Leeham News and Analysis
There's more to real news than a news release.
Bjorn’s Corner: Aircraft engines maintenance, Part 2
By Bjorn Fehrm
March 10, 2017, ©. Leeham Co: Last week we started the series how airline turbofans are maintained. We described the typical work scopes and what the intervals were for different single-aisle engines.
Before we can describe the engine maintenance market we must get a feel for the market size for different engine types.
Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.
We will start with understanding the single-aisle engine maintenance market. Read more
Engine OEMs diverge on technology for next generation
March 7, 2017, © Leeham Co.: Representatives of the four major commercial engine
GE9X, the final engine in a decade-long engine renewal program for GE Aviation and CFM International
manufacturers have divergent views of the next round of engine development, either for the Middle of the Market/New Mid-range Airplane (NMA) or New Small Airplanes (NSA) coming in the next decade.
Officials of CFM, GE, Pratt & Whitney and Rolls-Royce appeared at the annual ISTAT conference in San Diego yesterday.
PW’s Rick Deurloo, SVP of Sales, Marketing Commercial Engines, had the added task of dealing with the highly-publicized teething issues surrounding its new Geared Turbo Fan engine on the Airbus A320neo.
Bjorn’s Corner: Aircraft engine maintenance, Part 1
By Bjorn Fehrm
March 3, 2017, ©. Leeham Co: We will now go through how airline turbofans are maintained. First, we will describe the typical work which is performed, then look into the markets for engine maintenance.
In the markets for engine maintenance, we will look at who the players are, how they are related to the engine OEMs and why the market dynamics are very different between engines for single-aisle aircraft and wide-bodies.
Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.
Bjorn’s Corner: Aircraft engines in operation, Part 6
By Bjorn Fehrm
February 24, 2017, ©. Leeham Co: After having analyzed how the engine gets stressed during different phases of flight, we now look into how engines are used. The de-rating of engines for takeoff is important, as not 100% thrust is needed for all takeoffs. If the aircraft is lightly loaded or is taking off from a long runway, with low temperatures or altitude, the engine can be thrust de-rated so that it experiences less stress.
Once in the air, the engine is run below maximum settings by use of cost-index. These actions will result in less fuel usage and also longer engine operation between overhauls. We will now finish the operations part of our engine clinic with how airlines keep the engines away from the workshops by swapping the engines between fleet aircraft.
Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.
A visit to the engine workshop costs in the millions of dollars, so the longer the engine can operate before a shop visit, the better. Read more
Ryanair: cheapest and most profitable airline in Europe
By Bjorn Fehrm
February 22, 2017, ©. Leeham Co: Ryanair is Europe’s airline with the lowest fares. And it’s the most profitable, despite growing faster than even the Middle East carriers (growth needs money).
It’s time to dive deep in this locomotive. I even flew their business class before writing the report, to understand what is going on. Read more
Bjorn’s Corner: Aircraft engines in operation, Part 5
By Bjorn Fehrm
February 17, 2017, ©. Leeham Co: In our journey of an airline engine’s life, we will now look at the maintenance which is necessary to keep it fit for flight.
An engine is only in top condition once in its life, at delivery. As soon as it’s operated on the aircraft, in-service wear of its different parts will reduce its performance.
Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.
The engine manufacturer’s prescribed maintenance is designed to keep the engine in good health during its life, despite all its hardship. Read more
Bjorn’s Corner: Aircraft engines in operation, Part 4
By Bjorn Fehrm
February 10, 2017, ©. Leeham Co: We now continue our journey how an airline engine is operated during a typical mission.
Last week we explained basics for engine control and Take-Off flat-rating. We now continue with Climb, Cruise and Max Continuous ratings and why these are important.
Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.
We also touch on de-rating and Cost Index and how these affect how the engine runs.
Assessing the future of COMAC programs
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Introduction
Feb. 6, 2017, © Leeham Co.: China’s effort to become a viable commercial aerospace alternative was filled with rocky fits and starts for its two signature airliner programs, the AVIC ARJ-21 and the COMAC C919.
COMAC, a spin off from AVIC and yet another government-controlled entity, is already casting eyes on a 250-seat, twin-aisle design, the C929—ostensibly in a joint venture with Russia’s United Aircraft Corp.
The ARJ-21 regional jet finally entered service after delays of eight years. The C919 target EIS is now 2019, six years after the original date. The first flight hasn’t even taken place.
Chinese officials set a target EIS for the C929 of 2026.
A rough road remains ahead for each program.
Summary
- Exceedingly slow delivery ramp up for the ARJ-21.
- First flight of the C919 planned this year.
- Wide-body C929 will challenge the Airbus A330 and Boeing 787.
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
Bjorn’s Corner: Aircraft engines in operation, Part 2
By Bjorn Fehrm
January 27, 2017, ©. Leeham Co: In the last Corner, we began looking at the in-service operation of a Turbofan. We covered how thrust and fuel consumption varies in the different phases of an airliner’s mission.
Now we will dig a little deeper into how a mission will stress the engine’s different parts.
Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.
With this knowledge, we will later look at how operators make sure their engines are safe and in good operational condition over the 20 years life of an aircraft. Read more