Leeham News and Analysis
There's more to real news than a news release.
Bjorn’s Corner: Aircraft engines in operation, Part 3
By Bjorn Fehrm
February 3, 2017, ©. Leeham Co: In the last Corner, we went through how our airliner engine reacts to the different phases of flight, including what happens when we operate in a hot environment.
We also showed how engine manufacturers make a series of engines with different thrust ratings by de-rating the strongest version through the engine control computer.
Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.
We will now look deeper at how engines are controlled and why so-called flat-rating is important. Read more
MRJ regional jet delayed until mid-2020
By Bjorn Fehrm
January 23, 2017, ©. Leeham Co: Mitsubishi announced a further two years delay of the MRJ regional jet project in a press conference in Tokyo today.
The 90-seater variant of the aircraft will be delivered to the first customer, All Nippon Airways (ANA), mid-2020.
The previous scheduled Entry Into Service (EIS) of mid 2018, was announced December 2015. In total, the MRJ program has announced five delays, totaling seven years. Read more
The regional market and scope clauses
By Bjorn Fehrm
January 17, 2017, ©. Leeham Co: Union contract Scope Clauses–the provision limiting the weight, capacity or number of aircraft operated by airlines for major carriers–are unlikely to be modified any time soon, panelists at the Air Finance Journal conference in Dublin said.
The restrictive Scope Clauses are predominate in the US. These limit the ability of small airplane manufacturers to sell aircraft in the US. Most affected are Embraer, Bombardier and newcomer Mitsubishi.
Contract negotiations in December, concluded before Christmas, resulted in no changes, surprising some. This will impact planned purchases of aircraft.
We sat with Bombardier’s Ross Mitchell, vice president of commercial operations, to understand why the scope clauses are so important and why they did not change. Read more
Bjorn’s Corner: Geared turbofans
By Bjorn Fehrm
January 13, 2017, ©. Leeham Co: The time has come to go through the reasons why some turbofan engines are designed with a gearbox between the fan and the low pressure shaft.
The principle design is shown in Figure 1. It’s a graphical representation of a geared turbofan from the engine analysis software GasTurb.
Figure 1. GasTurb principal representation of a geared turbofan. Source: GasTurb.
The base idea is to have the low pressure spool of the engine to run at a considerably higher RPM than the fan. Read more
Airbus sets new delivery record for 2016
By Bjorn Fehrm
January 11, 2017, ©. Leeham Co: Airbus Commercial Aircraft presented a new record in yearly deliveries at its Press Briefing in Toulouse today. The division of an integrated Airbus (therefore Airbus Commercial Aircraft, ACA) delivered 688 aircraft during 2016, thereby beating its target of 650 aircraft for the year.
Airbus A321neo with Pratt&Whitney engines was certified end 2016. Source: Airbus.
Orders were also higher than expectations at 731 net orders, giving a Book to Bill of 1.06. The market, including LNC, widely expected Airbus to fall somewhat short of a 1:1 book:bill.
There were no formal forecasts given for 2017. ACA President Fabrice Bregier stated that he expects it to be over 700 deliveries but full details will given at the Airbus Group’s financial press briefing in February.
Bjorn’s Corner: Turbofan developments in 2017
By Bjorn Fehrm
January 06, 2017, ©. Leeham Co: Before we finish of our series on airliner turbofan technology, let’s spend this Corner on what will happen on the airliner engine front during 2017.
While there is no totally new engine that comes into the market during 2017 there are a number of new variants of existing engine families that will be introduced.
Figure 1. GasTurb principal representation of a three shaft turbofan like our reference Rolls-Royce Trent XWB. Source: GasTurb.
If we start with the engines for regional/single aisle aircraft and then climb the thrust scale, we will cover the engines in climbing thrust class.
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.
Bjorn’s Corner; Turbofan engine challenges; Part 6
By Bjorn Fehrm
December 08, 2016, ©. Leeham Co: We have now come to the turbine in our trip through a modern turbofan. The turbines make up the rear of the engine, before the propelling nozzle.
The turbines are the workhorses in the engine. They take the energy released by the fuel in the combustion chamber and convert it to shaft hp to drive the fan or compressors.
Figure 1. GasTurb principal representation of a three-shaft turbofan like our reference Rolls-Royce Trent XWB. Source: GasTurb.
The hotter they can operate, the better. They can then generate more hp on a smaller size turbine. The temperature of the gas entering the high pressure compressor is one of the key parameters of a gas turbine. It dictates the power efficiency of the core and how much work it can perform to drive the fan and the compressors. Read more
Deferrals grow as airlines fight to keep bottom line
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Introduction
Jan. 09, 2017, © Leeham Co.: Airlines have deferred or are thinking about deferring more than 400 airplanes in the near term, a review of decisions and deliberations that have been made during the last 12 months.
LNC tracked announcements last year of deferrals and statements by airlines that they are thinking about doing so.
We began identifying macro-level issues last week in our posts about emerging concerns for the 787 and LNC’s Outlook for 2017.
Reasons vary widely for the deferrals, these reports indicated. Low oil prices. Slowing economies. Declining financial results. Worries about two of the three top Middle Eastern carriers. A capital squeeze in China. Pressure on long-haul carriers from the emerging sector of low cost, long-haul airlines. Preserving capital expenditures to keep the bottom line in the black.
Today we detail the deferrals we tracked.
Summary
Read more
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Posted on January 9, 2017 by Scott Hamilton
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