Dual fuel aircraft to be unveiled at Oshkosh

OSHKOSH – Airplane manufacturer Aviat Aircraft and Minneapolis-based Aviation Foundation of America will unveil the first dual fuel, piston powered aircraft to operate on both compressed natural gas (CNG) and aviation gasoline at this year’s AirVenture.

The Aviat Husky CNG will be on display outside the Innovations Pavilion throughout AirVenture 2013, which takes place in Oshkosh, Wis., from July 29 through Aug. 4.

“This is a remarkable proof-of-concept airplane,” said Stu Horn, president of Aviat Aircraft. “While adapting our standard Husky aircraft into this dual fuel configuration was not without challenges, it was well worth it. The performance and ease of operations have exceeded our expectations.”

The Aviat Husky CNG, which flew more than 1,000 miles from Aviat’s headquarters in Afton, Wyo., to be at AirVenture, can be powered by CNG or 100LL aviation gasoline with the flip of a switch. It is a standard Aviat Husky A1-C that has been fitted with a CNG fuel tank in addition to its standard aviation gasoline tanks with a capacity of 50 gallons. The aircraft is powered by a 200 hp, four cylinder Lycoming aircraft engine with a cruise speed of 143 m.p.h. The flight endurance at 65 percent power setting is approximately seven hours.

Greg Herrick, president of the Aviation Foundation of America, approached Aviat’s president in early 2013 with the idea of building an aircraft to demonstrate the advantages natural gas can offer general aviation aircraft.

“Among the many advantage of using CNG are fuel cost savings, cleaner burning fuel and no lead emissions,” said Herrick. “I’m impressed with how Aviat readily agreed to tackle this project, working with a team of engineers and craftsmen within the aviation and natural gas industries. The result is a sophisticated solution which can be readily applied to a variety of piston powered aircraft.”

Compressed natural gas power is up to 80% less expensive than the national average of $6-per-gallon aviation gasoline. There is no lead in compressed natural gas. It is also a much cleaner burning fuel, reducing smog pollutants by 90% and reducing CO2 emissions by 30%. Engine oil remains significantly cleaner, therefore improving engine life, while aircraft performance is enhanced as CNG typically burns 138 octane versus the current 100 octane of aviation gasoline, company officials note.

“One aspect we’re particularly excited about is the opportunity to dramatically reduce the cost of learning to fly,” added Herrick. “If a flight school installs a simple CNG refueling station they can cut the cost for the student’s fuel, perhaps by thousands of dollars. And, the fuel is available where ever there is a natural gas line.”


  1. peter says

    what happens when the gas cylinders become old and start to crack…how can we regulate it?
    what happens when there is an accident, the tanks have a higher chance of explosion as they are pressurised.
    the safety concerns with refuelling…
    if a bird strikes the tanks, the tank may rupture due to the pressure imposed and finally;

    pressure changes due to height…how high can an aircraft go without the tanks exploding under the pressure?

  2. Richard Baker says

    The logic of natural gas in aircraft escapes me. Is there any logic or is this one more of the many “green” goofy ideas?

  3. Kent Misegades says

    Another point – Did Aviat also consider a simpler means to lower the cost of flying? Use the INPULSE water-injection system from AirPlains of Wellington, KS to allow the engine to operate on cheap mogas. All that is needed in addition to the electronics and water injectors is a small tank of water/methanol mixture for the short duration of take-offs. Since mogas contains 3%-5% more BTUs than 100LL avgas, the difference in performance due to the slightly higher weight of the INPULSE system should be a wash. The lower cost of mogas will allow payoff of the system in a short time. Mogas is plentiful and requires no heavy tanks, use the same as for Avgas. Plus the two fuels can be mixed depending on availability of avgas in the future.

  4. Kent Misegades says

    Wait a minute – one gallon of gasoline has an energy equivalence (GGE) of 5.75g of CNG. Thus, a 50g tank of CNG would be equivalent to an 8.7g of gasoline, less than a J-3 Cub! Or put it in other terms, to fly as far as with 50g of avgas, the CNG tank would need to have a capacity of 287 gallons. CNG tanks are pressurized to 2400 psi, requiring a massive, heavy tank. These aircraft will be flying bombs. Maybe I am missing something here, but the lower cost of natural gas is only one small aspect of this idea. But it is surely worth looking at, why not?

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