Ref Post #324 Aerodink
"7000' @ RIC
1500' @ 12nm BK
0' @ 3nm BK
The first 5500' to 6000' took the aircraft around 12 - 13 nm and the last 1500' approx 9 nm."
My reading of the ATC log is that the aircraft was as much as 9 miles north
(3 minutes) of YSRI when the aircraft was turned around. That's around 33 miles from YSBK according to a quick check on Google Earth.
At three miles per minute the aircraft would have been descending at around 800fpm to get to 1500' at 12 miles from YSRI, 7 minutes later. The ATC log indicates that the 12 mile call was made at 8 minutes. That translates to a descent rate of around 700fpm.
After that the descent rate slows to around 500fpm if you still allow 3 miles per minute, but more like 375 fpm if airspeed fell to 2 and a bit miles per minute.
Initially I thought there was a case for an assumption that the aircraft may have been 'stepped down' somewhere in the initial 21 miles, however I believe there is an equally valid assumption that the aircraft could have lost the altitude at the best available configuration. I'm sure there are engineering types out there who could advise on the rate of descent from 7000' to 1500' vs 1500' to 0'. I wouldn't be surprised if in fact it was double early on where the air is markedly thinner.
It seems more likely that the rate of descent of around 700 fpm (which would be a fairly normal rate to comply with the steps) was selected under the assumption that the aircraft had reserve power to hold altitude at 2500' - 2000' until the normal final descent to 11C, but when the power was asked for it just wasn't there.