Ask The Pilot

[Must...Fly!]

Fabulous videos as always jb747!

Makes me really want to get back in the air again, even though I am just sitting back watching a few movies!

 

[Moody]

Off topic .... at near 2200 posts this thread needs a sub-editor to hack and slash the dross!

On topic .... I'm not an Aircrash Investigation tragic but it seems that when there is pilot error involved, the co-pilot must also shoulder some of the blame. They are, after all, meant to be there as a back-up for the imperfect human element. So this is perhaps a sticky question to ask of you, JB, but how many times has the PNF saved you from an embarrassing or potentially dangerous mistake - and vice-versa?

 

[jukebox333]

Galleys, toilets, phone system. Things in peoples' bags. I don't know what it was, but there are certainly many things that can go 'whoop' in the middle of the night/aircraft.

Ralph Fiennes & Lisa Roberston, for example....

 

[JohnM]

A couple of new videos for those interested in such things.

This one coughpit view A380 wake encounter.m4v - YouTube shows what happens when an A380 runs into a 747's wake.

The other, coughpit view A380 London approach and landing - YouTube is about the last 20 miles of a flight from Singapore to London.

Very interesting, thanks JB.

During the approach to LHR there are several calls of a number followed by what seems to be the word 'blue' (eg. "three thousand blue"). What does all that mean?

 

[anat0l]

The other, coughpit view A380 London approach and landing - YouTube is about the last 20 miles of a flight from Singapore to London.

Thanks for the videos, jb747.

For this quoted video, once the system announces "1000" (which I assume to mean 1000 ft altitude), one of the pilots (can't tell if it's you or your accomplice) announces "Cat III dual... Manual landing... Visual!"

I think (and this is mass media so ) the A380 was touted as having one of those systems that would allow the plane to be able to "land itself" (irrespective of the other 99 things you mention that need to be done to enable that). Is this a case where this would not work, and what was the reasoning behind that? (I assume it had something to do with the talk around the instant I mention above, except I don't have an idea what the context of those are either...)

 

[jb747]

Very interesting, thanks JB.

During the approach to LHR there are several calls of a number followed by what seems to be the word 'blue' (eg. "three thousand blue"). What does all that mean?

In the Airbus, systems that are armed, but not yet active, show up on the PFD in a blue font. For instance, if the aircraft were in heading mode pointed at the FMC track, and the MCP HDG button is pushed, it will remain in heading mode, but NAV will appear on the PFD in blue.....it would then automatically capture the FMC track off the current heading, at which point the HDG annunciation would disappear, and NAV would change to green.

In the case of altitude changes, the MCP altitude (which we set to whatever ATC clear us to) will appear above or below the VSI, depending upon whether we are climbing or descending. It shows up in blue if that is the altitude that the system is climbing or descending to, or magenta, if there is some form of constraint built into the FMC. We actually don't see magenta very often, but we will on departure from London (where I'm writing this) as ATC are very likely to clear us above 6000 feet quite early, even though the standard departure has a 6000 foot constraint that lasts for quite a while. To get rid of such a constrain, you can delete it in the FMC load stage on the ground (dangerous, 'cos they might want it today), remove it from the FMC at the time (which just takes a few seconds head down), or switch to a non managed navigation mode (i.e. HDG instead of NAV).

 

[jb747]

For this quoted video, once the system announces "1000" (which I assume to mean 1000 ft altitude), one of the pilots (can't tell if it's you or your accomplice) announces "Cat III dual... Manual landing... Visual!"

At 1000' AGL, depending upon who is flying and the procedures that we've chosen to use, there are a number of standard calls. If the captain is flying, and we're flying some form of approach, the chosen procedure will always be 'low vis'. Our options are 'low vis', 'instrument' and 'visual'. They define how the aircraft will be flown, and where individual pilots will look during the course of the approach. The thousand foot call is a read out of what is displaying on the PFD, and of my intentions. So, in that case, Cat III dual means that both autopilots are engaged, and it's in an automatic landing mode, manual landing is my intention, and visual means I have the criteria for a visual approach at that point. Of course, as the whole thing was flown on a nice 'visual' morning, the FO already knew that.

A little later you hear "disconnecting, Cat 1", which means I've just disconnected the autopilot, and the system automatically degraded to Cat 1. The various Cats, I, II, and III are all associated with slightly different procedures, and very different minima.

I think (and this is mass media so ) the A380 was touted as having one of those systems that would allow the plane to be able to "land itself" (irrespective of the other 99 things you mention that need to be done to enable that).

Those 99 things ALWAYS have to be done. In fact you have to intervene to make it leave its cruising altitude. In this particular instance, we've actually done them, so with no further intervention it would have continued the approach and landed itself. Basically it's a last point check that we've done the 99.

 

[harvyk]

or switch to a non managed navigation mode (i.e. HDG instead of NAV).

How often would you switch to HDG instead of NAV? Multiple times per flight? A couple of times a month, never unless the situation called for it?

If you do switch to HDG, obviously that turns off LNAV, but what about VNAV is that kept on in HDG mode?

If VNAV is also turned off, how is vertical navigation done? Alt Hold or V\S (as infrequently as it's used)? Manually?

 

[jb747]

I'm not an Aircrash Investigation tragic but it seems that when there is pilot error involved, the co-pilot must also shoulder some of the blame. They are, after all, meant to be there as a back-up for the imperfect human element. So this is perhaps a sticky question to ask of you, JB, but how many times has the PNF saved you from an embarrassing or potentially dangerous mistake - and vice-versa?

If a crew stops working as a team, then you're well on the way to problems. My briefing to any new crew, always includes something along the lines of..."There is no point scoring. Points are neither gained nor lost. If you see something you don't like, or which isn't procedurally correct, just speak up. I won't be trying to be different...it will just be a mistake". You then have to be careful about just how steep the gradient is across the coughpit...too steep and the comment above is just hot air, too shallow and it's a democracy, and that is not how you lead or run an aircraft.

Whilst I don't recall really having my proverbial saved by an FO (or SO) for that matter, they all, on every flight, make various inputs that tidy up the operation. Even on the video I've just put up, you can hear the FO at one point asking if I want managed speed...and whilst I decide not too at that point, it is a very valid suggestion from him.

It is always a team effort (though that is a much misused word these days). People who run the coughpits like a single pilot operation, or in which the gradient (both of personality and knowledge) is too steep, are accidents going somewhere to happen. "Face" has no place in a coughpit.

You don't need to look very far afield to find examples of broken crew structures....the ATSB makes good reading there, and some are far too close to home.

 

[jb747]

How often would you switch to HDG instead of NAV? Multiple times per flight? A couple of times a month, never unless the situation called for it?

Well, "never unless the situation calls for it", happens to equate to multiple times per flight.

There will normally be a SID loaded, and the aircraft will transition to NAV shortly after take off. But, in many places, you won't complete the SID, with ATC giving vectors for a while before clearing you back onto the planned route. On the arrivals side, they vary from almost complete disregard of the STAR, to following it exactly (Melbourne is probably best at this). You simply change as needed.

If you do switch to HDG, obviously that turns off LNAV, but what about VNAV is that kept on in HDG mode?

LNAV and VNAV are Boeing terms. In a Boeing if you select HDG, VNAV will remain engaged, but in an Airbus, as soon as you select HDG, you also lose the vertical mode (in a climb it goes to 'open climb', and in a descent to 'v/s'). There are arguments both for and against both systems.

If VNAV is also turned off, how is vertical navigation done? Alt Hold or V\S (as infrequently as it's used)? Manually?

Well, if you can multiply by 3 or 4 then you can work out the altitudes/distance in your head (and you have to keep an eye on it anyway, as the computers quite regularly lose the plot with regard to vertical nav). In both types, deviation from the planned vertical path is displayed one one of the performance pages of the FMC. All of us have a few energy gates that we need to hit too...250 knots, 20 miles, and 5000 feet...works for everything.

Altitude hold isn't used often. It's a mode that stops the climb or descent at the point you are now. It's a bit abrupt from the passenger perspective as it may be associated with a large power change. Actually the most common use is in the sim, at the clean up stage after an engine failure. V/S on other hand, is used a lot on descents, very rarely on climbs (as it has drawback that can be dangerous). Open descent is used if you want idle power. It would be a very rare flight in which all of the modes....open, V/S, and managed...aren't used, with multiple changes between the modes.

 

[dodgeyhack]

While we're talking about the autopilot.
What modes are used during or after take off and when are they enabled/activated?
Is it possible to get a distinct change when the ap is activated? Does the computer always try to smooth out the transition, or is that the pilots job?

And many thanks for all the answers.

 

[mannej]

In line with another topic, how often are ground checks performed on the A380/747?

What are your thoughts on the reduced number of 737-800 pre-flight ground checks?

 

[jb747]

While we're talking about the autopilot.
What modes are used during or after take off and when are they enabled/activated?

No modes are used during take off. Use is restricted on all types to a couple of hundred feet and 5 to 20 or so seconds. You basically need to get the aircraft to a steady state before it can be engaged.

Is it possible to get a distinct change when the ap is activated? Does the computer always try to smooth out the transition, or is that the pilots job?

Computers are dumb. They don't really try to smooth anything out. When the autopilot engages, it simply goes into whatever mode the flight director happens to be in (otherwise some form of attitude hold). Before engaging the a/p you always make sure the aircraft is in a steady state. That could be in a turn, but not within a rolling or pitching action. It will not save your cough if you're losing control of the situation (in a 737 loss of control accident in the Med a couple of years ago, an attempt was made to engage the a/p at some quite extreme angles of bank).

 

[jb747]

In line with another topic, how often are ground checks performed on the A380/747?

What are your thoughts on the reduced number of 737-800 pre-flight ground checks?

I don't see an issue with it, as long as the procedures are what the makers intended when they built the aircraft. Systems change. We don't fly the same way we did 20 years ago, and engineering has moved along too.

I think you'll find the procedures are being used only on new short haul aircraft. They're actually still looked at very regularly...but not every 90 minutes. The long haul stuff probably won't change a great deal....they get looked at every 15 hours or so. As the engines use oil, at the very least, that always needs to be topped up. It will last a day of domestic ops, but not multiple long sectors. Plus, on the long flights, there is never a sector on which something isn't broken at the end of the flight.

In many cases, even with a 380, the pilots can already turn the aircraft around...otherwise we'd never get going again after a diversion.

 

[harvyk]

I think you'll find the procedures are being used only on new short haul aircraft.

The news article I've read they are also talking about including A330's in this.

 

[jb747]

The news article I've read they are also talking about including A330's in this.

Like I said, new short haul aircraft......

 

[userlame]

JB - thanks again for contributing so much time to this thread.

My question - sometimes after a flight we'll see the captain standing at the coughpit door, giving passengers a smile and a wave as we debark. Other times the coughpit door is closed and there's no one for us to thank for the flight.

I've even seen it done after a particularly hard landing when I was sure the captain would rather be hiding, but he was there all grins and goodbyes.

Is the 'goodbye' a policy thing or a personal preference? Which camp to you fall in to?

 

[Must...Fly!]

You mentioned something is always broken after a long flight. Is there something in particular that is notorious for needing a fix on the ground?

 

[jb747]

My question - sometimes after a flight we'll see the captain standing at the coughpit door, giving passengers a smile and a wave as we debark. Other times the coughpit door is closed and there's no one for us to thank for the flight.

It's a personal preference. Sometimes there a few things to debrief or take care of with the engineers, and, on a smaller aircraft, by the time you've done that everyone is gone. It was always the 'done thing' on the 767, and those who came through on that aircraft still seem to be keeping it up. If you have a short turnaround, you might need to get off immediately to start the next preflight, or to move to another aircraft.

I've even seen it done after a particularly hard landing when I was sure the captain would rather be hiding, but he was there all grins and goodbyes.

Heck no...come back and blame the FO.

Is the 'goodbye' a policy thing or a personal preference? Which camp to you fall in to?

I always try to do it. On the 380 that ends up with me saying 'bye to the economy class passengers.

 

[jb747]

You mentioned something is always broken after a long flight. Is there something in particular that is notorious for needing a fix on the ground?

Not really. But, they are incredibly complex machines, and after 15 or so hours in the air, there will always be something to look at. On digital aircraft, the fix can be as simple as rebooting/powering it...though that can be extremely time consuming.

If anything, the cabin gives a lot more trouble than the actual aircraft.