Is there any benefit with respect to scheduling delays by utilizing a turnaround time greater than the minimum time necessary to reach a ~1% possibility of delay?
Yes.
Statistically only 1 (or less) out of 100 flights will be canceled or heavily delayed. If you have it at say 20% then statistically every fifth fligfht will be heavily delayed or canceled (might be more or less in the one or the other week).
High percentage of cancellations [over 2-3%] or a high percentage of heavily delayed flights [more than 15-20% or a punctuality of 80-85% or less] will reduce your Company Image for which to work against you have to pay more for marketing. (and you also have no income from these canceled flights, so a double-loss for you!)
Jona L.
Quote from: e36power on June 04, 2011, 06:53:29 PM
Is there any benefit with respect to scheduling delays by utilizing a turnaround time greater than the minimum time necessary to reach a ~1% possibility of delay?
The longer the turnaround time, the less the delays. It's impossible to have 0% chance of delay, which is why you always see ~1%. There is a benefit to having more than the minimum ~1% turnaround time. If you plan on replacing your fleet in the future, you should look up turnaround times and make sure you can switch it over to the future fleet without compromising your entire schedule. For example, you can turn around a BAC 1-11 in 60 minutes with ~1%, but it takes 70 minutes for an MD-81. If you plan on phasing out your 1-11's with MD-81's in the future, you should schedule your 1-11's with a 70 minute turnaround time so you don't have to change the departure of every single route or even reschedule the routes at different times (assuming you have maximum fleet utilization). The MD-81 does fly faster and thus gets to it's destination quicker and for longer routes this doesn't matter, but I'm using this for sake of having an example. If you're going from a prop to a jet on a short route, the differences can be huge (20+ minutes).
Quote from: Jona L. on June 04, 2011, 09:16:48 PM
Yes.
Statistically only 1 (or less) out of 100 flights will be canceled or heavily delayed. If you have it at say 20% then statistically every fifth fligfht will be heavily delayed or canceled (might be more or less in the one or the other week).
High percentage of cancellations [over 2-3%] or a high percentage of heavily delayed flights [more than 15-20% or a punctuality of 80-85% or less] will reduce your Company Image for which to work against you have to pay more for marketing. (and you also have no income from these canceled flights, so a double-loss for you!)
Jona L.
Makes sense. Diminishing returns, but if you have 30 minutes of down time, might as well add that to turnaround time.
Lemon wrote some really good tips there. Use them.
I wonder if the OP asked if you get less than 1% if you go for an even longer turn around time than the limit for 1%. Basically, would an A320 with 70min turnaround time get more delays than an A320 with 100min turnaroundtime? If a possibility is 1% on both, shouldnt it be equal? 1% is 1% no matter when as Ive understood it.
Now Im curious :laugh:
Quote from: lilius on June 04, 2011, 11:04:37 PM
Lemon wrote some really good tips there. Use them.
I wonder if the OP asked if you get less than 1% if you go for an even longer turn around time than the limit for 1%. Basically, would an A320 with 70min turnaround time get more delays than an A320 with 100min turnaroundtime? If a possibility is 1% on both, shouldnt it be equal? 1% is 1% no matter when as Ive understood it.
Now Im curious :laugh:
I think you will have fewer delays with the 100 min turnaround, however, it is diminishing returns. Don't do 100 minute turnarounds unless you have 30 minutes of downtime on the aircraft, in that case might as well, may reduce your delays marginally.
Quote from: lilius on June 04, 2011, 11:04:37 PM
Lemon wrote some really good tips there. Use them.
I wonder if the OP asked if you get less than 1% if you go for an even longer turn around time than the limit for 1%. Basically, would an A320 with 70min turnaround time get more delays than an A320 with 100min turnaroundtime? If a possibility is 1% on both, shouldnt it be equal? 1% is 1% no matter when as Ive understood it.
Now Im curious :laugh:
I think from the 1% threshold it doesn't matter how long you let the aircraft turn anymore. The crew has at that point enough time to turn the aircraft around without delay.
Yes I lean to the theory that you have Quinoky.
The more time you schedule for turnarounds, the lower the chance of delay. It's just that the returns are so small past that 1% mark (note it says ~1%, not 1% dead, that can be anything down to 0.0000001%) that it's normally not worth scheduling.
Think about it, it makes sense. If the aircraft arriving from the previous flight is delayed by an hour, then a scheduled turnaround time of 50 minutes will result in a scheduling delay, however a 90 minute turnoarund should allow the aircraft to depart on time, even if the % chance for delay for both is ~1%.