BERKUT JET PICTURES

[JonC]

Originally Posted by SteveWrightNZ

pity the BD-10 went the way of the dodo... what a bird! I think too many people tried to pop its sound barrier - which is a pity, coz its a nice aeroplane even without the supersonic bit.

S

I think previous Bede events probably left a very bad taste in people's mouths about Bede aircraft..... Just a thought.

[johnd01]

How much thrust does a cozy IV need?

[JonC]

Originally Posted by johnd01

How much thrust does a cozy IV need?

Most people don't use thrust to describe a piston aircraft due to the amazing number of combinations of engine and propellors (which all produce different amounts of thurst), so I kinda doubt if it has been figured that it is a well known number.

We know that Greg's T58 is more than enough to move a Cozy... as to how much thrust output it has... who knows... it started life as a turboshaft engine, not a pure gas/thrust producer.

[Strider]

The jet Berkut is Jerrod's, located in Ft. Collins-Loveland airport, north of Denver. I haven't met Allen, but we recently lost the planned test pilot for this plane. Troy Theodos was killed two weeks ago flying with Dan Hardesty in Dan's VariEze. Both are sorely missed.

The Berkut jet has full wet wings for Jet-A, built up with glass ribs like a Lancair. The cockpit seats two, with lots of space for them (especially compared to my VariEze). Jerrod invented the speedbrakes, which Greg Richter copied on his Cozy jet. Jerrod is still sorting out some cockpit controls and weight and balance issues. AFAIK, the jet Berkut has not flown yet. Also, it will still need an Inconel exhaust cone, just as the Harris's built for Greg Richter. The modified T-58/J-58 turbojet doesn't make full power without the critical nozzle-tail cone assembly. As installed in the Maverick twinjet, the J-58 is rated at 750 lbs thrust. Last I heard, Jerrod's was not quite producing that much yet. This is a very loud airplane, regardless.

[SteveWrightNZ]

according to X-Plane, it needs about 130lb thrust approx for 160kts ish travel. It needs more for takeoff - dont recall what that was.

750LBs thrust on a cozy is well past the "wow thats too much" category, and bordering on the "dont do that" category IMO, but bring it on I say.

[eracer113]

Rule of thumb for a jet is thrust should equal 30% of the AC weight. I believe the Berkut has a gross weight of 2250 lbs. 30% would be 775 lbs of thrust.
This is strictly what I was told.

Jack
E Racer 113

[SteveWrightNZ]

Originally Posted by eracer113

Rule of thumb for a jet is thrust should equal 30% of the AC weight.

Wow. I dunno jack about it of course, other than X-Plane says 124lb approx at 160kts @ 8,000ft.

What fuel consumption will an engine like that have ?


S

[JonC]

Originally Posted by SteveWrightNZ

Wow. I dunno jack about it of course, other than X-Plane says 124lb approx at 160kts @ 8,000ft.

What fuel consumption will an engine like that have ?


S

A Williams FJ33-1 (Turbofan) would burn 56gal/hr doing 775lb of thrust. (.486 SFC)
A GE CJ610-1 (LearJet 23 Turbojet) would burn 114gal/hr doing 775lb of thrust. (.990 SFC)
A Turbomeca Marbore 6c would burn 127gal/hr doing 775lb of thrust. (1.110 SFC)

Varies widely by the engine...

Small Turbofans typically hover in the high .4's to the mid .5's.
Large Turbofans (>10k lb thrust) can get down in the .3's

Turbojets are in the high .8-1.1 range.

[Nathan Gifford]

When Phil had his Cozy tied off to some trees with a strain guage, I think he measure the thrust from his Subue/prop combo somewhere around 500 lbs.