Aircraft

First public flight for largest hybrid-electric plane to ever take to the skies

First public flight for larges...
On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport
On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport
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LA’s Ampaire has now put into the air what it says is the largest hybrid-propulsion plane to ever take flight
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LA’s Ampaire has now put into the air what it says is the largest hybrid-propulsion plane to ever take flight
The Ampaire 337 plane is based on the six-seat Cessna 337 Skymaster
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The Ampaire 337 plane is based on the six-seat Cessna 337 Skymaster
Ampaire plans to continue flight testing its plane multiple times a week from June through August
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Ampaire plans to continue flight testing its plane multiple times a week from June through August
There’s plenty happening in the world of environmentally friendly aviation
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There’s plenty happening in the world of environmentally friendly aviation
On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport
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On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport
Ampaire plans to continue flight testing its plane multiple times a week from June through August
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Ampaire plans to continue flight testing its plane multiple times a week from June through August
On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport
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On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport
The Ampaire 337 plane is based on the six-seat Cessna 337 Skymaster
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The Ampaire 337 plane is based on the six-seat Cessna 337 Skymaster

There's plenty happening in the world of environmentally friendly aviation, with a string of clean-burning aircraft notching up milestones in recent years, including the first flight of an electric light sport aircraft in Australia, the first electric test plane to tow a glider into the sky, and the first electric aircraft to cross the English Channel. LA's Ampaire has now put into the air what it says is the largest hybrid-propulsion plane to ever take flight, with plans to kick off commercial operations in the next couple of years.

We've seen quite a few hybrid electric aircraft concepts and prototypes over the years, including the futuristic Volta Volaré, the Terrafugia Transition flying car and a test plane from the University of Cambridge and Boeing.

But never before has a hybrid-electric aircraft of this size flown before, at least according to Ampaire. Its Ampaire 337 plane is based on the six-seat Cessna 337 Skymaster, which it retrofitted with its own electric propulsion system. That means yanking out one of the two combustion engines and putting a battery-powered electric motor in its place, with the two now working together for optimal efficiency through the air.

On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport
On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport

On Thursday, the Ampaire 337 took flight for the first time in a short jaunt at Camarillo Airport, with a test pilot and flight engineer in the cockpit. Following the first outing of this prototype, Ampaire plans to continue flight testing the plane multiple times a week from June through August and gather data about the performance of its electric propulsion systems.

The information gleaned throughout will then guide the team in building a new prototype that will be used in a pilot project exploring the potential for a commercial route in Hawaii. The company imagines eventually using its hybrid aircraft to service commercial routes for regional airlines covering short distances, and hopes to begin operations in 2021.

A video of the test flight can be seen below.

Source: Ampaire

Ampaire in Flight

10 comments
shaun63
Can't a 337 cruise on one engine anyway? Seems kind if pointless. An airplane cruising on one engine is more efficient than one cruising on one engine and an electric motor. Shutting down the rear engine and feathering the prop is probably way more efficient than this. They probably effectively made the airplane worse.
Towerman
Electric is the indisputably the Future !
Username
Remarquable lack of information provided. Does the ICE power the electric motor? are there batteries? Fuel consumption comparison? Range? etc?
flyerfly
As a pilot (and engineer) I approve... to those who say this is pointless here is why it is good. 1. Safety. Having redundant systems on planes is primarily for safety and not because it is more efficient. If one fails people don't die. I have been in a plane where the engine failed and I had to land without power. Trust me...having redundant is good! 2. Electric can be more reliable than internal combustion but it does not have good range. So having the hybrid system gives you both...and redundancy. I don't think pure electric will come into play for awhile for longer commercial flights because of the lack of high energy density batteries. Hybrids are good for medium range and short range. For long haul I don't even think hybrids can compete with combustion engines. As a plane keeps flying fuel is consumed and it gets more efficient...with a pure electric you carry that weight even if the batteries are dead. Trust me, they did not make the 337 worse. This plane was not noted for its high efficiency. The reason it was made like it was is so that it was safer to fly. It is push pull and does not have adverse yaw if one engine fails like typical twins do. There is special training that goes into flying twins that have an engine on each wing. BTW cruising on one engine with the 337 is marginal at best...it is meant as a safety to get you to an airport...I have not personally flown a 337 though so I can't say from experience.
shaun63
One of the guys I know flew a 77 Skymaster for years. He used to say there were two ways to get ridiculous range out of the plane while staying at or below 10,000 feet. One - lean the engines out and play the mixture-management game like a madman. Two - fly on the rear engine and feather the front prop. He would say at it below 10,000 feet he could cruise at 130kts on the rear engine alone. Taking a plane that can already cruise on one engine and putting an electric motor in it and saying "it's efficient now!!" While turning 2 props is silly. That spinning prop on the electric motor is more draggy than a feathered prop. There's no way it's more efficient. Especially if the plane is hauling around batteries too
shaun63
As for redundancy, the airplane already had redundancy. We don't know if it still has redundancy. Can it fly only on the electric motor? Does the electric motor make at least as much power as the engine it replaced? Will it have the range on the electric motor that it would've had in one engine? If the answer to any of these questions is "no", then they effectively made the airplane worse.
Scottsdale Bob
I showed my Wife the story and her only question about the electric engine was how do they keep the extension cord from wrapping around stuff while it's flying?
Paulinator
On many multi engine aircraft it is common practice to shut down an engine or two for range extension on long ferry flights. There's the odd brave ferry pilot that will shut down one engine on a twin so that they can pocket the fuel savings. Mr Obvious tried to prove the obvious, but got it wrong by keeping the electric fan spinning in cruise.
toyhouse
Thinking outside the box,... perhaps the electric motor pitch goes full-feathered, shut-down once at cruise then locked out of rotation? One engine provides cruise and hybrid system re-charge. Pitch changed once again to provide further hybrid system re-charge and controlled decent rate. Just trying to think outside the box as this is mostly new ground being covered that most folks don't really know much about. Yes, vaguely familiar with the skymaster. Family members once went shopping for one many years ago. Many pilots in our family. With a completely different engine, maybe single engine cruise is well within reason. It doesn't mention that. Nor does it mention which end is which. But it does mention that it's a "test bed". As for the keyboard experts who always seem to know these things and instantly know when they can't work,.... someone did the engineering design work and ran the numbers, thought it worth the time and money to invest in and build a working "study platform". A platform that it does state in the story; is being used to gather information for building a new prototype. Does that mean buying up old 337's for conversion where they hope they can fly on one original engine for a commercial airline service in hawaii, lol? I'll leave that for others to ponder. Good for them anyway! And after just one test flight,....they already know more than most of us. They're actually doing it.
Mb
My question is which engine was electric. Personally, the rear should be. The weakest point of the 337 was that rear motor.. basically cooling. It's easy to cool the front, but the rear was far more troublesome to cool... Not to mention cabin noise and vibration from the ICE. Changing that to an electric would make the most sense as it would cut down on cabin noise and a lot of the vibration as the motor won't have multiple moving parts (pistons for instance).. Granted, the range would be lacking on electric, but that's rapidly changing.. perhaps adding high efficiency solar cells along the roof line and built into the wings can increase this. For naysayers . Planes routinely fly ABOVE the clouds, especially on an overcast day.