Overstated BRW

[GeorgeCluney]

Hi all,

To what degree may an overstated take-off weight impact on performance?

Using a 737 for example, a group of 100 kids are checked in as adults as the child edit was not entered. This overstates the weight on your loadsheet by 3600kg in using averaged weights. Will your aircraft actually rotate significantly later than expected and will your aircraft tend to "balloon" on landing with touchdown a little further along the runway than expected?

Kind regards,

George

[411A]

With most large jet transports, a 10,000 pound error on the loadsheet will make little difference in actual performance.

DP Davies, in his book, Handling The Big Jets, said about the same thing.
Now, in a commuter jet, 10,000 pounds is significant.

[BOAC]

"To what degree may an overstated take-off weight impact on performance?" - no significant effect

"Will your aircraft actually rotate significantly later than expected" - no - later than 'necessary'

"will your aircraft tend to "balloon" on landing with touchdown a little further along the runway than expected?" - providing correct techniques are used, no noticeable effect. If it does 'float' a little further than usual this should be offset by the reduced landing roll at a lighter weight.

If your enquiry is from a dispatcher's p.o.v. I would suggest that the concern would be that the mistake happened and could be significant if the kids were not evenly spread around the trim sheet, and thus the a/c balance could be adversely affected and, of course, the mistake could be made the other way.

[GeorgeCluney]

Thanks for your replies. All makes sense. My concern of course is with such a mistake occuring in the first instance. GIGO. Wrong info, wrong weight, wrong stab setting, wrong V1, VR, V2 calculations .. all because of a booking error or that the little tackers went unnoticed as the teachers or group leader handles the checkin. On that however, we tend to seat groups about the non-influence zone to avoid a re-trim if the entire group no-showed.

Thanks again for your input. I remind myself and my colleagues to treat each flight as if one's own Mother was aboard. (Unless of course one doesn't get along with one's mother)!

[BOAC]

Whatever you do, do not treat it "as if one's own Mother-in-law was aboard":)