aa737
Posts: 830
Joined: Wed Oct 06, 1999 5:49 am

Extended Range

Mon May 01, 2000 12:45 am

I have a few questions about ER aircraft.

1) I belive to make a plane ER, the manufacurer just makes the planes have a higher maximum take off weight so that they can carry more fuel. Am i right or is there more to it?

2) Why do airlines operate ER and non-ER version of the same aircraft? (example: UA 777-200s) Wouldn't it be easier to have all the planes the same? In the case of UA, if all the 777s were 772ERs they could use any plane on any route and not worry during planning about if the plane will have the range. If you don't need the range is it more economical to use the non-ER version?

Can anyone offer a little help here?
 
Citation
Posts: 30
Joined: Tue Nov 08, 2005 7:03 pm

RE: Extended Range

Mon May 01, 2000 2:26 am

There is more to it than that.
There has to be additional electrical generator capability, additional fire suppresant capability in the baggage compartment, the engines have to meet certain historical shutdown rates per flight hours, plus more things.
The correct term for ER operations is ETOPS (Extended Twin OPerationS).
I don't think may ETOPS aircraft have additional fuel capability.

I have flown 757 ETOPS from SFO to Maui, LAX to Maui, 767-200 ER from Chicago to Manchester, England.

Regarding question 2
The airlines that have both ER and non-ER aircraft in their fleet have a large enough fleet that they don't need the commonality, and the expense of configuration and maintaining all their aircraft in the ETOPS configuration.
 
Flying-Tiger
Posts: 3924
Joined: Mon Aug 23, 1999 5:35 am

RE: Extended Range

Mon May 01, 2000 3:14 am

Don´t forget that many airliners become an -ER after they are in service for some time. This is the reason why airlines operate both the non and the -ER version.

Regards
Flying-Tiger
http://fly.to/rorders The regional plane orders page
Flown: A319/320/321,A332/3,A380,AT4,AT7,B732/3/4/5/7/8,B742/4,B762/763,B772,CR2,CR7,ER4,E70,E75,F50/70,M11,L15,S20
 
Guest

RE: Extended Range

Mon May 01, 2000 3:23 am

ETOPS aircraft cost more to buy and more to operate, as they have to meet higher minimum equipment and maintenance standards - plus carry more equimpment, like back up generators, liferafts etc.

Because of this airlines usually only have the number of ETOPS aircraft they actually need, the rest of the fleets being standard variants. If the airline wants total flexibiity they can have an all ETOPS fleet, but an airline the size of United is large enough to justify operating non-ER 777s.
 
Guest

RE: Extended Range

Tue May 02, 2000 1:22 am

I disagree with what has been stated concerning ETOPS and ER versions of an aircraft. ER are different aircraft models from the manufactrer ( higher MTOW etc.) whereas ETOPS is the authorization to operate twin engine aircraft overwater for an extended period. An ER aircraft is only ETOPS if the airline operates per the requirements, not all ETOPS aircraft are ER models.
 
ZRH
Posts: 4371
Joined: Tue Nov 16, 1999 11:32 pm

RE: Extended Range

Tue May 02, 2000 9:30 pm

I agree with Yaki1. ER and ETOPS is not the same. ETOPS is only for twin jets. They have the authorization to reach the next airport within 120 or 180 min with only one engine working.
ER means "extended range". There are also ER aircrafts with three engins, for example the DC 10-30ER (Swissair has flown them). These a/c have normally a higher maximum take-of weight, they carry more fuel.
 
desertjets
Posts: 7570
Joined: Fri Feb 18, 2000 3:12 pm

RE: Extended Range

Thu May 04, 2000 4:51 pm

For your first question basically ER's are designed to carry more fuel. And ETOPS is seperate. But of some note, a lot of airlines that have mixed fleets of ERs and non-ERs, Say United with their 762's and 772's they operate all aircraft at ETOPS specs (though I could be mistaken now about the 762s since they only do transcon flights) for maintance commonality. And remember UA was the launch customer for the 777 and the IGW version was not available for about 18 months.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia
 
Citation
Posts: 30
Joined: Tue Nov 08, 2005 7:03 pm

RE: Extended Range

Fri May 05, 2000 9:46 am

According to the Boeing web site, the difference between a 777-200 and 777-200ER is fuel capacity, max takeoff weight (545,000 vs 656,000), and different thrust engines (77,200 vs 90,200).
There may also be differences in a beefed up landing gear for the higher gross weights; takeoff and landing.

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