Interesting UK development

[Deskpilot]

I doubt we'll ever be able to do this but it's very tempting to forget the rules. Enjoy.

 

 

 

[Jaba-who]

You could do it here. Have to register it as GA experimental though I would have thought.

 

 

[kasper]

Or build it yourself and keep it under 300kg and 95.10 is fine. It’s the only class of ultralight in Australia that allows both multi engine and turbines so either find yourself an old 95.10 sapphire - several available for around $8k - and grab a couple of big model jets - many available around the $6k each - and for less than the cost of a good drifter yours burning kero at a prodigious rate and making phenomenal noise.

 

 

[Deskpilot]

Yep, noisy for sure and not very fast either.

 

 

[kasper]

No - if you used a sapphire not particularly fast - probably only around the 100kt mark.

 

But if you went for a flying wing new build and went for something along the lines of a Jetcat 550N Single

 

 

Or a couple of much cheaper engines in the 240-250N range like the ATJ 250SV

 

 

In any event the cost of the jetcat pays for 3 of the ATJs but still cost less than a 912 80hp even before you buy the prop

 

 

[Round Engines]

There is a twin jet cri cri that operates out of YSEN. And it sounds awesome! I think it uses engines similar to the ones above.

 

 

[kasper]

There is a twin jet cri cri that operates out of YSEN. And it sounds awesome! I think it uses engines similar to the ones above.

I guess much smaller versions than even the 250N ones ... cri cri flies on twin 12-15hp ... 245N is similar in total thrust to around 30hp

[Jim McDowall]

As CAO 95.55 requires that an aircraft to which it applies has a single engine and a single propeller probably means would have to be experimental GA or if single engine 95.10 if less than 300kg AUW and 30kg/m2.

 

Some glider guys have done jet mods with variable results.

 

 

[turboplanner]

A big issue for hobby jets is fire, caused by a less than perfect fuel supply system which develops leaks. Fuel hits the hot engines and up it all goes. Fuel delivery design is everything.

 

 

[kasper]

As CAO 95.55 requires that an aircraft to which it applies has a single engine and a single propeller probably means would have to be experimental GA or if single engine 95.10 if less than 300kg AUW and 30kg/m2.Some glider guys have done jet mods with variable results.

To be 100% complete you could be mad enough to put them on a 95.32 home built weightshift ... but seeing as they generally cruise in the 60-65kn range you really would be burning a heap of kero and making a noise for no great effect

[Birdseye]

Its odd that there seems to be nothing more on this since the 2011 first flight, unless I've missed something.

 

 

[Downunder]

So...I guess an Aerolite would fit nicely within our 95.10 regs?

 

An Aerolite 103 is 88kg without engine..(my calcs, 106 kg less 18 kg for the Hirth). 24 kg/m2 at MTOW 272 kg. (Whether the owner wants to push it to 300 is up for debate but I'm guessing wing loading is still under 30)

 

What would you be looking at in costs of turbines? A couple of these ATJ 250's are looking like 10 to 12 grand aussie fitted to me.

 

Any "ball park" conversions of thrust Vs horsepower? I'm a bit confused about that. Would a single jet me more efficient overall fuel wise? Perhaps weight wise as well.

 

 

[kasper]

So...I guess an Aerolite would fit nicely within our 95.10 regs?An Aerolite 103 is 88kg without engine..(my calcs, 106 kg less 18 kg for the Hirth). 24 kg/m2 at MTOW 272 kg. (Whether the owner wants to push it to 300 is up for debate but I'm guessing wing loading is still under 30)What would you be looking at in costs of turbines? A couple of these ATJ 250's are looking like 10 to 12 grand aussie fitted to me.

 

Any "ball park" conversions of thrust Vs horsepower? I'm a bit confused about that. Would a single jet me more efficient overall fuel wise? Perhaps weight wise as well.

Ok. The atj 250 are new and quite pricey. The ATJ220SV are under $4,300 each delivered with gst paid ready to install with all controllers.One thing to be very careful of - because RAAus and/or CASA will start patrolling it is that you cannot register a new 95.10 that came from a kit unless that kit is an approved kit ... and there are no approved kits. So if you’re looking to do a bit of getting around you are really limited to buying an existing 95.10 airframe and modifying it or designing and building from scratch.

 

And 95.10 if fully enforced would even see minimaxes and other plans built refused rego because they are not approved plans.

 

95.10 is for self design and self build for all new registrations. Be very causious of trying to tap dance around it with anything that comes from a factory because If CASA audit the 95.10 register there are quite a few that would fall into cancelled registration and needing to move to 95.55 ... and you can’t take a jet or multi engines airframe into that register. .

 

 

[Marty_d]

Can I just say two words... "fuel economy".

 

I think the guy said those turbines suck 0.7 litres per minute... each... that's 84 litres per hour.

 

 

[kasper]

Can I just say two words... "fuel economy".I think the guy said those turbines suck 0.7 litres per minute... each... that's 84 litres per hour.

Yes. But 1.4L per minute will be such good minutes ... andvthwts at full throttle ... once you get to circuit height it’s down to only 1L per minute ... I’ll take 25minutes please

[Litespeed]

Got me thinking about the fun that could be had...........what about a big single or twin flying wing aka facet opal. That would go like stink.

 

Just need a bucket of dollars, a bucket of time and two bucket size balls.

 

Perfect for the bucket list.

 

 

[Litespeed]

But I am a mad bustard, my doctors say so. Always dream about doing a revised AR5 because 213 mph on 65 HP is kinda slow. Just add a Simononi with 110 HP. Now that would be a rocket ship under 300kg.

 

 

[jon123]

Jet engines are becoming mainstream as sustainer engines for sailplanes - check out the Jonkers Sailplanes website.

 

Not much range on the engine so you mad bastards may have to become real pilots and learn to soar!

 

There are few already flying in Australia.

 

 

[Birdseye]

Yes. But 1.4L per minute will be such good minutes ... andvthwts at full throttle ... once you get to circuit height it’s down to only 1L per minute ... I’ll take 25minutes please

The thought crossed my mind that at least you could burn cheap kerosene; then when I checked on the 'web' there doesn't seem to be such a thing, its going for the same price or more than avgas.

 

 

[Mike Borgelt]

Really bad idea on low speed draggy low wing loading ultralights. Makes sense on self launch or sustainer sailplanes, although if you want to fly very far in the sustainer sailplane you are better off to trade weight of fuel for an extra engine. Sounds crazy but you just climb burning all the fuel, then retract engines and use the high L/D of the glider for range, otherwise you are burning fuel and not climbing). Reason it works is modern gliders have low drag at high speed (best rate of climb speed for an adequately powered glider with a thrust/weight in the 0.125 to 0.15 region is around 100KIAS giving a rate of 800 to 900 fpm) and duty cycle on the engines is low, unlike the 100% duty cycle on a powered aircraft

 

I have a nice spreadsheet that gives performance for jet powered gliders. Rate of climb, takeoff distance etc. Would work for powered aircraft if you can get a good estimate of the speed polar and also would work for prop driven aircraft if you can figure out the static thrust and diameter of the prop.

 

If you want a jet power plane, start by flop molding a glider cockpit, put small wings and retractable or buried landing gear on it and use a couple of the 40 Kg plus thrust engines. Do check that you have adequate single engine performance, EXPERIMENTAL Amateur built and you have a nice machine to go out into the training area and do jet aerobatics. Not a travelling airplane.

 

 

[pluessy]

This is on my bucket list for retirement: a 2/3 scale DeHavilland DH-100 Vampire with a ducted fan or ~75kg mini jet. This would give it a similar thrust/weight ratio as the original.

 

The 2/3 scale has about 10m2 wing area and should be possible with a MTOW of 300kg = 95.10. Only drawback is that 95.10 doesn't allow aerobatics:thumb down:

 

I have a set of 1/5 scale model plans to start from. Any interest?

 

Currently building a Spacek SD-1 Minisport to learn about the new foam/carbon/ply/timber construction techniques (130kg empty, 6m2 wing area, 33-35hp, 85-90kts cruise).

 

 

 

[Mike Borgelt]

Get a TJ-100 turbine as on the Sonex Jet. Has a real oil system. All the other small jets mix the jet oil in the fuel. Fine for self launch gliders but for a real jet aircraft use the TJ-100 unless you want two engines. Two TJ-100s are pretty expensive.

 

How about a Hawker Sea Hawk in the same concept? hawker sea hawk - Google Search

 

Pretty aircraft. Original was single engine Rolls Royce Nene but two small engines would fit in the wing roots with plenty of space for fuel. Roughly the equivalent of the Grumman Panther.

 

 

[Mike Borgelt]

AMT jets www.amtjets.com have some larger engines. 80Kg thrust Nike and 160 Kg Lynx engines. Two Nike's were being used by David Mayman on his JB-10 jet pack. The latest JB-11 jet pack uses six AMT Titan's of 40Kg thrust each for engine out redundancy.

 

Interview: David Mayman debuts the faster, safer, six-engine JB11 jetpack

 

 

[pluessy]

Thanks Mike, I'm aware of that. $150 for 100lt of fuel and $100 for the 4.5lt of oil! The PBS TJ80 is hopefully available with the same lube system as the TJ100 by the time I'm ready. Or AMT has the Nike with a separate lube system.

 

I have a soft spot for the Vampire, sort-of grew up with them and they were the first jet fighters in both of my countries (CH and AUS). And it just looks good and has the right proportions for a scale replica.

 

 

[Mike Borgelt]

I know the Hobby King Vampire R/C electric ducted fan flies very nicely. Watched Nigel Arnott flying his once.

 

Yes, the cost of oil is the reason you would want a real re-circulating oil system for a powered aircraft. For a self launching or retrieving glider the fuel cost is a minor consideration as 5 to 6 litres gets a 2000 foot launch. An aerotow costs about $50 nowadays and burns more fuel.

 

I agree the Vampire looks nice and seems to have no handling vices.

 

All this silly 95.10, 95.55 Experimental amateur built etc blah blah blah is just nonsense. Replace the RPL medical with the current RAAus one, allow owner maintenance on aircraft under 600Kg and the RAAus can go back to being an advocacy organisation run by and for its members, instead of a sheltered workshop for would be aviation bureaucrats who arean't smart enough to get even cushier jobs with CASA.