A-320 Single Engine Taxi out Myth Busters
08-06-2010, 05:45 AM
#71
Gets Weekends Off
Joined APC: Apr 2008
Position: LAX ERA
Posts: 3,457
I was pondering all this last night and came up with my usual "firm grasp of the obvious" epiphany.
The north guys says it's not safe (break away power, high power in alleys etc). That implies that the south guys are "unsafe".....not something you say to your friends.
South guys say north concerns range from unprofessional to down right theft from my profit sharing check........again not something to say to your friends.
I really think we are prisoners of how we are trained during initial school. Shoot, look at little things we do in the FMS. You can spot an "old school" guy in a minute because he still does thing old ways even though there are easier ways to do it.
What I'm saying is, on the north side, we had NO procedure for single engine taxi premerger (on the 757). I would suggest it will change over time as we get more crossflow. I'm a perfect example, when I move to my southie base in Sept and do it a few times I may get comfortable with it and change my opinion. Plus, over time, guys will come out of the school house who don't know any other way.
But, until then, can we stop insulting each other over the issue? Lets move on to something really important, like who puts what into the FMS when
Ferd
The north guys says it's not safe (break away power, high power in alleys etc). That implies that the south guys are "unsafe".....not something you say to your friends.
South guys say north concerns range from unprofessional to down right theft from my profit sharing check........again not something to say to your friends.
I really think we are prisoners of how we are trained during initial school. Shoot, look at little things we do in the FMS. You can spot an "old school" guy in a minute because he still does thing old ways even though there are easier ways to do it.
What I'm saying is, on the north side, we had NO procedure for single engine taxi premerger (on the 757). I would suggest it will change over time as we get more crossflow. I'm a perfect example, when I move to my southie base in Sept and do it a few times I may get comfortable with it and change my opinion. Plus, over time, guys will come out of the school house who don't know any other way.
But, until then, can we stop insulting each other over the issue? Lets move on to something really important, like who puts what into the FMS when
Ferd
08-06-2010, 06:13 AM
#72
Line Holder
Joined APC: Aug 2010
Position: A-320 Capt
Posts: 37
My personal wish list? I’d like to see the cross bleed procedure revisited. Currently the A-320 requires the parking brake set for cross bleed start making that option impractical in most SE taxi scenarios. My data shows that if the APU could have been shut down, and cross bleed utilized for the second engine start an additional 715 pounds of fuel would have been saved.
I think we should be able to start one engine, shutdown the APU, and start the other engine while on-the-move. How's that for controversial?
08-06-2010, 06:17 AM
#73
Banned
Joined APC: Jun 2008
Position: A320 Cap
Posts: 2,282
Oh doubting Spackler. For fuel savings to be equal, the N1 of the operating engine would have to be twice that of idle. It ain't....sorry no study.
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!
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!
08-06-2010, 06:23 AM
#74
Banned
Joined APC: Jun 2008
Position: A320 Cap
Posts: 2,282
Really Carl? A few seconds of breakaway thrust versus many many mins of idle thrust.
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.
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.
I used to taxi SE, but then my union told me they don't recommend it, so I stopped. We had an incident at UAL where we had a runway incursion that almost let to an accident.... a bad one.... and I BELIEVE (though not sure) that starting the second engine distracted the FO who failed to catch the Captains taxi oopsy. Whether or not that is the reason our MEC gave us the frown on SE taxi or not, I'm not sure. But until they tell me to do it full bore, I listen to what they say.
Lastly, a heads up on the A320. I've had this happen a few times. Turning into the gate, Gen 2 shut down already, I've had the FO cage #2. On more than one occasion, the brakes have released momentarily. I now make sure if I'm going to shut down #2, I'm NOT close to the gate headed towards the terminal. I've confirmed with a couple of other A320 pilots that I'm not the only one that has had this occur.
Not saying SE taxi is safe or not, or prudent or not. Just FYI.
08-06-2010, 06:43 AM
#75
Gets Weekends Off
Joined APC: Sep 2008
Position: Kickin’ Back
Posts: 6,971
I really think we are prisoners of how we are trained during initial school. Shoot, look at little things we do in the FMS. You can spot an "old school" guy in a minute because he still does thing old ways even though there are easier ways to do it.
What I'm saying is, on the north side, we had NO procedure for single engine taxi premerger (on the 757). I would suggest it will change over time as we get more crossflow. I'm a perfect example, when I move to my southie base in Sept and do it a few times I may get comfortable with it and change my opinion. Plus, over time, guys will come out of the school house who don't know any other way.
But, until then, can we stop insulting each other over the issue? Lets move on to something really important, like who puts what into the FMS when. Ferd
What I'm saying is, on the north side, we had NO procedure for single engine taxi premerger (on the 757). I would suggest it will change over time as we get more crossflow. I'm a perfect example, when I move to my southie base in Sept and do it a few times I may get comfortable with it and change my opinion. Plus, over time, guys will come out of the school house who don't know any other way.
But, until then, can we stop insulting each other over the issue? Lets move on to something really important, like who puts what into the FMS when. Ferd
Seriously, I was very skeptical about taxiing on one engine with the APU off and doing a crossbleed start.........only having one electrical source at night etc. But I've become a convert.At your new base most of the time you can probably save about 5 min by SE taxi. For me, a typical flight is start one engine, taxi out of the alley, make the turn on bravo to 25R and then start the second engine because there is not much of a line to TO.
UH OH! Now you've REALLY opened up a can of worms!!!
About the FMS I mean!Denny
08-06-2010, 06:46 AM
#76
Gets Weekends Off
Joined APC: Jun 2009
Posts: 5,113
I was pondering all this last night and came up with my usual "firm grasp of the obvious" epiphany.
The north guys says it's not safe (break away power, high power in alleys etc). That implies that the south guys are "unsafe".....not something you say to your friends.
South guys say north concerns range from unprofessional to down right theft from my profit sharing check........again not something to say to your friends.
I really think we are prisoners of how we are trained during initial school. Shoot, look at little things we do in the FMS. You can spot an "old school" guy in a minute because he still does thing old ways even though there are easier ways to do it.
What I'm saying is, on the north side, we had NO procedure for single engine taxi premerger (on the 757). I would suggest it will change over time as we get more crossflow. I'm a perfect example, when I move to my southie base in Sept and do it a few times I may get comfortable with it and change my opinion. Plus, over time, guys will come out of the school house who don't know any other way.
But, until then, can we stop insulting each other over the issue? Lets move on to something really important, like who puts what into the FMS when
Ferd
The north guys says it's not safe (break away power, high power in alleys etc). That implies that the south guys are "unsafe".....not something you say to your friends.
South guys say north concerns range from unprofessional to down right theft from my profit sharing check........again not something to say to your friends.
I really think we are prisoners of how we are trained during initial school. Shoot, look at little things we do in the FMS. You can spot an "old school" guy in a minute because he still does thing old ways even though there are easier ways to do it.
What I'm saying is, on the north side, we had NO procedure for single engine taxi premerger (on the 757). I would suggest it will change over time as we get more crossflow. I'm a perfect example, when I move to my southie base in Sept and do it a few times I may get comfortable with it and change my opinion. Plus, over time, guys will come out of the school house who don't know any other way.
But, until then, can we stop insulting each other over the issue? Lets move on to something really important, like who puts what into the FMS when
Ferd
As always, a very even-keeled post. The problem I see with your logic is that we DO have a procedure for SE taxi, and furthermore, SE taxi IS the standard procedure. We've already moved beyond the dabate phase, pretty much on an industry-wide basis: we all taxi SE whenever possible.
The world moves on. Just as we probably failed to follow some basic IT developments, failing to taxi SE is basically failing to recognize evolutionary trends in our industry.
I don't have any beef with different philosophies, and with healthy debates. The result of those debates will be some sort of procedure, whichh can go according to one group, or another. Once that happens, we will all make the individual choice of accepting it, or fighting it. It will not be a question of "can't", but of "won't" for those who don't comply.
Everything we do at Delta might be different, and it might be annoying, but it's fairly consistent as a system, and it's designed to allow for SE taxi, from the AWABS timing, to the F/O starting engines.
As we go forward, I'm sure we'll come up with a variety of mutually agreeable "best practices", but in this area I doubt we'll make this huge airline of ours go backwards in time, and push out more dinosaurs on the way to the runway. Now, I will admit that we didn't enjoy going to SE taxi, and that it took some time. We also had a bunch of guys arguing against it, and it took a while after we started going along, before people accepted the idea of doing a crossbleed start. There was a lot of SE taxi with the APU running, for quite a while. So that may be where we are now: slowly adapting. I've said it elswhere before: we pilots are surprisingly resilient to change. So I don't blame anyone for not liking the changes.
Another point: I for one am philosphically opposed to showing any dissatisfaction by pi$$ing out money (i.e. the needless SATCOM use), when there is no appreciable or noticeable effect. Or when the timing is wrong. On the other hand, I'm all for a pilot group that knows how to comply when it wants to, and knows how to use its' discretion to turn it off when it doesn't. Having all sorts of individuals routinely pulling in different directions precludes that sort of thing. Put differently, when we get to the point where we might withold services, I want those services to be highly valued, and sorely missed.
08-06-2010, 06:55 AM
#77
Gets Weekends Off
Joined APC: Apr 2008
Position: LAX ERA
Posts: 3,457
Got that right..........that and where does the ships headset go? My gawd, the inhumanity of it all!!Ferd
PS Speaking of headsets, now that I'm seeing more and more Dave Clarks I guess I'm going to breakdown and get a Telex 850. Cheapest noise reduction I've found for my APU battered ears. <------howz THAT for thread drift!
08-06-2010, 07:16 AM
#79
Gets Weekends Off
Joined APC: Jan 2008
Position: 767-400
Posts: 797
At UAL, we taxi single engine with Gen 2 selected off (the A320 can do some WEIRD things with a power transfer if you are on the steering or brakes, so the procedure here is to go hands/feet off before the FO selects Gen 2 on) - and the Yellow Electric pump on to keep the barking dog quiet.
Lastly, a heads up on the A320. I've had this happen a few times. Turning into the gate, Gen 2 shut down already, I've had the FO cage #2. On more than one occasion, the brakes have released momentarily. I now make sure if I'm going to shut down #2, I'm NOT close to the gate headed towards the terminal. I've confirmed with a couple of other A320 pilots that I'm not the only one that has had this occur.
Thanks for the info…
I used to taxi SE, but then my union told me they don't recommend it, so I stopped. We had an incident at UAL where we had a runway incursion that almost let to an accident.... a bad one.... and I BELIEVE (though not sure) that starting the second engine distracted the FO who failed to catch the Captains taxi oopsy.
Well as a MD88 FO I have a very very busy job from the gate to the runway. I know there are plenty of ways to mitigate these threats. Most CA's says "...start #2 at your discretion...", #3ish in line for T/O works good for me. There you're in line, on tower, no where to go but the runway, with normally nothing to cross. Just practice professional airmanship and do not rush anything. If you're not ready, wait till you are ready...
Based on the culture that UAL management has created over the last 5 years, my guess is we all know the answer to that question!
08-06-2010, 07:20 AM
#80
No longer cares
Joined APC: Mar 2008
Position: 767er Captain
Posts: 12,109
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
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