Thanks for the information, Jay!
The NH site says about 5 cal per average/12-step flight for a 150 lb person. . . so adding roughly 50% for a 248 lb person would make it about 7.5 cal per average flight for me.
Fitday tells me 10 cal per minute for a 248 lb person, so it seems Fitday is assuming 1.33 average flights per minute.
This seems slow to me, at least for the first few flights
I'm going to do some experimenting/timing, and I'll keep you posted!