The goals of the project are :
Minimum requirement out of the box is 500 nautical miles. Targeted objective is 1,000 nm. We need to be able to get to the larger airports from small rural fields; at this point I'm not interested in transcontinental performance (I've flown from Hawaii to California in a turboprop, seriously, get a ticket on a jet for the long haul).
The intent is to allow the operator to make two round trips before having to refuel, each round trip to be approximately 200 nautical miles in length on average.
Initial range and performance to be done with Jet A, or the current commercial equivalent. Once we have that, then we can do a trade study to switch to ethanol or bio-diesel. From what I've read in the trades, hydrogen is a long way down the line, but I can buy ethanol today.
Twenty paying passengers with two air-crew. I'm not familiar enough with part 135 operations to know if a cabin crewmember will be required.
Remember, this is an air-taxi and not a scheduled operation we are supporting. Therefore, twenty seats may well be at the large end. My thought is that at ten seats and below, we are competing with Cessna and over forty seats, I think we go head-to-head with Bombardier. I don't have any real data that supports my assertion that there is a hole in the market at twenty seats, but that's my feel. Clearly, we want to stay out of the hundred seat (give or take twenty seats) market.
Building a four to ten seat personal airplane is very do-able. Getting a twenty-seat airplane built for commercial use is a very different project, but still in the range of quite feasible. We aren't talking billions of dollars here. In fact, with good academic support we may well be able to build the prototype for very little indeed.
Tentatively planned to be a Pratt and Whitney PT-6 of some form or other. The reason I am specifying a turboprop instead of a small turbofan is because of the short, soft field that I expect to be a significant part of air taxi operations all around the world. Turbofans have a bit of a lull in acceleration, which can be operationally significant. I'm willing to trade performance at altitude for better short runway performance. As for other engines, I'm perfectly open to whatever you guys have data for.
The initial configuration, the baseline if you will, is a high-wing, tricycle-gear, three-surface turboprop with the engines situated above the wing in the same manner as the YC-14 and the QSRA for upper surface blowing.
The trailing edge flaps are single slotted and plain with variable camber Krueger flaps on the leading edge. This is entirely notional at this point.
The main deck of the aircraft is the upper surface of the broad keel beam that forms the structural backbone. A "crown beam" extends from the wing center section forward to the cockpit (41 section) and aft to the pressure bulkhead at the end of the 46 section. The main and nose landing gear attach to the keel beam.
The keel-beam volume is to be “protected,” or blocked from penetration by other systems in order to be able to use that volume later in the program for extra fuel.
There is no cargo deck, no separate cargo compartment. Baggage is all carry-on to be stowed beneath the passenger's seat, in the overhead bin or in the closets. There are still unanswered questions about what to do for skis and golf clubs.
The seats face aft for better crashworthiness. Seats are designed to allow baggage tucked underneath
The body resembles the Piaggio P-180. The intent is to get some lift from the body, or at least a very nice nose-up pitching moment.
After exchanging emails with John Leslie of the UK, we are adding some cool features:
Multiple large and powerful landing lights with big off-axis taxi-lights as well.
In lieu of an FMC, add a GPS/IRS moving map like the Garmin’s G1000.
The cockpit windows are all interchangeable so that a crack in a windscreen won’t cause a grounded aircraft. Just shift that pane from the front to the side and re-dispatch.
Large, aerodynamically-balanced control surfaces for good low-speed control. No wing spoilers for roll control, just ailerons. No hydraulic boost, no fly-by-wire, just manual control.
The tires are big and soft to operate out of grass fields. The mains are duals using the same tire as on the nose. Gear is retractable.
A large main-deck cargo door forward of the wing on the freighter, combi, and air-ambulance variants. (A “combi” is a Boeing term for an aircraft that is designed to fly both passengers and cargo on the main deck at the same time.)
The aircraft is designed for pressurization, but the initial model likely to be designed and built without the air-conditioning pack for systems simplification and weight.
Single-pilot certification for cargo-only.
We are still discussing whether a lav should be on-board or not. The comfort argument is obvious, but the weight and complexity argue against it. Perhaps the best thing to do is to block out space, structural, and systems provisions for a lav, but not to design it in on the initial models. Anyone have any thoughts?
The guy behind the project has setup the world airplane blog http://worldairplane.blogspot.com/