A-320 Single Engine Taxi out Myth Busters
08-05-2010, 08:00 PM
#61
Gets Weekends Off
Joined APC: Jan 2008
Position: 767-400
Posts: 797
A-men brother. Apparently it must be Utopia working for airlines like DL where everyone sings kumbaya together.
Until AA management actually shares profit sharing with us and stops stealing from us to enrich their own coffers, they can shove their S.E. taxi where it's dark and gloomy.
Two engine taxi out with APU for takeoff, two engine taxi in and APU stays on at all times at the gate. Safety first, crew/pax comfort second, fuel savings = FUPM!!
Until AA management actually shares profit sharing with us and stops stealing from us to enrich their own coffers, they can shove their S.E. taxi where it's dark and gloomy.
Two engine taxi out with APU for takeoff, two engine taxi in and APU stays on at all times at the gate. Safety first, crew/pax comfort second, fuel savings = FUPM!!
08-05-2010, 08:00 PM
#62
Da Hudge
Joined APC: Oct 2006
Position: Poodle Whisperer
Posts: 17,473
There's also just the cost of running the engine itself on top of the fuel burned.
Carl- some guys tend to be a bit heavy on the gas. Also, when youre running one engine and spool it up- it really sounds different (more revved) than 2 engines at the same power setting when you're riding in the back. Something I've noticed.
The fact is that running one engine is nearly always going to be more efficient.
Carl- some guys tend to be a bit heavy on the gas. Also, when youre running one engine and spool it up- it really sounds different (more revved) than 2 engines at the same power setting when you're riding in the back. Something I've noticed.
The fact is that running one engine is nearly always going to be more efficient.
08-05-2010, 08:04 PM
#63
Gets Weekends Off
Thread Starter
Joined APC: Feb 2006
Position: A320 CA
Posts: 973
reddog,
Is there any data to support the actual savings of fuel at the heavier weights? Is there a published report where two planes at identical weights travel the same taxi route and show the difference between fuel used? What I see in ATL during my commutes is a lot of high power settings during breakaway, acceleration and during uphill taxi segments. Then there's the high power settings during crossbleed start. I've never seen an actual side by side comparison.
Carl
Is there any data to support the actual savings of fuel at the heavier weights? Is there a published report where two planes at identical weights travel the same taxi route and show the difference between fuel used? What I see in ATL during my commutes is a lot of high power settings during breakaway, acceleration and during uphill taxi segments. Then there's the high power settings during crossbleed start. I've never seen an actual side by side comparison.
Carl
If you find yourself going uphill then yes, that would be an excellent time to start the 2nd engine.
Doubt if you've seen high power cross bleed starts on the 319/320. Currently prohibited unless the brake is set, so it makes that impractical for most second engine starts.
You want data? You can't handle the data!
08-05-2010, 08:07 PM
#64
Gets Weekends Off
Thread Starter
Joined APC: Feb 2006
Position: A320 CA
Posts: 973
I can empathize with my American brothers. Time may come at DAL when we too will experience that.
08-05-2010, 08:17 PM
#65
Gets Weekends Off
Joined APC: Jan 2008
Position: 767-400
Posts: 797
reddog,
Is there any data to support the actual savings of fuel at the heavier weights? Is there a published report where two planes at identical weights travel the same taxi route and show the difference between fuel used? What I see in ATL during my commutes is a lot of high power settings during breakaway, acceleration and during uphill taxi segments. Then there's the high power settings during crossbleed start. I've never seen an actual side by side comparison.
Carl
Is there any data to support the actual savings of fuel at the heavier weights? Is there a published report where two planes at identical weights travel the same taxi route and show the difference between fuel used? What I see in ATL during my commutes is a lot of high power settings during breakaway, acceleration and during uphill taxi segments. Then there's the high power settings during crossbleed start. I've never seen an actual side by side comparison.
Carl
As for the A320 I commute on United probably 3 times a month, they nearly always taxi se on the airbus. They have pretty big fleet and seems to be their standard.
On United I never hear any hear any hyd pump noises when riding in the back expect at the very end of the taxi as we get into to gate and right after the engine start. I do notice when in the cockpit they do something against the "black panel" theory when on a se taxi, however I don't know anything about the bus, but I think it has something to do with the quite se taxi.
08-05-2010, 10:37 PM
#67
Gets Weekends Off
Joined APC: Dec 2006
Position: I was acquired, Not Hired
Posts: 1,784
08-05-2010, 10:42 PM
#68
Gets Weekends Off
Joined APC: Apr 2008
Position: 767A
Posts: 791
I was actually commuting on an Airbus from SLC the other day. The Captain elected to two engine taxi. It was a short flight so we were pretty light. The Captain had to ride the brakes out to the runway to keep from taxiing too fast. We approached the end of the runway and the brakes overheated so we had to wait for them to cool down before taking off. I guess that can be another advantage to single engine taxiing. You don't heat up the brakes!
Bingo!
I've always thought it easier to taxi SE, with the exception of breakaway on asphalt and resuming a taxi into a gate turning into the operating engine.
08-05-2010, 10:57 PM
#69
Gets Weekends Off
Joined APC: Apr 2008
Position: 767A
Posts: 791
Carl,
9,000 hours on the 757/767. Gotta call hogwash. I taxi near max gross most of the time, and rarely out of idle except for breakaway and hills.
08-05-2010, 11:07 PM
#70
Gets Weekends Off
Joined APC: Sep 2008
Position: Kickin’ Back
Posts: 6,971
The problem I run into is attaining breakaway thrust especially on cross country flights from airports that have blacktop pavement in the ramp areas (JFK, LAX, DCA, etc). I have ended up starting both engines to get out of the ramp area so I won't use excessive breakaway thrust (and have to talk to the CP
) and then shut one down if the taxi is going to be long. Tsquare or Sailingfun could probably answer this but I believe Delta came out in the past with a memo/bulletin that said something like.........if you have started both engines and then find out you will have more than (X) amount of minutes until you will takeoff, it's cheaper to shut the engine down and then restart it. I want to say about 10 minutes but cannot remember the exact number.Denny
Thread
Thread Starter
Forum
Replies
Last Post
