Positioning to remote stand.
CH3CH2OH
Thread Starter
Positioning to remote stand.
On a 320 CEO yesterday returning from the Canaries to the UK. Inbound was about 45 mins late due to all the usual factors, this meant we would not make our departure slot. New slot was about 45 mins after the crew called ready and they were trying to negotiate an improvement.
We pushed back and started (not sure if only one or both) and then taxied to a remote stand and shut down again. The Captain advised that we had done this to remove dependence on ground services in order to be able to go at short notice which all seems eminently sensible. As it turns out we were able to get going again after about 10 mins waiting.
Does this type of operation have any impact on engine cycles and therefore time between maintenance ops, are there cool down timings required before restart or is this all fairly negligible in the overall scheme of things?
We pushed back and started (not sure if only one or both) and then taxied to a remote stand and shut down again. The Captain advised that we had done this to remove dependence on ground services in order to be able to go at short notice which all seems eminently sensible. As it turns out we were able to get going again after about 10 mins waiting.
Does this type of operation have any impact on engine cycles and therefore time between maintenance ops, are there cool down timings required before restart or is this all fairly negligible in the overall scheme of things?
Son of Slot
Super Senior Moderator
Super Senior Moderator
Hello 5711N0205W, I don't think I've seen you in the cabin before. What a very interesting question. I have oftended wondered that myself when you see E75/95s and A319s making short hops or postioning flights from, say, LGW to STN.
The following 2 users liked this post by S.o.S.:
CH3CH2OH
Thread Starter
Thanks S.o.S, I have been around these parts for a wee while though maybe not in this cabin recently.
Moderator
Does this type of operation have any impact on engine cycles and therefore time between maintenance ops, are there cool down timings required before restart or is this all fairly negligible in the overall scheme of things?
As for cool down before next start, it's a consideration, but manageable. There may be a maximum temperature at which fuel may be introduced during the start, to prevent a hot start. For my experience (starting "manual" turbine engines), you can prolong the cranking a little to reduce the engine temperatures during the start, then introduce the fuel. The important need is to prevent a hot start. If need be, the start can be aborted to prevent a hot start. But, if a start is aborted, the need for a cool down period is likely. FADEC turbine engines, which I have not flown, may be a little different.....
The following 2 users liked this post by Pilot DAR:
CH3CH2OH
Thread Starter
It’s actually normally the ground crew and tug drivers (AMS I’m looking at you) that are in short supply. Early Push and start and remote holding allows those personel to go on to the next job, rather than hang about waiting for your slot.
Most maintenance tasks are based on flying time ( airborne time only) and the taxi time is not recorded in techlog.
Most maintenance tasks are based on flying time ( airborne time only) and the taxi time is not recorded in techlog.
"Most maintenance tasks are based on flying time ( airborne time only) and the taxi time is not recorded in techlog."
Hmmm - I've spent as much time taxying around JFK and similar where the tax it time was almost identical to the flight time.............
Hmmm - I've spent as much time taxying around JFK and similar where the tax it time was almost identical to the flight time.............
Push and remote hold can be used for various reasons. One is autonomy as given by your Captain, another is to cheat the 'on time' stats as a push off stand 'on time' and a 45 minute (or 4.5 hr) delay elsewhere on the airfield is still 'on time' for the bean-counters - or at least it was in my last company.
Engine cycles? Never heard that raised as a consideration so assume cycles aren't an issue. I have a vague recollection that they only come into play if the aircraft is employed mainly or exclusively on short sectors (ie averaging well under an hour). For all normal ops they are not a limiting factor.
Cooling? As explained above jet engines don't need cooling periods as such. They can be re started as soon as they've been shut down - the only conideration is that the EGT is below the appropriate limiting figure and to achieve that with a hot engine you merely motor it for a few extra seconds to pull cold air through the core until the EGT is within limits and then fire it up. A hot engine does tend to flash-up with a bit more alacrity than a cold one though, you sometimes hear a definite 'bump' as it lights up. Hot start? Ditto as long as the EGT didn't get too high (you're supposed to prevent that...) which would require an engineering inspection and an awkward interview without coffee.
One of the considerations in remote holding is fuel consumption. With the modern attitude of some Captains to fuel policy (ie rigid adherence to minimum carriage) an hour burning the APU can leave one having to be a bit creative with fuel figures on occasion, and also tempt the more 'company minded' (ie uttely unimaginative and toady) Captains to turn off the aircon even in hot conditions in order to save fuel to the extreme discomfort of the pax. Remote holding on skosh fuel plus a longer delay might require a return to stand to refuel and that really buggers up everyone's day. It's also thoroughly unpleasant for the environment and neighbours, but where permitted (some airfields have strict limits on APU usage).
Engine cycles? Never heard that raised as a consideration so assume cycles aren't an issue. I have a vague recollection that they only come into play if the aircraft is employed mainly or exclusively on short sectors (ie averaging well under an hour). For all normal ops they are not a limiting factor.
Cooling? As explained above jet engines don't need cooling periods as such. They can be re started as soon as they've been shut down - the only conideration is that the EGT is below the appropriate limiting figure and to achieve that with a hot engine you merely motor it for a few extra seconds to pull cold air through the core until the EGT is within limits and then fire it up. A hot engine does tend to flash-up with a bit more alacrity than a cold one though, you sometimes hear a definite 'bump' as it lights up. Hot start? Ditto as long as the EGT didn't get too high (you're supposed to prevent that...) which would require an engineering inspection and an awkward interview without coffee.
One of the considerations in remote holding is fuel consumption. With the modern attitude of some Captains to fuel policy (ie rigid adherence to minimum carriage) an hour burning the APU can leave one having to be a bit creative with fuel figures on occasion, and also tempt the more 'company minded' (ie uttely unimaginative and toady) Captains to turn off the aircon even in hot conditions in order to save fuel to the extreme discomfort of the pax. Remote holding on skosh fuel plus a longer delay might require a return to stand to refuel and that really buggers up everyone's day. It's also thoroughly unpleasant for the environment and neighbours, but where permitted (some airfields have strict limits on APU usage).
Last edited by meleagertoo; 31st Mar 2024 at 09:42.
The following 2 users liked this post by meleagertoo:
That's the whole answer, nothing to add.
