Excerpts on the Grasshoppers, Sentinel and Vigilant, book by Reed Kinert
EVEN THE light plane has gone to war. These small planes now follow their civilian pilots into uniform. They have proved their worth under grueling field tests and in the face of considerable skepticism.
The War Production Board has now ordered manufacturers to deliver all planes with less than 500 h.p. for use only by the Government, by our Allies, or by civilian organizations engaged definitely in war work. There is a strong feeling that the “Aerial Jeeps” should be flown by non-Air Force pilots, because Air Force pilots are more at home in heavier ships and because their very costly special training is not necessary for light-plane operation. Light-plane pilots could be trained quickly, and by the Army ground organizations. This whole question is still under consideration.
Easily maneuverable in small areas, these little liaison craft hop over rough country, skim the treetops, peer right down into the remotest areas, and bring back, or radio, reports that are the basis for tactical movements by the ground forces. Without these bird’s-eye views of terrain and the minute detail that can be secured by flying close to the ground, military planning is restricted in modern warfare. Quick troop movements to the right places may easily be planned from aerial observation.
In the picture on the opposite page [below] are the L-4B Cub, built by PIPER; the Defender L-3B (left background), by AERONAUTICAL CORPORATION; and the L-2B (right background), a TAYLORCRAFT. All three are powered by the Continental or other 4-cylinder, 65 h.p. engines. Top speed is 75 to 85 m.p.h., each design differing a little, and cruising speed is 65 to 70 m.p.h. Construction is similar in all three makes—steel-tubing fuselages, fabric-covered, and wings of spruce spars with either wood or metal ribs, fabric-covered. Gross weight of each runs about 1100 pounds, and range is under 300 miles. Wingspreads are all about 35 or 36 feet.
The production of these little planes formerly used by sportsmen means that private flying, in a sense, is being kept alive in America—the only belligerent nation where this is true.
SENTINEL · STINSON L-5
NEW TO THE RANKS of the Army’s liaison-type craft is the STINSON L-5. It is replacing the VULTEE-STINSON L-1. It is much smaller than the L-1 and can perform the same duties, its smallness allowing it to be less conspicuous; it also operates much more economically, with less fuel and less maintenance.
The Sentinel is a redesign of the commercial Voyager 105 three-place private plane and looks very much like the Voyager except for a modification about the rear of the cabin, where extra clear plastic has been added for increased vision in its military duties.
Wing leading-edge slots and large trailing-edge flaps enable the Sentinel to take off and land in a short space. It is powered with a Lycoming 190 h.p. 6 cylinder opposed engine and should have a substantial increase of speed over the Voyager, which was powered with a 75 h.p. engine and which had a cruising speed of 109 m.p.h. No performance details have been released on the Sentinel.
The fuselage is constructed of welded steel tubing faired to a streamline contour with wood strips and covered with fabric. Wings are of solid spruce spars and aluminum-alloy ribs. Tail surfaces are of welded steel, fabric-covered. Wingspan is 34 feet, length is 24 feet, and height is 6 feet 6 inches.
Two-way radio for communication with air and ground forces should prove valuable while hovering near objectives. During World War I these duties were handled by the vulnerable “sausage” balloons. Liaison planes such as the Sentinel are painted completely olive-drab instead of having the undersides painted light blue. This type flies so low on its missions that it is better camouflaged among the trees and hills in its all-drab coat.
VIGILANT · VULTEE-STINSON L-1
THE VULTEE-STINSON L-1 is the grandfather of all the liaison aircraft in use by the U. S. Army.
It is no longer in production because it has been found that smaller craft could do the same duties with less horsepower and, as aircraft materials are scarce, the saving is substantial.
The L-1 can land much more slowly than the smaller liaison craft, with the possible exception of the new Sentinel built by the same company. To see a Vigilant land sends cold chills up the backs of pilots who are used to seeing planes land at 35 m.p.h. or faster. With its full-length automatic wing slots and trailing-edge flaps, the “Swoose,” as it has been nicknamed, comes in at a steep angle, levels off, and plumps gently down at 10 m.p.h. It can land at zero in a ten- or twelve-mile-an-hour wind, and in a stronger wind it could be brought in to land while going backwards over the ground! The plane is very hard to stall, and in a stall one simply relaxes the stick pressure and the plane recovers nicely by itself.
The Vigilant is a high-wing monoplane and the cockpits are enclosed with a large greenhouse canopy for good vision. Like other liaison craft it was designed for cooperation with the infantry, artillery, and mechanized units. It can also be used successfully as an ambulance plane because of its ability to get in and out of small areas.
It is powered with a 295 h.p. Lycoming engine and has a top speed of over 100 m.p.h. Wingspan is 51 feet, length is 34 feet, and height is 10 feet. The fuselage is built up of welded tubing and metal stringers and is fabric-covered. Wings are of metal spars and ribs, fabric-covered and the tail surfaces are also built up of metal, fabric-covered.