Originally Posted by
djohannw
I have booked a flight in the far future that changes from 763 that operates now to 772 then (via 788 sometime in between, but no experience with that so far). Currently the flight has a block-time of 11:50, but with the change to 777 the time is reduced to 11:05.
Having flown this flight a few times in the past on the 763 the actual flight time has always been around 11:00-11:30 hours, and currently (according to flightstats) it's even worse with flight-duration in the 11:45-12:15 area. Adding the normal average taxi-time at the departure airport of 15+ minutes that would mean the flight is almost guaranteed to be late an hour+ if the 777 does not fly substantially faster to warrant such a reduction of flight duration - assuming it pushes back right on scheduled departure-time (which it usually does NOT).
Assuming you mean FRA-IAH, here's the average published block times for the last 4 years as deltas in minutes from 11h by aircraft type and month:
Code:
carrier | orig | dest | month | b763 | b764 | b772
---------+------+------+-------+------+------+------
UA | EDDF | KIAH | 1 | 46 | 34 | 25
UA | EDDF | KIAH | 2 | | 29 | 21
UA | EDDF | KIAH | 3 | | 29 | 12
UA | EDDF | KIAH | 4 | 36 | 12 | -13
UA | EDDF | KIAH | 5 | 50 | 10 | -1
UA | EDDF | KIAH | 6 | 37 | 9 | -8
UA | EDDF | KIAH | 7 | 35 | 14 | -11
UA | EDDF | KIAH | 8 | 35 | 10 | -9
UA | EDDF | KIAH | 9 | 13 | 9 | 0
UA | EDDF | KIAH | 10 | 17 | 17 | -7
UA | EDDF | KIAH | 11 | 50 | 37 | 14
UA | EDDF | KIAH | 12 | 50 | 38 |
(I've blanked some cells with small sample sizes)
So they do block longer in the winter than the summer, and block longer on the 767 than the 777.
Here's the average actual flight times for the last 4 years as deltas in minutes from 10h by aircraft type and month:
Code:
carrier | orig | dest | month | b763 | b764 | b772
---------+------+------+-------+------+------+------
UA | EDDF | KIAH | 1 | | 60 | 22
UA | EDDF | KIAH | 2 | | 62 | 37
UA | EDDF | KIAH | 3 | | 44 | 35
UA | EDDF | KIAH | 4 | 56 | 41 |
UA | EDDF | KIAH | 5 | 36 | 33 | 20
UA | EDDF | KIAH | 6 | 34 | 17 | 10
UA | EDDF | KIAH | 7 | 63 | 23 | 12
UA | EDDF | KIAH | 8 | 26 | 29 | 12
UA | EDDF | KIAH | 9 | 51 | 48 | 8
UA | EDDF | KIAH | 10 | 49 | 39 | 15
UA | EDDF | KIAH | 11 | | 54 |
UA | EDDF | KIAH | 12 | | 72 |
(I've blanked some cells with small sample sizes)
Same trend here, fly longer in the winter and in the 767.
Now look at the difference between the schedules and the actuals to see how consistent the taxi padding is:
Code:
carrier | orig | dest | month | b763 | b764 | b772
---------+------+------+-------+------+------+------
UA | EDDF | KIAH | 1 | | 34 | 63
UA | EDDF | KIAH | 2 | | 27 | 44
UA | EDDF | KIAH | 3 | | 45 | 37
UA | EDDF | KIAH | 4 | 40 | 31 |
UA | EDDF | KIAH | 5 | 74 | 37 | 39
UA | EDDF | KIAH | 6 | 63 | 52 | 42
UA | EDDF | KIAH | 7 | 32 | 51 | 37
UA | EDDF | KIAH | 8 | 69 | 41 | 39
UA | EDDF | KIAH | 9 | 22 | 21 | 52
UA | EDDF | KIAH | 10 | 28 | 38 | 38
UA | EDDF | KIAH | 11 | | 43 |
UA | EDDF | KIAH | 12 | | 26 |
The taxi padding on the 777 fleet looks solid - consistent throughout the year, and consistent with the 767 fleet. B763 seems to have the most variation, possibly they add conservatism due to sUA metal from an PMCO hub.