Ask The Pilot

[chrisb]

Hi JB,

When the decision to divert is made, would you tell the pax immediately or delay it until closer to landing so that the cabin isn't disturbed?

Would that be different for example on QF94s complete 180 back to LAX the other day vs a more subtle decision to go to MEL BNE or CBR instead of Sydney like this mornings flights? (I'm not sure how early they would have known about the fog but I imagine there are some situations that could see you decide to divert quite a few hours out of the destination)

 

[jb747]

Boeing 787 Stall Tests - YouTube talks about 787 stall testing. There are some 747 stall test videos kicking around also that are more dramatic.

Well, perhaps they do then.

 

[harvyk]

I like many others this morning spent a whole lot of time on the tarmac going no where, and it got me thinking, whilst us pax are lucky enough to have movies / music / games to entertain us, is there anything pilots do (either because they have to, or because it's a great way to pass the time) once they have a whole load of pax, but haven't got and can't get clearance to go anywhere (due to fog or some other event at the destination), and don't have engines started.

 

[jb747]

I like many others this morning spent a whole lot of time on the tarmac going no where, and it got me thinking, whilst us pax are lucky enough to have movies / music / games to entertain us, is there anything pilots do (either because they have to, or because it's a great way to pass the time) once they have a whole load of pax, but haven't got and can't get clearance to go anywhere (due to fog or some other event at the destination), and don't have engines started.

We've been known to fall asleep....

During the delays you can still be surprisingly busy. It can be quite a battle to get yourself inserted back into the queue in a position that works for you. Often you'll need to reorder the fuel, and perhaps have a new plan run. You might take the time to say hello to some passengers. But, basically, you're at work....you don't need entertainment.

 

[QF WP]

jb747, when I spoke to Richard Champion de Crespigny yesterday morning after his talk at our Conference, I asked how he was enjoying the sim practice for landing in Dubai and how different it was to the real thing. I was surprised to learn that he has only had flight there thus far - which made me think, how many A380 captains are there?

He did mention that the sand made for some different issues (getting in engines, etc) - have you any additional checks taking off from DXB from the standard?

 

[jb747]

jb747, when I spoke to Richard Champion de Crespigny yesterday morning after his talk at our Conference, I asked how he was enjoying the sim practice for landing in Dubai and how different it was to the real thing. I was surprised to learn that he has only had flight there thus far - which made me think, how many A380 captains are there?

The flying isn't distributed evenly over a short period. Dubai only started about 7 weeks ago, so there have only been 98 (in round figures) trips there so far. I think Richard is currently on a blank line (as am I) which means you do standby and fill in, but don't get any flying pre allocated to you. It would be quite possible to finish the two month roster without going anywhere near Dubai. With the roster coming up to half over, I've only been given a flight to LA. I have done one Dubai, but that was from the last roster (which is where I expect RdC got his). Since the service started, the max number someone could have done would be four. I'm sure there are quite a few who haven't done any at all.

Including management and training, there are about 100 A380 Captains.

He did mention that the sand made for some different issues (getting in engines, etc) - have you any additional checks taking off from DXB from the standard?

Not really...unless you happen to be there in a sand storm, in which case the best idea is to divert.

 

[docjames]

Not really...unless you happen to be there in a sand storm, in which case the best idea is to divert.

I think you mentioned previously there may be maintenance issues / extra checks required?

On a slightly different angle to that, is it possible to give us an idea of what kind of problems cause a "must be fixed before departure" vs "can carry to next airport"? I gather there would be some (minor) differences between aircraft and airlines?

eg. How many toilets can be u/s? What does the APU status need to be? Any flap restriction?

I guess as a pax i've got a list in my head of "stuff that's delayed me" - typically they fall (broadly) into engine, air conditioning and flap/throttle/mechanical issues whereas I've (not unreasonably) got basically no idea of what stuff is "ok" to "go without"?

 

[jb747]

I think you mentioned previously there may be maintenance issues / extra checks required?

On a slightly different angle to that, is it possible to give us an idea of what kind of problems cause a "must be fixed before departure" vs "can carry to next airport"? I gather there would be some (minor) differences between aircraft and airlines?

eg. How many toilets can be u/s? What does the APU status need to be? Any flap restriction?

I guess as a pax i've got a list in my head of "stuff that's delayed me" - typically they fall (broadly) into engine, air conditioning and flap/throttle/mechanical issues whereas I've (not unreasonably) got basically no idea of what stuff is "ok" to "go without"?

There's a set of quite huge 'books' put out by all of the manufacturers, called 'Minimum equipment lists' (MELs for short). Individual airlines can make the list more restrictive, but not less so.

Toilets aren't airworthiness items, and I expect they could all be u/s and we could still take the aircraft flying. Obviously though, we wouldn't actually take any passengers with us in that case.

Flap/throttle/mechanical (which is a pretty broad brush) will generally stop the flight until fixed.

Engines must obviously be working (although some airlines indulge in 3 engined ferry flights), but, it may be acceptable for the autothrottle to be u/s, or a FADEC mode to be unavailable. A bleed valve could be locked closed, or perhaps reverse thrust locked out. The MEL will also come with time limits by which it must be fixed, and also procedures for both engineers and pilots. The MEL may also include performance penalties that need to be applied.

The requirement for the APU varies. The 380 and 747 don't need it at all, though it can be very inconvenient not to have one. The ETOPS twins will be restricted without the APU, as it's assumed that the APU would be available to help with the air and electrical loads if an engine were to fail.

With items like Air Data Computers, it may be possible to fly with one u/s, but the failure may only be allowed on one of the three carried, and so they might need to be physically moved around to ensure the failure is from the correct position.

The procedural changes and limitations thrown up by the MELs make the final decision to accept or reject their application subject to the Captain's approval. For instance, an MEL might say that the aircraft is not to be flown in icing conditions, and perhaps that seems like no problem to an engineer who is working in 40º in Sydney when despatching an aircraft to an equally hot destination...but, icing conditions will exist at altitude no matter how hot it is on the ground, so that MEL is basically always unacceptable.

 

[docjames]

Thanks jb747.

 

[drross]

I know others have said it before, but this is a really interesting thread. Thanks jb747

 

[RooFlyer]

There's a set of quite huge 'books' put out by all of the manufacturers, called 'Minimum equipment lists' (MELs for short). Individual airlines can make the list more restrictive, but not less so.

<snip>

The procedural changes and limitations thrown up by the MELs make the final decision to accept or reject their application subject to the Captain's approval. For instance, an MEL might say that the aircraft is not to be flown in icing conditions, and perhaps that seems like no problem to an engineer who is working in 40º in Sydney when despatching an aircraft to an equally hot destination...but, icing conditions will exist at altitude no matter how hot it is on the ground, so that MEL is basically always unacceptable.

JB, I guess you may have simplified that last item, but at face value, it sounds like the manufacturer may be able to put in a MEL to the effect "don't fly in icing conditions", so that if a Captain decides to sensibly over-ride that, any adverse consequences are on his/her shoulders and the manufacturer gets itself off the hook. "Well, you knew full well we said not to fly the plane in those conditions."

More generally, do you find situations like this occur? The aircraft is issued with documentation / 'rules' that are simply unworkable, requiring exercise of a Captain's discretion, which essentially becomes a liability transfer to the Captain?

If so, do pilots/Captains have any protection via agreements with their employer, or otherwise?

 

[mjt57]

JB, just flew back in from London today (Emirates EK 404, B777).

We had to park facing away from the terminal and were bussed inside. Next to us was an SIA A380, presumably its pax were also offloaded via stairs, etc. That would've taken some time.

Question is, do you know what they're doing around that part of the airport which forced us not to use a gate?

Also, getting back to flying into DXB, when we landed there yesterday (Emirates A380) I noticed that the only non-Emirates aircraft was a QF 380. What was your view of the place, other than in terms of operating into or out of it?

 

[jb747]

JB, I guess you may have simplified that last item, but at face value, it sounds like the manufacturer may be able to put in a MEL to the effect "don't fly in icing conditions", so that if a Captain decides to sensibly over-ride that, any adverse consequences are on his/her shoulders and the manufacturer gets itself off the hook. "Well, you knew full well we said not to fly the plane in those conditions."

You cannot override an MEL. If you can't abide by the conditions, then it cannot be applied, and the aircraft remains on the ground. Imagine the avenues that would exist for the less scrupulous airline operations to bring pressure to bear if such overrides were allowed.

More generally, do you find situations like this occur? The aircraft is issued with documentation / 'rules' that are simply unworkable, requiring exercise of a Captain's discretion, which essentially becomes a liability transfer to the Captain?

If so, do pilots/Captains have any protection via agreements with their employer, or otherwise?

Ah, you mean the rule that says 'don't crash the aircraft'...so if you do, you must have broken the rules. I'd expect a court would consider that they weren't worth the paper they were written on.

 

[jb747]

JB, just flew back in from London today (Emirates EK 404, B777).

We had to park facing away from the terminal and were bussed inside. Next to us was an SIA A380, presumably its pax were also offloaded via stairs, etc. That would've taken some time.

I think we needed eight buses the other day. Very slow.

Question is, do you know what they're doing around that part of the airport which forced us not to use a gate?

What airport are you talking about. Melbourne? I expect the bays were simply full.

Also, getting back to flying into DXB, when we landed there yesterday (Emirates A380) I noticed that the only non-Emirates aircraft was a QF 380. What was your view of the place, other than in terms of operating into or out of it?

Opinion of the city or the airport?

The city seems interesting enough, and I'm sure will keep me amused taking pictures for a while yet.

The terminal is a mix of shops and big....and as such the same as every other new terminal in the world. The LED lighting outside is the brightest I've ever seen.....

 

[Major]

I recently watched a rerun of the "Gimli Glider" and wondered about current fuel situations.

As the Captain, at what stage of the pre flight do you decide on what fuel you want and how do you inform the ground staff ?

Has there been standardisation of fuel measurement between pounds/kilos/tonnes/ litres ?

Do you request an addition of....or a total of...?

 

[jb747]

I recently watched a rerun of the "Gimli Glider" and wondered about current fuel situations.

As the Captain, at what stage of the pre flight do you decide on what fuel you want and how do you inform the ground staff ?

Has there been standardisation of fuel measurement between pounds/kilos/tonnes/ litres ?

Do you request an addition of....or a total of...?

Well, the Americans are still the Americans, so I wouldn't be surprised if they order in fluid ounces. Since I left the military, I've only ever seen kilos and litres used. The trucks pump it onboard in litres, but we are only really interested in kilos, so it's converted on the paperwork. The aircraft measures the volume, but displays the result as kilos.

We order the fuel about an hour before departure. When we fill in the paperwork, it will contain the additional fuel (if any), the adjusted endurance, the new final fuel load, the take off and landing weights, and the new RTOW (regulated take off weigh, the maximum actually available for that departure, which could be a lot different than MTOW). A copy of this is passed to the ground staff. The engineers generally just come up to the coughpit and ask. The final fuel, at the completion of loading, is passed via the radio to load control.

Speaking of fuel, somebody asked a few weeks ago about water checks. Apparently they're done on a daily basis. The aircraft are pre-fuelled to about 50 tonnes, and it's allowed to settle for a few hours, then the content is checked.

 

[RooFlyer]

<snip>

The terminal is a mix of shops and big....and as such the same as every other new terminal in the world. The LED lighting outside is the brightest I've ever seen.....

Apologies for o/t diversion. In a former life, when I was in an Investment Bank (late '90s), and we were advising a UK client on potential purchase of a couple of the larger Australian airports, I recall a solid week of meetings with the client to get the inputs for valuation model. It was only on day 4 that we talked about aircraft, landing fees, and anything ex terminal building: capex and opex spend etc. Most of the week was spent talking about the terminal, retail, fees for taxis, retail, which nationalities spend the most#, did I say retail? etc etc.

For Brisbane, the Client asked if we could stop the then new Airport Train from stopping at 'their' airport, as it would reduce the taxi fee revenue ("AMAZING idea, Client, (grovel, fawn, grovel) but, um, that might prove a bit problematic ....").

Even then of course airports were basically shopping malls with an airstrip attached.

# South Koreans, at that time. Almost 50% more than any other nationality IIRC.

 

[jb747]

Apologies for o/t diversion. In a former life, when I was in an Investment Bank (late '90s), and we were advising a UK client on potential purchase of a couple of the larger Australian airports, I recall a solid week of meetings with the client to get the inputs for valuation model. It was only on day 4 that we talked about aircraft, landing fees, and anything ex terminal building: capex and opex spend etc. Most of the week was spent talking about the terminal, retail, fees for taxis, retail, which nationalities spend the most#, did I say retail? etc etc.

I don't know whether true or not, but the story did the rounds some years ago, that the Sydney owners planned on closing 07/25 as soon as 16L/34R was finished, and using the space for various non aviation functions. Apparently it came as a shock when they were informed that that would result in the airport being closed for quite a few weeks each year. Crosswinds weren't something that shop owners ever considered.....

The recent modifications at Melbourne, in which at least one bay was sacrificed so that they could fit more shops in (and also make the walk to the aircraft appreciably longer) was pretty typical...

 

[defurax]

Well, the Americans are still the Americans, so I wouldn't be surprised if they order in fluid ounces. Since I left the military, I've only ever seen kilos and litres used. The trucks pump it onboard in litres, but we are only really interested in kilos, so it's converted on the paperwork. The aircraft measures the volume, but displays the result as kilos.

Is there a temperature probe/sensor inside the aircraft fuel pipes or the fuel temperature to calculate density is provided only by the fuel supplier? I imagine that in places like Dubai or Uluru the fuel stored in trucks would go through quite a volume expansion and change in density between night and day?

 

[jb747]

Is there a temperature probe/sensor inside the aircraft fuel pipes or the fuel temperature to calculate density is provided only by the fuel supplier? I imagine that in places like Dubai or Uluru the fuel stored in trucks would go through quite a volume expansion and change in density between night and day?

There are innumerable temperature sensors in the aircraft fuel tanks.

The density is supplied when refuelling. I assume it's measured at the time, though I've never had cause to look. I don't know that the fuel temperature would change all that much at places that have very large amounts stored. The loaded fuel is never particularly hot, or cold.