By Bjorn Fehrm
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Introduction
December 15, 2016, ©. Leeham Co: In our article series around the engine for a Boom SST, we established the thrust requirements for the engines in Part 3.
To fulfill these requirements, we have now designed four different engines. Three are of the type that Boom says it is considering, an engine that is based on an existing core.
Figure 1. Boom Technologies Boom Mach 2.2 45 seat airliner. Source: Boom.
We based these around a military core with the right characteristics for a low-to-medium bypass SST engine. The fourth engine is a custom-designed straight turbojet, very similar to the engine that propelled the only operational SST, the Concorde.
We will use the reference turbojet to understand the difference to a turbofan in this application and why the selection of an engine for a SST follows different rules than for a normal airliner.
Summary:
- Supersonic flight requires engines with low frontal areas and low mass flows.
- Should the engine be designed as for a normal airliner, the inlet drag would be prohibitive.
- The engine also must have a low pressure ratio core; otherwise the energy of the fuel is wasted on non-productive work.
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2017: the year ahead
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Introduction
Jan. 3, 2017, © Leeham Co.: The New Year is here and it doesn’t look like a good one for commercial aerospace, if measured against previous outstanding years.
There are some troubling signs ahead, piling on to a slowdown in orders from last year that didn’t even reach a 1:1 book:bill.
This year looks to be worse than last. Airbus and Boeing will give their 2017 guidance on the earnings calls this month and next. Bombardier and Embraer earnings calls are a ways off, when each will provide its guidance.
But LNC believes the Big Two in particular will be hard pressed to hit a 1:1 book:bill this year and may even struggle to match 2016 sales.
Boeing’s year-end order tally comes Thursday. Airbus’ comes on Jan. 11.
Summary
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1 Comment
Posted on January 3, 2017 by Scott Hamilton
Airbus, ATR, Boeing, Bombardier, CFM, Comac, CSeries, E-Jet, Embraer, Etihad Airways, Farnborough Air Show, GE Aviation, Irkut, Leeham News and Comment, Middle of the Market, Mitsubishi, Pratt & Whitney, Premium, Rolls-Royce, Sukhoi
Airbus, Boeing, Bombardier, CFM, Comac, Embraer, GE Aviation, Irkut, Mitsubishi, Pratt & Whitney, Rolls-Royce, Sukhoi
Airbus, Boeing Top Customers mix of stable, risk and reward
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Introduction
Dec. 22, 2016, © Leeham Co.: When it comes to comparing backlogs of Airbus and Boeing, the latter likes to point to what it calls a better quality of customers.
The fact is, both companies have large orders with airlines that may be characterized as less than top quality, or which appear to have over-ordered.
Summary
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1 Comment
Posted on December 22, 2016 by Scott Hamilton
Airbus, Airlines, Boeing, Premium
Airbus, airlines, Boeing, Lessors
Boeing announces 2017 job cuts
No number was given by Boeing for the workforce reduction.
Just a week ago, LNC predicted more job cuts would be coming at Boeing–and at Airbus.
Boeing’s message to employees is below.
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50 Comments
Posted on December 20, 2016 by Scott Hamilton
Airbus, Boeing
Airbus, Boeing, Kevin McAllister, Ray Conner
Pontifications: Leeham News’ approach to the news
By Scott Hamilton
Dec. 19, 2016, © Leeham Co. Two thousand sixteen is almost over. This will be my last Pontifications of the year.
We approach our job with a little different perspective than the daily newspapers and aviation trades. They have greater resources than we do and have a greater ability to report the news. So LNC tries to bring news with perspective that those outlets don’t.
Analysis, economics, forecasts
We provide analysis of events and of aircraft economics and performance. Not even the trades do the latter. We also make our own forecasts of trends and production rates. Sometimes it takes a few years to be proved right or wrong. So far, we have a good track record of being right.
We’re also not afraid to take on controversy—and be controversial. And we don’t hesitate to call bullshit when we see it.
This gets often us into hot water with the subjects of the controversy.
This is what sets LNC apart.
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28 Comments
Posted on December 19, 2016 by Scott Hamilton
Airbus, Boeing, Pontifications
737 MAX 200, 777 Classic, 777X, 787, A321LR, A321NEO, A330, A350, A380, Airbus, Boeing
The Boom SST engine challenges: Summary
By Bjorn Fehrm
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Introduction
December 19, 2016, ©. Leeham Co: It’s time to round off our article series around the engine for a Supersonic Transport Aircraft (SST). The series was triggered by Boom Technologies’ plans to launch a business class-only SST with Virgin Atlantic signing up to buy the aircraft if Boom succeeds.
Our initial articles described the problems involved in making a Mach 2 SST. We singled out the engine with nacelle as the most difficult challenge.
Figure 1. Boom Technologies’ Mach 2.2 airliner with 45 business seats. Source: Boom.
Subsequent articles focused how to select an engine for such an aircraft. The requirements are pretty unique and forces design choices which are contrary to a normal airliner engine.
Today, the words “low bypass ratio” and “low overall pressure ratio” are nonexistent in engine OEMs’ brochures. Yet this is what we need for our SST. Having covered the cruise phase in Part 4, we now close with take-off/landing and what else to think of when propelling an SST.
Summary:
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1 Comment
Posted on December 19, 2016 by Bjorn Fehrm
Uncategorized
Boom SST, Concorde, Virgin Atlantic
US appeals WTO ruling over prohibited subsidies
Dec. 16, 2016: The US filed a notice of appeal today of the WTO ruling that Washington State tax breaks granted to entice Boeing to locate a wing plant for the 777X and assemble the airplane at Everett ((WA) was a prohibited subsidy.
The move was expected.
At issue were $8.7bn in tax breaks.
12 Comments
Posted on December 16, 2016 by Scott Hamilton
Airbus, Boeing
Airbus, Boeing, World Trade Organization, WTO
Bjorn’s Corner; Turbofan engine challenges, Part 7
By Bjorn Fehrm
December 16, 2016, ©. Leeham Co: After the turbine comes the engine’s exhaust system. This is where the thrust characteristics of the engine are formed. It is also the environment that defines the back pressure for the fan and turbines. It’s therefore more high-tech than one thinks.
For the very high bypass airliner engines of tomorrow, the common fixed bypass exhaust of today (Station 18 in Figure 1) will not be acceptable. Variable exhaust areas will have to be introduced.
Figure 1. GasTurb principal representation of a three shaft turbofan like our reference Rolls-Royce Trent XWB. Source: GasTurb.
On engines that function in high supersonic speed, it gets really complex. Not only is the exhaust area variable, it must have a dual variation exhaust, a so-called Con-Di nozzle.
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5 Comments
Posted on December 16, 2016 by Bjorn Fehrm
Bjorn's Corner, CFM, GE Aviation, Pratt & Whitney, Rolls-Royce
CFM, CFM56, GE Aviation, Geared Turbo Fan, IAE, Pratt&Whitney, Rolls-Royce
Top 10 Leeham News stories of 2016
Dec. 15, 2016, © Leeham Co.: The story about a Boeing official who asserted that the Airbus widebody strategy is a “mess” proved to be LNC’s most read story of 2016.
Our second most-read story is why the 787-8 is no longer favored by Boeing.
We list our Top 10 posts each year as we head for a wrap. LNC plans to finish 2016 on Dec. 23, returning Jan. 3, unless there is major, breaking news.
Here are the Top 10 LNC posts in 2016:
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27 Comments
Posted on December 15, 2016 by Scott Hamilton
Airbus, Boeing, Bombardier, Leeham News and Comment, MOM
737-7, 747, 777-10, 777X, 787, A320, A350-1000, A350-2000, A350-800, A350-900, Airbus, Boeing, Bombardier, CS300, Dennis Muilenburg, Jim McNerney, Kevin McAllister, Leeham News, Middle of the Market
The Boom SST engine problem, Part 4
By Bjorn Fehrm
Subscription required
Introduction
December 15, 2016, ©. Leeham Co: In our article series around the engine for a Boom SST, we established the thrust requirements for the engines in Part 3.
To fulfill these requirements, we have now designed four different engines. Three are of the type that Boom says it is considering, an engine that is based on an existing core.
Figure 1. Boom Technologies Boom Mach 2.2 45 seat airliner. Source: Boom.
We based these around a military core with the right characteristics for a low-to-medium bypass SST engine. The fourth engine is a custom-designed straight turbojet, very similar to the engine that propelled the only operational SST, the Concorde.
We will use the reference turbojet to understand the difference to a turbofan in this application and why the selection of an engine for a SST follows different rules than for a normal airliner.
Summary:
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4 Comments
Posted on December 15, 2016 by Bjorn Fehrm
Future aircraft, Rolls-Royce
Boom, EJ200, Rolls-Royce, SST
Boeing cuts 777 production rate again
Dec. 13, 2016: Boeing yesterday announced another production rate cut for the 777 Classic, effective next August.
Boeing 777 production rates will decline to 5/mo in August 2017. The delivery rate will fall to 3.5/mo. Photo via Google images.
The rate goes to 5/mo. Because of the transition to the 777X, the actual delivery rate will be 3.5/mo.
Leeham Co. was the first in March 2014 to identify a major production gap and predict rates would have to come down significantly from the then-current 8.3/mo. Aerospace analysts on Wall Street began recognizing the gap shortly after.
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52 Comments
Posted on December 13, 2016 by Scott Hamilton
Boeing
777 Classic, 777X, Boeing, Goldman Sachs, Morgan Stanley, Wells Fargo
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