Electric S.T.O.L

The articles of Chris Wharton, in your magazine, were always interesting and also inviting discussion. His story of the Woomera, the spear thrower, the leg bone of a kangaroo. The elegance of a boomerang design and build, from the cross shape to a flying wing structure. Cpt Cook is reputed to have swapped an axe for a boomerang, which became the master design for boat propellers. This enhanced the industrial revolution for Great Britian, if you like,changed history.

The following is my take on Ducted propellers,' have seen articles on a speed limit of ducted fans being around 100 knots. Except I have seen model ducted fan aircraft, a pseudo-jet, easily top 200 mph. The take of run of these little petrol engine units is very,very short. These little 70omm ducted fans are rockets.

We saw as children a S.T.O.L. Sea-Fury with the multiple bladed propellers,from an Air-Craft carrier. The Sea Fury gave the carrier protection from attack. The noise of the two propellers lining up while rotating was almost as loud as a helicopter. Obviously this was at the end of W.W.2. when everything was on display.

At present we have the Hawker Harrier Jump Jet, showing the capability of a movable thrust and the Molner air car with the movable thrust from boxed propellers. Another article on a V.T.O.L. aircraft, the American Osprey,using a jet engine on the end of each wing, driving a huge three bladed propeller. The jet engine and the propeller being able to pivot from horizontal to vertical.

The rotation of the engine and propeller gives a vertical take-off and like a Harrier changing the thrust direction to forwards, drives the aircraft into horizontal flight. The Osprey is a large aircraft capable of carrying as much or more than an Iraquoy, a double rotor helicopter. An Osprey in level flight capable of three hundred mph, a very strategic unit indeed.

The articles on ducted fan being developed in the Czech Republic with a 1,000 rpm increase lifting the thrust from 50kg to 70kg. A duct of 0.45m diameter giving 70kg thrust is an impressive number and usefull on light aircraft. This leads to the Martin Aircraft ducted fans, with a different blade shape, with better than double the thrust of the Czech units. A much bigger power supply is needed for the Martin units. About a hundred years ago a New Zealander Ernest Rutherford was a world leader in Particle Physics, the Ducted Fan technology of the Martin company may be as significant.

An article on the Sonex aircraft with their development of powerfull electric motors and controls is the start of different air craft. The large passenger planes mostly have a jet driven powerplant at the rear of the fuselage. The air intake is somewhere near the rudder and the residual thrust adds to the plane's speed. These jet driven power plants are about as efficient a power producer as is possible. Metropolitan areas rely on large jet units to take up peak loads, as they can start and stop quickly in minutes. Natural gas as a fuel supply and are relatively quiet. I can remember an article on a jet plane power plant that had achieved a million hour life,still going. If the metropolitan area units last as long and are as efficient, what a money maker.

All of which leads to using a jet power plant to power Sonex type motors, to power ducted fans to give a different air craft. Some city and suburban areas already use helicopter transport, so a better thing could/would be used. As a Sonex motor weighs 50Ibs for 50 hp,I am not proposing a light air craft, more likely a commuter type air craft. Unlike the Osprey rotating the propeller at the end of the wing, have a shorter wing and rotate the whole wing. Not 90 degrees maybe 45 degrees, so that like a flap control on a fixed wing, slow flight and an increase in lift co-incide.

Short wings could mean a changed shape, with the pilot central and at the front,a single seat. Behind two seats and then four, then luggage then the jet generator. Perhaps have three sets of wing stubs, front middle and back, each with ducted fans at their end. Just as the Martin Aircraft single seater uses a Recovery Chute, so this vehicle would too.

When I started this I considered it just on the edge of possible. The November Top Gear magazine has an electric Jaguar sports car with two jet generaters in the back. Each provides 70kw of power at 80,000rpm on almost any fuel and made by Bladen Engineering of Britain. Also in the same magazine is an article on the Martin Jet pack. So rather than being in the fore front, in all probability various Skunk works have already achieved a new type of S.T.O.L. aircraft.