Airbus Drivers: Single-Engine Taxi 'n APUs

Same way at an airline I flew for awhile back and to top it off the captain had to do the start so it was a Real PItA
 
scooter2525 said:
A random bit of information, the engine anti ice generally gives enough bleed to start the other engine with the lever at idle. No it's not our technique and no I don't do it.
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Sounds like a great way to cook the leading edges of the nose cowls.
 
Cptnchia said:
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That was the exact argument that some Northies had when they adopted Southie procedures. From what I observed, didn't take too long for them to change their minds. The only plane in the fleet that crossbleed starts is not a good idea is the MD88. Due to the amount of air required from a low bypass turbojet, the engine has to be almost to takeoff power. That one, we use the APU for a rolling start.
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Translation=the Southies told the Northies what to do.

:)
 
Cptnchia said:
.

That was the exact argument that some Northies had when they adopted Southie procedures. From what I observed, didn't take too long for them to change their minds. The only plane in the fleet that crossbleed starts is not a good idea is the MD88. Due to the amount of air required from a low bypass turbojet, the engine has to be almost to takeoff power. That one, we use the APU for a rolling start.
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Resistance is futile!
 
What portions of the L-NWA FOM survived?

Or was it more of a here is your new manual type of moment for a lot of your coworkers?

:)
 
Seggy said:
What portions of the L-NWA FOM survived?

Or was it more of a here is your new manual type of moment for a lot of your coworkers?

:)
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Gotta ask the office types for specifics, but a lot of the FOM was the same. In the beginning, adopt and go ended up 75/25 DAL/NWA. As we move further away from SOC, it's reaching more of a balanced equation. Remember, it was easier to add more changes to the smaller pilot group. Less guys to retrain in a short amount of time.
 
Cptnchia said:
Gotta ask the office types for specifics, but a lot of the FOM was the same. In the beginning, adopt and go ended up 75/25 DAL/NWA. As we move further away from SOC, it's reaching more of a balanced equation. Remember, it was easier to add more changes to the smaller pilot group. Less guys to retrain in a short amount of time.
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So... Resistance is futile! :)
 
Cptnchia said:
. The only plane in the fleet that crossbleed starts is not a good idea is the MD88. Due to the amount of air required from a low bypass turbojet, the engine has to be almost to takeoff power. That one, we use the APU for a rolling start.
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The 717 APU starts are SOP, and crossbleeds the abnormal.

As far as the "the FOMs were about the same". Not going to rehash that remake of "Rent", but let's just say I just spent about 5 minutes cleaning the Cheerios off my monitor.

Richman
 
PeanuckleCRJ said:
The power required for a crossbleed is less than two engine break away thrust. It's widely accepted around widget land.
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I'll be interested to hear how the A321 is with this. At Eskimo Airlines they're trying to push single engine taxi as much as possible. This works great in the 737-700 all the time pretty well on par with what you're saying. However in the -800 you have to be light. In the -900 it's darn near impossible. They tell us to target 40% for breakaway thrust and if you have to go past 45 to start the other engine. On an -800 going farther than a couple hours or a -900 anytime you're looking at 60%+ for single-engine breakaway thrust. Perhaps they weigh more than the Airbus? I don't really know just interesting to compare notes.
 
Kingairer said:
"I know we didn't have any of these before you brought them over here, but let me tell you the best way to fly it :)."
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Seggy said:
What portions of the L-NWA FOM survived?

Or was it more of a here is your new manual type of moment for a lot of your coworkers?

:)
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Cptnchia said:
Gotta ask the office types for specifics, but a lot of the FOM was the same. In the beginning, adopt and go ended up 75/25 DAL/NWA. As we move further away from SOC, it's reaching more of a balanced equation. Remember, it was easier to add more changes to the smaller pilot group. Less guys to retrain in a short amount of time.
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The FOMs absolutely weren't the same. NW culturally did not do single engine taxi pre-merger, whereas the south side had an aggressive single engine taxi program. With fuel skyrocketing, guess which prevailed? We had some issues when south 757s started flying out of DTW- the DTW rampers were so used to them taking forever to start both engines that they had gotten lax and saluted us a few occasions when everyone wasn't quite clear assuming it would be a bit. Then we show up, start 1 engine and start moving as soon as they salute... yikes!

Unfortunately, the better manual structure that NW had did not prevail. :(
 
Dan208B said:
I'll be interested to hear how the A321 is with this. At Eskimo Airlines they're trying to push single engine taxi as much as possible. This works great in the 737-700 all the time pretty well on par with what you're saying. However in the -800 you have to be light. In the -900 it's darn near impossible. They tell us to target 40% for breakaway thrust and if you have to go past 45 to start the other engine. On an -800 going farther than a couple hours or a -900 anytime you're looking at 60%+ for single-engine breakaway thrust. Perhaps they weigh more than the Airbus? I don't really know just interesting to compare notes.
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youll experience the same with the 321
 
Dan208B said:
I'll be interested to hear how the A321 is with this. At Eskimo Airlines they're trying to push single engine taxi as much as possible. This works great in the 737-700 all the time pretty well on par with what you're saying. However in the -800 you have to be light. In the -900 it's darn near impossible. They tell us to target 40% for breakaway thrust and if you have to go past 45 to start the other engine. On an -800 going farther than a couple hours or a -900 anytime you're looking at 60%+ for single-engine breakaway thrust. Perhaps they weigh more than the Airbus? I don't really know just interesting to compare notes.
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The 321 is 20,000 lbs heavier at MTOW than a 739ER! It also has much higher thrust engines (33k), so perhaps we'll be able to SE taxi still. It may end up like the 767-300s with the small motors where above 300,000 lbs, don't even bother trying SE taxi. We may find a similar cutoff weight for the stretched poodles.

NW used to have those max targets for breakaway thrust which were very very conservative- silly conservative now that I look back at it. In general it's around 50% here, but it's not a hard number since one size does not fit all when it comes to conditions.
 
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Richman said:
The 717 APU starts are SOP, and crossbleeds the abnormal.

As far as the "the FOMs were about the same". Not going to rehash that remake of "Rent", but let's just say I just spent about 5 minutes cleaning the Cheerios off my monitor.

Richman
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Didn't know that about the 717. As far as the FOM, just passing on what some of the fNWA captains I flew with told me. Might want to take that up with them. I have no reason to disbelieve what they said.
 
PeanuckleCRJ said:
The fuel burn data suggests otherwise. It's so simple to do the rolling crossbleed (up until this discovery about the fire bottles) there was no systemic reason to not do it. It saves gas, saves engine wear, and so on. It's not much of a distraction... thrust lever a half knob width up, yellow pump off, ignition selector to start, and master switch on.
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I'd be willing to wager the fuel burn data is overall data and I would not argue that it shows less fuel burn. As I said, single engine taxi has it's appropriate uses. Single engine taxi on a one hour taxi out at JFK will certainly save fuel, but single engine taxi out on a twelve minute taxi out at SLC saving fuel is highly suspect. The pilots, in my experience, are using significantly higher than normal thrust settings for break away and after each 90 degree taxi turn. That uses more fuel than two engines running at idle or just above idle. I would say there is a time cut-off somewhere in the 15-20 minute range below which single engine taxi burns more fuel. Further, proper engine warm-up prior to takeoff reduces engine wear, just as proper engine cool down prior to shutdown reduces engine wear.


Typhoonpilot
 
typhoonpilot said:
I'd be willing to wager the fuel burn data is overall data and I would not argue that it shows less fuel burn. As I said, single engine taxi has it's appropriate uses. Single engine taxi on a one hour taxi out at JFK will certainly save fuel, but single engine taxi out on a twelve minute taxi out at SLC saving fuel is highly suspect. The pilots, in my experience, are using significantly higher than normal thrust settings for break away and after each 90 degree taxi turn. That uses more fuel than two engines running at idle or just above idle. I would say there is a time cut-off somewhere in the 15-20 minute range below which single engine taxi burns more fuel. Further, proper engine warm-up prior to takeoff reduces engine wear, just as proper engine cool down prior to shutdown reduces engine wear.


Typhoonpilot
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That's great conjecture. The data proves otherwise with highly detailed FOQA analysis. Proper engine warm up is required to be respected, but I'm sure you knew that.
 
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