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First officer in part 121 operation observed discrepancies in takeoff data for weight and balance while taxing out for takeoff.
| Attributes | |
| ACN | 1370877 |
| Time | |
| Date | 201607 |
| Aircraft 1 | |
| Make Model Name | Large Transport |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Taxi |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Data Processing |
| Person 1 | |
| Function | First Officer Pilot Not Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 240 Flight Crew Total 20000 Flight Crew Type 14089 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Deviation - Procedural Weight And Balance |
Narrative:
I've noticed an odd event since we switched from accuload to the current system of obtaining weight and balance information and take-off data. For the last six years; my flying is primarily caribbean and I wonder if the hot temperatures there are a factor.if you're familiar with caribbean flying; you know how busy it gets from push back to take-off. We're about to push or pushing when perf-init uplinks and the weight manifest prints out. I then take the gross weight on 1L and plug that into the request for take-off data (from the performance menu). The V speeds/trim upload and I print out the take-off data. I look at the take-off ref page 1 and see the two weights down at 4R match. Great...but....here's the problem.one day; while back taxing on the runway (getting a clearance as usual); and after we ran the before take-off checklist; I noticed the weight on the left of the slash (gw) on the take-off page (under the V speeds at 4R) has increased a few hundred pounds. Strange. I quickly send a new take-off data request for this heavier weight. When it loads; the weight to the right of the slash (take off weight) reflects the weight I sent which matches the current weight. A lot of work while back taxiing on an active runway.then; it happened again...and again. All different [aircraft] and different caribbean airports. The largest weight gain I've had was NAS with close to a 1;000 pound increase (I don't recall the exact amount).I guarantee that once the before take-off checklist is run; pilots will likely not notice they are heavier than the weight they used to obtain take-off data. This is not their fault; but it seems either taxiing or heat (or combo or something else) causes the aircraft gross weight to increase.since the third or so occurrence; I've started to add 500 pounds when I send for take-off data. It's the only (conservative) way to avoid a problem on an active runway; especially in the caribbean where the nearest exit is halfway back down the runway.this doesn't happen on every flight; but it does happen often enough to be an issue for me.
Original NASA ASRS Text
Title: First Officer in Part 121 operation observed discrepancies in takeoff data for weight and balance while taxing out for takeoff.
Narrative: I've noticed an odd event since we switched from Accuload to the current system of obtaining weight and balance information and take-off data. For the last six years; my flying is primarily Caribbean and I wonder if the hot temperatures there are a factor.If you're familiar with Caribbean flying; you know how busy it gets from push back to take-off. We're about to push or pushing when perf-init uplinks and the weight manifest prints out. I then take the gross weight on 1L and plug that into the request for take-off data (from the Performance menu). The V speeds/trim upload and I print out the take-off data. I look at the take-off ref page 1 and see the two weights down at 4R match. Great...but....here's the problem.One day; while back taxing on the runway (getting a clearance as usual); and after we ran the Before Take-off checklist; I noticed the weight on the left of the slash (GW) on the take-off page (under the V speeds at 4R) has increased a few hundred pounds. Strange. I quickly send a new take-off data request for this heavier weight. When it loads; the weight to the right of the slash (Take Off Weight) reflects the weight I sent which matches the current weight. A lot of work while back taxiing on an active runway.Then; it happened again...and again. All different [aircraft] and different Caribbean airports. The largest weight gain I've had was NAS with close to a 1;000 pound increase (I don't recall the exact amount).I guarantee that once the Before Take-off checklist is run; pilots will likely NOT notice they are heavier than the weight they used to obtain take-off data. This is not their fault; but it seems either taxiing or heat (or combo or something else) causes the aircraft gross weight to increase.Since the third or so occurrence; I've started to add 500 pounds when I send for Take-off data. It's the only (conservative) way to avoid a problem on an active runway; especially in the Caribbean where the nearest exit is halfway back down the runway.This doesn't happen on every flight; but it does happen often enough to be an issue for me.
Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.