Ask The Pilot

[smeacs]

We then jump to London for a low vis package. These are always flown by the captain, and supported by the FO. A couple of take offs are done, with the visibility at 125 metres, and 10 knots of crosswind (both of which are limits). There will be an engine failure resulting in an abort, and another from which you continue the take off. You might even do one where things work. In all cases the engine failures are worked to completion of the ECAM and passenger PAs, so just stopping on the runway isn't the end. The GO case invariably involves an outboard engine…the hardest case.


After the 3 engined take off, you clean the aircraft up, and then go through the steps you'll need to consider. Can you go back, or must you divert? As the vis is so poor, to go back you'll need CAT IIIB, but with a generator gone, you're reduced to CAT III A, so can you get the capability back? Will the engine restart (it virtually never will, but it needs to be considered). We elect to go back and start the APU to get another generator. The approach is normal until about 200 feet, at which point the localiser tracking goes outside of limits, so a 3 engined go around. Shoot the approach again, and this time land.

What makes loosing an outboard engine the hardest?


When you say that a "generator gone" means some options are not available does this mean they are "high power" systems? how much flexibility do you have to move power between systems?

 

[jb747]

What makes loosing an outboard engine the hardest?

Think about the geometry of it. An outboard is furthest from the centre of the aircraft, so the good engine on the opposite side has much more moment arm (than the asymmetric inboard case). It will often require full rudder to keep the aircraft straight, and that's with the engines derated. Pushing to full power could actually run you out of rudder (and is restricted in some take-offs).

The absolute worst case possibly appears simple to a non pilot. An engine failure during the later stages of the initial power application, at about 30 knots, so you end up with t/o power on (say) #1 and nothing on #4. There is not enough rudder, nosewheel steering or differential braking to keep that straight, and it will have you off the side of the runway in seconds unless you slam them all closed instantly.

When you say that a "generator gone" means some options are not available does this mean they are "high power" systems? how much flexibility do you have to move power between systems?

Not high power, but we need multiple sources to provide the redundancy required for Cat IIIB landings. We'll need 4 different generators, which can be achieved by 3 engine generators and 1 APU. Lose any more, and you'll revert to either Cat III A or Cat II. Automatic landings require lots of things that we wouldn't even consider for a manual landing.

The electrical system is largely automatic. It load sheds as it needs to provide power to important functions.

 

[MEL_Traveller]

Hi JB,

Sorry if this question has already been asked, the other day I heard the FA say over the intercom that "L2 Cabin Secure" (sitting at Door 2, we where right up the front, and the FA had a loud voice). Would that have been said to the CSM who would then pass onto the pilots that the cabin (in general) was secure? Or would the FA have been talking to one of the pilots directly.

What stage of the flight were you in and which aircraft were you on? The 'cabin secure' usually comes from the CSM, who will be sitting, for example, at 2L on a 747. It will usually be the end result of the enitre crew having issued similar assurances to the CSM that each of their respective cabins are secure.


An example of this is prior to departure on a 747. after crew have been asked to 'arm doors and cross-check' you will hear a chime in the cabin. On that chime, each crew member responsible for a door will pick up the phone for a conference call. Beginning at the rear of the aircraft (5R) they will relay words to the effect of (this will vary slightly for different airlines) '5R door armed, pin stowed, equipment checked' (pin stowed refers to the pin with a flag on it which is inserted to lock the door in the unarmed position while on the ground). This will continue with 5L, 4R, 4L etc etc, then the upper deck, then finally the CSM responsible for door 2L will state that their door is armed (still on the conference call). (Upper deck has a slightly different call because there is no pin for example). Once all crew have reported in they all hang up their phones.

The reverse happens after doors are requested to be disarmed on arrival. Similar procedures are in place for ensuring the cabin is secure for take-off and landing.

Different aircraft will have different procedures. Smaller aircraft may only require crew to give a visual indicator to the CSM that their doors are armed and equipment checked. Where possible it is prudent for crew to check the girt bar is properly engaged (either they can see it is mechanically done - for example on a 737 - or they will check for the appropriate indicator).

The reason for all the phone calling is because the flight deck didn't used to have an electronic indicator that doors were armed. I'm not familiar however with more modern aircraft such as the A380 - which I thought had some sort of indicator in the flight-deck?

 

[jb747]

What stage of the flight were you in and which aircraft were you on? The 'cabin secure' usually comes from the CSM, who will be sitting, for example, at 2L on a 747. It will usually be the end result of the enitre crew having issued similar assurances to the CSM that each of their respective cabins are secure.

After the seat belt sign is turned on for turbulence, the CSM will call the coughpit to confirm that the cabin is secure. We expect to get this call within roughly a minute. Individual crew will respond to an 'all stations' call from the CSM, but only he/she rings the coughpit. The secure call has nothing to do with the doors, though the call back mechanism is the same.

The reason for all the phone calling is because the flight deck didn't used to have an electronic indicator that doors were armed. I'm not familiar however with more modern aircraft such as the A380 - which I thought had some sort of indicator in the flight-deck?

It does. We have a display which shows the status of the doors. We check it just before engine start, and prior to switching off the seat belt sign when we reach the terminal.

 

[MEL_Traveller]

After the seat belt sign is turned on for turbulence, the CSM will call the coughpit to confirm that the cabin is secure. We expect to get this call within roughly a minute. Individual crew will respond to an 'all stations' call from the CSM, but only he/she rings the coughpit. The secure call has nothing to do with the doors, though the call back mechanism is the same.

Yes I was aware the 'cabin secure' had nothing to do with the doors. My example was to show how the process works for the conference call and other instances where this communication with the flight-deck occurs.

 

[mjt57]

A decent bump can easily put cabin crew, and their carts, into the air....and then where they land is in the lap of the gods.

Or that of the pax...

 

[mannej]

Out of interest, what is the typical rate of climb for the 380 on take of and how does that compare to other typical commercial aircraft 747/767/330 ?

 

[jb747]

Out of interest, what is the typical rate of climb for the 380 on take of and how does that compare to other typical commercial aircraft 747/767/330 ?

It's very hard to directly compare the types, because the way we calculate the derate is quite different.

Nothing can match a 767...it's the sports car of the airline industry.

The 380 compares pretty favourably with a 747. Its vertical performance is a lot better than I expected. A recent flight at what would be just about a minimum t/o weight (310 tonnes) threw up pitch attitudes I hadn't seen since the 767 days. It was still at 3,000 fpm at FL300..... At normal operating weights it is, of course, a lot more benign, but, it normally goes about 2-3,000 feet higher than the 747, and it doesn't take forever to get there.

 

[ChrisGibbs]

We have a display which shows the status of the doors. We check it just before engine start, and prior to switching off the seat belt sign when we reach the terminal.

JB747 - Back in April 2003 I was on the QF409 A330 service from SYD - MEL. I was sitting in the first row of economy and had a good view of door L2. All the doors were closed with everything going as per normal. Just prior to pushback door L2 was reopened for what looked to be additional paperwork to be carried onboard. Very soon after the door L2 was re-opended and with the aerobridge still attached the push back commenced and continued for about 5-10 seconds before being halted. The resulting damage to the door / aircraft and aerobridge looked to be significant.

I'm not sure as to what the cause/s of this incident were however I heard later that Load Control realised the aircraft was out of trim and asked for the door to be reopened by the ground staff without the knowledge of the tech crew. A couple of questions:

- If the aircraft was out of trim wouldn't any new information be provided to the tech crew by ACARS?
- As a result of this incident what sort of procedural changes would be implemented to stop something like this happening again?

Thanks in advance.

 

[jb747]

JB747 - Back in April 2003 I was on the QF409 A330 service from SYD - MEL. I was sitting in the first row of economy and had a good view of door L2. All the doors were closed with everything going as per normal. Just prior to pushback door L2 was reopened for what looked to be additional paperwork to be carried onboard. Very soon after the door L2 was re-opended and with the aerobridge still attached the push back commenced and continued for about 5-10 seconds before being halted. The resulting damage to the door / aircraft and aerobridge looked to be significant.

I'm not sure as to what the cause/s of this incident were however I heard later that Load Control realised the aircraft was out of trim and asked for the door to be reopened by the ground staff without the knowledge of the tech crew. A couple of questions:

- If the aircraft was out of trim wouldn't any new information be provided to the tech crew by ACARS?
- As a result of this incident what sort of procedural changes would be implemented to stop something like this happening again?

I recall that particular incident. A brand spanking new 330 damaged by people who ignored already existing rules.

Once the doors are closed, they are not to be opened again without the tech crew's approval. The bridges too, are not to be reconnected unless coordinated through the company (who will call the pilots). Obviously, once the pilots see that the doors are closed, and the bridge removed, then they're ready for push back.

Putting the bridge back onto the aircraft, and reopening a door, requires quite a few people to be involved. The engineers below, to ensure that the aircraft isn't moved, the pilots, the bridge operator, the cabin crew, and the company. Making the decision in isolation leads to a pretty expensive result.

Out of trim? Doubt it...and anyway, a piece of paper won't fix that. Provisional load sheets are provided in paper form by the gate staff, but the pilots would have had that about 30 minutes prior to departure. Finals are provided by ACARs. Both would have been there before the pilots were ready for departure (often the final is the last thing that has you waiting for pushback).

 

[samh004]

Amsterdam is a very likely diversion field (I took a 747 there once). Plus it has the procedural hold that I mentioned. There's no point to doing exercises at places we never/can't go to.

AMS is also pretty much right on the great circle route for SIN-LHR.

With the EK deal beginning next year, is AMS likely to change as a very likely diversion field, or will the route be fairly similar from Dubai?




 

[jb747]

With the EK deal beginning next year, is AMS likely to change as a very likely diversion field, or will the route be fairly similar from Dubai?

There are currently two routes that already overfly Dubai. The 'different' part of the flight next year will be from WA to Oman.

AMS will remain as usable as ever. It's a diversion to the destination, so that really wouldn't change with route choice, unless perhaps we were coming from the USA. And even then, it's one of the closer decent choices. If London is so bad that we can't land a 380/744, then it's unlikely that Gatwick or Stansted are much better.

 

[samh004]

There are currently two routes that already overfly Dubai. The 'different' part of the flight next year will be from WA to Oman.

AMS will remain as usable as ever. It's a diversion to the destination, so that really wouldn't change with route choice, unless perhaps we were coming from the USA. And even then, it's one of the closer decent choices. If London is so bad that we can't land a 380/744, then it's unlikely that Gatwick or Stansted are much better.

Oh yes, I completely forgot about the first leg of the route

 

[mjt57]

There's no code mate, I just announce it every now and then.

22/9 QF2 ex SIN

Did you get a chance to catch any of the GP?

 

[Major]

I know first hand of the variations that are possible in wind speed and direction from ground level to 1000ft. Also we have the jet streams which are at higher altitude and run West to East. I think they run above about FL230

Are there regular wind patterns below these jet streams or is it a case of any direction at any speed at any time ?

 

[jb747]

Did you get a chance to catch any of the GP?

I could hear the practice in the distance. Singapore was quite buzzing, with lots of activity around the Clarke Quay area. The excitement of a GP hasn't worn off on them yet.

 

[jb747]

I know first hand of the variations that are possible in wind speed and direction from ground level to 1000ft. Also we have the jet streams which are at higher altitude and run West to East. I think they run above about FL230

Are there regular wind patterns below these jet streams or is it a case of any direction at any speed at any time ?

Whilst wind can come from any direction, there tend to be prevailing (seasonal) directions. It is, for instance, rare to see strong easterlies in Melbourne, so 09 is a rarely used runway (direction). As a general rule, the winds over Sydney, irrespective of the wind on the ground, are reasonably strong westerlies.

A few years ago, I heard there was a proposal to close 07/25 in Sydney, on the basis that the wind did not often force its use. Presumably this would have made land available for non aviation use. Apparently it came as a shock to the airport owners that such a closure would mean that for about 60 days per year, the airfield would have to close to all operations, as the crosswinds would exceed the aircraft maximums. I guess the wind is something that banks can't control....

 

[markis10]

A few years ago, I heard there was a proposal to close 07/25 in Sydney, on the basis that the wind did not often force its use. Presumably this would have made land available for non aviation use. Apparently it came as a shock to the airport owners that such a closure would mean that for about 60 days per year, the airfield would have to close to all operations, as the crosswinds would exceed the aircraft maximums. I guess the wind is something that banks can't control....

07/25 was closed after the third runway was opened, it did not remain closed for long.

 

[simongr]

I guess the wind is something that banks can't control....

Give them time

 

[johnny_the_knife]

Possibly a silly question, but what does the process of (dis)arming the doors actually do?