VTOL Supercruise Tandem Wing Airlifter
(The nondelivery, instrument-pallet variant could be called MissionHawk
(This entry--one of 17 that I initially submitted--was originally named SpeedHawk
). This aircraft features a blended and contoured fuselage more integrated with the wings.
Inspiration for the design
: I was originally inspired by wing suits, flying squirrels, butterflies, several large-wingspan birds, and other natural shapes such as sea creatures--dolphins, plesiosaurs etc.; plus early successful tandem wing experimental gliders. I also have an appreciation for certain composite canard aircraft. Beyond that, I took some interest in 1950s multi-winged rockets--early space shuttles really--that at the time were predicted to be the type of craft that would eventually reach the moon.
Ultimately, I chose a tandem wing for several solid practical reasons, which give this design certain advantages relevant to the specific mission requirements of the aircraft type requested for this challenge.
In a tandem wing configuration, both wings generate lift. Both moments are countered by a delicate balance among moments, placement of the wings, and the CoG of the entire aircraft.
In the past, for designers and engineers to achieve this delicate balance may have proved more difficult that the endeavor was worth pursuing. But here today, with the aid of modern computers, especially with the unique problems to be solved for this particular aircraft design assignment, I believe the time has come for the tandem wing.
Perhaps the most important feature is--like with canards--tandems don't enter unrecoverable stalls; and without a stall, there can also be no spin. (For more on this, scroll down to 'Failsafe Components
Another advantage is efficient space management. With a tandem wing, the overall dimensions of the aircraft--particularity wingspan--can be smaller for the given cruise and glide lift generated. This means smaller hangar space, smaller and safer landing zone footprint, and potentially easier disassembly, storage and transport.
Explanation of Design Details
: Lift props are integrated and flush in the wings for improved aerodynamics, and especially for added safety.
A rear prop guard/shroud is included also for safety considerations.
The tail vertical stabilizers are 'tipsails'--drag-reducing wingtip sails--or winglets--with integrated rudders providing all of the aircraft's directional stability and control, in place of a less attention-getting conventional tail. In addition to certain other advantages, this allows unimpeded ease of access and maintenance for the rear pusher motor and its prop shroud.
is fixed in place for simplicity but features some shock absorption properties inherent in its structure. The forward landing gear is mostly an open wire frame structure, so that air may pass through it without it acting like a forward rudder which could result in yaw instability.
The lower rear landing gear is a pair of fins (which may include additional rudders if deemed desirable to augment the tipsails). These lower landing post fins each also feature an integrated internal flotation device as part of the inherent structure. Their lower ground-contact surfaces could have a rubberized coating.
Regarding 'weatherproofing' or 'weatherproofness'
-- the modern structure is created with tight tolerance, so that the computer-designed-and in some cases 3D printed--parts fit exceptionally well together. Additionally though, there are synthetic gaskets where necessary at joints and connectors to keep out moisture, sand and dust.
Modularity/Shippablilty/Ease of handling
: The aircraft easily breaks down into several major manageable-sized components--connected with rods and high-precision designed and fabricated push joins. The entire aircraft can be carried by two typical people, broken down with only five minutes of training, and placed into its specially designed protective shipping case. Two of these aircraft will fit into a Sprinter-type cargo van.
: The 25kg target is observed. Lightweighting is achieved through design and materials/structure. Composites and smart 3D printing--creating empty structural voids where there can be--are employed to this end.
: In addition to having a standard parachute onboard, perhaps the most significant airworthiness reliability feature of this design to prevent catastrophic failure of the mission is its virtually stall-proof tandem wing configuration. Specifically:
Upon nearing a stall condition, unlike with conventional aircraft, with a tandem wing this is what happens:
- The wing with the highest wing loading gets closer and closer to
its point of stall. This also provides time and the possibility for the
remote pilot to react. Otherwise, though, even then only the one wing will enter a
- The wing enters a stall. Although here, in tandem wing
configuration, the front wing will stall. The result is that the nose
drops a bit--but the rear wing is still holding the airplane
up somewhat. It can't hold it up completely, so the aircraft will
sink while its nose drops a bit--but this lessens the angle of the
aircraft and its wings...so the wing
lifts again, once the angle is good enough, and the nose
rises again. The remote pilot (or onboard AI eventually?) gets another change to react to the stall.
- The result is that a wavelike movement is entered--sinking gradually
while the nose is going down and up again. In a loss of power emergency, this situation can be continued to use it as a kind of hard controlled
descent. Or otherwise there is just more time to react to this event, by recovering engine thrust and
giving more power, or to lower the nose. The point is, there is a much longer timespan in which a remote pilot is given a greater chance to successfully manage a problem.
In addition to the lift rotors being housed in guards integrated within the wings, the rear pusher prop is contained within a shroud/guard to prevent the stationary blades from being touched (especially by children) while on the ground.
There may also be a laser projection ''landing zone grid" that brightly--even in daylight--appears as a laser vector (even animated) projection outline on the ground immediately before the aircraft touches down--warning people on the ground to stay clear of that area momentarily. There can also be audio and video projection and a two-way comm system for the operator. This all may be located in the forward transparent lower camera pod area.
: An auxiliary cargo door is featured on top for easy manual access if desired for the cargo box loading and unloading, while in one possible scheme the lower 'bomb bay' style doors open for automated delivery of the packages, and can also be utilized as a loading point from below, as per the project specification requirements.
Another option may be opening a side door in the mid to lower fuselage--then pulling out a drawer. The front of this structure may drop down laterally to facilitate loading and unloading of heavier cargo.
For automatic cargo loading, laser guidance may be used, and a mobile robot pallet--which I call RoboP.A.L.S.--for Robotic Palletized Automatic Loading System
, perhaps featuring tracked treads around its wheels for rough 'in the field' loading--would be available. Much of this system could be fielded using existing 'off the shelf' technology. (I can provide sources and references for these components upon request.)
Otherwise, a third cargo loading/unloading option would be a side-opening door with a pull-out cargo drawer.
All cargo schemes feature securing panels (and dividers if necessary) that are spring loaded to hold the cargo box in place with sufficient lateral pressure until delivery. This also prevents smaller loads from shifting. Molded-in guide tracks in the cargo door and cargo bay area are also there to augment securing of the cargo. These guide tracks in the doors may also help gently auto-dispense the cargo box using just gravity and friction.
The cargo bay may be climate controlled and insulated like a cooler to keep medicines--or transplant organs, etc--fresh. Otherwise, the delivery box itself may set up to function as a cooler.
Optional chrome trim embellishment may be specified, as at some point 'styling' may become some factor as a sales tool in the decision-making process for private (nonmilitary and nongovernmental) users.
More specifically, in a future competitive drone segment, I expect that eventually, much like has ultimately happened with automobiles and now private general-aviation aircraft, aesthetics may become more of a selling-point consideration beyond just engineering and performance. An organization may wish to be more closely associated with a 'cooler,' more slick-looking drone over another more dowdy or 'purely functional' looking one. (Think UPS, FedEx, etc.)
They may even desire an additional profit stream by selling miniature toy replicas of their 'awesome' drone with their corporate logo on it; or for marketing purposes, hand them out as promotionals at trade shows, etc.
Pastel colors--'friendly' schemes--could be specified, to make less concern for people on the ground when sighting this particular drone. (e.g. 'the shiny pastel peach and chrome' ones are not attack or surveillence drones.)
There could also be large 'Airlift Angel' wings pained on the bottom, symbolic of 'relief from celestial beings of the sky...'
In addition to numbering each aircraft and having them may be all different colors, each could be named--perhaps after nurses; e.g. "Florence Nightingale" or "Clara Barton"--in the same spirit that Disneyland names their trains--and Pan Am named each of their 'Clippers' individually as well.
This aircraft still adheres to the requirement of having bottom-side access for the cargo module; yet in addition features a loading door/cargo access on top, for improved ergonomics when direct interface with human users is involved, vs. still allowing for full automation of cargo management from below. This allows for the best practice of either loading scheme.
Work in progress...more to come. (I do have up to sixteen entries in progress...testing both digitally and with foam gliders etc...I'm something like 400 hours into all of these by now...stay tuned.)