Airbus Drivers: Single-Engine Taxi 'n APUs

derg

derg

Apparently a "terse" writer
Staff member
Do you single engine taxi?

And if you do, do you have the APU on or off?
 
Why would you turn the APU off? You guys like cross bleed starts? Not being an ass just wondering the logic.
 
Don't fly the A320 series, but I spend a lot of time up front on ours and don't think I have ever seen the crew shut down the APU when doing a single engine taxi.

That being said, our SOPs are pretty harmonious across all the fleet types and on my type, the APU is running if doing a single engine taxi out. It's at the Captain's discretion on taxi in.
 
Cool.

Well the question was very specific as we generally would shut the APU down and crossbleed the critical engine but now, immediately, we're directed to burn the APU.
 
@Derg

I had some time to kill, so I pulled our manual on the A320.

It directs the crew to leave the APU running if taxiing single engine with the X BLEED in AUTO. Further states that an APU start is more efficient than a crossbleed start.


Don't know if that help or not.
 
Derg said:
Cool.

Well the question was very specific as we generally would shut the APU down and crossbleed the critical engine but now, immediately, we're directed to burn the APU.
Click to expand...
Story time? I'm with ctab that it is more efficient to burn the APU. How much does it burn an hour on the Airbus?
 
skyw82 said:
at some airlines there is zero incentive to single engine taxi.
Click to expand...

In my experience, ~5% of CA's single engine taxi for departure. The APU remains on.

It's also pretty standard to do a dual engine taxi in, also with the APU on...
 
We religiously try to single engine taxi. We leave the APU bleed off during taxi.

Depending on what we can expect for braking temps, we'll try to shut down 1 ASAP after landing. Almost to the point of "after landing checklist.....shutdown 2." (Whether we need a cool down or not because of thrust reverse usage)

I haven't seen a cross bleed yet. That doesn't sound like efficiency when you have APU bleed available.
 
skyw82 said:
at some airlines there is zero incentive to single engine taxi.
Click to expand...
You know I hear that quite a bit, but rarely is that totally true. Even at my airline where "someone else" buys the fuel our fuel usage is compared to competitors.
Even if there is no direct financial incentive such as performance pay or profit sharing fuel does figure into a company's expenses which affects profits which, in the long term, affects pay.
 
I ride on Delta a lot and just shake my head when they use significantly more than idle thrust to taxi out on one engine. One engine at high thrust versus two engines at idle thrust, which airplane is burning more fuel? Then the crew are distracted on an active taxiway, often right before takeoff, starting the other engine and finishing up checklists.

I can see doing this in situations where there will be an extended taxi out time, but they are doing it at SLC when there is no traffic and less than 10 minute taxi outs.

In regards to the APU on an A320 can't help you, but remember the DC-9 that crashed into a parked aircraft at Minny a few years back? It's been quite a few years and my recollection is not perfect but old DC-9s had a two position selector for the hydraulic brakes (Left or Right). If you had it in Left and shut down the left engine guess what happened to your brakes when the accumulator ran out of pressure? Newer DC-9s had a Left, Both, Right selector. It was normally kept in the Both position, but a non-normal could have one select either left or right. I forget, or never read, the final report from that incident but upon first hearing about it my thoughts went straight to what position that selector was in and if they had shut an engine down on taxi-in.



Typhoonpilot
 
@Derg roastin' @Screaming_Emu like:

whaletaxi.png
 
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