Aircraft Engines

Piston vs Turboprop vs Jet

Currently there are 3 major types of engines: piston, turboprop, jet (or Turbofan).

Turboprop is basically a jet engine connected to a propeller.

Both piston and turboprop are propeller driven, however

  • piston: low cost, low fuel burn.
  • turboprop: simpler, lighter, more powerful, but with a higher cost and higher fuel burn.

Jet Engines

The big 3 engine makers:

  • GE Aviation (GE), a subsidiary of General Electric, largest market share
  • Rolls-Royce (RR), 2nd largest
  • Pratt & Whitney (PW), a subsidiary of Raytheon Technologies

And 2 joint-ventures:

  • Engine Alliance (EA) is a 50/50 joint venture between GE Aviation, a subsidiary of General Electric, and Pratt & Whitney, a subsidiary of United Technologies.
  • CFM International (CFM) is a 50-50 joint venture between American GE Aviation and French Safran Aircraft Engines. CFM makes LEAP ("Leading Edge Aviation Propulsion") engines

Here's a summary of the current and future airliners (that's why you do not see 757 or 747-400 here):

GE EA PW RR
A220 PW1500G
A319/320/321 CFM56-5B IAE V2500A5
A319neo/320neo/321neo LEAP-1A PW1100G
A330 CF6 PW4000 Trent 700
A330neo Trent 7000
A350 Trent XWB
A380 GP7200 Trent 900
B737 NG CFM56-7B
B737 MAX LEAP-1B
B747-8 GEnx-2B67
B777-200/200ER GE90 PW4000 Trent 800
B777-300 PW4000 Trent 800
B777-200LR/300ER/777F GE90
B777X GE9X
B787 GEnx-1B Trent 1000
C919 LEAP-1C
Irkut MC-21 PW1400G

A few observations:

  • EA only makes GP7200 for A380. Once A380 is discontinued in the near future, would this joint venture dissolve?
  • Trent engine family covers the most of the wide-bodies: A330, A340, A350, A380, B777, B787.
  • LEAP is used in all next generation mainline narrow-bodies: LEAP-1A for A320neo, LEAP-1B for B737 MAX, and LEAP-1C for the future C919
  • PW covers smaller jets, except for (soon to be deprecated?) PW4000. PW1000G competes with LEAP.

Regional Jets: the older generations were using GE's CF34, while the newer generations are using PW engines.

GE PW
ARJ 21 CF34
CRJ 700/900/1000 CF34
E170/175/190/195 CF34
E175-E2 PW1715G
E190-E2/E195-E2 PW1919G/21G/22G/23G
Mitsubishi M90/M100 PW1200G

PW1000G Family

  • Airbus A320neo: PW1100G (alongside the CFM International LEAP-1A)
  • Airbus A220: PW1500G
  • Embraer E-Jet E2 family : PW1700G E-Jet E2 175 & PW1900G E-Jet E2 190/195 (exclusive)

Turboprop Engines

Almost all still in production turboprop airliners chose Pratt & Whitney (PW).

PW100

PW100: 1,800 to 5,000 shp (shaft horsepower)

Aircraft Engine Power
ATR 42-600 PW127M 1,953 kW
ATR 72-600 PW127M 1,953 kW
Dash 8 Q400 PW150 3,782 kW
M60/M600 PW127J 2,051 kW
M700 PW150C

PT6

PT6A turboprop engine covers the power range between 580 and 1,940 shp. Used by smaller turboprops: King Air, Cessna 208, PC-12, TBM, Air Tractor, etc.

  • PT6A: turboprop
  • PT6B/C are turboshaft variants for helicopters.
  • PT6E: the PT6E is a large PT6A derivative equipped with digital engine control. (used on TBM 960)

Piston Engines

Light aircraft: MTOW <= 12,500 lb (5,670 kg)

Light piston aircraft engines can either use AvGas or Jet Fuel (with a Diesel engine). Leaded AvGas will eventually go away, but unleaded gasoline is not widely available. Many brands come up with diesel versions (e.g. Piper Archer DX).

The FAA recently estimated that nearly 170,000 aircraft operate today on 100 low lead (LL) fuel, burning 150 to 175 million gallons annually.

The most common engines are Lycoming and Continental. Both have AvGas and Diesel engines.

To decode the engine type:

  • A: Aerobatic (dry sump)
  • AE: Aerobatic (wet sump)
  • E: Electronic
  • G: Geared (reduction gear)
  • H: Helicopter
  • I: Fuel Injected
  • L: Left Hand Rotation Crankshaft
  • M: Designed for unmanned drone
  • O: Opposed Cylinders
  • R: Radial Cylinders
  • S: Supercharged
  • T: Turbocharged
  • V: Vertical installation (usually for helicopters)
  • X: X-type engine
  • Y: Experimental

AvGas Engine vs Diesel Engine

Diesel engines are heavier than AvGas engines (~100kg), but have better fuel economy.

Diesel engines and more costly to build, especially the fuel delivery system is much more expensive than fuel injection systems for gasoline pistons, since diesel fuel systems run at a much higher pressure to cause atomization of the fuel for a clean burn.

Lycoming Engines

Powers more than half the world's general aviation fleet, both rotary and fixed wing. A subsidiary of Textron, the parent company of Cessna and Beechcraft.

  • Number: displacement (in cubic inches).
  • O: Opposed engine.
  • I: fuel Injection.
  • T: Turbocharged.
  • AE: Aerobatic.

Examples:

  • IO-360: 361 in³ (5.92 L) displacement, four-cylinder air-cooled horizontally opposed engine; used by Cessna 172S, Piper Archer LX.
  • IO-540: 541.5 in³ (8.9 L) displacement, six-cylinder air-cooled horizontally opposed engine; used by Cessna 182, Cessna 206.

Continental

http://continental.aero/

Part of Aviation Industry Corporation of China (AVIC). Also owns Centurion engines as the result of Thielert acquisitions.

Builds both AvGas engines and Jet Fuel (Diesle) engines.

Centurion aircraft Diesel engines, used by Diamond D40 and D42.

Rotax

Offer both four-stroke and advanced two-stroke engines. Often used in light aircraft.

air cooled or water cooled

Rotax engines are water-cooled