Glom
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What's The Deal With Engine Choices?

Thu Jul 28, 2005 2:04 am

How does having multiple engines benefit the airline? Why would an airline prefer one to the other for the same aircraft presumably doing the same job? If having engine choice is good, why has Boeing done so many exclusivity deals?
 
wrighbrothers
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RE: What's The Deal With Engine Choices?

Thu Jul 28, 2005 3:45 am

Hi Glom

It's all about what the airline wants . For example , you can chose what engine or interior trim you have in your car . If airlines want a choice , Boeing offer a choice . And it depends on what they want , e.g. - SAY a P&W engine is more powerful ( more thrust ) but is less fuel efficient , that's great , but not all airlines want their whole fleet to have more fuel as this could lead to the aircraft being heavier and more UN-enviromentally friendly , so they might want some with a longer range , and some more fuel efficient for shorter range routes a routes over major cities , therefore less pollotion and smaller fuel bill . I hope this explanes all

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irelayer
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RE: What's The Deal With Engine Choices?

Thu Jul 28, 2005 3:52 am

Loyalty is also a huge consideration. Most of CX's fleet use RR engines almost exclusively because of their obvious ties to each other (I believe they recently leases some 744's from SIA that are non RR, can anyone confirm?). So does BA for that matter, and Qantas. This has the side benefit of also being good business. CX can cut down on maintenence costs and training and their mx staff are experts with close ties to RR and they know what they are doing. Sometimes an inferior engine choice is offered to appease one customer...I believe UA 777's and NW's 753's and DC-10-40's are a good example...the P&W engines on these reduce performance on all three of these aircraft but these were what they wanted. I believe in the case of the 753's P&W compensates NW for the performance difference.

-IR
 
ConcordeBoy
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RE: What's The Deal With Engine Choices?

Thu Jul 28, 2005 3:53 am

Depends on the airline and what they want to use the aircraft (and the relative strengths of various engine choices) for.

VN is a great example:
  • They employ the cheaper/weaker PW4084 on their regional 772ERs... less performance, but less cost. That works great for them on those shorter routes.
  • They employ their much more powerful GE90-94B 772ERs for most of there intercontinental routes, and soon for their transpacific routes.



    As for exclusivity, that's usually a function of market demand, and the desires of the OEMs.

    For example, GE and PW didnt think the market was big enough for more than 1 manufacturer to compete for the longer range 777s. RR was the only one who did, but they didn't have an engine suitable to the thrust Boeing wanted within the time frame that it wanted them; and RR also didn't want to share in the direct investment for the model line. GE had/could do both of these, but would only do so if Boeing agreed to only use GE engines for the 700K.lb+ 777s. As a result, Boeing chose to grant GE exclusivity.

    Basically, the same thing happened with the 787, 'cept there was room for two OEMs instead of just one.

    [Edited 2005-07-27 20:55:38]
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    Glom
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 5:16 am

    If different engines give different qualities to an aircraft, is that why the interchangeability of the 787 is so important?
     
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    N328KF
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 5:21 am

    The ability to negotiate price, and keep innovation going through competition is another.
    When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt
     
    ConcordeBoy
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 5:24 am

    Quoting Glom (Reply 4):
    If different engines give different qualities to an aircraft, is that why the interchangeability of the 787 is so important?

    Interchangeability allows the airline to conform the aircraft to whatever its prefered (or already-used) engine is; which saves the airline from additional costs, and increases the resale value of the aircraft.
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    AirbusA6
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 5:42 am

    Politically it can be useful too, so that an airline worried about being seen to be too reliant on the US can specify RR engines, while can airline wanting to buy Airbus, but not offend the US too much can specify GE engines...

    During the 70s and 80s there was lots of pressure on BA to buy Airbuses, which it refused, but by specifying RR engines on its Boeings (742, 744, 757, 767) and L011, it could point to the British jobs being supported.
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    PM
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 8:06 pm

    Quoting Glom (Reply 4):
    Is that why the interchangeability of the 787 is so important?

    "So important"? Boeing are talking this up but I think the jury is still out on this one. Has any airline yet said that this was a decisive factor in their choice of the 787?
     
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    scbriml
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 8:39 pm

    Quoting ConcordeBoy (Reply 6):
    Quoting Glom (Reply 4):
    If different engines give different qualities to an aircraft, is that why the interchangeability of the 787 is so important?

    Interchangeability allows the airline to conform the aircraft to whatever its prefered (or already-used) engine is; which saves the airline from additional costs, and increases the resale value of the aircraft.

    That's the theory, but it will be interesting to see what happens in the real World.

    Having a choice of engine (for example on the A320 vs not on the 737) does give the airlines an extra area for negotiation and competition to drive prices down.
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    phollingsworth
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 9:48 pm

    There are several engine properties that an airline will consider in the rational portion of their decision making process (lots of irrational factors also play in the decision making).

    Engine weight - Counts toward payload capability
    Engine thrust - Take-off performance (Higher T.O. weights for same runway length)
    Engine SFC/fuel burn - More range per fuel consumed
    Availability/reliability
    Cost to the airline (purchase & operating)

    Depending on the mission mix that the airline feels they are going to fly one specific combination of weight, thrust, and SFC will show more profitable for the airline. However, this only counts if the maintenance and costs are equal.

    Airlines, at least in the US, are legally required to make their decisions based upon what would maximize shareholder value. Of course when projecting out twenty, twenty-five years this is nearly impossible to determine. This means that cost can often drive the decision.

    An example thought experiment imagine an airline has negotiated an engine purchase price of $1.5 billion for a fleet from two manufacturers, deliveries starting 1 year from now. Along with this they have negotiated two mtc contracts for 20 years at the same price. To differentiate themselves one engine man offers a $5 million discount on the mtc contract. The other offers $95 million upfront. Which one, all other things remaining equal, would be the best choice for the airline? Obviously (for most discount rates) it is the $95 million discount upfront. As money today is worth more than money tomorrow. The discount rate that would make these two deals worthwhile is 0.49%. In almost all cases inflation alone will exceed this rate, let alone risk-free interest rates.
     
    AirbusA6
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    RE: What's The Deal With Engine Choices?

    Thu Jul 28, 2005 10:00 pm

    Taking US airlines and the 777 (all including 772ER variants)

    AA and DL chose RR
    UA chose PW
    CO chose GE

    Presumably all made rational decisions, based on the business case, but came to different answers.
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    RE: What's The Deal With Engine Choices?

    Fri Jul 29, 2005 12:18 am

    Quoting PM (Reply 8):
    "So important"? Boeing are talking this up but I think the jury is still out on this one. Has any airline yet said that this was a decisive factor in their choice of the 787?


    I am guessing that the genesis for the interchangable engine concept is not the airlines themselves, but from the big leasing companies (except GECAS, of course) and the banks.

    On a side note, will the engines on the A350 be interchangable as well?
    When they call the roll in the Senate, the Senators do not know whether to answer 'Present' or 'Not guilty.' -Theodore Roosevelt