turbo prop

[eightyknots]

Here's a Part 103 US ultralight with a jet engine:

 

 

 

[flyvulcan]

The original AMW engine in the Bug weighed in at 135 lbs installed including water cooling system. While Milt is installing the Jab3300 in his Bug, the approx 180 lbs is really too much. Ideally, we are looking for a sub-140 lbs installation but this simply may not be possible for a reliable solution and we may need to look at using the heavier engines in the production kit (and do the appropriate mods to incorporate a heavier engine installation). The Viking would be under consideration if we have to go for a heavier engine.

 

 

[Guest Howard Hughes]

Bug looks like it needs a four or five blade prop to me, how do you slow it down?

 

 

[flyvulcan]

Bug looks like it needs a four or five blade prop to me, how do you slow it down?

When we fly it, I'll let you know!! The red Bug that we have in the US was last flown 3 years ago when it had a partial engine failure of the AMW engine. The pilot got it down on 2 cylinders with the rear one having been cooked. While he had around 30 hours on the aircraft, he hasn't given us too many pilot reports on it's handling. He's really only given us the guidance that "it flies like any other aircraft and is quite responsive". Not much info really...

 

We shall probably just need to give it an extra mile to slow down... Also, partially winding the nose-gear down would slow it down fairly quickly.

 

 

[Bryon]

Make the front undercarriage leg cover a bit wider to act as an airbrake

 

 

[flyvulcan]

Hi Bryon,

 

The nose-gear cover is extremely draggy as it is now, according to those that have flown the Bug, so we expect it to do the job of airbrake as-is.

 

Cheers,

 

Dave

 

 

[Danger Mouse]

Hi Dave

 

The Bug looks fantastic, I hope you are successful with it, looks like it would be great fun to fly.

 

Have you considered a Sauer engine? They have a 100hp 3cylinder liquid cooled 2stroke with a dry weight of 99 lbs (excluding prop/gearbox). It is 490 long x 280 wide and 420 high. I don't know anything about them but stumbled across it one day researching motors.

 

Just google Sauer s950r 100 and it should pop up with the manuals and spec sheet

 

 

[Guest Maj Millard]

Powerfin in the States has a nice carbon 5 blader that may suit that aircraft.............................................Maj...

 

 

[flyvulcan]

Thanks guys, I now have the Sauer on my watch list.

 

I've also been learning propellor theory on another forum that I participate in and the pro's/con's/reasons for a particular number of blades are being explained to me. With a prop diameter limit of 54" for the Bug, getting the right prop to suit the Bug will take some evaluation, but fortunately, I have the help of some experienced prop makers.

 

Cheers,

 

Dave

 

PS Not having to worry about props is a great reason for going for a jet!

 

 

[kingo]

How long is it, Brett? The engine that is, from prop flange to aft of the exhaust? Could you redo the exhaust for tractor configuration?After successful airborne testing on a gyro and if it physically fitted, perhaps you might be interested in fitting it into this actual aircraft:

 

[ATTACH=full]19593[/ATTACH]

 

You would be doing faster than 160 knots (normal top speed with 100hp 2 stroke is around 200kias with a Vne of 225) and it only has one seat.

 

We could come to some arrangement... It's ready to fly (done around 40 hours already), it just needs to be re-engined (we wont be flying it again with the AMW that's in it!)

 

Dave

Hey Dave,

 

the engine is 1050mm from exhaust to prop flange, and yes the exhaust will need to be redone was a quick job out of 1mm stainless to clear the test stand.

 

centre of balance for the engine is 30mm in front of inlet..

 

And am already all but deaf, sounds like a vacuum cleaner to me.

 

Brett.

 

 

[damkia]

Hi Nev,If anyone can point me in the direction of a suitable powerplant for the Bug, I'm all ears. We have a few under consideration but all of them are compromises on the original concept of a closely cowled 100hp 2 stroke.

 

We may still put the fairly bullet-proof Rotax 912/914 in it, but we've looked at all the 2 strokes (Hirth/Simonini etc.), the D-motor, Jabiru, AeroVee, etc. and we don't have a "perfect" engine yet for it. The main feature of the Bug design is it's capability for real speed (i.e. 200 knots) but to make the Bug a success, it must have a suitable, reliable, affordable powerplant.

 

We've looked at several rotary conversions but have not found a suitable one yet. If you know of any, please let me know in case we haven't yet seen that product. Bear in mind that engine bay space on the Bug is at a premium.

 

As for a prop, with the large speed range of the Bug (60 - 200kias), we are looking at IFA props to maximise it's performance potential. The existing props start running out of pitch at around 180 knots so we are definitely looking at IFA options for the "performance" Bug. A "regular" Bug would be ok with a fixed pitch prop up to around 180kias, but for those with the real need for speed, we will definitely be working with an IFA prop maker to provide an optimum performance prop for those who are pepared to pay the extra for more knots.

 

If Kingo's T62 conversion is viable and reliable, and we could organise for conversions to be made readily available (such as Helicycle do with their T62 conversions), it might be a nice option to be able to offer for the Bug.

 

This is why I am watching Kingo's conversion with interest and would be keen to see it in a Bug, once it had a history of safe operation in a gyro.

 

Cheers,

 

Dave

Have you considered a UL Power engine? Their big 4 pot (UL 350iS) is a bit lighter than the Jab 3300 with better power/torque characteristics and better fuel economy.

http://www.ulpower.com/engines/ul350iS/index.html

 

 

[kingo]

I never get the whole less lt/ hr thing works.

 

if you go 2000nm@ 80kt @ 20 lt/hr @ $1.70lt =$850 flight

 

2000nm@ 180kt @ 55lt/hr @ $1.30=$794 flight with out three day of flight time three nights in a motel @$150 + two extra day of food say fifty bucks a day then sure glad I went with that engine.

 

Brett

 

 

[flyvulcan]

Hi Brett,

 

The current distance from the front of the prop flange to firewall in the Bug is 980mm so with some creative cowl work, we could possibly squeeze in your engine. Can the oil sump be remotely located or is it necessary for it to be on the base of the engine where it is currently located (we have a centre keel that the current engine is mounted to using bed type mounts)? Can the depth of the exhaust be reduced at all to reduce the overall length of the engine (even 30mm would help)?

 

FYI, fuel capacity of the Bug is 90 litres and with your engine at 10,000' should probably TAS out at around 200ktas for cruise.

 

Brett, you are right in considering Specific Air/Ground Range (SAR/SGR) as well as the cost of hotels/landing fees/food etc. that can result in significant additional costs on top of fuel costs.

 

UL Power engines had been looked at thanks Damkia. We are trying hard to find something inline to keep the cowling narrow but at the end of the day, we may have to go with something that has opposed cylinders and accept that the current clean lines will be compromised.

 

The inline 110hp Simonini and 100hp Hirth 2 strokes can be made to fit but we are trying to get away from the 2 strokes.

 

We would really like a Turbine...

 

Cheers,

 

Dave