Veloce 600, 6 seat pressurized twin auto-converted engines.

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Alessandre

Well-Known Member
I got surprised with this model that I occasionally saw in my facebook today, this is a new model with twin aeromomentum engines:

PRESSURIZED VELOCE 600 TWIN – Aeromomentum 260 HP / TIO-540 270 HP

Cruise speed Stall Speed Climb Rate Range 35,000 ft 302 knots 35,000 ft 302 knots 57 knots w/flaps 69 knots w/o flaps 59 knots w/flaps 71 knots w/o flaps 2285 ft/min 1 engine 1020 ft/min 2200 ft/min 1 engine 1000 ft/min 2289 NM IFR w/R 1950 VFR 2100 NM IFR w/R 1850 VFR over 50 foot 1130 ft over 50 foot 1280 ft over 50 foot 1120 ft over 50 foot 1360 ft 2200 lbs 2600 lbs 1600 lbs 1200 lbs 35.5′ 35.5′ 27′ 27′ 9.9′ 9.9′ $100,000 – show special$100,000 – show special

In my opinion 2 auto-converted engines could solve the issue of less reliability of the auto converted engines keeping their low maintenance cost.

"Want a 6 seat pressurized plane that does 302 KTS at 35,000 ft or 270 kts at 25,000 ft, burning 22 GPH of AV or MOgas for $220k all in if you build yourself in 1200 hours.$220k your cost all in for engines, avionics, interior, gear, and kit? You assemble in about 1,200 hours. Kit is $100k for composite parts (full list of prices for what is needed below) Or fully completed ready to fly for$500k with really nice options.
Electric de-ice, AC, Garmin dual glass panel suite and auto pilot, custom paint job of your choice, custom interior of your choice, and more.

aeromomentum

Well-Known Member
The performance specs seem pretty optimistic. Not going to go 300 knots on 22 gph IMO. Climb at 1000 fpm on one engine with apparently FP props? Electric de-ice with piston engines and alternators- hmmm not with a composite structure unless electro-pulse type which isn't cheap and needs aluminum skins to my knowledge. Probably not going to weigh only 2200 pounds empty either with at least 600 pounds of powerplant weight here.

Why don't designers wait until the prototype flies before releasing numbers? Neither of these engines are proven to fly at 35,000 feet. That's a tall order if you've never done it before.

Range doesn't add up with 6 aboard, baggage etc. At most, 3 hours of fuel at 22 gph, 900 NM. Maybe with 2-3 people aboard.

Edit: It seems Mark from Aermomentum designed this plane. I respect Mark but don't believe these projected numbers will be anywhere close to actual ones. That WOULD be a revolution if it does. Wish Mark the best on this project anyway and hope he proves me wrong.
Yes it will go 300 knots on 22gph. Case in point, the similar weight Lancair doing 291 knots on 17-18gph.
The props will be constant speed and we have been talking with a few manufacturers.

As the designer, I did not release any numbers. That was the marketing person.

Initial engines/turbo are to max performance cruise power at 24kmsl like most turbocharged aircraft. But engineering data looks like 35k is about the limit with these engines and single stage large turbos.

Like almost all (every?) aircraft, the maximum range is at reduced payload and at an economy cruise not max performance cruise.

aeromomentum

Well-Known Member
FYI, our program is starting with a proof of concept fixed gear and non pressurized version. Only after this as flown and completed a real test program will we add retracts and pressurization.

TarDevil

Well-Known Member
Flown with pilot only, is ballast required to stay in CG?

Vigilant1

Well-Known Member
The projected single engine climb rate is 45% of the projected two engine climb rate. Is there another existing twin that can do this? The implication is that this design, at its 3800 lb MTOW, requires only 2.5% of the installed power (about 13hp) to achieve level flight at Vy and also that single engine asymmetrical trim drag will be very small.

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tspear

Well-Known Member
Mark,

We talked about this design a number of years ago. Nice to see you are finally going to make it happen.

Tim

aeromomentum

Well-Known Member
The projected single engine climb rate is 45% of the projected two engine climb rate. Is there another existing twin that can do this? The implication is that this design, at its 3800 lb MTOW, requires only 5% of the installed power (about 26hp) to achieve level flight at Vy and also that single engine asymmetrical trim drag will be very small.
The 1020 ft/min single engine climb is what I calculated. The two engine rate of climb should be about 2850 ft/min. I think the 2285 was a typo. So this is about 10.5% of the installed power (55hp) to maintain level flight at best L/D. This is not uncommon for a very clean high installed power aircraft. I did not take into account the drag of a feathered prop or the trim drag. Yes, there is less asymmetrical thrust than conventional light twins due to reduced prop spacing.

aeromomentum

Well-Known Member
I very much like the comments and am open to criticism! Hopefully constructive. I would rather find flaws now than during flight test. I also do not mean to come across as a know it all defensive or over confidant in my design/calculations. I have been working on this design for some time and have had a few other engineers look over my work and provide useful changes but no one can think of everything or be right all the time.