Ask The Pilot

[smeacs]

Just to clarify, If you are using bleed air to run the aircon you aren’t using that air for thrust hence the problems in hot weather ?

And when you refer to a “duct leak” due to overheating where is this “duct” physically located and what air travels down this “duct” ?

thanks.

 

[jb747]

Just to clarify, If you are using bleed air to run the aircon you aren’t using that air for thrust hence the problems in hot weather ?

Basically the engines have a maximum temperature limit, and they produce a set amount of air at that temperature (in given conditions). We can use that air for thrust or 'bleed' some of it off for other functions. If we want the maximum thrust, we have to reduce the bleed requirement. Hence packs off, or packs on APU, take offs.

And when you refer to a “duct leak” due to overheating where is this “duct” physically located and what air travels down this “duct” ?

There are two main ducts. One runs across the wing, and allows for the collection of bleed air from all of the engines. The other comes from the tail/APU. Bleed air is not only used for air con, but also to start the engines, so bleed from one side, might be used to start the other. It's not at particularly high pressure (40 psi or so).

In the 747 there were also some (bleed) air driven backup hydraulic pumps, and some of the flap drives were also pneumatic.

 

[mjt57]

but also to start the engines, so bleed from one side, might be used to start the other. It's not at particularly high pressure (40 psi or so).

That sounds awfully low. Our gas turbines (P&W FT4Cs, similar B707 and B737 engines in rating) had a 3,000 kpa compressed air system to start 12 engines. The air driven motors would spin N1 or N2 ( I forget which) up to 1,800 rpm for 20 secs before firing. Given that the Trent 900s are many times the size I'm surprised that 700-800 kpa is enough to spin them up...

 

[andmiz]

That sounds awfully low. Our gas turbines (P&W FT4Cs, similar B707 and B737 engines in rating) had a 3,000 kpa compressed air system to start 12 engines.

3,000kpa in the tank, but probably a regulated low output. The 747 can be successfully started with a duct pressure down to about 20psi.

 

[Flying Fox]

Hi JB

Just wondering if you feel anxious when in the captain's seat and performing an auto Cat III ILS landing knowing that the computers are in control and not yourself?

I also imagine that the first time doing one of these landings would be quite a test of courage?

Similarly, how well do you travel as a passenger on a flight vs a pilot? Do you think/worry that you could have done something better/different?

Thanks

 

[jb747]

Just wondering if you feel anxious when in the captain's seat and performing an auto Cat III ILS landing knowing that the computers are in control and not yourself?

I also imagine that the first time doing one of these landings would be quite a test of courage?

Similarly, how well do you travel as a passenger on a flight vs a pilot? Do you think/worry that you could have done something better/different?

I don't think that I think about it in the same way that you might. Whilst the computers are flying the aircraft, we can see exactly how they are doing, and my hands are on the autopilot disconnect/joystick and throttles/GA switch at all times. When practicing these things, they go wrong regularly (i.e. they feed some form of fault in), so I think we're pretty relaxed with them.

Cat II/III is also for use in fog, so it's generally nice and smooth. It's much harder work in gusty/windy conditions (the sort of thing you get in a Hong Kong storm), and then the autopilots aren't all that much use.

As a passenger, I don't travel on airlines that bother me, so I just relax and generally sleep quite well.

 

[RooFlyer]

JB, I had an odd and slightly disconcerting experience aboard a Thai flight MEL-BKK the other day.

It was a 777, which has a forward galley and a J loo to the left (forward) of the forward entry door. Then the coughpit door.

I was hovering in the forward entry door area waiting for the toilet to be vacated. I heard the latch, so stood waiting to move forward. To my surprise, the gent who was in the loo then stood in front of the coughpit door and pressed some buttons on the door keypad. He then stood still and looked up at the camera. A second later, the coughpit door opened and he went in. I was about a meter from the coughpit door with a clear view in and there was a FA in the galley, who didn't bat an eyelid or tried to usher me away.

The gent was, I would guess over 60, in civvies and apparently of Thai extraction.

I was pretty shocked at both the civilian going into the coughpit and my being allowed to be just behind him as he did. I'm guessing he was a relative of one of the coughpit crew or maybe a retired pilot friend of one of them.

JB, how does this fare on the shocked / appalled / report their cough - meter? We were in Australian airspace.

Or should I put it down to the wonderful tapestry that is international flying?

 

[Flashback]

JB, I had an odd and slightly disconcerting experience aboard a Thai flight MEL-BKK the other day.

It was a 777, which has a forward galley and a J loo to the left (forward) of the forward entry door. Then the coughpit door.

I was hovering in the forward entry door area waiting for the toilet to be vacated. I heard the latch, so stood waiting to move forward. To my surprise, the gent who was in the loo then stood in front of the coughpit door and pressed some buttons on the door keypad. He then stood still and looked up at the camera. A second later, the coughpit door opened and he went in. I was about a meter from the coughpit door with a clear view in and there was a FA in the galley, who didn't bat an eyelid or tried to usher me away.

The gent was, I would guess over 60, in civvies and apparently of Thai extraction.

I was pretty shocked at both the civilian going into the coughpit and my being allowed to be just behind him as he did. I'm guessing he was a relative of one of the coughpit crew or maybe a retired pilot friend of one of them.

JB, how does this fare on the shocked / appalled / report their cough - meter? We were in Australian airspace.

Or should I put it down to the wonderful tapestry that is international flying?

Could have been an anti-terrorist agent.. who knows!

 

[jb747]

It was a 777, which has a forward galley and a J loo to the left (forward) of the forward entry door. Then the coughpit door.

I was hovering in the forward entry door area waiting for the toilet to be vacated. I heard the latch, so stood waiting to move forward. To my surprise, the gent who was in the loo then stood in front of the coughpit door and pressed some buttons on the door keypad. He then stood still and looked up at the camera. A second later, the coughpit door opened and he went in. I was about a meter from the coughpit door with a clear view in and there was a FA in the galley, who didn't bat an eyelid or tried to usher me away.

The gent was, I would guess over 60, in civvies and apparently of Thai extraction.

I was pretty shocked at both the civilian going into the coughpit and my being allowed to be just behind him as he did. I'm guessing he was a relative of one of the coughpit crew or maybe a retired pilot friend of one of them.

Different countries have different rules on carrying people in the coughpit.

No point guessing who he was. He literally could have been just about anyone...and if you think about it, there are lots of people who have valid reasons to be carried in the coughpit, but may not actually be uniformed staff.

For a number of reasons, I'd prefer not to discuss coughpit access to any degree.

 

[Fruitcake]

For a number of reasons, I'd prefer not to discuss coughpit access to any degree.

That's a shame, I was going to ask whether paddle pop sticks were any good on the A380 or whether that trick only worked on Q400s .

 

[jb747]

Roster for the next couple of months...

QF9 21/12 MEL-DXB
QF9 24/12 DXB-LHR
QF2 26/12 LHR-DXB
QF2 28/12 DXB-SYD

QF93 06/1 MEL-LAX
QF94 07/1 LAX-MEL

QF9 15/1 MEL-DXB
QF9 18/1 DXB-LHR
QF2 20/1 LHR-DXB
QF2 22/1 DXB-SYD

QF1 04/2 SYD-DXB
QF1 07/2 DXB-LHR
QF10 09/2 LHR-DXB
QF10 11/2 DXB-MEL

And the proviso that anything can change, and in particular I always try to swap sectors that involve Sydney.

 

[Skyhigh777]

Looks like you'll be enjoying christmas in London.

 

[Major]

Roster for the next couple of months...

QF9 21/12 MEL-DXB
QF9 24/12 DXB-LHR
QF2 26/12 LHR-DXB
QF2 28/12 DXB-SYD

QF93 06/1 MEL-LAX
QF94 07/1 LAX-MEL

QF9 15/1 MEL-DXB
QF9 18/1 DXB-LHR
QF2 20/1 LHR-DXB
QF2 22/1 DXB-SYD

QF1 04/2 SYD-DXB
QF1 07/2 DXB-LHR
QF10 09/2 LHR-DXB
QF10 11/2 DXB-MEL

And the proviso that anything can change, and in particular I always try to swap sectors that involve Sydney.

So much for Christmas at home :shock:

 

[smit0847]

Roster for the next couple of months...

QF93 06/1 MEL-LAX
QF94 07/1 LAX-MEL

36-ish hours between flights? Gosh they work you hard!

 

[Flying Fox]

I don't think that I think about it in the same way that you might. Whilst the computers are flying the aircraft, we can see exactly how they are doing, and my hands are on the autopilot disconnect/joystick and throttles/GA switch at all times. When practicing these things, they go wrong regularly (i.e. they feed some form of fault in), so I think we're pretty relaxed with them.

You are correct there.

Very reassuring to know that you are a split second away from taking over control should the auto-landing system start to to something unusual.

 

[mjt57]

Very reassuring to know that you are a split second away from taking over control should the auto-landing system start to to something unusual.

In my industry we have a saying that bad automatics are generally better than "good" manual operations. However, in JB's case we'd have to hope that the reverse is true. Thing is, they do this all the time and 'planes aren't falling out of the sky because if it, are they?

 

[ozmille]

36-ish hours between flights? Gosh they work you hard!

I would definitely hope the pilot of an A380 gets the opportunity to rest and get over the jetlag a bit before flying hundreds of passengers back

 

[jb747]

Looks like you'll be enjoying christmas in London.

Pretty much as usual. I think that in 28 years, I've had only about five Xmas days off, though I never minded them in Singapore.

 

[jb747]

36-ish hours between flights? Gosh they work you hard!

I'm sure they would give us a shorter slip if they could. But, the first flight that you could possibly take is only about 12-14 hours after your arrival. It's inside the CASA mandated rest period before/after a long haul flight, and given that it would be totally useless 'daytime' rest, when hotels are at their noisiest, it's probably a good thing. You're back on the road as soon as possible. Another gotcha with schedule planning is that if you make the slips too short, and then suffer an inbound delay, you won't have a crew for your next flight.

 

[legroom]

Hi JB

Is the route itself important enough for additional training / check ?

E.g. if you were to be asked to fly QF11 / QF12 instead of the "routine" DXB/LHR route, would you just turn up the next day for "work" or you need additional "route check" ?

... in case you get lost over the Pacific ??

Thank you in advance.