RANGE

[DEINIOLENMAN 0]

I am puzzled about the range that 800/900 aircraft (as modelled by PDMG) can fly. According to the fuel load estimates, a 737/900 has a range of 5000 miles at 33000ft and 2000 miles at 37000 feet. The 737/800 seems to have an even greater range. I cannot see what payloads these estimates are for; am I correct in saying that they are for full capacity payloads?It therefore appears that the 737 is a truly transatlantic airliner - are they actually used as such?DM

[Jack_C 1]

I am puzzled about the range that 800/900 aircraft (as modelled by PDMG) can fly. According to the fuel load estimates, a 737/900 has a range of 5000 miles at 33000ft and 2000 miles at 37000 feet. The 737/800 seems to have an even greater range. I cannot see what payloads these estimates are for; am I correct in saying that they are for full capacity payloads?It therefore appears that the 737 is a truly transatlantic airliner - are they actually used as such?DM

Not sure where it says that but no matter what config or altitude a 900 does not have a range even close to 5000 miles.Jack C

[DEINIOLENMAN 0]

According to the PMDG fuel load estimations the 737/900 has a range of 2000 miles at FL370 and 5000 miles at FL310. If this is correct, it would bring the 737/900 within the orbit of transatlantic range. Jim C

Not sure where it says that but no matter what config or altitude a 900 does not have a range even close to 5000 miles.Jack C

[scandinavian13 5,192]

For what it's worth, you're never going to get hard numbers from anyone who knows anything about aviation - there are too many variables. Wind/Weather are the biggest factors in that variation, while beyond that it's passenger/cargo load, and so on. What may be 2000nm one day will be 1500nm the next because of wind and weight.Are they used across vast portions of water? Yes:http://flightaware.com/live/flight/COA173/history/20101228/0025Z/KLAX/PHNLDoes that require special aircraft certification? Yes, so many airlines run on the thought that if I'm paying to get a twinjet certified across a certain expanse of water, I'm going to pack it full of people, which would mean something larger than a 73.

[DEINIOLENMAN 0]

I don't follow that. It is a fairly simple calculation to determine whether or not a given type of aircraft can cross the Atlantic. For the extreme you assume the worst weather conditions and full load and work from that basis. Small aircraft do fly scheduled flights between Britain and the USA: both Delta and Continental use B757's.JC

[Ray_the_pilot 0]

Are you sure you are not using km? According to Boeing's own "Facts", the 737-900ER can fly up to 3200 nm, which would be 5925 km. And that is the ER version.

[DEINIOLENMAN 0]

Kilometers? Not in this country! No, the figures are those that come with the PMDG 737/800-900. They are part of the pdf documentation entitled Cruise Flight.

Are you sure you are not using km? According to Boeing's own "Facts", the 737-900ER can fly up to 3200 nm, which would be 5925 km. And that is the ER version.

[Chock 17,769]

Some 737s make transatlantic flights, but not that many and those which do tend to be specialist versions that are fitted out completely with first class seating and an improved galley so that the food matches the service expectations and ticket prices (see Privat Air for example). Even smaller airliners than the 737, such as the A318, make transatlantic flights, but they too have all first class seating and an improved galley (see BA London City connection to the US).The copious fuel capacity of some 737 variants is to a large extent about it being able to make lots of smaller flights to poorly equipped regional airports without the need to refuel rather than one big long flight, which is one of the reasons why the 737 also has airstairs. The 737 was designed from day one to be the kind of airliner you could do that with, which is also why it was designed to be operated by a crew of two pilots rather than three.Al

[DEINIOLENMAN 0]

It will be like going back to when I first flew - all first class and with a flight deck complement of five: Pilot, FO, Radio, Nav and Engineer. Only two cabin crew.

Some 737s make transatlantic flights, but not that many and those which do tend to be specialist versions that are fitted out completely with first class seating and an improved galley so that the food matches the service expectations and ticket prices (see Privat Air for example). Even smaller airliners than the 737, such as the A318, make transatlantic flights, but they too have all first class seating and an improved galley (see BA London City connection to the US).The copious fuel capacity of some 737 variants is to a large extent about it being able to make lots of smaller flights to poorly equipped regional airports without the need to refuel rather than one big long flight, which is one of the reasons why the 737 also has airstairs. The 737 was designed from day one to be the kind of airliner you could do that with, which is also why it was designed to be operated by a crew of two pilots rather than three.Al

[scandinavian13 5,192]

I don't follow that. It is a fairly simple calculation to determine whether or not a given type of aircraft can cross the Atlantic. For the extreme you assume the worst weather conditions and full load and work from that basis. Small aircraft do fly scheduled flights between Britain and the USA: both Delta and Continental use B757's.JC

The 757 isn't exactly a "small" aircraft. For one, it had its own weight class up until last year, though that was because its wake properties were enough to bump it up a category. Second, the aircraft is large enough to merit being thrown in on longer routes. BAW uses them as an all-business-class flight between the UK and IAD. The only reason this is viable is because business class means less passengers, which means less weight, which means longer range. It being business class also means that all the passengers paid more to get on that flight. Basically, the cost of cutting out passengers was mitigated by making everyone pay more.I'm very serious about the range value. When have you ever seen a firm value? There's too much variation. To add to what I mentioned above, there are aircraft all within the same fleet that have different operating numbers because one has a galley where lav is on another, whereas another has extended range tanks. Each one of those is going to have a different range. The type of engine used will have an effect on range. How clean the aircraft is has an effect on range. I'm not kidding. If someone gives you a "hard" range, they're either guessing or lying. Here's another wrench in your idea: define "worst weather conditions."To me, worst weather conditions would mean a headwind that is equal to your cruise speed with nasty icing and turbulence. Then your range is zero. What good is the number now? I'm not trying to belittle anyone here, I'm just trying to prove a point: there's no real value in assigning arbitrary numbers to aircraft.

[fencer 16]

Even smaller airliners than the 737, such as the A318, make transatlantic flights, but they too have all first class seating and an improved galley (see BA London City connection to the US).Al

Hello Al,As you are probably well aware, with the prevailing winds, the A318, has to make an intermediate stop going westward. I guess this is due to TO weight/runway lenght limitations at London City.Bruno

[DEINIOLENMAN 0]

Are you not in danger of splitting hairs here. All aircraft have a quoted 'notional' range (which is, of course, dependent on the elasticity of conditions); my difficulty was in determining what it was for the 737/900. Most of the printed matter say one thing, PMDG says another and states that the 737-900 has a maximum endurance of over eleven hours (page 2-12 of Cruise Flight).Continental and Delta use the 757on daily flights from the UK to New York et al with third class configuration.Jim

The 757 isn't exactly a "small" aircraft. For one, it had its own weight class up until last year, though that was because its wake properties were enough to bump it up a category. Second, the aircraft is large enough to merit being thrown in on longer routes. BAW uses them as an all-business-class flight between the UK and IAD. The only reason this is viable is because business class means less passengers, which means less weight, which means longer range. It being business class also means that all the passengers paid more to get on that flight. Basically, the cost of cutting out passengers was mitigated by making everyone pay more.I'm very serious about the range value. When have you ever seen a firm value? There's too much variation. To add to what I mentioned above, there are aircraft all within the same fleet that have different operating numbers because one has a galley where lav is on another, whereas another has extended range tanks. Each one of those is going to have a different range. The type of engine used will have an effect on range. How clean the aircraft is has an effect on range. I'm not kidding. If someone gives you a "hard" range, they're either guessing or lying. Here's another wrench in your idea: define "worst weather conditions."To me, worst weather conditions would mean a headwind that is equal to your cruise speed with nasty icing and turbulence. Then your range is zero. What good is the number now? I'm not trying to belittle anyone here, I'm just trying to prove a point: there's no real value in assigning arbitrary numbers to aircraft.

[Spin737 102]

The only way you're getting 5000nm out of a 737 is with additional tanks in the belly and wings, a la BBJ. Regular airline service is closer to 2500nm. 3000nm maybe if you're taking off from a cold airport with a long runway and heading east.

[fencer 16]

Are you not in danger of splitting hairs here. All aircraft have a quoted 'notional' range (which is, of course, dependent on the elasticity of conditions); my difficulty was in determining what it was for the 737/900. Most of the printed matter say one thing, PMDG says another and states that the 737-900 has a maximum endurance of over eleven hours (page 2-12 of Cruise Flight).Continental and Delta use the 757on daily flights from the UK to New York et al with third class configuration.Jim

No offence, but are you calculating real range (ie taking into account reserve fuel, etc - especially with ETOPS operations in mind)? For example, JFK to Heathrow might be only about 3000 nm on a great circle route but with two engines you must go much further north (ETOPS operations) and I guess the flying distance (even without wind) is probably between 3,500 and 4,000 (I never really took a close look). And that is without taking into account the legal reserves needed.Also, I don't know why the PMDG chart shows up to 73,000 lbs of fuel since this is way above the max fuel capacity of the aircraft. If you play with PMDG's load manager (among other tools and documents), you'll see that max fuel load is around 46,000 lbs. And, with a reasonable load (passengers and cargo) the same load manager shows you won't be able to load much more than 40,000 lbs of fuel (in fact not more than 35000 on a fully loaded 900). Look at the theoretical range you get with that amount. Now take all contingencies into account (wind, reserves etc) and you get back very easily to Matt's 2,500 nm.Granted, there is an extended range version (not modelled by PMDG) but I don't know what additional range you would get out of it and I guess other planes would be more economical to operate on very long flights.Bruno

[DEINIOLENMAN 0]

That's a good point. I hadn't thought of checking maximum fuel load against the tables. As you say, the max is 46060 pounds which gives an endurance of 7 hours 44 minutes which would be cutting things very fine over the Atlantic. At least the point has now been cleared up - many thanks.Jim