Originally published at: United Airlines Flights Resume Following Widespread Tech Glitch - AVweb
A system failure in United Airlines’ weight and balance software triggered a nationwide ground stop Wednesday evening.
Computer Weight and Balance brining an airline to its knees? Really? We used average weights and zones for pax and actual weights for bags and cargo. Has the industry been dummied down to the point that a crew can’t calculate weight and balance with a Takeoff CG? Wow… that’s all I can say… Wow.
Of course, they can calculate W&B but, stick with me here, maybe, just maybe, the airline doesn’t allow it. Maybe their written procedures require the use of the automated system for let’s say incredible accuracy (read that less liability).
Things change, and it’s not your day anymore as in “back in my day”
Back in my day we didn’t have cell phones and you could read as fast as that newly upgraded 1200 baud modem could spit it out.
Lol.
Oh my, you had to remind me of 1220 baud modems. Yikes that was the Stone Age.
Not that simple - CofG is crucial, safe envelope may vary with total weight - need paper and pencil in flight deck.
You had a 1200 baud modem? I’m so jealous, I could barely afford a 300.
Every airline I flew for, both domestic and foreign we were trained to accomplished takeoff and landing data when the computers were down. It was part of the line training process that crew had to demonstrate proficiency in as well. I trainer a carrier, that is a major presence in the Pacific. Their fleet consists of 737NGs and Air Buses. We flew the NG to remote islands, some of which were remote. Communications to Mother Earth were sketchy at best. We had to first, calculate the weights… MTOW based on Required Runway Lengths 2nd and Final Segment Climb Gradients. Then Landing Weight Next Station, Zero Fuel Weight Plus Required Trip Burn. MEL/CDL Restrictions. Then with those numbers we determined the C/G adjustments to the final to ensure we were in the envelope from ZFW/LDG WT/MTOW.
I flew for LCC in Europe. The ground handler completed the W&B - C/G calculations manually. I ferried heavies around the world. Also, had to determine the same factors manually.
As a line trainer,
That said, I’m surprised that Airlines, with Load and Trim data within their manuals don’t train, or use a manual method. It’s not difficult. It was intimidating use to the size of the aircraft. But the process is the same be it a C-150 or B744. Can’t speak for Airbus and their methods.
Ayup.
Today you can have at least 1200 baud over HF radio, using a computerized interface unit.
Good point about needing to know performance limits. They can be complex - B737-200 original with -9 engines at YEG was running near runway length and climb performance limits
An oddity was B727-100C allowing CofG range to be extended forward but only with Flaps 30 (not 40), useful in Combi configuration headed into the High Arctic. (I couldn’t convince Boeing to issue an affordable SB kit for nose wheel brakes, as some -200s had.)
In theory, but you had practice.
There re computers on board aircraft these days, one crew in Scandinavia realized before getting far in their takeoff that they had entered an incorrect weight in computer that calculated thrust setting
(Good to know how far down the runway you should be at a check speed such as 80 knots. (Such a speed is used to check engines then leave thrust along.)
But I question if many airline crews are capable of the calculation, I say that in part because some pilots for US majors did not have a clue abut takeoff performance when I described limiting factors in a maximum weight takeoff, in an AVSIG thread.
As a rule of thumb in narrow body jets including the B767, about the 1,000-foot markers my IAS is 80 Kts.
I compared the W&B from the computer sheet by simple math. BOW plus Actual cargo weight. Pax multiplied by average weights plus fuel on board. That’s how I’ve discovered errors in the computerized W&B sheet. One was so glaring as to input a fuel load twice that of what a B-737-800 holds. I had one the other way when ferrying a B747-400… under weight reported by 75,000 lbs.
Same ilk couldn’t grasp why one would fly all night to get people where they wanted to go.
I had told of encountering a Check Captain coming into the Ops Centre building as I was going out to catch a flight. He said he had just returned from Smithers, mechanicals and weather had disrupted flying on that route that day, so they flew all night to catch up. (As check captain he’d be on reserve list and probably happy to get some time in. He was coming into the ops centre to talk to them.)
As the only fast airplane service to that settlement the airline was motivated to serve customers.
The more we use “automation” the more we are helpless without it.
So far, everyone appears to be missing the big picture which is a 2nd and maybe a third system in place in case the primary system fails as it did. Common everywhere I know except on aircraft where weight always comes into play. But since this is a ground system, at least one back, preferrably two backups should be in place! Software 101! And United Airlines does not know this? God help us!
This topic was automatically closed after 7 days. New replies are no longer allowed.