@glum
Regarding your design...
With an AUW of 7500kg, we have a payload of 2500kg. Not great when compared to some of the pure helicopters in that range!
I agree with 212man that these seem optimistic. In general, I find historic structural weight of aircraft to be roughly 1/3 for fixed wing and 1/2 for rotary wing, +/-. The remaining 2/3 and 1/2 is fuel plus payload. Any performance projections significantly better are usually based on stripped down aircraft, or expections of some future breakthrough in materials or engines. All our work is done at current, off-the-shelf, component and subsystem technology levels to enable an apples-to-apples comparison.
Range of 750nm, ceiling of 25,000 feet and cruise of mach 0.55.
Range and ceiling are what one would expect for a tiltrotor, but cruise mach seems optimistic. Physics caps efficient fixed diameter proprotor aircraft speed in the neighborhood of 200kts to 260kts. Squared/cubed law pushes cruise speed higher for heavier aircraft, but for 7500kg would be closer to 200kts.
A methodology for sizing rotorcraft was developed and reported in the following U.S. Government report,
http://www.baldwintechnology.com/FY0...ign_Report.pdf , and was implemented in a MATLAB program.
Are you looking to certify in CS 25 and CS 29?
Actually, I'm looking to develop a community of overwhelming support that motivates action towards a sustained U.S. Government development program. I've been successful so far with cadres of support in the US Army, Marines, DoD, and Congress which pays the bills on a year-to-year basis. Seems to me a military demonstrator preceeds civil certification.
How big will the final aircraft be?
Our initial concept studies in 2004 spanned from 2ton to 20ton payload. We then created a conceptual/preliminary point design at 3000 lbs payload (9400 lbs gross weight), and have developed a lot of engineering and CONOPS data on this design. We're currently flight testing at 10-15 pounds.
Does there need to be a pilot at all, and if so, does he really need to be sitting where he can see the load?
Depending on the aircraft's application and the maturation of autonomy, a piloted configuration could likely be needed. For weight and balance a cockpit is best located forward of the mast in hover, particularly for smaller configurations where the pilot's weight impacts balance. On the other hand, the U.S. Marines are testing unmanned cargo helicopters, and the U.S. Navy is testing the VTUAV. Pilot location is less critical if tasks are more managerial than hands on sticks. To cover all our bases, we've began working with acedemia on some tremendous breakthroughs in helicopter autonomy.
Can you land in conventional aircraft mode, or does it have to be helicopter?
The design has tail dragger landing gear configuration on the airframe. We will likely test forward flight horizontal landing with the mast vertical using our small RC functional flight demonstrator.
I'm sure there will be many more questions after I've read the info fully! Best of luck.
Thanks. Anytime.
Doug