AT From United States of America, joined Jul 2000, 1163 posts, RR: 0 Posted (12 years 8 months 3 weeks 3 days 9 hours ago) and read 2394 times:
A friend of mine and I were just discussing a while earlier British Airways' decision to retire their A market (non ER) 777s, and he asked, couldn't they convert them to ERs instead?
Is this possible? If so, have any types of aircraft (757, 767, 777, etc) been converted after being manufactured into an ER configuration? And what modifications would that entail.
Also as an aside, I know that ER is NOT the same thing as ETOPS, but does ER have any effect on ETOPS? The reason I ask is that British Airways, for example, used all their A market 777s to the Middle East, and 777ERs to the US/Canada East Coast cities, although the distances to the middle East are actually longer. Was this choice because of the 777ERs are better equipped for overwater flights?
Elwood64151 From United States of America, joined Feb 2002, 2477 posts, RR: 5
Reply 1, posted (12 years 8 months 3 weeks 3 days 9 hours ago) and read 2385 times:
It is possible to convert aircraft from one version to another. McDonnell Douglas even developed a kit for converting MD-82s into MD-83s back in the mid eighties.
But it is usually expensive to convert aircraft from one type to another, which is why the two-engine 727 concept never worked out and why perfectly good 737-200 airframes are not converted to 737-300 engines. So much has to be done that you might as well just keep operating what you have until you simply can't use it anymore and you buy or lease whatever is on the market when it comes time to replace them.
Actually, the decision is usually made at least two years before that the old a/c type has to go, and a new one is usually selected at least a year and a half before replacement is scheduled to begin. This time period is shortened with leased aircraft, and the process might take only 6-9 months from decision to replace to first replacement.
Those who fail to learn history are doomed to repeat it in summer school.
Ejazz From United Arab Emirates, joined May 2002, 731 posts, RR: 33
Reply 3, posted (12 years 8 months 3 weeks 3 days 9 hours ago) and read 2376 times:
An ETOPS approved aircraft is one built and operated to very strict rules and regulations allowing it to operate on ETOPS routes. An ER aircraft has Extended Range meaning additional fuel tanks, possibly more powerful engines and a crew rest. The two though do not necessarily go together. Boeing did certify the B777 with ETOPS approval but acceptance of that is based on the Countries own Aviation Authority where the aircraft is to be registered.
Cloudy From , joined Dec 1969, posts, RR:
Reply 9, posted (12 years 8 months 3 weeks 3 days 4 hours ago) and read 2297 times:
It all depends. In some cases, the difference between a higher gross weight version and lower gross weight version is merely in the certification. The same hardware is there, it is just that some airframes are certified to carry more than others are. This is done by manufacturers so they can charge more for customers that want more - even though it costs them the same to produce it regardless. This practice is analogous to that of the software industry - in most software packages, a commercial version does more things and costs more than the consumer or educational version. This is despite the fact that although the commercial version may cost more to develop, once the development costs are paid, there is no difference between the cost to ship a commercial version and the cost to ship an educational version. Usually the additional features are still there but just disabled.
In this case, all you need to do is go to the manufacturer buy the right to use a higher certified gross weight. This is the case for the 737 series - various gross weights are offered but there is no difference in the actual plane you receive, just in the price you pay and the contract you sign.
However, in other cases, there are huge structural differences. I believe this is the case with the B-market 777's, as well as the 747-400ER. Here Boeing had to beef up the wings and allot of the fuselage load bearing parts. To retrofit these modifications would be cost-prohibitive.
FlagshipAZ From United States of America, joined Jan 2001, 3419 posts, RR: 13
Reply 10, posted (12 years 8 months 3 weeks 3 days 3 hours ago) and read 2275 times:
Yes, even to the point of adding more range to an already long-ranged aircraft. A case in point...the DC-10-30. This plane was already long-legged, but some carriers added more fuel tanks in the belly, and they became known as the DC-10-30ER. Even the standard 757-200 can get more range. American had some converted into 757-223(ET), for extra tankage. It can be done to most aircrafts, but you'll be giving up revenue generating payloads. Just my two cents here. Regards.
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