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Qantas 737 “tailstrike” was caused by iPad data entry fail
On August 1 last year, a Boeing 737-838 (VH-VZR) operated by Qantas performed a "tailstrike" while taking off from Sydney airport. Today, the Australian Transport Safety Bureau (ATSB) has concluded that the strike was caused by the co-pilot fat-fingering the plane's takeoff weight: instead of typing the plane's actual weight of 76,400kg into the iPad, he accidentally typed 66,400kg. As a result, the plane didn't have quite enough thrust to clear the runway without… (arstechnica.com) Más...Sort type: [Top] [Newest]
Shouldn't there have been enough data in the iPad at some point so the app could have cross-checked everything to see if it was all reasonable? Should have triggered an error message along the way such as "Are you sure? Takeoff weight, PAX, fuel, and ETE don't seem to add up. Either you've got very skinny passengers, or it's going to get very quiet up there well short of your destination." Sure, GIGO, but cross-checking all the "GI" should have detected a 10,000 kg discrepancy.
That's the crew's job to make sure the calculations are reasonable. As it is now everything regarding payload is average weights. How many pax have you observed that are 170 lbs. with their carry on bags. The Aero Data system has a lot of biuilt in protections. To prevent errors like this one. There's even a simple formula for determining weight of the aircraft after its in flight in cruise. It's True airspeed times 1,000. Divided by total fuel flow. Which will give you NAM. That nautical air miles per 1'ooo lbs. go into the cruise chart for the altitude your at with NAM. That will tell you the weight of aircraft .
Priceless!
http://avherald.com/h?article=48f6d32b&opt=0
Engage brain, before putting fingers into gear! Made my day, thanks!
Michael. On my aircraft we get weight and balance and performance calculations on our iPad app. We put the weather, fuel, pressure, runway in use and pax number in the FMS and it computes the take-off performance and power again. The two should agree. Obviously the 737 set-up is slightly different or the explanation is inaccurate as it sounds like they take the results and put them in FMS. In addition, we still have all the quick reference charts, so we can have a third check completely manually. (We even have an updated paper copy!) ;-)
Apps don't generally cross check. They compute on the basis of input. Cross checking is for the brain behind the inputs. Us!
Apps don't generally cross check. They compute on the basis of input. Cross checking is for the brain behind the inputs. Us!