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Two new aircraft engines from Bombardier Recreational Products could
change the face of general aviation and calm worries about rising
prices on aviation gas (avgas). The V-220 and V-330T from the Canadian
company run on various grades of automotive-grade gas, avgas, and even
combinations of both.
Avgas is the fuel of choice for most
small, piston powered aircraft. The problem is that the low octane fuel
contains lead and world governments are actively trying to phase it
out. To add insult to injury, refineries aren't producing as much avgas
as they once did, a sign they are anticipating an outright ban of the
fuel and are preparing to completely stop production. This further
drives up the price.
One reason the engines can use different
grades of gas is that they carry a Fadec (full-authority digital-engine
control). Fadec's knock sensing lets the engine use various grades of
aviation and automotive gas. The controller also makes for simple
start-ups, despite hot or cold temperatures. And the electronic
ignition and fuel injection provides peak fuel efficiency at all times.
There is no carburetor and venturi inlet, so icing at the air inlet is
practically eliminated. Fadec also lets a single lever control
throttle, fuel mix, propeller pitch, and, in the V-300T, the turbo
wastegate and intercooler pop-off valve. This will cut pilot workload
considerably.
The Bombardier engines have several other
innovative features, including their V configuration and all aluminum
engine blocks. Earlier " all aluminum" blocks needed steel cylinder
liners, which added weight. Bombardier has coated the cylinders of
these engines with Nikasil, an electro deposited-nickel coating
containing hard particles of silicon carbide. All of this give the
engines the best power-to-weight ratios in their class, which makes for
longer ranges and more load carrying capacity.
Both engines are
built around a 120°-V layout, making them smaller than engines with
similar power. The compact shape will let cowlings be slimmer and more
aerodynamic. And the V configuration lets engineers use straight,
pin-type crankshaft journals, so the crankshaft is shorter and the
engine generates less torsional vibration when running. The V shape
also means the ignition sequence is symmetrical, with each cylinder
firing at 120° from the last, creating a smooth sound, fewer
vibrations, and better pilot comfort.
Because the engines are
small and light, the manufacturer plans on packaging them as complete
assemblies (Power Plant Integrated Assembly), including induction,
exhaust, fuel, oil, and coolant systems, as well as engine mounts and
isolators. (The V-300T, a turbocharged engine, comes with turbocharger
and intercooler.) Users need only bolt the assembly to the firewall and
plug it in.
A propeller speed-reduction unit with a gear ratio
of 3:1 keeps the propeller under 2,000 rpm, limiting tip speed and
reducing noise levels inside and outside the aircraft. There's also a
1.6-gallon muffler to help quiet the engine.
The engines use
liquid cooling, which keeps them operating at nearly constant
temperatures and avoids thermal shock and stresses from abrupt altitude
or throttle changes. The 3-gallon system uses a 50/50 water/antifreeze
mix and lets the engine operate at the leanest fuel settings for the
best fuel efficiencies. It also reduces emissions, especially carbon
monoxide, and lets the plane use automotive-style cabin heating. This
cuts the risk of monoxide poisoning for the pilot and passengers.
The
engines are undergoing final development and certification for aircraft
and helicopters and should be on the market sometime next year. They
will be compatible with the glass cockpits airframe makers are building
for general aviation, letting engine parameters show on multifunctional
displays.
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