BMI single engine taxi-out
 

I noticed a BMI 319 the other day at Heathrow taxiing out for departure on single engine.

I thought Airbus hasn't given approval for such. Something to do with tailpipe fires. i.e. If you have one you won't know about it.

Any BMI guys with some gen on above?

I'm interested because at our operator we're specifically not permitted to do it.
Only taxiing in.

Regards.

Jet Blue & easyJet have been doing OETD for years on A320 series.

US Airways do it as well

It sounds good, but I would end up doing a one engine takeoff...

Or going round in very quick circles!

It is in the FCOM 3, Supplementary Techniques and we were allowed to do it after a sim session in the A330 ( and since been put on hold), including two engine taxi out in the A346 at 381.2 tons!

At what point is the second engine started? Is this procedure allowed on an aircraft with cold engines?

I you only start the second engine close to point of departure I don't know how I feel about that. isn't it like redlining your car on a cold engine?

There is an Airbus approved procedure in FCOM 3 for single engine taxi prior to departure.

At bmi we have been doing this for quite sometime now and don't seem to be having any problems with it. All the normal engine warm up times apply so no problems with taking off with a cold engine, you just need to manage it (or not bother doing it in the first place) if you have been shut down for 2 hours of more. Officially there is no limitation on weight but my experience is that at high weights on the 321 you struggle.

There are various tech. and weather criteria that must be satisfied and also extra procedures for after start and engine start phases and these are all contained in a different coloured "normal" checklist that we use from before start to take-off if we have decided to do a s/e taxi out.

All works well most of the time, just occasionally someone (not me of course!) gets the timing wrong and isn't ready to line up when cleared but its pretty rare and the procedure can easily save 100kg of fuel on a 09R day at LHR so its well worth doing in the right circumstances.

Just to add to Max's comments. LHR departure ATIS reminds crew to notify ATC if intending to taxi out single engine. ATC, ground or tower, will normally give you a heads up on expected airborne time to simplify the guessing game of when to crank the spare up:ok:

Just to clarify Max Angle's statement. There is indeed an FCOM3 procedure for single engine taxi out but the bmi company proceedure is a slightly modified (& approved by Airbus) version of this.

The only difference is we do not open the cross bleed after start (pack 2 is normally switched off at this point anyway in the bmi SOP).

There are a number of other airlines employing reduced engine taxi out procedures at LHR. Notably Etihad use a 2 engine proceedure on their A340s.

There is arguably a higher chance of a tail pipe fire on shut down but no one seems to worry too much about shutting an engine down during taxi in!

Boeing's views
 

This is what Boeing often recommends:

"Because of additional operational procedural requirements and crew workload, taxiing out for flight with an engine shutdown is not recommended. High bypass engines require warm up prior to applying takeoff thrust and cool down prior to shutting down. If the engine has been shutdown for several hours, it is desirable to operate at as low a thrust setting as practical for several minutes prior to takeoff."

I never understood S.E taxi in and out.

All it seems to achieve is adding to the bottom line which tends to go straight to managers pockets by way of gross and unrealistic bonus's.

As far as I remember on the line; it complicated our day further, got us out of sequence, made us miss helpful ATC ammended line up clearances and increased the likelihood of tea and biscuits with said management.

All very odd..!

But yes - time limits pre-take off, not in LVP's, not when slippery, not first flight of the day and not if a taxiing for extended uphill periods.

Decurion, however accurate your post is, what is it's point?

The thread is about Airbus, specifically A319.
We do however use the same technique across the 320 and 321s as well.

We used to use it on the F100.
I never operated the B737, but doubtless Max or someone will enlighten us.

We have time restrictions on warm up times depending on previous shut down time (2 mins if less than 2 hours, 5 mins if longer).

Our SOPs give guidance on when these procedures should not be used, and when they are appropiate and aid fuel efficiency.

They have been approved by both the CAA and Airbus.

As I posted earlier ATC give us a heads up on expected airborne times.

An OK pilot is a safe pilot.

A good professional pilot is an efficient pilot :rolleyes:

If it annoys you doing more than the absolute minimum to do a better job, well .... :(

Here, here, Checkboard.

Single engine taxi at out LHR saves on average about 80kg per time which with fuel prices as they are is not to be sneezed at. It adds 2 more short checklists to the normal proceedure but I wouldn't say that it complicates things much. You don't get out of sequence because it is built into the SOP. As far as line up clearances go ATC at LHR are extremely helpful when they know we are single engine. In any case most crews err on the side of caution, timewise, taking the view fuel saved up to second engine start is a bonus rather than fuel wasted after start being wasted.

In answer to Nubboy's query we did single engine taxi in on the 737 but not taxi out. I suspect the only reason was to be different to th DC9!

Cheers TTO.

(Thread drift I know, but when I started on the F100, all I heard from the old crusties was how good the DC9 was:ok:)

I always thought that we do it on the airbus, but not the Boeing as the airbus engine start is fully monitored, whereas the Boeing required a pilot to shut the engine down if there was a problem.

Was the DC9 start fully monitored as well then? :ok:

bmi company memo put out 17xxx kg saved in 1 yr by someone who kept a record.