Interest in a 200 knot LSA?

[facthunter]

It's easy to air-cool fast planes and you might even get some thrust effect IF you do it properly. All pistons are unsafe relatively.  Nev

[RFguy]

What's the 200 kts with ?  with a Jab 3300 and airmaster CS prop  and 1 pax and full fuel ?

How does it compare to a Lancair 360    ??  (76 sq ft wing, 500kg empty) , that's about a 200kts plane, also.

[skippydiesel]

2 hours ago, facthunter said:

It's easy to air-cool fast planes and you might even get some thrust effect IF you do it properly. ...........................  Nev

It's often the challenge of staying cool while on the ground (slow speed) that occupies home builders.

Edited January 14 by skippydiesel

[facthunter]

You already know I'm a cowl gills person . Getting things UP  to temperature has been a bigger problem. and time waster. Merlin engined planes can't stay on the ground long. Nev

[Rapture]

3 hours ago, RFguy said:

What's the 200 kts with ?  with a Jab 3300 and airmaster CS prop  and 1 pax and full fuel ?

How does it compare to a Lancair 360    ??  (76 sq ft wing, 500kg empty) , that's about a 200kts plane, also.

Currently 196ktas with the Jab3300 and ground adjustable 2 bladed Bolly Optima Series 5 with 64” (I think but not certain without checking with the owner) diameter.  Pitched for speed, static rpm is abysmal and climb rpm is not much better at 120 knots and is around 2400rpm so the Jab is way down on power in the climb, but it still climbs at circa 1500fpm.  We are looking for a suitable IFA prop for it at the moment to maximise performance across the entire flight envelope.  Those numbers are with Pilot and about 1/3 to 1/2 fuel.

 

The owners Dad owns a respectable performing Lancair 360 and at the moment, both top out at about the same speed.  The 360 has a constant speed prop.  From 120 knots, the Bug accelerates much better than the Lancair, even with the fixed pitch prop and reduced power available at the start of the acceleration.

[facthunter]

Schneider Trophy seaplanes had fixed pitch props and IF you can get airborne and up near the top speed  you then become quite efficient.  An adjustable in flight prop is still a compromise.  Nev.

[turboplanner]

1 hour ago, skippydiesel said:

It's often the challenge of staying cool while on the ground (slow speed) that occupies home builders.

Even in the factory builds, really a neglected subject and stuffs up the day at a big and busy airfield where there are plenty of waits and long taxying.

[RFguy]

welll at Oshkosh this year I watched a airplane departure traffic jam over 2km worth (looped back on itself) and it was about 32C and 90% humidity... all chuggin away, some decided to shutdown.
 

OK on the performance. I know the airmaster IFA has the most numbers for Jabiru 3300s, but I would think a 912 and a after-turbo would be a better user package  (air air gets thin, doesnt matter....) . Much nicer to hang a CS off.  I'd be careful of how much  is hung on the front of the Jab engine, the airmaster that people use- the moment of inertia is miles beyond the jabiru max spec (but I dont know if Jabiru factory just set that number to suit their own propeller, or not, IE if it is  just a number, or if there is any science behind it.)  . Still, I have heard of NO  Airmaster IFAs coming off jabs.

Understood on the static RPM completely sucking.  yeah that's expected ...... I'd actually like an airplane like that that did about 170 TAS at 12,000' / 4h endurance  to go and see my mum in. . that would be a nice improvement over my 120TAS. 

Edited January 14 by RFguy

[facthunter]

IF you aren't facing into wind when idling you will soon overheat. None of the cooling is evaporative so the humidity would mainly  affect the occupants who could end up in a state not exactly suited for piloting a plane well.  Nev

[skippydiesel]

2 hours ago, facthunter said:

Schneider Trophy seaplanes had fixed pitch props and IF you can get airborne and up near the top speed  you then become quite efficient.  An adjustable in flight prop is still a compromise.  Nev.

That's true Nev however you neglect to mention they potentially have the longest runway on earth, can remain in ground (water) effect as long as they like, to gain sufficient speed to climb, with no terrain issues except the occasional ship.

 

In most other applications, a fixed pitch must be a compromise to have sufficient climb performance for safety, combined with an acceptable cruise speed.

 

A CS while still compromising (mainly aerofoil shape/design) gives great TO/CO and good cruise.

[facthunter]

It may be a LONG runway but the float that's pushed down by the torque  often buries itself if you don't get unstuck quickly. There's FAR more drag on water than with wheels. The first Spitfires had fixed pitch props .. Nev

[Litespeed]

I think it's a given that we won't be using this design as a float plane.

 

A IFA prop with the Jabiru sounds a great solution, all the speed you should want and the climb/acceleration you need to get out of sticky situations in lessor machines.

 

 

I think I would much prefer this over a Rotax and all its extra bits and costs. The extra speed naturally is appreciated as well. 

 

I always lusted after the Arnold AR5 but wanted a four stroke or a 110hp  Simononi Italian motor rather than the 65hp of the original. Naturally that meant a new design etc ..., But this is a lovely solution esp if it could meet RAA regs.

 

I will just need a suitable donor of kidneys to sell on the black market...

[skippydiesel]

The Rapture Bug looks to be a single seater - is this correct?

 

If so, it's only going to be attractive to a very small market.

 

I would like to see the following:-

Performance verified by a third party (for a given engine).

Empty weight

Fuel capacity

Max TO weight

Stall 55 Knots

 

It it amazes me, that an Australian made/modified, Rotax 912 ULS powerd, two seater aircraft exists, with third party verified performance (252 Knots), 40 Knot stall, known fuel capacity (103L) & payload (90Kg adults x 2 + all camping equip) and  and its basically ignored.

 

 

[Student Pilot]

For the price this will retail at you will be able to buy a Bonanza and take 4 of your friends with you.

[RFguy]

I'd buy the bonanza . And a J160 for when I wanted to go cheap, and hold my J160 to a high maintenance level. (WRT- Bonanza) -  I feel older certified aircraft are very good value for money , with their advantage of 50 years of knowledge about them and most bugs known.... These days I probably wouldnt touch a factory built aircraft model any less than 10 years old- it hasnt had enough time to accumulate some ADs !

Edited January 18 by RFguy

[facthunter]

The floats analogy was only about high drag take offs and the Schneider trophy was a big international deal where engine power thrust and and speed was the thing. (like Reno).  RFguy, corrosion and maintenance is  the thing with planes like Bonanza's.  A brand new on would be the duck's guts but what would one cost these days.?  I flew a new  A-36. Nev

[skippydiesel]

I have always liked Bonanzas' but even if I could afford one (which I can't) I would never be able to fill the seats - one of the reasons I moved to RAA was lack of passengers - good decision/no regrets. I have often thought about going single seat but like the little bit of extra room in a 2 seater.

[pmccarthy]

That second seat is where you put your flight bag.

[facthunter]

You don't mean your girl friend , do you?   Nev

[Rapture]

23 hours ago, skippydiesel said:

The Rapture Bug looks to be a single seater - is this correct?

 

If so, it's only going to be attractive to a very small market.

 

I would like to see the following:-

Performance verified by a third party (for a given engine).

Empty weight

Fuel capacity

Max TO weight

Stall 55 Knots

 

It it amazes me, that an Australian made/modified, Rotax 912 ULS powerd, two seater aircraft exists, with third party verified performance (252 Knots), 40 Knot stall, known fuel capacity (103L) & payload (90Kg adults x 2 + all camping equip) and  and its basically ignored.

 

 

Yes, the Bug is a single seater.

 

A small but steady market is all that is needed to make it a viable proposition.  Through my TurbAero business, I am very close to a lot of the kit manufacturers and have a very good idea about their delivery volumes and in some cases, the margins on their kits.  The advice of the manufacturers that I have received will be extremely helpful in making the determination whether a kit/RTF Bug could be a viable business.

 

Validation of the existing flying Bugs performance would be straightforward.  We have both TAS and GPS readouts to confirm our numbers.  The only record of a third-party validation of the performance of a Bug was back when it was first released in the 1990s.  The prototype, fitted with a 90hp two stroke engine participated in the Sun100 air race at Sun 'n fun airshow.  While the Bug did not finish the race because the engine grenaded, so officially, a speed was not recorded for the Bug, it was noted that before the engine failure, it was easily overtaking the Glasairs etc that finished with a recorded average speed north of 240mph / 209 knots, with the Bug pilot noting that he was indicating around 250mph at the time of the engine failure.  That said, we are building up a new build Bug from carbon that will be much lighter than the existing Bugs.  It will also be tweaked for the engine installation so performance should be better than the currently flying ones.  We will focus on getting verified data from that new one.

 

As for Robin Austin's Sonerai, Robin has done an amazing job in tidying that airframe and achieving the performance that he has achieved.  However, the performance that you refer to and for which it has achieved world records for is not ktas, it is knots ground speed, i.e. with wind.  Robin clearly states in his write up for the aircraft (refer Sonerai World Record Plane - Robin Austin) that he achieves an honest 170 knots cruise at maximum continuous cruise power with the stock 100hp Rotax 912ULS.  That would intimate a full power maximum straight and level speed in the region of 175-180 knots.  Our stock Rotax 912ULS powered Bug exceeds that, but we are not comparing apples to apples because the Bug is a single seater.  That is not a fair comparison.  Again, I reiterate that Robin has done an amazing job on a 2 seater.  The climb performance of Robin's Sonerai is also exceptionally good for a Rotax powered aircraft, also testament to his attention to drag reduction.

 

FYI, the following text has been cut and pasted from Robin's website about his aircraft.  He gives a summary of the cruise performance capabilities of his aircraft:

 

As the speed envelope expanded, the need for an In Flight Adjustable (IFA) variable pitch propellor increased. Problem was, there are none available that suit Rotax’s low propellor RPMs and SGS's speed range. Fortunately, I became involved in the development of a brand new, IFA propeller with a leading propeller manufacturer Bolly Props Australia and was afforded a clean slate re blade design. After a year of solid engineering, development and static and dynamic testing, the prototype propeller flew. The utility of SGS was further transformed and with the new propellor and other airframe improvements it now climbed at 1920 ft per min with a maximum cruise speed of 170 knots. This speed is not particularly economical however, nor used frequently for regular cruising. 

 

Cruising speeds of 160 to 165 knots are more practical, economical and without any turbulence constraints once above 8000’. 160 knots cruise is achievable up to FL140 and provides added flexibility to stay above most weather (& yes, SGS has mixture control and oxygen). At 160 knots, engine RPM can be as low as 4600 and fuel consumption is typically 16 litres/hr depending on altitude. Cruise speeds reduce with increased loading, however even when carrying a passenger and baggage, 160 knot cruise is still practical between SL and 10,000'.

 

That text gives some context to the true cruise capabilities of his aircraft.

 

[facthunter]

There's no assurance of smooth air above 8,000 ft. The Inversion layer in the centre of Australia is often above fl 120 in the afternoon.  Nev

[Rapture]

52 minutes ago, Arron25 said:

So.. dumb question... Was there ever a design consideration for a two seat tandem variant of the original Lightning or the Raptor Bug?

Not a dumb question at all. With our consideration being given to the 66 sq.ft. wing for the Rapture Bug, we are considering the same wing for a tandem Bug.