Single engine taxi
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Single engine taxi
1) With the massive fuel increases, I just wondered whether single engine taxi OUT (to the runway) is now commonplace among airlines nowadays, and whether this is awkward for pilots or whether it's not a problem. I would imagine (silly though it may sound) that the aircraft is harder to control with one engine, and would want to swing to the left (or right). Is this so?
Also, could someone please give me the A320 procedure for a taxy out? I understand on taxi IN, you simply switch on the APU, flick on the Y ELEC Pump (to save the PTU) and get onto stand, flicking the Y pump off once ENG 1 is shut down.
But how do you do a taxy OUT single engine on the 320?
Cheers
1234
Also, could someone please give me the A320 procedure for a taxy out? I understand on taxi IN, you simply switch on the APU, flick on the Y ELEC Pump (to save the PTU) and get onto stand, flicking the Y pump off once ENG 1 is shut down.
But how do you do a taxy OUT single engine on the 320?
Cheers
1234
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Never seen anyone Taxi out with one at my company (737NG), we are also a procedure crazy company and there is no documented procedure for taxi out on one so I would be very hesitant to try, because for sure if you made an error and took off with the Packs or bleeds misconfigured you would be shot! More then all this however is that we mainly operate to secondary airports, where taxi times in and out are very rarely more then 5 mins, in which case you need to allow time for warm up and cool down anyway.
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More of a problem is the increase thrust needed to taxi the aircraft and the subsequent excessive jet blast that affects those on the ground. I personally think it should be banned.
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Nearly every US carrier endorses SE taxi in/out. The notable exception being Southwest. Strangely the European consensus on these boards is that it's similar to juggling flaming batons. We do it every single leg unless a very short taxi, or contaminated surfaces. Also on our A320s we don't bother to crank the APU on taxi-in, just Y Pump on and Master Off. It's really not too much trouble, and a competent FO can flick the necessary switches in his sleep.
And to answer the OPs question: Leave APU running, Y Pump On, Eng 2 Gen Off. Then when it's time: Y Pump Off, Eng 2 Start, Eng 2 Gen On (with brakes and steering neutral), APU Off.
IIRC this doesn't hardly resemble the FCOM procedure.
And to answer the OPs question: Leave APU running, Y Pump On, Eng 2 Gen Off. Then when it's time: Y Pump Off, Eng 2 Start, Eng 2 Gen On (with brakes and steering neutral), APU Off.
IIRC this doesn't hardly resemble the FCOM procedure.
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Yes the system copes! It`s a bus... 
On the 737 you would loose some elecs, but not on the bus, 1 engine gen copes with all systems. But not recommended by airbus, before Eng master off, make sure that APU is available, so that elecs will transfer from that gen to APU and not the other eng gen.
Procedures for single eng taxi out on the A320... we do it often!
-Start engine 1 in order to have green sys pressurized by eng pump, because of brakes and steering
-Yellow elec pum on before taxi
-keep APU running
-make the normal after start scan, but hold the after start checklist and all other usual checks and briefings and DONT do the flight controls check (but they will be done after the after start checklist anyway).
When it`s time to start Eng 2:
-Yellow pump off
-start the engine
-revise status page
-perform after start checklist
-APU off
-all normal procedures thereafter (they will take about 3 minutes, the number you need for engine warm up when eng cold)
Now remember, don`t do it when:
-contaminated surfaces
-heavy aircraft
And know the airport you`re on. Know the taxiways and their slope.
Easy procedure to do and quite entertaining...
enjoy
On the 737 you would loose some elecs, but not on the bus, 1 engine gen copes with all systems. But not recommended by airbus, before Eng master off, make sure that APU is available, so that elecs will transfer from that gen to APU and not the other eng gen.
Procedures for single eng taxi out on the A320... we do it often!
-Start engine 1 in order to have green sys pressurized by eng pump, because of brakes and steering
-Yellow elec pum on before taxi
-keep APU running
-make the normal after start scan, but hold the after start checklist and all other usual checks and briefings and DONT do the flight controls check (but they will be done after the after start checklist anyway).
When it`s time to start Eng 2:
-Yellow pump off
-start the engine
-revise status page
-perform after start checklist
-APU off
-all normal procedures thereafter (they will take about 3 minutes, the number you need for engine warm up when eng cold)
Now remember, don`t do it when:
-contaminated surfaces
-heavy aircraft
And know the airport you`re on. Know the taxiways and their slope.
Easy procedure to do and quite entertaining...
enjoy
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We aren't taxiing out single engine yet! - but we are txiing in single eng if taxi time over 4min'ish.
Have done a fair bit of 'push and parking' recently to ensure on-time push mainly due to our ground operators dissapearing if we have incurred a slot. When doing this we have shut-down both engines at the hold using only the APU. Care must be taken to ensure ALL checklist items are complete, otherwise you could miss something.
I would imagine that sooner or later we will adopt a single eng taxi out policy as in the US, just a matter of time IMHO.
Have done a fair bit of 'push and parking' recently to ensure on-time push mainly due to our ground operators dissapearing if we have incurred a slot. When doing this we have shut-down both engines at the hold using only the APU. Care must be taken to ensure ALL checklist items are complete, otherwise you could miss something.
I would imagine that sooner or later we will adopt a single eng taxi out policy as in the US, just a matter of time IMHO.
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On the 737 you would loose some elecs, but not on the bus, 1 engine gen copes with all systems. But not recommended by airbus, before Eng master off, make sure that APU is available, so that elecs will transfer from that gen to APU and not the other eng gen.
I'm surprised an airline operates a procedure not recommended by Airbus.
-Yellow pump off
-start the engine
-revise status page
-perform after start checklist
-APU off
-all normal procedures thereafter (they will take about 3 minutes, the number you need for engine warm up when eng cold)
-start the engine
-revise status page
-perform after start checklist
-APU off
-all normal procedures thereafter (they will take about 3 minutes, the number you need for engine warm up when eng cold)
Also, can you start engine whilst taxying, or does the aircraft have to be stationary?
1234
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I use to stop two engines when taxi in if I have to wait for the parking or long taxiing 
(A343). The only consideration is the hyd for the brakes (Y elec pump on the A320) and very important to wait at least 3 minutes to shutdown the engines. The same aplies when taxi out. The more important cuestion is to warm up 3 minutes before aplying TO PWR. On the Bombardier CRJ it is very usual to taxi on one engine because you have to be braking all the way up, or using the reversers, with two engines at idle. There has been a Bombardier circular about a company that broke one engine two times during the TO. The circular explained that it is important to warmup for the rings of the turbine axis to get its work temperature and seal correctly. Otherwise you can damage the engine and loose it during the TO 
(A343). The only consideration is the hyd for the brakes (Y elec pump on the A320) and very important to wait at least 3 minutes to shutdown the engines. The same aplies when taxi out. The more important cuestion is to warm up 3 minutes before aplying TO PWR. On the Bombardier CRJ it is very usual to taxi on one engine because you have to be braking all the way up, or using the reversers, with two engines at idle. There has been a Bombardier circular about a company that broke one engine two times during the TO. The circular explained that it is important to warmup for the rings of the turbine axis to get its work temperature and seal correctly. Otherwise you can damage the engine and loose it during the TO
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Why.
Could you imagine a situation where you taxi out with one eng and when it is time to start the other eng it does not start and you have a start fault.
Imagine being no. 2 for t.off and having seven a/cs behind you.
wouldn't the whole idea of doing a single eng taxi be defeated by the amount of fuel used for returning back.
We do single eng taxi after landing regularly, the procedure is clearly laid down
in the fcom. And really it is no big deal, there is only a minimum amount of nose wheel steering required to keep the a/c on the centreline. And almost never a need to open pwr to keep the a/c moving.
Imagine being no. 2 for t.off and having seven a/cs behind you.
wouldn't the whole idea of doing a single eng taxi be defeated by the amount of fuel used for returning back.
We do single eng taxi after landing regularly, the procedure is clearly laid down
in the fcom. And really it is no big deal, there is only a minimum amount of nose wheel steering required to keep the a/c on the centreline. And almost never a need to open pwr to keep the a/c moving.
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kkanthony
Where does it say you can not single taxi out?
Where does it say you can not start without maintenance being present?
Where does it say you need maintenance on a headset to start?
Fact you CAN and we do for ALL of them!
cj1234 ..... taxi out on 1 eng is no probs on the bus
-Y pump on
-Start no.1
-After start scan/actions (just leave APU running)
-Taxi
-5 mins before TO,
-APU bleed on
-Y Pump off
-Start Eng 2
-APU+Bleed off
-Check Flt Cont.
-TO Conf. Test
Off you go, and the world is a greener place ... Yippy
Where does it say you can not single taxi out?
Where does it say you can not start without maintenance being present?
Where does it say you need maintenance on a headset to start?
Fact you CAN and we do for ALL of them!
cj1234 ..... taxi out on 1 eng is no probs on the bus
-Y pump on
-Start no.1
-After start scan/actions (just leave APU running)
-Taxi
-5 mins before TO,
-APU bleed on
-Y Pump off
-Start Eng 2
-APU+Bleed off
-Check Flt Cont.
-TO Conf. Test
Off you go, and the world is a greener place ... Yippy
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Could you imagine a situation where you taxi out with one eng and when it is time to start the other eng it does not start and you have a start fault.
Imagine being no. 2 for t.off and having seven a/cs behind you.
wouldn't the whole idea of doing a single eng taxi be defeated by the amount of fuel used for returning back.
Imagine being no. 2 for t.off and having seven a/cs behind you.
wouldn't the whole idea of doing a single eng taxi be defeated by the amount of fuel used for returning back.
No way! How many times have you had trouble starting an engine?
I`m a pilot with the airlines for 10 years and so far had only 5 aborted engine start that i can remember. Only 2 of them made return to the gate. An "Igniter fault" and a "no oil pressure" (later prooved to be an instrument failure)
The most comon reason for an aborted engine start is an igniter fault. On the 737, an igniter B fault was a no go item and would make you return to the gate, but on the A320 unless your flying ETOPS, there are no restricions. Just write it down on the Tech log and go on.
Once again know what you are doing, if taxing out SE, be prepared for it, know your aircraft, for example:
- be ahead of the aircraft, think about what failures you may get and what will you do. Statistically you might have an igniter fault
- according to regs, MEL is not applicable after the aircraft is moving under own power. But if taxing SE, consider the MEL applicable until 2nd engine start is completed.
And one more question...
How many times have you had to return to the gate due to other problems non related with engine start?
I`ve had several. ELAC fault, spoiler fault, Nose wheel steering fault, hydraulic fault. Statistically you will return to the gate for other reasons rather then an engine start fault.
SO, once again, YES its OK to taxi SE. Even if you do have an engine start fault, it`s not embarassing having to return to the gate...
Cheers,
safe flying
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CJ1234
Yes it is
You can do it while taxing. I prefer to do it stationary at the holding point when we have several aircraft ahead. IF I`m number 1, or 2 or 3 for departure, I`ll do it taxing, but I`ll have my copilot do it for me, as I`m busy taxing.
Cheers
Just to confirm - it's prefectly alright to turn the Y ELEC pump off FIRST, then start the engine. Is that right?
Also, can you start engine whilst taxying, or does the aircraft have to be stationary?
Cheers
I've done quite a few S/E taxi outs on the 777... Well, shut one down when confronted with a long delay and a need to keep moving. Unfortunately, our manuals have been changed (Boeing?) to forbid S/E taxi above MLW, I guess due to jet blast.
Came out of JFK last year on a Sunday morning. Asked ATC if there were any delays: "No". Taxied round the corner to find about 60 aircraft in front; nearly two hours later got to take off. If we hadn't shut down one we'd have been back for more fuel and another long wait...
I don't have a problem with starting an engine a few minutes before launch - if it doesn't want to go then I don't particularly want to fly with it anyway!
Came out of JFK last year on a Sunday morning. Asked ATC if there were any delays: "No". Taxied round the corner to find about 60 aircraft in front; nearly two hours later got to take off. If we hadn't shut down one we'd have been back for more fuel and another long wait...
I don't have a problem with starting an engine a few minutes before launch - if it doesn't want to go then I don't particularly want to fly with it anyway!
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Came out of JFK last year on a Sunday morning. Asked ATC if there were any delays: "No". Taxied round the corner to find about 60 aircraft in front; nearly two hours later got to take off. If we hadn't shut down one we'd have been back for more fuel and another long wait...
Do you mean you shut down an engine after it had been started when you saw all those aircraft ahead?
Interesting...
I had never tought about it... IŽll keep that one to ask the maintenance guys. By the way does your company have anything written about that... another engine cycle Vs fuel saved... I`m just interested to know.Don`t fly the 777, but I remember reading some time ago, that on the B773, you`re not allowed to taxi SE anytime. Maybe any ppruner flying the B773 could confirm that.
Lots of power, those GE90-115!
