kbmiflyer
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AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 4:42 am

Hi Folks,

I was on AA flight #1102 from MCI to ORD on Sunday (12/12).

Shortly before boarding, they requested that anyone flying with children please check in at the gate counter. I thought this was kind of odd. After a few minutes, they said they were ready to board, but the plane was overweight and they needed 3 volunteers to bump to a later flight. They said the reason they needed the number of children was to calculated a more accurate take-off weight.

Note that the temperature was probably around 30F (0 C) at both MCI and ORD. Both airports were experiencing very high winds.

My question is, why would such a short flight (flight time was scheduled for less than 1 hour) need to remove passengers for weight issues. The 737-800 can fly cross-country (AA has schedule flights from SAN to BOS). It seems like we wouldn't need very full fuel tanks for such a short flight.

Thanks
 
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ERJ170
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 4:44 am

Perhaps it was the 2nd leg of the flight they were thinking of.. in order to save money, they may be superfilling the tank at MCI and using the superfilled tank on the MCI-ORD-??? flight.. (not filling at ORD).. just a thought
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jayhup
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 4:54 am

When US started using Sabre for weight and balance they had problems with 737's being overweight.

I had an explative filled chat (he wasn't cursing at me, he was cursing at Sabre) with a gate agent in CLT a few years ago and he was telling me about it...

JH
 
Big777jet
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 5:07 am

Sometimes, airlines want to save money to bring extra fuel in the tank to someplace than large city expense too costly refueling. Kansas City has cheaper fuel price to carry more fuel then next flight not neccesary refuel at ORD to next flight.

One time, I was visiting in the cockpit. United Captain told me the fuel tank was almost half fuel tank to ORD from CLE. Because we want to save money not to refuel at ORD for next flight. I said, oh cool. That's why some airlines do that. Well, I don't know why AA dumped a few passengers! It should have a hundred pound off the fuel to stay passengers to Chicago. Who cares about a few hundred dollars off?


Stuart



 
GroundStop
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 5:18 am

The practice of carrying more fuel than necessary in order to fuel less at a downline station is called 'Tankering'. All airlines do it from day to day. At my airline, a list of fuel prices at each market is distributed which gives the dispatchers an idea of what cities to tanker out of. However, we would never carry more fuel at the expense of revenue passengers. A likely scenario is that the flight was planned with a certain number of pax/bags and fueled accordingly. That number may have increased closer to flight time and after the aircraft had been fueled. At that point, its easier, and less expensive to treat it like an oversell than it is to defuel the aircraft and re-release the flight plan.
 
ckfred
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 5:20 am

There was an article in the Chicago Tribune this week telling that with state and City taxes, fuel at ORD and MDW is getting close to prices at West Coast airports. So UA, headquartered in suburban Chicago, and AA, one of the larger employers in the metro area, have reduced fuel buying at ORD and are doing a lot of "tankering".

My wife has been doing a lot of flying from ORD to CAK for business. Even if the flight is less than half full, they have been moving passengers around for weight and balance, because Air Wisconsin and Sky West are buying extra fuel at CAK.
 
kbmiflyer
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 5:23 am

Thanks for the replies folks. Everything you said makes sense.

Groundstop probably has a point, as the flight before ours to ORD was cancelled. They may have added some passengers to the flight after our plane was brought to the gate (I think it was brought over from the AA maint hanger at MCI, but I am not real sure). Our flight didn't depart until 6:30, but the plane was at the gate when I arrived at the airport at 3:45 for a 4:40 departure (stupid chicago winds causing delays).
 
uafedexflyboy
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 5:34 am

What everyone is referring to is called tankering. A lot of airlines have adopted such a principal in order to save, quite a lot, of money.

The only other reason I can think of that they would have a weight problem is, and this happens sometimes where I work, the aircraft was originally scheduled on a longer flight but was swapped to the shorter MCI-ORD flight therefore there was too much fuel on board. Depending on the availability of the fuelers, a truck to "defuel" the aircraft wouldn't be available for a good 45 mins. at the least. So instead of delaying the flight they weight restrict it and leave the excess fuel on-board thus requiring a few passengers to be left behind. I know it sounds like bad customer service but inconveniencing 3 passengers sounds better to them than delaying the next 500 passengers (just throwing out a number) for the rest of the day who would be on that aircraft.

J
 
OPNLguy
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 5:54 am

>>>Note that the temperature was probably around 30F (0 C) at both MCI and ORD. Both airports were experiencing very high winds.

The only thing I'd add to the various explanations here is that on short hops, it really doesn't matter all that much (except in the summer months) what the temperatures are.

All aircraft have a max takeoff weight (what the aircraft can get off the ground with) and a max landing weight (most often a structural limitation) of how much you can land with).

Using 737-700 numbers as as an example, the max takeoff weight is 154,500 lbs. and the max landing weight is 128,000 lbs.

If I were to takeoff from MCI weighing the max 154,500, I'd burn (consume) about 6,000 lbs of fuel to get to ORD, and the aircraft would weigh 148,500 lbs on arrival, which is about 20,500 lbs. over the 128,000 lb. max landing weight limit.

What the airline (usually the dispatcher here in the US) does is to take the fuel burn for the flight (6,000 lbs in this example) and add it to the max landing weight (128,000 lbs.) resulting in a weight of 134,000 lbs. Irrespective of the fact that you can actually get 154,500 lbs into the air at takeoff, restricting this flight to 134,000 lbs will prevent the aircraft from arriving too heavy at ORD.

The longer the flight, the more the burn, and the closer the the landing-limited weight gets to the max takeoff weight, and at some point, they'll be the same. For really longer haul flying, you'll almost always be takeoff limited.

All this assumes "normal" runway lenths, airport elevations, and non-summer temperatures. Put any/all of those factors into the mix and things can change, but the general concepts are the same.

If a flight is landing weight-limited, it's alot easier to inadvertently overgross it with unexpected payload (extra pax, bags, cargo) shows up, especially if the aircraft is already fueled (tanker fuel, high fuel load due to destination weather). The options in that case are to use child weights (if there are any onboard), defuel some, or pull non-revs, freight, or (last choice) fare-paying passengers.

[Edited 2004-12-17 22:03:03]
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
1MillionFlyer
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 6:29 am

I have had the same thing happen on a DL MD-80 from ATL-BNA (214 Miles)

MDW-BNA on a WN 737-200 (442 Miles) and on a Comair CRJ, IAD-CVG (334 miles)

Remember also, all planes have a maximum zero fuel weight which is an airframe limit regardles of fuel. If they had heavy cargo this could cause the plane to be at max zreo fuel weight also.


Golf Foxtrot you are cleared for departure
 
OPNLguy
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 6:37 am

I thought about mentioning the ZFW aspect, but didn't want to confuse ths issue...  Big grin
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RDUDDJI
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 6:38 am

If ORD was experiencing high winds, I'm sure they were in a GDP or GS. The "extra" fuel was likely for any airborne holding they expected (which is extremely likely when ORD gets into a program) en-route and also for their ATL fuel.

There are other factors in play too...If the flight wasn't originally booked to capacity, the dispatcher may have planned to tanker. Then the flight fills up and you're overweight. It's also possible (although this usually only happens at hubs) that that plane was sched to do maybe a MCI LAX leg or somthing longer and it was swapped at the last second for a MCI ORD leg after it had been fueled for the longer flight.

I seriously doubt they would bump pax to tanker fuel. IMO AA has more sense then that.

Cheers
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CPDC10-30
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 6:41 am

There was someone a couple months ago reporting the same problem on a NW DC-9-30, on a flight YYZ-DTW. Thats a whopping 186nm trip.
 
Ken777
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 6:43 am

Looking for pax that are willing to be bumped is also a good way to solve the problem - mainly because the airline will give them a voucher for a future flight. That gets the plane in the air and gets the bumped pax back on future flights.
 
OPNLguy
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 7:00 am

>>>that plane was sched to do maybe a MCI LAX leg or somthing longer and it was swapped at the last second for a MCI ORD leg after it had been fueled for the longer flight.

When I get a message to swap an aircraft that's on a long-haul flight (and thus scheduled to be gassed to the gills) I always call the station to make sure they jump on the change as far as getting them to alert the fueler ASAP so s/he doesn't fuel the now "old" aircraft (that may well have been re-assigned to a much shorter flight not needing that much fuel) When one doesn't get caught, it can get ugly, delay-wise...

Defueling can be quite problematic at times, basically because of the lack of an empty ruck to put the fuel in. When they're empty, they fill them up, and you sometimes have to wait for them to fuel another aircraft before they have any space on the truck.
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
ltbewr
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 7:14 am

Could the 'tankering' by a given a/c be done to for a faster turnaround at an intermediate stop, so don't lose time with topping off the fuel tanks? Does WN do this on a/c used in short hop flights?
 
OPNLguy
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 7:30 am

Back when fuel was a fraction of what it is now, non-standard tankering (i.e., not for the usual economic reasons) could be planned, but since turn times have also increased over the years (the 10-minute turn disappeared years ago), fueling isn't the big hold-up on a turn.

I tankered two flights out of CLE the other day, one CLE-MDW-LAS and the other CLE-BNA-LAS, since the loads allowed it. Based on fuel prices, the airline saved $310 on one flight, and $550 on the other. Now, had the flights been fueled and then the payload gone up (from another flight cancelling, etc.) I'd have been hurting...  Big grin
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
aa777flyer
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 8:22 am

While on the subject of AA 737's. Has AA toyed with the idea of adding winglets to their 738's. It seems most carriers are adopting this cost savings measure with fuel prices so high.
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asteriskceo
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 11:43 am

cough cough 717!! Would solve that.
 
ckfred
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 11:52 am

AA777Flyer:

AA has looked into adding winglets to the 737s. The pro is that it will save fuel, particularly if oil stays over $40 a barrel, which is seems inclined to do.

There are 3 cons: cost to install, cost to maintain, and the biggest problem, additional wingspan. A 737 without winglets has a 112-foot wingspan. With winglets, the wingspan is 117 feet. So, a 737 without winglets can park at almost any gate that handles an MD-80. But with the winglets, it cuts down on the number of possible gates, particularly at a place like ORD and LGA, which have some tight gates
 
N1120A
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 12:01 pm

>Has AA toyed with the idea of adding winglets to their 738's. It seems most carriers are adopting this cost savings measure with fuel prices so high<

Given that they are stretched thin to pay their debt right now, taking on something like a million dollars per 737 is not high on the list right now

>717!! Would solve that.<

Different mission, but yes, it would help
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qqflyboy
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 12:12 pm

AA777flyer...

The question pops up regularly now in company "Questions and Answers" sessions. AA has twice already looked into winglets and decided against them. However, we were informed in the last month that AA is, once again, evaluating winglets based on persistently high fuel costs. There is also more data available on their performance which AA is taking into account. So, yes, they have and are considering them, but, the proverbial fat lady hasn't sung. Since the company keeps revisiting the idea I think it's just a matter of when, not if.

And as everyone else has mentioned on this board, AA has dramatically stepped up "tankering." We are routinely flying fully fueled now to the west coast so as to not have to get fuel, or very little fuel, in California and Nevada. I know this comes into play in a lot of other markets, this is just the region recently highlighted by the company for some of the highest fuel prices.
The views expressed are mine alone and do not necessarily reflect my employer’s views.
 
mattbna
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 12:59 pm

Given that they are stretched thin to pay their debt right now, taking on something like a million dollars per 737 is not high on the list right now


Surely you are kidding?!?! What does it really cost to put winglets on a 737?


Also, from what I have read above, we are usually always dealing with thousands (if not tens of thousands) of pounds here.... So what is removing three people from the plane going to really do? Lets say that three people got off of the plane that all weighed 220 pounds - that would only be 680 pounds. If they had 150 pounds of luggage between them we still wouldn't even break 1000 pounds. Seems like we'd need to save quite a bit more than just 1000-1500 pounds to make a huge impact on the overall problem of the plane being tens of thousands of pounds over weight.

Of is there something deeper that I am missing?


Thanks,
Matt

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B4REAL
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 1:07 pm

I was on a completely full B737-800 going SFO-ATL on DL and the TOW was 179,000 lbs and I swear it took the ENTIRE runway (the long one @ SFO).

Is the 738 adequately powered?
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AAR90
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 1:59 pm

Surely you are kidding?!?! What does it really cost to put winglets on a 737?

Last time I checked.... $1 MILLION per set.

...tens of thousands of pounds over weight.

Of is there something deeper that I am missing?


I think you're missing the LEGALITY mindset. FAA doesn't care if you are one pound or 10,000 pounds overweight. If I takeoff over weight I will probably lose my pilot license (and who knows what will happen to the support folks who "allowed" the flight to go out overweight). FAA likes to put this type incident in the "careless and reckless operation of an aircraft" category.

"USN taught me how to fly,
AA taught me how to fly LEGALLY...
and the two shall never meet!"  Crying
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OPNLguy
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 2:03 pm

>>>Is the 738 adequately powered?

They the CFM56-7B26 installed on theirs (26,000 lbs. of thrust), so I wouldn't say so. But then again, I'm not a pilot, and am only giving the dispatcher perspective...  Big grin
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
masseybrown
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 3:34 pm

OPNLguy, thanks for the hard numbers on savings. Dec 6th Aviation Week says that AA plans to save $15 million/year by tankering. All those $300-$500 savings add up.
 
AAplatnumflier
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 3:39 pm

Yes they do. AA also is reducing the fuel that they carry for the reserces from 10% to 5%. They are also starting taxiing on one engine which is saving them a lot of money. So as Massey Brown said every cent adds up.
 
N1120A
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RE: AA 737 Too Heavy For Short Trip

Sat Dec 18, 2004 3:39 pm

>Is the 738 adequately powered?<

It is, even with the less powerful engines, but you may have to use more runway to get full range when flying heavy. Remember, a 737/A32S uses more runway than a 757
Mangeons les French fries, mais surtout pratiquons avec fierte le French kiss