Originally Posted by
wiggy
FWIW as a very rough ballpark/back of the envelope figure you can work on dumping at 2 tonnes a minute (it’s a different rate Centre tank vs. Wings but 2/min will do as a first approximation)..
Now all we need is to continue the Monday A.M quarterbacking is the Take off weight and the Zero Fuel Weight.....
And just remember, these Deltoids don't know anything about tonnes or tons, it's all in thousands of pounds with the decimal sometimes there, sometimes not on the paperwork which in turn is on a tablet these days.
An old B-772 FCOM gives these numbers in pounds:
One Or More Tank Quantity Indications Blank:
Determine jettison time using the following rates:
• Fuel in center tank: 5400 lbs./minute
• Center tank empty: 3100 lbs./minute
While being vectored Delta 89 gave the fuel as 209.8. And they gave an approach speed of 157 knots which might be a clue to the landing weight.