Oct 25, 2017, 9:30 pm
Last edit by: JDiver
Seat Loss / Change Due to Weight and Balance Issues
Weight and balance requirements are established for each aircraft type, and they may be impacted by such factors as runway length and airport density altitude (altitude calculated with temperature and humidity). Passenger and baggage, fuel load, how they are distributed from the center of gravity, etc. are part of these calculations, are all required to be done before the aircraft can fly.
Additionally, there are generally different weight and balance tables for takeoff, level flight and landing. The smaller the aircraft, the more critical the W&B calculations are.
See FAA Weight and Balance Handbook here (PDF)
These requirements may cause fewer seats to be sold, denial of boarding, baggage removal and passenger seat redistribution, including downgrades.
FAA classifies aircraft as follows:
- 71 or more passenger seats, large-cabin aircraft; weight changes of +/- 10 lbs must be noted
- 30-70 passenger seats, medium-cabin aircraft; weight changes of +/- 5 lbs must be noted
- 5-29 passenger seats, small-cabin aircraft; weight changes of +/- 1.0 lbs must be noted
Q. How does AA calculate passenger weight?
FAA Advisory Circular AC120-27E establishes these weights:
Summer weights:
Average adult passenger weight 190 lb
Average adult male passenger weight 200 lb
Average adult female passenger weight 179 lb
Child weight (2 years to less than 13 years of age) 82 lb
Add 5 lb per in winter
Further information on passenger and baggage weights may be seen here (PDF), governed by Title 14 of the Code of Federal Regulations (14 CFR) part 91, subpart K of part 91, and parts 121, 125, and 135.
Weight & balance related changes, downgrades, seating, denied boarding etc.
Apr 30, 2009, 12:02 pm
#1
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Weight & balance related changes, downgrades, seating, denied boarding etc.
Last evening, during the end of my MR from AUS, SFO, BOS, BOS SFO, LAX, AUS, flight 2246 on a MadDog 80, was delayed thirty five minutes.
There was a tear in the rear baggage compartment.
All the bags had to be stowed in the middle, and forward baggage compartments.
The GA came on board and announced that four people who were
currently seated in FC would have to relinquish their seats and return to
Steerage. They selected the returnees by order of their status. There were
four unhappy campers who went back.
Later, I observed that the FA brought food and drinks back to the displaced ones.
The GA stated that the FC passengers had to move to the rear to balance the plane.
I've not seen this happen before, except on much smaller aircraft.
There was a tear in the rear baggage compartment.
All the bags had to be stowed in the middle, and forward baggage compartments.
The GA came on board and announced that four people who were
currently seated in FC would have to relinquish their seats and return to
Steerage. They selected the returnees by order of their status. There were
four unhappy campers who went back.
Later, I observed that the FA brought food and drinks back to the displaced ones.
The GA stated that the FC passengers had to move to the rear to balance the plane.
I've not seen this happen before, except on much smaller aircraft.
Last edited by JDiver; Feb 25, 2015 at 4:48 pm Reason: Restore original post title
Apr 30, 2009, 12:08 pm
#2
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That's because on the mainline aircraft they can move bags between the forward and aft cargo areas to take care of the balance. When they lost the ability to do that they were in the same situation as the smaller aircraft and had nothing to move expect passengers.
Apr 30, 2009, 12:12 pm
#3
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While I understand the weight and balance issues that require moving people, might it have been possible to move several people out of rows 7-11 or so to the back of the plane and thus avoid the need to move people out of F?
Apr 30, 2009, 12:29 pm
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I believe they use formulas to determine how many average people need to be where. I always found this comical because on one UA flight I took they came on and IDBd someone (last to check in) and it was someone who couldn't have weighed more than 100 lbs. But I guess the plane then had the proper number of people based on the formula, even though we each could have had 25lb carryons. Kids generally are not considered to be "people" as I understood from that incident, so I suspect they would have moved 4 adults.
Apr 30, 2009, 12:30 pm
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Apr 30, 2009, 12:33 pm
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Apr 30, 2009, 1:10 pm
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It's all about leverage, i.e. as the center of gravity on MD80 is quite far to the rear, so it's not just about the weight to be moved, but also about the distance from the center point of that weight. Less pax have to be moved from the farthest forward seats than from seats closer to the center ... therefore only 4 pax from F, but maybe 6 to 8 if from rows in Y.
Apr 30, 2009, 1:10 pm
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Apr 30, 2009, 1:14 pm
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Of course, there might not have been enough empty seats in the back to accomodate a dozen people; perhaps there were only four empty seats.
Apr 30, 2009, 1:24 pm
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Apr 30, 2009, 1:26 pm
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Apr 30, 2009, 1:35 pm
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I'm assuming people are making remarks like this because they're assuming that the displaced passengers were upgraded to first, since they were downgraded based on status. If that's the case, I would think a refund of the 500 mile certificates, if any were pulled, should suffice. If it was paid first class, I would hope people would expect more in the way of compensation than getting to their destination, which is no compensation at all. You already paid for that.