Routing of airline from Pt A – Pt B

Having spent more than a couple of years working for an aircraft manufacturer I can assure you that detailed studies of an airline’s route network and suitability for the aircraft are made by the manufacturer prior to a sale. These would include airfield performance, taking into account weather – wind, temp, surface condition; range with all the variations and challenges outlined above; economics with fuel burn, atc and airport costs etc. and more.

Guarantees would be provided by the manufacturer that their aircraft would be capable of operating to and between specified airports and any limitations would be noted.

The oft quoted max or typical range of an aircraft is nothing more than a very rough guide to start your investigations into possibilities.

Try to get hold of a book ‘The Airline Business’ by Rigas Doganis which would give you a good background knowledge of these things.

Thank you. Agree completely. Especially this part:
“Guarantees would be provided by the manufacturer that their aircraft would be capable of operating to and between specified airports and any limitations would be noted.”
When those guarantees aren’t met, conflict occurs, then resolution. Happens all the time. I have witnessed it.

The manufacturer most definitely does “publish what routes it can achieve.” (Quote from post 13)

Airlines purchase airplanes that “only just fit the bill” all the time. Buying a larger airplane is wasteful, and we live in a business world now driven by bean counters and MBA’s that don’t know doodledy squat about airline operations, or anything else other than massaging numbers and making their goals, IMHO. Believe it or not, the airlines have entire departments that do nothing other than optimize (their words) the equipment onto continually longer and more challenging routes, with less and less downtime for maintenance between flights. They are measured by how “well” they use the available airplanes, they do not have to answer for the dispatch reliability, or the fuel stops, or the involuntary denied boardings, or the bags left behind. Everyone lives in their own little silos.

IMHO, the initial poster really was asking questions which go right to the heart of what it takes operate an airline. All the factors that go into flying from point a to point b are the guts of airline operations. It takes lots of people other than pilots to make that operation go. I have 22 years experience doing that at a major airline, and am far from naive regarding these topics, but still consider myself an enthusiast also.

At last, some really interesting threads are currently being discussed on this forum!:D

I would like to throw another couple of related questions into the mix, but first my apologises to Dandpatta for hijacking his original thread…I feel your question has been answered, and rather than starting another related thread I think its best to keep it altogether here, hope you don’t mind?

So, the questions…

How do airlines decide where to send their aircraft on a daily basis, as in what routes to serve each day and at what times?.

Obviously I already know that no airline has just one aircraft flying on one particular route every single day of the year (unless it is a very small airline that just operates one/two routes with just one aircraft – i.e Lyddair ;)).

So, for example: ABC Airlines flies from London to…Manchester, Edinburgh, Glasgow and Belfast…

How does ABC Airlines manage to work out what is best in terms of efficiency for the airline from a business/revenue perspective, but also from a passenger perspective of offering a flight to a particular destination at the most convenient time to suit their customers needs?’

Also, what happens in the event of a delay/cancellation?

Obviously if it is the last flight of the day that is delayed/cancelled, then the scale of the problem is somewhat reduced, but what happens if the delay/cancellation occurs at the beginning, or throughout the day…

What steps would ABC Airlines go through when deciding if they should delay/cancel another flight and use that available aircraft to operate the original flight that would have been delayed/cancelled, or whether they should just keep the original flight delayed/cancelled and try to work out a different solution?

Apologises if my questions seems long-winded or do not make sense, but that is how I thought I should word them to help people understand?:o:confused:

Any info would be greatly appreciated.:cool:

Wow, big questions, none with simple answers! Here’s some brief input on the subject for now:

How do airlines decide where to send their aircraft on a daily basis, as in what routes to serve each day and at what times?.
How does ABC Airlines manage to work out what is best in terms of efficiency for the airline from a business/revenue perspective, but also from a passenger perspective of offering a flight to a particular destination at the most convenient time to suit their customers needs?’

Market research, past demand and yields, industry data from sources like the major GDSs (google MIDT for example), overall traffic trends including connection analysis to establish true origin-to-destination flows… And of course their own aircraft capacity and availability to meet market demands, etc. In many well served markets there is a strong drive to create a predictable service – ie. a set frequency, even with “clock-face” type timetables on high-frequency routes, etc. Optimising aircraft utilisation also comes into the balance – no point in setting a timetable that leaves a/c sat on the ground in various locations for lengthy periods…

What steps would ABC Airlines go through when deciding if they should delay/cancel another flight and use that available aircraft to operate the original flight that would have been delayed/cancelled, or whether they should just keep the original flight delayed/cancelled and try to work out a different solution?

If an airline doesn’t have a “service backup” aircraft (aircraft sitting idle that can be used to substitute for a long delayed or tech aircraft – which the airline I used to work for did have quite regularly), then it comes down to a juggling combination of issues including:

A

Cloud_9, I work in ops but unfortunately most of your questions are irrelevant for our set-up. Someone like EGNM (Steve) would be a good bet to answer your questions, although as with everything in airline ops there are far too many other variables to give a realistic/definitive answer.

At last, some really interesting threads are currently being discussed on this forum!:D

I would like to throw another couple of related questions into the mix, but first my apologises to Dandpatta for hijacking his original thread…I feel your question has been answered, and rather than starting another related thread I think its best to keep it altogether here, hope you don’t mind?

So, the questions…

How do airlines decide where to send their aircraft on a daily basis, as in what routes to serve each day and at what times?.

Obviously I already know that no airline has just one aircraft flying on one particular route every single day of the year (unless it is a very small airline that just operates one/two routes with just one aircraft – i.e Lyddair ;)).

So, for example: ABC Airlines flies from London to…Manchester, Edinburgh, Glasgow and Belfast…

How does ABC Airlines manage to work out what is best in terms of efficiency for the airline from a business/revenue perspective, but also from a passenger perspective of offering a flight to a particular destination at the most convenient time to suit their customers needs?’

Also, what happens in the event of a delay/cancellation?

Obviously if it is the last flight of the day that is delayed/cancelled, then the scale of the problem is somewhat reduced, but what happens if the delay/cancellation occurs at the beginning, or throughout the day…

What steps would ABC Airlines go through when deciding if they should delay/cancel another flight and use that available aircraft to operate the original flight that would have been delayed/cancelled, or whether they should just keep the original flight delayed/cancelled and try to work out a different solution?

Apologises if my questions seems long-winded or do not make sense, but that is how I thought I should word them to help people understand?:o:confused:

Any info would be greatly appreciated.:cool:

Having spent more than a couple of years working for an aircraft manufacturer I can assure you that detailed studies of an airline’s route network and suitability for the aircraft are made by the manufacturer prior to a sale. These would include airfield performance, taking into account weather – wind, temp, surface condition; range with all the variations and challenges outlined above; economics with fuel burn, atc and airport costs etc. and more.

Guarantees would be provided by the manufacturer that their aircraft would be capable of operating to and between specified airports and any limitations would be noted.

The oft quoted max or typical range of an aircraft is nothing more than a very rough guide to start your investigations into possibilities.

Try to get hold of a book ‘The Airline Business’ by Rigas Doganis which would give you a good background knowledge of these things.

Fair enough mate, didn’t have enough info from your post to clarify that. Thanks for clearing it up 🙂

How is this the manufacturer’s problem?

Come on Gents, surely your not that naive as to think a manufacturer will publish what routes it can achieve, this is why it states the range it will achieve.

Deano, I’m not agreeing with Ship’s points about airlines buying an aircraft and basing their judgement on the published range. The airline I work for has quite complex software in place to make sure we don’t offer flights to customers that the aircraft wouldn’t actually be able to fly (even if it does appear to be within range). I’m merely saying that for the average forum viewer who might not know much about flight planning, he is making a valid point in that published range isn’t equal to the distance it can fly from x to x. I have friends who still think that planes take off, turn in the direction they want to go in, and then find their way in a straight line by ‘SatNav’!

Perhaps I stated it poorly.

What if you bought the airplane to fly a particular long range route that was just barely capable per the promised literature, and then due to political/overflight fees/authorizations, winds, airways, terrain, takeoff performance, etc. you were unable to fly the route without an intermediate fuel stop or leaving passengers behind?

Why would an airline do this? Surely they wouldn’t look at Boeing’s or Airbus’ website and say “ah, the 7×7/A3xx will fly x nm”. Great, we need them to fly to x airports. Let me see, x airport is x miles away. Ok, it should do it”
Alot of planning goes on behind the scenes before contracts are signed. Routes are worked out, route distances are worked out, cost basings are worked out, performance is worked out (already known by the manufacturer) etc etc etc. Only then if the plane fits the airlines will purchase. Unfortunately Ship it isn’t as black and white as you put it.

The effective range of the aircraft in actual service is reduced due to these considerations, and the airline might have a claim against a manufacturer.

The effective range is never reduced. Do you really think the airlines would purchase an a/c that would “only just fit the bill” as far as range goes? Don’t you think this is asking for trouble? No airline in their right mind would go into this with their eyes shut.

And the airline might have a claim against a manufacturer.

And you really think this would stand up in court?
/Mr Airline – “ah, but Mr Airbus said this plane would fly x miles, but we didn’t do our planning right and realised that the aircraft didn’t make x airport by 100nm, we had to tech stop.”
/Mr Judge – “hmm, so how many miles did it actually fly?”
/Mr Airline – “Well it did actually fly x miles, but because of routings the great circle distance path was shorter than what was flown”
/Mr Judge – “so it did actually fly what was stated?”
/Mr Airline – “er yes, technically, it flew x miles as stated but because of routings it fell short”
/Mr Judge – “Get out of my court, how dare you waste my time”.

Sorry Ship, it absurd to a) think airlines wouldn’t do their homework & b) to assume they’d have a case against the manufacturer because over certain parts of the globe a re-route means more miles to fly.

I know what Ship741 is saying and he has a good point.

There is no point to Ship’s point, if the manufacturer states that their a/c will fly x miles and it actually can, then that is the end of discussion. Like the ol’ advert that used to be on here – Ronseal (Boeing?), it does exactly what it says on the tin

So an aircraft that can supposedly fly 1000nm might only be able to reach places approx 800nm away on the Great Circle route.

How is this the manufacturer’s problem?

Come on Gents, surely your not that naive as to think a manufacturer will publish what routes it can achieve, this is why it states the range it will achieve.

(In response to the original question) Could it have anything to do with a lack of ETOPS certification on the aircraft? I’m going to guess by the length of the route that it was either a 767 or 777. Both these aircraft are not ETOPS certified straight from the manufacturer. The airline has to earn it through a record of good safety and some inspections.
If you’re not familiar with ETOPS, it is a certification that allows your aircraft to fly further away from an airport (for instance, in the atlantic you can be hundreds of miles from an airport). An aircraft without ETOPS cannot fly too far from an airport it is certified to land at in an emergency (sure I read somewhere it was 30 minutes. But honestly dont know.). So in this case the aircraft was not allowed to fly directly over the Indian ocean because it would have taken it too far away from an airport incase of an emergency such as engine failure.

I know what Ship741 is saying and he has a good point. Published range figures for an aircraft are true in the sense that that is how far they can fly, but if you draw a range ring on a map to match that figure it’s unlikely the aircraft will actually reach some of the destinations inside that ring.

Routing in the US is pretty easy, there are thousands of airways going in different directions and it’s normally quite straight forward to fly very close to the Great Circle route. However, in Europe you probably fly about 120% the Great Circle route a lot of the time. So an aircraft that can supposedly fly 1000nm might only be able to reach places approx 800nm away on the Great Circle route.

Perhaps I stated it poorly.

What if you bought the airplane to fly a particular long range route that was just barely capable per the promised literature, and then due to political/overflight fees/authorizations, winds, airways, terrain, takeoff performance, etc. you were unable to fly the route without an intermediate fuel stop or leaving passengers behind? The effective range of the aircraft in actual service is reduced due to these considerations, and the airline might have a claim against a manufacturer.

I hope you will agree that an airliner flying around in circles is rather useless to the operator.

Ship

Your argument holds no water. The plane still flies the stated range whether it goes in a straight line or flies round in circles.

Sorry, but I can’t resist adding that all of the reasons listed above are why manufacturer claims of range capabilities on their products must be taken with a grain of salt.

An airliner may be delivered with a promised range of 7000 miles, but once all the other considerations get factored in 6400 might be the “real” max range. (i just randomly selected those numbers).

Another reason, which probably isn’t applicable here, but could be in some African States can be a lack of overflight permits Some countires simply won’t provide overflight permits to carriers from countries where there are diplomatic tensions with the country of origin or country of the carriers origin.

One route the company I work for Operates on behalf of an African Carrier has around a 200nm (nearly 30mins flight time) re-route around Sudan and Ertrea.

Gentlemen (Sam & WannaBpilot)

Thanks so much for your detailed explanations.

With appreciations and warm regards,
Dandpatta

As Sam has pointed out, planes can’t simply take off and fly in the direction they want to. They have to follow a Flightplan, which is made up of airways (a corridor or ‘road’ in the sky) and waypoints (like the junction connecting roads). Unfortunately there aren’t airways covering every direction of the Earth, so most routes are indirect. I also imagine that the route you took could have something to do with them having to stay with in a certain distance of land (incase of an engine failure) as opposed to just setting off right across the middle of the Indian Ocean.

There are various factors which are taken into consideration when planning a route and cruising altitude.