Ultra High Bypass Jet Engine Green Technology Airline Flight Test

The buzzwords in clean power for jet planes today are Geared Turbofan (GTF) and Advanced Turbofan (ATF). But in 1989 when this award winning story was produced, everyone was talking about Ultra High Bypass (UHB) jet engines. General Electric (GE) was testing the Unducted Fan (UDF) and a team of Pratt & Whitney and Allison were experimenting with a geared PropFan design. Test platforms consisted of a Boeing B-727 and a then Douglas MD-80 with most flights taking place at California's Mojave Airport. This video also includes an appearance by the late brilliant Aviation Week Editor Michael Dornheim. He will be missed. Clearly, this video is from our archive, not a recent production. For more current news about the leading edge of safety, tactics and technology, please visit http://www.AeroSpaceNews.com/ We'd appreciate links from your website and blogs too.

Category:

Autos & Vehicles

Tags:

• Pratt & Whitney
• P&W
• green
• jet
• turbine
• jet engine
• GE
• General Electric
• UDF
• un-ducted fan
• UHB
• ultra high bypass
• prop fan
• global warming
• greenhouse gas
• airline
• airliner
• airlines
• air travel
• fuel efficiency
• mike dornheim
• aviation week
• airplane
• aviation
• aircraft
• turbofan
• fanjet
• advanced turbofan
• ATF
• geared turbofan
• GTF
• business jet
• corporate jet
• learjet
• Gulfstream
• falcon
• citation
• md-80
• Douglas aircraft
• boeing
• B-727
• mojave
• opec
• oil
• industry
• jet fuel
• open rotor

[AviationNation787]

$1 a gallon fuel costs?! What is the world coming to?

[aerospacenews]

@AviationNation787 - Very funny. At the time this video was produced that was a bit of a spike for the bulk users in the airline industry. It was down from all time highs though.

[pontifix]

What they don't mention is that contra rotating propellers are so noisy, they cannot pass noise certification tests with existing designs. That is why you don't see them today. But wait, because research is being made to make them quieter...

[aerospacenews]

@pontifix Yes, don't assume blade technology will remain static. But at the time this video was produced these systems were producing more noise than conventional high bypass fanjets.

[Ouroboros22]

@MaverickOOO1

Actually Russia reentered the project in 2009

(Source: Aviation Week & Space Technology - 4 October 2010 - "Antonov An-70")

[cinndave]

@Guywhowearsunderwear Another drawback is that their top speed is lower than a turbofan. 450 mph might not be fast enough. And the 10,000 hp these have might not be enough for the bigger more popular planes.

[cinndave]

@AviationNation787 Airliners buy jet fuel by the boatload or trainload, so it's inexpensive to deliver, compared to gasoline.

[cinndave]

@pontifix Correct. One way is to have one propeller with 1 blade fewer than the other, so they don't all align and chop air simultaneously. Another old trick is to curve back the blades like a scimitar. I wonder if they're using evolutionary algorithms on a supercomputers to find a better design....

[Tigerwarhawk]

@pontifix Actually, the GE 36 unducted fan engine was stage III compliant, so noise was not a problem for this variant. However, falling fuel prices shelved this project. Ain't that something? I suspect that airlines like Delta and American would LOVE these engines on their Maddogs!

[CheetahFoxx]

@boggedmaffus That was more of a public complaint issue. People diddnt like hearing a clap of thunder (sonic boom) on a clear day so the airlines made fo fly supersonic were RESTRICTED TO SUBSONIC when over land. Noise complaints are the same reason that killed the UHB.

[brightonjonny81]

We do actually see these every day on every modern jet liner, these were just the early tests for a bypass fan concept. Today, of course, the fans have been brought to the front of the system and a cowling placed around the entire assembly - and viola - today's modern high bypass ratio turbofan jet engine. Also the contra-rotating blade idea has been dropped if favour of just one fan. I'm not sure why that is (i'll ask my lecturer - im an aviation student) but I would guess cost and weight.

[mohicannoir]

@AviationNation787 Do you think $1 is expensive for one gallon of fuel ? It is is ultra cheap... Here in France, a LITER is today almost 2 EUROS (3.5 USD for ONE LITTER)...

[seiaaro]

While these engines seem to be more gas efficient, I wonder about the practicality of use with them in commercial use. 1. What how do they stand up against, snow, ice and freezing rain. 2. What about FOD ingestion and Bird Strikes, 3. What would happen if a fan blade failed... would it penetrate the cabin causing decompression? Sever flight control?

[abhiginimav]

50c to $1 per gallon! AHHHHHHHHHHHH! oh wait its higher now....AHHHHHH!