Leeham News and Analysis
There's more to real news than a news release.
Bjorn’s Corner: Engine rubbing
09 October 2015, ©. Leeham Co: Last week an Airbus A320neo prototype with Pratt & Whitney’s (PW) GTF had a problem while testing hot and high conditions at Al-Ain airport in Abu Dhabi. The engine suffered a rubbing problem and PW and Airbus decided to replace the engine before returning the A320neo to Toulouse.
I had the opportunity to discuss what happened with PW people at ISTAT this week and decided it makes for a good follow up to our two other engine Corners to write about what happened and how serious it was.
The problem was compressor blades rubbing against the compressors stator wall. PW knew that this engine individual could have that problem. They saw when assembling the engine it was a bit tight in the compressor area. PW said they told Airbus there was a risk with this particular unit, and sure enough, there was rubbing to be seen when they boroscope checked the engine after the test.
Here what it was all about and what to do about it. Read more
Evaluating airliner performance, Part 2
By Bjorn Fehrm
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Introduction
Sep. 24 2015, ©. Leeham Co: In the second part of our series about comparing and evaluating economic and operational performance of airliners, we look at the parts beyond fuel that make up the Cash Operating Costs (COC) for an airliner.
While fuel consumption, crew costs and aircraft maintenance costs can be evaluated in a way which closely resembles reality, other costs in the COC are too complex to model in their true form.
This is the case for underway or airway fees, landing fees and station fees. Here, just about every country/airport in the world has taken the liberty to invent its own charging principles and formulas. With several hundred different formulae for these charges, the way out is to use industry-accepted approximation for these costs.
Summary:
- We establish how crew cost are modeled for our evaluation missions, taking into account the complex world of work time regulations for pilots and cabin crew.
- We also describe how we handle airframe and engine maintenance costs and how these get allocated to our missions.
- Finally, we describe how the complex underway and landing/station costs are modeled with the accepted approximations these require.
Bjorn’s Corner: USAF Tanker program
By Bjorn Fehrm
25 September 2015, ©. Leeham Co: When Scott Hamilton asked me to give my view on his article “Pontifications: Duelling refuelling tankers” I accepted. I was not involved in the project and was only following it casually over the years.
I will also not give my view on what would have been the most suitable tanker for the US Air Force. I simply don’t have the relevant military competence for that, having never operated my fighters with aerial tanking nor been in an aerial tanker aircraft.
Where I have relevant competence is in writing military specifications for important aircraft procurements and the excerpts I have seen from the tanker RFQ on key specification points don’t impress. Let me explain.
Bjorn’s Corner: Engine efficiency
18 September 2015, ©. Leeham Co: The debate around the market’s two single aisle combatants is quite heated, with fans of the one side saying “the limited space for a high bypass engine on the 737 MAX will cripple it forever” and the other side saying “the tighter design of the 737 will make it highly competitive against the A320neo, it is the A320 which has a weight and size problem”.
One of the arguments is that each inch of engine fan diameter brings 0.5% in increased propulsive efficiency. Therefore the A320 with up to 81 inches fans will win against the 737 MAX, which has a 69 inch fan. Having all the tools to check out if this is really the truth, I fed our airplane model with all the facts and looked at the result. It’s not so easy, guys…
A320 FAL “good for US aerospace,” says Airbus
Sept. 16, 2015, © Leeham Co., Mobile (AL): The opening of the Airbus A320 Final Assembly Line here
achieves a major set of goals set by the company 10 years ago for its own strategic purposes, but officials are also mindful of the larger impact on US aerospace.
David L. Williams, VP Procurement, Airbus Americas. Photo via Google images.
Top executives point out that the Mobile plant reestablished a second commercial aviation assembly site in the US since the last MD-11s and MD-95s rolled out of the former McDonnell Douglas plant in Long Beach (CA) after its acquisition by The Boeing Co in 1997. Boeing continued production of the MD-11 until the end of 2000 (with deliveries occurring in 1Q2001). The last MD-95, renamed the Boeing 717, was produced in 2006. There were 200 MD-11s and 156 717s produced.
With nearly 10 years elapsing between that last 717 and the first A321ceo coming out of Mobile, Airbus officials say the creation of the FAL is not only good for Airbus and Alabama, it’s good for US aerospace.
New single aisles on home stretch
By Bjorn Fehrm
16 Sep 2015, © Leeham Co.: Boeing released pictures yesterday of the first 737 MAX 8 being on the Renton Final Assembly Line (FAL) having completed the wing-to-body joins. With the Airbus A320neo now flying again with both Pratt & Whitney GTF and CFM LEAP test vehicles and Bombardier completing 85% on CSeries (having passed 2,400 hours of flight testing), one can say the new single aisles are on their home stretch.
737 MAX on the Final Assembly Line at Renton, Seattle. Source: Boeing.
Original planning had the CSeries entering service in December 2013, nearly two years before A320neo (October 2015) and four years before the 737 MAX (4Q2017). With the 737 MAX now on the FAL one can start to review the Entry into Service (EIS) for all three. It will be tighter than the companies have said.
Boeing’s 767 revitalized as a MOM stop gap, Part 2
By Bjorn Fehrm
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Introduction
Aug. 31 2015, ©. Leeham Co: Last week we started to look at Boeing’s 767 to see if it can serve the passenger and range space which is not well covered by modern aircraft: the 225 passenger/5,000nm sector. Boeing calls this the Middle of the Market or MOM. Boeing recently said that there is some increased interest for the 767. We analyze why and what can be done to increase any chances of it having a new life as a passenger aircraft.
We started with comparing the 767’s different variants to the most likely MOM aircraft from our series “Redefining the 757 replacement requirement for the 225/5000-sector”. We will now continue and look at the 767 in detail, its strong suits and its less efficient areas. We will also discuss what can be made to address the less efficient areas.
Summary:
- Boeing’s 767 has the right cross section for passenger transportation in the 225 passenger/5,000nm segment.
- It also carries cargo containers, not as efficiently this time. We show what the consequences are.
- Finally the wing is not the slender wing of the modern aircraft. We show what impact it will have on overall efficiency.
- Combined with engines from the 1990s, this gives less than stellar fuel economics. We investigate what can be done about this and how much of an impact it will have in today’s low fuel prices.
Airbus ‘confident’ engine makers can ramp up production
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Introduction
CFM makes about 50% of the engines on the A320 Family and has about 50% of the backlog for the New
Tom Enders, CEO of Airbus Group. Airbus photo.
Engine Option version. Pratt & Whitney has about the same market share for the NEO, depending on what month it is, with a large number of orders for which no engine has been selected.
Airbus and Boeing are each studying whether to ramp up production of the A320 and 737 families above the record rates already planned.
In an interview Sunday with Leeham News and Comment in advance of the A320 Final Assembly Line opening here, Enders said studies continue whether to take A320 production rates to 60 a month. Boeing is studying rates of 60-63 a month.
Summary
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Posted on September 17, 2015 by Scott Hamilton
Airbus, Boeing, CFM, Leeham News and Comment, Pratt & Whitney, Premium
737 MAX, A320NEO, A380, A400M, air force tanker, Airbus, Airbus Group, Boeing, CFM, Fabrice Bregier, John Leahy, KC-46A, KC-X, Pratt & Whitney, SkyMark, Tom Enders, Transaero, USAF, Virgin Atlantic Airways