How much of an NMA market will the Airbus A321XLR capture, Part 3?

By Bjorn Fehrm

Subscription Required

Introduction

August 1, 2019, © Leeham News: We wrap up our study of what part of an NMA market the Airbus A321XLR could capture with looking at the difference in available engine technology between the A231XLR and the NMA generation of airliners.

Summary:

  • The generational improvement in fuel efficiency of airliner turbofans has been over 10% in the last decades.
  • We examine if these improvements will still be the case for the NMA generation of aircraft.

Read more

Embraer’s KC-390 nears delivery

May 28, 2019 © Leeham News: Embraer’s KC-390 multi-role tanker transport is nearing delivery of the first aircraft to the launch customer, the Brazilian Air Force.

KC-390. Photo: Embraer.

In a briefing in advance of the Paris Air Show at Embraer’s Unidade Gavião Peixoto Airport 225 miles from its Sao Jose dos Campos headquarters, program VP Walter Pinto said that most of the required testing is complete.

What’s left?

Read more

Narrowbody and Widebody engine developments, Part 2

By Bjorn Fehrm

Subscription Required

Introduction

April 19, 2018, © Leeham News: In an article last week, we discussed the reason the new narrow-body engines are catching up to the fuel consumption of the wide-body engines.

Today we dig a bit deeper into the efficiency changes of the different engines and discuss which parameter changes have caused what changes in engine efficiency.

We will use our engine modeling software GasTurb to analyze what happens in a Turbofan when we change certain parameters.

Summary:

  • The engine’s Core or Thermal efficiency changes with Turbine Entry Temperature (TET).
  • To fully utilize such an increase in efficiency we need to adapt the overall design of the engine.

Read more

Narrowbody and Widebody engine developments

By Bjorn Fehrm

Subscription Required

Introduction

April 12, 2018, © Leeham News: In an article yesterday about Long-Haul LCC costs we observed how the new Narrowbody engines are catching up to the fuel efficiencies of the Widebody engines.

Traditionally the Widebody engines were the efficiency leaders. The Narrowbody companions were designed to be durable rather than efficient.

Figure 1. Cut through of the Narrowbody LEAP engine. Source: CFM

We use the engine modelling software GasTurb to understand why this catching up of the Narrowbody engines has happened.

Summary:
  • The new Narrowbody engines for Airbus’ A320 series and Boeing’s 737 MAX are close in specific fuel consumption to the new Widebody engines.
  • We use the GasTurb engine modelling software to find the root cause of this change.

Read more

Pratt & Whitney’s Indian trouble

By Bjorn Fehrm

March 14, 2018, ©. Leeham Co: India’s Directorate General of Civil Aviation (DGCA) grounded Airbus A320neos equipped with Pratt & Whitney GTF engines with faulty compressor seals Monday.

Affected are eight A320neos of Indigo airlines and three A320neos of GoAir. The Indian groundings are unusual as they go beyond the directives of EASA and FAA for the problem.

Read more

Bjorn’s Corner: Aircraft engines, sum up

By Bjorn Fehrm

April 14, 2017, ©. Leeham Co: We’ve been talking engines on Fridays since October 2016. The Corners covered several areas, from technologies to operations.

And we could go on and dig deeper. But we will move on.

Before we go, we sum up what we have learned in the 24 Corners around airliner Turbofans.

Figure 1. Principal picture of a three-shaft wide-body turbofan. Source: GasTurb.

Read more

Bjorn’s Corner: Aircraft engine maintenance, Part 3

 

By Bjorn Fehrm

March 17, 2017, ©. Leeham Co: In the last Corner,  we showed graphs of the yearly flight hours for engines on single-aisle aircraft. Now we will deduce the market for engine overhauls from these graphs.

These will show which engines generate a maintenance volume that is interesting for engine overhaul companies and which engines are niche.

Figure 1. Principal picture of a direct drive turbofan. Source: GasTurb.

Based on the market size, we will then go through how an engine is maintained when new, mature and at end-of-life.

Read more

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

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.

Read more

Bjorn’s Corner: Turbofan engine challenges, Part 4

 

By Bjorn Fehrm

By Bjorn Fehrm

November 18, 2016, ©. Leeham Co: In our series on modern turbofan airliner engines, we will now go deeper into the compressor part. Last week, we covered the fundamentals of compressors. As compressors and turbines use the same principles, we also covered the fundamental working principles of turbines.

We also described that compressors are temperamental parts, which can protest to wrong handling with violent “burps” (burst stalls with the combustion gases going out the front of the engine) or end up in a rotating stall where it simply stops working.

gasturb-graph

Figure 1. Stylistic cross section of a two shaft turbofan with both axial and radial compressor. Source: GasTurb.

Turbines, on the other hand, are your robust companions. Aerodynamically they just work, albeit more or less efficiently dependent on what one asks them to do (mechanically it can be very different; we recently saw a turbine disintegrate with large consequences on an American Airlines Boeing 767 in Chicago). More on the turbines later.

In the GasTurb cross section of a two shaft turbofan in Figure 1, the engine has both an axial and a radial compressor. We will consider why engine designers combine these two for certain engine types. Read more