Kurtjeter From United States of America, joined Feb 2011, 99 posts, RR: 0 Posted (4 years 1 month 4 weeks 21 hours ago) and read 3989 times:
A lot of us think that the aircraft we fly on from point A to point B is the same one we fly on as we fly back from B to A. I know it's not, but I find this particularly interesting in longer, transocean flights. For example, I flew a 777 from ORD to BRU and then returned (same airline) on an A330. Likewise, EWR to FRA, courtesy of a 777, but return to EWR (same airlines) on a 767.
My question: what happened to that 777 that took me from EWR to FRA? It obviously had to return to EWR by some route, at some time. And, likewise, how did that 767 get over to FRA in the first place to get me back to EWR?
comorin From United States of America, joined May 2005, 4908 posts, RR: 16
Reply 1, posted (4 years 1 month 4 weeks 20 hours ago) and read 3891 times:
Rest assured that the 777 does indeed return. One of two reasons for your dilemma - the airline has multiple flights per day: so you could go to ORD to BRU on one aircraft, and return on another while the original aircraft is scheduled for another flight. The other is that the airline can vary equipment depending on day of week, so you could come in on one and return on the other.
Viscount724 From Switzerland, joined Oct 2006, 26639 posts, RR: 22
Reply 2, posted (4 years 1 month 4 weeks 20 hours ago) and read 3884 times:
Airlines with more than one daily flight on a route try to match the demand with the capacity. Flights at different times of the day can have widely differing demand, so you want to use the largest aircraft on the most popular flight.
vgnatl747 From United States of America, joined Apr 2001, 1521 posts, RR: 2
Reply 3, posted (4 years 1 month 4 weeks 20 hours ago) and read 3818 times:
Routings are rarely back and forth (when flying to/from/between hub and/or focus cities). In a small regional airport, 99% of the time, the aircraft that flew from the hub to that city turns around and goes back to the hub, but once it gets to the hub it goes somewhere else (doesn't sit around and wait to go back to that small regional airport again).
Every airline and route is different. As an example, the 772 that flies IAH-LHR as CO34 returns as CO29 LHR-EWR. Now there's also a 772 that comes into LHR from EWR, along with a couple 752s. CO has that nifty "where's my airplane coming from" feature on their website that makes it a lot easier to figure some of that out (if your EWR example happened to be on CO metal).
Long story short, there's lots of reasons for having the routings the way they are. Specific aircraft are rarely route specific, and in the scenario where there's multiple daily flights on a given route they're not necessarily all of the same type. Depending on how the slots and the turnarounds are scheduled, an aircraft coming in from one city may be turned to go somewhere else. You need this to minimize wasted time on the ground, keep fleet utilization as efficient as possible, and allow for rotating of aircraft to facilitate maintenance. If you had one specific frame dedicated to fly back and forth between EWR and FRA, taking that frame out for maintenance (preventative or otherwise) get's much more difficult. You also run the risk of it sitting in FRA for an extended (wasteful) period of time until the next departure back to EWR. In addition, in the scenario of the ugly winter we've had this year, you run the risk of your metal being stuck somewhere else in the event of a major weather event (potentially crippling the fleet depending on how utilized everything is).
There's a real science that goes into fleet and route planning, and I can't even begin to explain it all. I think that's a high enough summary that answers your question though.
Aesma From Reunion, joined Nov 2009, 7489 posts, RR: 14
Reply 4, posted (4 years 1 month 4 weeks 20 hours ago) and read 3773 times:
A good start could be to use the airlines' websites and try to book the same leg at different times/dates to see the variation in aircraft (in the same direction). Then obviously the same applies in the other direction. When I book a certain flight I take often, I like to vary planes so I chose the flight according to the plane I want to fly, last time it was CRJ-200 one way, A318 the other way. Next time I'll try to get on a CRJ-1000.
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
kellmark From United States of America, joined Dec 2000, 696 posts, RR: 7
Reply 5, posted (4 years 1 month 4 weeks 19 hours ago) and read 3571 times:
One of the things that I did in my airline career was to route aircraft. The aircraft fleet types are scheduled according to passenger demand, crew capability and availability and aircraft performance capability and limitations. But the actual individual tail numbers within a fleet are generally scheduled according to maintenance requirements. These requirements are built in to the schedule as well. Each item has to be done within a certain specified required limit, measured in one of three ways, flight hours, calendar days, or cycles (takeoffs and landings). For example, an aircraft may need an overnight service, an A check, or engine inspections, or a flap lubrication, etc. These items are assigned to particular stations which have the capability to do the assigned items. It is also necessary to plan technician workload and parts availability or any special tools or facilities.
Normally, as noted above, if a station is at the end of a spoke of a hub, it just goes back. But if not, then any number of combinations may be possible. Also, irregular operations like weather diversions, crews timing out, security issues, airport closures or mechanical breakdowns can cause necessary changes. Aircraft routing is very much like a three dimensional chess game.
ANITIX87 From United States of America, joined Mar 2005, 3324 posts, RR: 13
Reply 12, posted (4 years 1 month 3 weeks 6 days 23 hours ago) and read 2689 times:
Another example is LX's JFK flights.
There are three daily flights to JFK. Two from ZRH, and one from GVA. Let's call the airplanes A, B, and C (all are A330-300). Airport "XXX" is another A330-300 destination in the network (any destination).