Yan104
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Technical stop duration

Mon May 01, 2017 9:58 am

Hello,

Following a research on the Net and being an aviation enthusiast with a specific attraction for civil aviation, I discovered your friendly community to which I decided to register !! ... I would like to point out that being french speaker, my English might not be the most understandable, which is why I would ask you to be patient and understanding...

I've noticed that during a report on an Air France A380, just arrived from a flight it seems it assured on Los Angeles, therefore of a duration of 12h of flight, it was programmed 3h after his park for a new flight on New York!!.... This time of stop seemed rather short to me: personally, I play a simulation of airline management, and for my long-haul planes, I set a stopover of 50% of the duration of flight that they make, that is to say that if my A380 makes a 12-hour flight, I leave it parked at destination for 6 hours before its return flight time, this in my opinion to not keep the reactors operating on stresses too sustained, potentially increasing the risk of failure. I would like to know whether there are any technical constraints or other factors which determine the minimum duration of technical stop for different types of aircraft?

Thank you for your answers.
 
mmo
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Re: Technical stop duration

Mon May 01, 2017 10:06 am

Just to clarify, what you are talking about is not a technical stop. A technical stop would be one where there would be just aircraft servicing such as a fuel stop. What you talking about would be a flight termination. Where the aircraft is cleaned, re-catered, fueled, the lavs are dumped, cargo/bags are off loaded and maintenance items are completed for a turn around/thru flight.

Airlines don't make money with aircraft on the ground. It is not uncommon to see a 3 hour turn at the home hub of an airline. Although, 1+30 is adequate to service a wide-body. A lot depends on slots and other factors but 1.5-3 hours is very reasonable.

Your 50% of the flight time is way too long. As I said, utilization is the key to making money.
If we weren't all crazy we'd all go insane!
 
mxaxai
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Re: Technical stop duration

Mon May 01, 2017 11:56 am

Actually 3 hours are rather long. Regardless of flight duration, deplaning, cleaning, basic technical checks, refueling and loading need a certain time depending on the local infrastructure and the aircraft type. A typical narrowbody can do all that in less than 25 minutes. Widebodies on long-haul missions usually need about 1 hour because everything is larger and especially refueling takes somewhat longer.
A380: http://www.airbus.com/fileadmin/media_g ... 161201.pdf (Page 177)
A350: http://www.airbus.com/fileadmin/media_g ... -Nov16.pdf (Page 200)

Additional time may be neccessary for scheduled maintenance but not after every flight. This is being reduced, though:
http://www.mro-network.com/airframes/a3 ... ncy-design
The A350 XWB is designed to have no scheduled maintenance below 10 days, apart from some visual checks at transit or daily check. The target is to have a first interval check at 48 hours for visual inspection of wheels, tyres and brakes that can be easily and quickly performed. The next group of tasks concerns the oil monitoring level. These tasks can be performed with just one man in about one hour, including access time. (The A350 will have the capability to monitor, to some extent, the hydraulics liquid and rotable components through the OMS and its associated pages.)

A checks and base maintenance

The target interval is at 1,200 FH; this can be compared to a current A check (today typically at 800 FH for the A330), with a more flexible check content based on operator utilisation.

There will be multiple such tasks at 2,400 and 3,600 FH which will include some Variable Frequency Generator (VFG, ATA 24) oil filters and some light operational check which can be easily performed onboard the aircraft through the OMS. All this will reduce the grounding time, because these tasks can be easily performed overnight.
 
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Starlionblue
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Re: Technical stop duration

Mon May 01, 2017 12:07 pm

As mentioned above says, 3 hours is long. For a longhaul widebody, 80-90 minutes is plenty. Certainly in many cases it is longer due to the nature of the timetable, but we don't need 3 hours.

Here's a very rough example timeline of a turn. Can be shorter or longer.
- Minute 0. Block on.
- Minute 1. Door(s) open.
- Minute 20. All pax off.
- Minute 25. Cleaners/catering on board to clean and prep for next sector. Inbound crew off.
- Minute 35. Outbound crew on.
- Minute 45. Preliminary fuel figure ready. Fueling starts.
- Minute 50. Cargo loading starts. Cleaners off.
- Minute 55. Boarding starts. Engineer signs off the aircraft.
- Minute 60. Final fuel figure ready.
- Minute 65. Fueling completed.
- Minute 80. Cargo and pax loading ends. Turnaround coordinator confirms the final pax number and closes the cockpit door.
- Minute 82. Door(s) closes.
- Minute 85. Pushback.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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77west
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Re: Technical stop duration

Mon May 01, 2017 7:44 pm

As pointed out above, 90 minutes is what Airbus uses as a standard timeframe. This may vary depending on what ground equipment is available (refuel rate, 3 vs 1 or 2 jetways, catering etc)

Also, some airlines do layover for 6 or more hours due to flight times; airlines flying to South Africa often park their planes for extended times on the remote stands at either end. They will use this time for some light maintenance, cleaning etc if possible. This is also done by Qantas on their flights to LAX.
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frmrCapCadet
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Re: Technical stop duration

Tue May 02, 2017 1:27 pm

Starlionblue - what is involved with preliminary versus/and final fuel figure, obviously more complicated than my Prius.
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Dalmd88
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Re: Technical stop duration

Tue May 02, 2017 1:58 pm

Yan,

I loved your comment about not keeping the reactors running. I'm sure it is a translation thing. I've been an aircraft mechanic for nearly 30 years an have yet to run across a reactor. I know the US Air Force thought about it in the 1950, but deemed it too risky. I've found through the years that planes in motion tend to stay in motion. The longer they sit, the more problems creep up. I think the power up cycle on the airframe is worse in may ways than leaving it on.

Turbine engines like to stay running also. It would not be wise to leave them running at the gate, but I bet they would be happiest that way. Some of the longest service turbines are used as power generators. They rarely get turned off compared to their aviation brothers. I was on a cruise ship that was solely powered by a single GE CF6 core. All the electric load including propulsion was generated by that core for the entire week. Of course they had more than one, but said one usually sat idle.

As for servicing modern turbines really don't need much. Oil top off is the biggest through flight chore usually. Filters and such are done on overnight visits at around 500 hours of flight time. A lot of the airframe service would be done at that time. For the airframe on through flights checking hydraulic fluid and tire or brake changes are the biggest tasks. Tires and brakes can be deferred if they are within certain limits and done down line when the sit time is longer.
 
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Starlionblue
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Re: Technical stop duration

Tue May 02, 2017 2:35 pm

frmrCapCadet wrote:
Starlionblue - what is involved with preliminary versus/and final fuel figure, obviously more complicated than my Prius.


The reason for the two step process is because if the fueler had to wait for the final figure before starting to pump there would not be enough time to get the fuel on board. So you give the fueler a "standby fuel" figure based on the flight plan, then fine tune once you have the final weight.

(In your Prius you probably just "fill up", but you almost never fill the tanks in an airliner because a) you can't have full tanks and a full load without exceeding MTOW and b) filling up means burning fuel to carry fuel.)

In more detail:
- We start with the flight plan, which has planned weight and fuel figures. Typically just take the fuel figure from the flight plan, but sometimes we alter it based on various conditions (predicted weather looks a bit dodgy, expected delays, etc...). Then deduct 2-3 tons (on a 330/350) because you can only add fuel, not remove fuel already on board**, and you have a standby fuel figure. So if the final weight is lower than flight plan you want some room to decrease from prelim to final.
- Give the standby fuel figure to the fueler and he/she start pumping.
- When we get the final weight, we can figure out a final fuel figure. Give that to the fueler and he/she tops up to that exact number. Tanks are now at our requirement, and the seat belt sign goes on.

** Ok, so you can technically remove fuel already on board, but it is a hassle since you need a dedicated bowser, and then that specific fuel can only be used for company aircraft. Massive hassle. Bottom line: You'd rather go with "too much" fuel and burn a bit more than defuel. And to avoid that you leave wiggle room in the standby figure.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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77west
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Re: Technical stop duration

Tue May 02, 2017 8:03 pm

Starlionblue wrote:
frmrCapCadet wrote:
Starlionblue - what is involved with preliminary versus/and final fuel figure, obviously more complicated than my Prius.


The reason for the two step process is because if the fueler had to wait for the final figure before starting to pump there would not be enough time to get the fuel on board. So you give the fueler a "standby fuel" figure based on the flight plan, then fine tune once you have the final weight.


There is also the situation that you end up with too much fuel, and have to offload fuel "defuel" which I believe is not a process that encourages happy thoughts...

This is a cool post by a captain for Virgin Aus:

http://www.infinidim.org/performance-limited-takeoff
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Starlionblue
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Re: Technical stop duration

Wed May 03, 2017 6:24 am

77west wrote:

There is also the situation that you end up with too much fuel, and have to offload fuel "defuel" which I believe is not a process that encourages happy thoughts...



I imagine a defueling event would result in tea and biscuits with the chief pilot. It is really, really something you want to avoid.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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77west
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Re: Technical stop duration

Thu May 04, 2017 2:10 am

Starlionblue wrote:
77west wrote:

There is also the situation that you end up with too much fuel, and have to offload fuel "defuel" which I believe is not a process that encourages happy thoughts...



I imagine a defueling event would result in tea and biscuits with the chief pilot. It is really, really something you want to avoid.


Especially at an outstation where the fuel cannot be loaded easily on another of your own aircraft.
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Yan104
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Re: Technical stop duration

Sun May 07, 2017 11:12 am

Hi guys,

Sorry, I did not have time to come back to the forum earlier because I was busy ... I see that there have been quite a few interesting interventions which I thank you ... I will answer the Point by point to each of them.
I see on the whole other frenchspeakers forums discussions in which I participated that a certain unanimity emerges for a delay of stop of final flight of 3h maximum for a long-haul before it starts again in the sense Inverse ... I even saw graphics of TRT the same style as that propounded by mxaxai that I did not really know how to interpret.

mmo

Just to clarify, what you are talking about is not a technical stop. A technical stop would be one where there would be just aircraft servicing such as a fuel stop. What you talking about would be a flight termination. Where the aircraft is cleaned, re-catered, fueled, the lavs are dumped, cargo/bags are off loaded and maintenance items are completed for a turn around/thru flight.
Airlines don't make money with aircraft on the ground. It is not uncommon to see a 3 hour turn at the home hub of an airline. Although, 1+30 is adequate to service a wide-body. A lot depends on slots and other factors but 1.5-3 hours is very reasonable.
Your 50% of the flight time is way too long. As I said, utilization is the key to making money.


I do know that there are a lot of taxes that companies have to pay by putting their planes on airports in addition to take-off / landing flights (taxes depending on the size of the aircraft, taxes per passenger, and i forgot some others...). I have no doubt that the size of the airplane depends on the amount of time it takes to get on the ground: an ATR-72 will not take the same time as an ERJ-190, just like an A318 compared to an A321. I was wondering precisely if there is not a possibility to "standardize" these TRT times by aircraft types for example on ATR, B737 / A320, B767 / A330 etc ...?

mxaxai

Actually 3 hours are rather long. Regardless of flight duration, deplaning, cleaning, basic technical checks, refueling and loading need a certain time depending on the local infrastructure and the aircraft type. A typical narrowbody can do all that in less than 25 minutes. Widebodies on long-haul missions usually need about 1 hour because everything is larger and especially refueling takes somewhat longer.


I think you exaggerate a little while estimating that one hour of stopover is sufficient for a widebody including all the operations on the ground !! ... The graph of TRT that you had the kindness to share with us for the A380 mentions a minimum time of turnaround of 90mn if the gangways of embarkation of the lower and upper decks are used simultaneously for boarding passengers (I know because a friend in another french forum presented it to me) ... And I also wondered whether for long-haul bi-reactors the time of cleaning of the cabin passenger and re-supply of kerosene are the same for example for B777-200 / 300 or A330-200 / 300 ? Do stewards / hostesses not train during their first train or refresher courses under different scenarios of cleaning a passenger cabin, to refine their treatment procedures in a way that increases speed and efficiency, from the cleanest with passengers endowed with a high sense of good citizenship, to the dirtiest with rather unruly passengers, and do the companies not re-define the standard TRT charts proposed by the manufacturers according to the reality of the ground? Does the cultural factor not play on the cleanliness of passenger cabins according to the lines and regions of the world served?! ...

Concerning the fuelling I also know that now in some airports the kerosene feeding of airplanes is done by an underground network of pipelines leading to the locations of airplanes: the fuel is then pumped from the ground and directly injected into the tanks of the planes, without needing a tanker truck . How long does it take a full tank of gas to run a bi-reactor? Does it depend on aircraft types and sub-types (B777-200 / 300, A330-200 / 300 etc)?
I have also heard that to reduce the time in fueling, low-cost make full of tanks to ensure at least a round-trip on certain lines whose range of action is less than the maximum flight time for narrowbodies aircrafts(B737/A320) (Which seems to me to be more or less at 5h autonomy): is it true? If so, is it not a hazardous approach in relation to the traffic on the ground and engorgement near the runways? Does it not extend the take-off distance especially with a plane filled to the max, whistling at great pace tanks as the reactors are at their maximum during this phase?

I'll stop here for today.
 
mmo
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Re: Technical stop duration

Sun May 07, 2017 11:38 am

I have to admit, you lost me!

In a true technical stop, there is no tax/passenger, just the landing fees and any other fees associated with the airport. I was merely trying to point out your terminology is incorrect! It is not a technical stop you are referring to. What you are referring to is a flight termination.

There are boundless references you can find on the internet which will have a "recommended" turn time. However, most airlines will usually have a minimum turn time and a desired turn time. And the turn times are pretty much standardized.
If we weren't all crazy we'd all go insane!
 
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Starlionblue
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Re: Technical stop duration

Sun May 07, 2017 12:07 pm

Yan104 wrote:

I think you exaggerate a little while estimating that one hour of stopover is sufficient for a widebody including all the operations on the ground !! ... The graph of TRT that you had the kindness to share with us for the A380 mentions a minimum time of turnaround of 90mn if the gangways of embarkation of the lower and upper decks are used simultaneously for boarding passengers (I know because a friend in another french forum presented it to me) ... And I also wondered whether for long-haul bi-reactors the time of cleaning of the cabin passenger and re-supply of kerosene are the same for example for B777-200 / 300 or A330-200 / 300 ? Do stewards / hostesses not train during their first train or refresher courses under different scenarios of cleaning a passenger cabin, to refine their treatment procedures in a way that increases speed and efficiency, from the cleanest with passengers endowed with a high sense of good citizenship, to the dirtiest with rather unruly passengers, and do the companies not re-define the standard TRT charts proposed by the manufacturers according to the reality of the ground? Does the cultural factor not play on the cleanliness of passenger cabins according to the lines and regions of the world served?! ...

Concerning the fuelling I also know that now in some airports the kerosene feeding of airplanes is done by an underground network of pipelines leading to the locations of airplanes: the fuel is then pumped from the ground and directly injected into the tanks of the planes, without needing a tanker truck . How long does it take a full tank of gas to run a bi-reactor? Does it depend on aircraft types and sub-types (B777-200 / 300, A330-200 / 300 etc)?
I have also heard that to reduce the time in fueling, low-cost make full of tanks to ensure at least a round-trip on certain lines whose range of action is less than the maximum flight time for narrowbodies aircrafts(B737/A320) (Which seems to me to be more or less at 5h autonomy): is it true? If so, is it not a hazardous approach in relation to the traffic on the ground and engorgement near the runways? Does it not extend the take-off distance especially with a plane filled to the max, whistling at great pace tanks as the reactors are at their maximum during this phase?

I'll stop here for today.


Answering some of that:
- Fueling times mostly depend on how much fuel you need. On a widebody, they're not typically limiting. That is, cleaning and loading take longer than fueling. Also two trucks obviously mean shorter fueling time than one.
- Flight attendants don't clean the plane. They do securing checks after a sector and security checks before a sector.
- Even with underground pipelines for fuel, you need a fuel truck to actually pump the fuel. The process is transparent to us pilots. We don't care if it comes from a bowser or from a pumping truck.
- I can't remember the figure off-hand but filling up a widebody is a question of maybe 30 minutes. However I've so far never seen full tanks. Filling up completely is a rare phenomenon. Again, typically not a limiting factor.
- There's always enough fuel for the upcoming sector. In some cases due to differences in fuel prices it is advantageous to load up extra fuel in order to minimize the fuel purchase at the next port, a practice known as "tankering". The plane will obviously weigh more for the first take-off than if we only had the required fuel for the sector. However this doesn't mean the take-off is unsafe. We always make the take-off calculations based on the actual weight.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Dalmd88
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Re: Technical stop duration

Sun May 07, 2017 12:31 pm

I think what we have here is a failure to communicate. The OP stated his English is very spotty. Judging by his posts I would guess he is using a program to translate posts. The terminology of aviation is getting scrambled in the process.
 
strfyr51
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Re: Technical stop duration

Sun May 07, 2017 2:05 pm

Starlionblue wrote:
As mentioned above says, 3 hours is long. For a longhaul widebody, 80-90 minutes is plenty. Certainly in many cases it is longer due to the nature of the timetable, but we don't need 3 hours.

Here's a very rough example timeline of a turn. Can be shorter or longer.
- Minute 0. Block on.
- Minute 1. Door(s) open.
- Minute 20. All pax off.
- Minute 25. Cleaners/catering on board to clean and prep for next sector. Inbound crew off.
- Minute 35. Outbound crew on.
- Minute 45. Preliminary fuel figure ready. Fueling starts.
- Minute 50. Cargo loading starts. Cleaners off.
- Minute 55. Boarding starts. Engineer signs off the aircraft.
- Minute 60. Final fuel figure ready.
- Minute 65. Fueling completed.
- Minute 80. Cargo and pax loading ends. Turnaround coordinator confirms the final pax number and closes the cockpit door.
- Minute 82. Door(s) closes.
- Minute 85. Pushback.

just exactly WHAT airplane are you talking about and just HOW much fuel are you loading?? Because 20 minutes might be fine for a narrowbody but for a
B777 or a B747 20 minutes isn't enough even with 2 trucks for a full load.
 
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Starlionblue
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Re: Technical stop duration

Sun May 07, 2017 2:39 pm

strfyr51 wrote:
Starlionblue wrote:
As mentioned above says, 3 hours is long. For a longhaul widebody, 80-90 minutes is plenty. Certainly in many cases it is longer due to the nature of the timetable, but we don't need 3 hours.

Here's a very rough example timeline of a turn. Can be shorter or longer.
- Minute 0. Block on.
- Minute 1. Door(s) open.
- Minute 20. All pax off.
- Minute 25. Cleaners/catering on board to clean and prep for next sector. Inbound crew off.
- Minute 35. Outbound crew on.
- Minute 45. Preliminary fuel figure ready. Fueling starts.
- Minute 50. Cargo loading starts. Cleaners off.
- Minute 55. Boarding starts. Engineer signs off the aircraft.
- Minute 60. Final fuel figure ready.
- Minute 65. Fueling completed.
- Minute 80. Cargo and pax loading ends. Turnaround coordinator confirms the final pax number and closes the cockpit door.
- Minute 82. Door(s) closes.
- Minute 85. Pushback.

just exactly WHAT airplane are you talking about and just HOW much fuel are you loading?? Because 20 minutes might be fine for a narrowbody but for a
B777 or a B747 20 minutes isn't enough even with 2 trucks for a full load.


330.

As mentioned "very rough" example timeline. Not meant to be super-accurate. The point was that 3 hours is not needed.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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Horstroad
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Re: Technical stop duration

Sun May 07, 2017 6:02 pm

There are daily checks and weekly checks or other small maintenance (more Service - ) events that can take place during these 3 hours. Some scheduled maintenance items from larger checks might be added to the daily/weekly checks to extend the time between these bigger checks that require a hangar visit.
Or the rectification of a MEL item was accomplished between the flights.
You don't always need the plane again right away. Just because you have the aircraft availlable does not make the following flight depart an hour earlier. So you use that time by scheduling some maintenance which might save some time tomorrow or next week when the flight schedule is tighter.
 
Budgie099
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Re: Technical stop duration

Mon May 08, 2017 2:51 am

When aircraft are on the ground for much longer than the minimum necessary, are they normally towed away to some kind of remote stand for the wait, or is it common for aircraft to sit at a terminal gate for hours and hours? I'm sure it must depend on how well-utilised the gates at this airport are, but what is the norm?

I know QF moves their A380s to a remote stand at LHR frequently/regularly. Is moving aircraft from the gate more common for visiting airlines, when compared to lets say BA or VS in Heathrow, KLM in Amsterdam, etc?
 
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Starlionblue
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Re: Technical stop duration

Mon May 08, 2017 2:58 am

Budgie099 wrote:
When aircraft are on the ground for much longer than the minimum necessary, are they normally towed away to some kind of remote stand for the wait, or is it common for aircraft to sit at a terminal gate for hours and hours? I'm sure it must depend on how well-utilised the gates at this airport are, but what is the norm?

I know QF moves their A380s to a remote stand at LHR frequently/regularly. Is moving aircraft from the gate more common for visiting airlines, when compared to lets say BA or VS in Heathrow, KLM in Amsterdam, etc?


AFAIK there isn't really a norm. It depends on the airport and on the time. If it is a quiet period, the plane might sit at the gate for 6 hours. If the airport needs the gate, the plane is towed away.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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Francoflier
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Re: Technical stop duration

Mon May 08, 2017 6:55 am

Dalmd88 wrote:
Yan,

I loved your comment about not keeping the reactors running. I'm sure it is a translation thing.


It is. Colloquial French for jet engine is 'reacteur' which translates literally to reactor...
It is called a reactor because it is one, technically, in which fuel and air are mixed and react chemically.
The technical name stuck in the common language and is now commonly applied to jet engines, in the same way the same term stuck in the english language, except that it refers to the nuclear kind...

Sorry about the OT semantics lecture.
:sorry:
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Starlionblue
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Re: Technical stop duration

Mon May 08, 2017 7:03 am

Francoflier wrote:
Dalmd88 wrote:
Yan,

I loved your comment about not keeping the reactors running. I'm sure it is a translation thing.


It is. Colloquial French for jet engine is 'reacteur' which translates literally to reactor...
It is called a reactor because it is one, technically, in which fuel and air are mixed and react chemically.
The technical name stuck in the common language and is now commonly applied to jet engines, in the same way the same term stuck in the english language, except that it refers to the nuclear kind...

Sorry about the OT semantics lecture.
:sorry:


Italian has the same quirk with reactor.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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77west
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Re: Technical stop duration

Mon May 08, 2017 7:22 am

Budgie099 wrote:
When aircraft are on the ground for much longer than the minimum necessary, are they normally towed away to some kind of remote stand for the wait, or is it common for aircraft to sit at a terminal gate for hours and hours? I'm sure it must depend on how well-utilised the gates at this airport are, but what is the norm?

I know QF moves their A380s to a remote stand at LHR frequently/regularly. Is moving aircraft from the gate more common for visiting airlines, when compared to lets say BA or VS in Heathrow, KLM in Amsterdam, etc?


Gate fees can be quite expensive so leaving it sitting there for hours on end is not always the best option, and often they are towed away, but as mentioned, it really depends. If it is an airline-owned terminal and they don't have fees by the minute, and don't need the gate, they may leave it there for a while. If this is done overnight, or for long periods, they often close all the doors, seal them with security tape and pull back the jetways. (same with a remote stand; they wont just leave it there open if the cleaners and so on are done.)

Then 90 minutes or so before departure (long-haul) it is towed back to the gate to begin loading, catering etc. Often the engineering team will do the power-up, various checks etc so the flight crew get a plane pretty much ready for the pre-flight prep to begin.

As you mention, yes, moving to a remote stand may be more common for visiting airlines as if the airline rents/owns the entire terminal, it would have less financial need to move them to remote stands.

Depends on the airport though, here at AKL they have under-invested in jetway gates so badly even normal A380 operations sometimes require boarding via busses and remote stands....
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BravoOne
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Re: Technical stop duration

Wed May 10, 2017 11:35 am

I think these guys are available during the off season. They could set some new standards for a quick turn.

https://www.youtube.com/watch?v=LkVX7Ahr04o
 
mxaxai
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Re: Technical stop duration

Wed May 10, 2017 10:00 pm

Starlionblue wrote:
Answering some of that:
- Flight attendants don't clean the plane. They do securing checks after a sector and security checks before a sector.
- I can't remember the figure off-hand but filling up a widebody is a question of maybe 30 minutes. However I've so far never seen full tanks. Filling up completely is a rare phenomenon. Again, typically not a limiting factor.

I am quite sure that some low-cost carriers do assign cleaning tasks to the flight attendants. Not the thorough cleaning performed at the end of the day but a guick walk-through to pick up any left-over garbage, check for lost items, remove spilled liquids if necessary. Then a short tidy-up of the bathrooms follows and garbage bags are removed from the plane. After some 5 to 15 minutes, the next passengers embark. It saves the company the hassle of supplying a full cleaning crew & truck every time.

You are probably correct but during the days of twin-engine narrowbody TATL, would the aircraft in question not rather run out of fuel volume than fuel weight? The tanks and wings of the 757 and A321 are relatively small compared to typical widebodies.
 
thegman
Posts: 513
Joined: Wed Nov 12, 2008 5:30 am

Re: Technical stop duration

Sat May 13, 2017 5:56 pm

Starlionblue wrote:
- Even with underground pipelines for fuel, you need a fuel truck to actually pump the fuel. The process is transparent to us pilots. We don't care if it comes from a bowser or from a pumping truck.

I'm going to say something to the contrary about this.

I care a lot whether the airfield has what we call 'fuel pits' that is pipes under the parking spot, or if they use trucks. If they are using trucks I also care how large their trucks are and how may they have.

Some places I go only have small trucks and it may take 4 full trucks to get me the load I need. Oh and of course they only have 2 trucks so in the middle of my fueling they are going to need to go back to where the fuel is stored and fill up again and drive out to me.

I've seen it take 3 hours to get ~100,000 lbs of fuel.
 
Newbiepilot
Posts: 1392
Joined: Tue Aug 30, 2016 10:18 pm

Re: Technical stop duration

Sat May 13, 2017 6:21 pm

Starlionblue wrote:
As mentioned above says, 3 hours is long. For a longhaul widebody, 80-90 minutes is plenty. Certainly in many cases it is longer due to the nature of the timetable, but we don't need 3 hours.

Here's a very rough example timeline of a turn. Can be shorter or longer.
- Minute 0. Block on.
- Minute 1. Door(s) open.
- Minute 20. All pax off.
- Minute 25. Cleaners/catering on board to clean and prep for next sector. Inbound crew off.
- Minute 35. Outbound crew on.
- Minute 45. Preliminary fuel figure ready. Fueling starts.
- Minute 50. Cargo loading starts. Cleaners off.
- Minute 55. Boarding starts. Engineer signs off the aircraft.
- Minute 60. Final fuel figure ready.
- Minute 65. Fueling completed.
- Minute 80. Cargo and pax loading ends. Turnaround coordinator confirms the final pax number and closes the cockpit door.
- Minute 82. Door(s) closes.
- Minute 85. Pushback.


Those are aggressive numbers for an international flight but good for a 767 or smaller A330. I would say on average widebodies get two hours on the ground. An A380 or 747 likely gets longer.

Cleaners usually get 20 minutes on a 747 or A380. It would take 30 people to clean an A380 in 10 minutes.

As others mentioned a full fuel load takes 60-90 minutes.

Many airlines are giving 40-45 minutes for boarding.
 
wpnstroop
Posts: 8
Joined: Fri May 19, 2017 1:27 pm

Re: Technical stop duration

Fri May 19, 2017 4:45 pm

Our planes are cleaned after EVERY flight...not necessarily well, but cleaners show up. On the Virgin 787 contract we work on, the plane is scheduled for 3 hrs down time. There are about 12 cleaners on that plane for ABOUT an hour and a half. Maintenance wise, we do a walk around, check fluids, walk the cabin real quick, check the flight deck/logbook for defects and clear them as required, play games on our phones for a few minutes, raid the galley for chocolate, monitor the fueling (while playing games on our phones) then kick the plane out. I think I MIGHT have used a screwdriver once or twice on the plane...other than that, it is pretty uneventful as far as mechanics are concerened.

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