in all directions, with a shock wave leading the charge. As that impinged upon the aircraft skin, it pushed it outwards until it ruptured. The part of the wave that went into the hold was largely absorbed/reflected by the packaged cargo. But, some of that pressure wave found its way to the other side of the hold, where it caused the overpressure doors to open.

The bottle failure was little different to any form of explosion...perhaps lacking heat as the only main difference.

 

[SenZubEanS]

For the general aviation pilots out there:

How much is the cost of flying lessons in say a single engine these days?

Notice that all the replies we about how many thousands it can cost etc. For reference I am learning out of an airport not based in a major city and am paying $300 an hour with an instructor in a piper warrior.

 

[Quickstatus]

SenZubEanS,

what do you want to do with your pilot training?

 

[bryanjones]

Hi Pilots - forgetting the trash in the first part of this article https://www.thesun.co.uk/news/20772...-sex-photos-in-stockings-taken-at-38000-feet/, but looking at the vancouver footage at the end, what would be the reason for the go-around? It looked like he floated for quite a while.

 

[AviatorInsight]

what would be the reason for the go-around? It looked like he floated for quite a while.

You just answered the question. There are many reasons/variables that command a go-around. In this case, it looks like the pilot floated too long missing the markers and executed a go-around.

 

[jb747]

....but looking at the vancouver footage at the end, what would be the reason for the go-around? It looked like he floated for quite a while.

The main reason can be seen in the background at about the 10 second mark. Have a good look at the windsock.

 

[petercr]

From my untrained eye, it appears he's landing with (rather than into) a cross wind??

 

[jb747]

From my untrained eye, it appears he's landing with (rather than into) a cross wind??

Headwind, cross wind, tailwind.

It looks like the wind is mostly tailwind, which would fit in with the result.

 

[bryanjones]

Pilots,

Are there any preferences as to the visual guided docking systems at the gate in terms of brand, or even having people do it?

 

[jb747]

Are there any preferences as to the visual guided docking systems at the gate in terms of brand, or even having people do it?

I've used a number of systems over the years, though I doubt that I've ever noted their names or brands. Originally, they were quite simple systems that used parallax to help you with line up and stop position, but while simple, they could easily lead you astray if you misidentified the correct markings for your type.

Probably all you ever wanted to know about them here: https://en.wikipedia.org/wiki/Stand_guidance_system and a video to give an idea of how it works: https://youtu.be/W3LR-CWRJ_o

Of the bunch I probably prefer the VDGS system, which I see in LAX and Dubai. (I looked up the names.) Both are intuitive. I do remind myself in the USA though, that I'll be seeing feet and not metres in the distance countdown.