The crew of a dhc-8-400 sent erroneous information through ACARS and received takeoff data in reply;...

Narrative:

Upon receiving the clear after departure time; my first officer put the info into ACARS weight and balance and received confirmation that we were ok for departure; associated weights; and V speeds. After departure we reviewed the data; caused by a discussion about how bag heavy we were; and determined that we had exceeded the aft cargo load limitation by 14 lbs. (Cargo limit was 2545 lbs and we had 2559 lbs) upon arrival maintenance control and I determined that because no major weight [had changed]; i.e. Mtw; mzfw or mlw; there was no inspection required and therefore no write up required; as this is was a minor exceedance and our whole weight and balance system is based on averages. My concern is: we also sent an incorrect amount of bags the first time that should have returned a 314 lb error and it also didn't. We noticed that error quickly and changed the numbers and re-sent the transmission and should have gotten an error of 14 lbs and didn't on either. Also; that a crew may inadvertently takeoff way over weight if the system information is not working properly; and the way we are trained. It should work. Find out why ACARS 'glitches' and did not; as it has every other time; given us an error with an associated solution...i.e. Aft cargo exceeded by X amount; or move X amount from aft to forward.

Original NASA ASRS Text

Title: The crew of a DHC-8-400 sent erroneous information through ACARS and received takeoff data in reply; then discovered after takeoff that the weight and balance system not only failed to detect and indicate the incorrect input; but also did not discover and indicate the obvious weight discrepancy.

Narrative: Upon receiving the CLR after departure time; my FO put the info into ACARS Weight and Balance and received confirmation that we were ok for departure; associated weights; and V speeds. After departure we reviewed the data; caused by a discussion about how bag heavy we were; and determined that we had exceeded the Aft Cargo Load Limitation by 14 lbs. (Cargo limit was 2545 lbs and we had 2559 lbs) Upon arrival Maintenance Control and I determined that because no major weight [had changed]; i.e. MTW; MZFW or MLW; there was no inspection required and therefore no write up required; as this is was a minor exceedance and our whole Weight and Balance system is based on averages. My concern is: We also sent an incorrect amount of bags the first time that should have returned a 314 lb error and it also didn't. We noticed that error quickly and changed the numbers and re-sent the transmission and should have gotten an error of 14 lbs and didn't on either. Also; that a crew may inadvertently takeoff way over weight if the system information is not working properly; and the way we are trained. It should work. Find out why ACARS 'glitches' and did not; as it has every other time; given us an error with an associated solution...i.e. Aft cargo exceeded by X amount; or move X amount from aft to forward.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1090144
Time
Date	201305
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Dash 8-400
Operating Under FAR Part	Part 121
Flight Phase	Parked
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Commercial
Events
Anomaly	Deviation - Procedural Published Material / Policy Deviation - Procedural MEL Deviation - Procedural Weight And Balance

The crew of a dhc-8-400 sent erroneous information through ACARS and received takeoff data in reply; then discovered after takeoff that the weight and balance system not only failed to detect and indicate the incorrect input; but also did not discover and indicate the obvious weight discrepancy.