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FLYING December 1950http://www.angelfire.com/ks2/janowski/other_aircraft/AG14/flying.html



Anderson-Greenwood AG-14

By Ed Hoadley

A PILOT of a B-29 bomber once said, in telling his old daddy how it felt to fly a big airplane, "You just sit on the upstairs front porch and drive the house around." That's the feeling I had while driving the new Anderson Greenwood AG-14 pusher airplane around the towers of Houston, Tex. The word "driving" is intentional.

Its looks are completely unorthodox and are guaranteed to stop operations at any airport while everyone looks it over. It also creates a sensation inside the pilot who flies it.

Before World War II in Houston, Tex., three young aeronautical engineers got together and formed a small company. Their purpose was to manufacture a small tandem trainer. Through the war years as Boeing engineers in Seattle, Ben Anderson, Marvin Greenwood, and Lomis Slaughter sweated on a problem of magnitude: what is the perfect lightplane?

It should have comfort, performance and utility with safety. They figured the only way to increase visibility and ease of entrance was to stick the propeller and engine in the rear‹which resulted in a pusher type. This also was the way to knock out propeller danger. It meant chopping the fuselage off and making it a "body" (which term is now standard in describing their fuselage). It meant twin outrigger booms such as Lockheed had employed on the P-38.

Along this same line of safety was the need for a tricycle gear. It was needed for (1) the elimination of groundloop, (2) the minimization of "bounce," and (3) adaptability to auto-type steering on the ground.

Aerodynamic problems placed the wing up towards the roof of the cabin in line with the booms. A high aspeet ratio wing (NACA 4418) with thick section contributed to satisfactory lift and unusually stable stalling characteristics.

The first test model of the AG-14 performed exactly as the three slip-stick artists had calculated. Not content with this model the current production model of the AG-14 has been conceived, manufactured, and jigs set up for the initial production of five like it. Only one problem remains. It is still unnamed.

Marvin Greenwood, who was in charge of flight testing the AG-14, was assigned to ride with me on our six flight checks. Getting into the airplane is one of the easiest things I've done in months. You simply sit down on the seat, pull your legs in, and you're ready to depart. Women pilots and modest wives may now enjoy the pleasures of flying without the singular embarrassments that they have encountered in the past.

Cockpit procedure is quite conventional. Aside from the gas shut-off valve being located in the rear of the cabin, everything is in its usual place. The instrument panel is quite simple and contains only the usual flight and engine instruments.

Master switch is pulled to "on" position, two shots on the primer, and after the foot has depressed the starter button, the key switch is turned on. Then the engine starts rumbling in the rear end. The oil pressure has to travel a long way to the instrument panel, so it takes some 20 seconds for the pressure gauge to react. It takes some 40 seconds for pressure to come up.

Taxiing this dragon-fly is just like driving a car. The control wheel steers the nose wheel, and without a propeller whirling in front, I felt just as if I were moving down the runway in an enclosed motorcycle sidecar. There is a tendency to drive too fast but the tricycle gear takes care of sudden stops.

The two-position flaps are mechanically operated, and actuated by a flap handle located on the floor between the seats. I moved the handle to the first notch from the floor, and with steering wheel well forward jounced over the turf.

Marvin told me the trick of taking off is to hold the wheel forward and steer it. As the airspeed approaches 40 m.p.h., the wheel is inched back. Anywhere along in here your rudders are effective. At 55 indicated the plane breaks ground and a normal take-off is completed.

As you gain altitude you look around and catch your breath. You seem to be looking down from the edge of a cliff. You miss that big expanse of engine cowl mercifully hiding that solid-looking ground. Down and forward visibility are awesome. You want to pull the nose way up to hide all that extra ground down there. One problem is that the Plexiglas bubble covers so much frontal and lateral area that there are no reference points. You cannot tell exactly what the attitude of the airplane is.

The large triangular plastic side vent finally gave me the reference point I needed for climbing correctly. The airspeed indicator gave a secondary reference at 75 m.p.h. for proper climb. I levelled off at 400 feet, moved the flap handle to "up" position and waited for the usual settling movement. None came. The altimeter didn't drop off at all.

I cleared traffic and as the thermals were troublesome I decided to go on up through the fleecy wool-packs to 6,000 for air work. During this climb a rate-of-climb indicator would have been quite handy. I checked the sensitive altimeter several times, and averaged out a 700 f.p.m. climb.

On the AG-14, the engine racket has been replaced by a flat quiet "buzz." The propeller churns away in resonating fashion, but does not interfere with normal conversation.

At 6,000 feet we levelled off. By this time I was beginning to enjoy the ability to see out and down. Trimmed up with the elevator trim tab, 2,350 r.p.m., 22 inches of manifold pressure, she cruised nicely at 105 m.p.h. indicated. She had no tendency to hunt, pitch, or yaw. The fins took care of directional stability. The rudder seemed to be a little on the loose side‹that is not sensitive to the foot touch; the aileron controls, on the other hand, gave me a quick reaction to any movement of the wheel. She was stable with hands and feet off.

I executed banks like a novice. My first banks to the left dropped the airplane some 200 feet and to the right gained 200 feet. There is a gadget on the nose that sticks out like a child's water pistol (the pitot tube). In desperation I seized on this as a reference point for turning movements. After a little practice I improved substantially.

I tried kicking full rudder without ailerons. Even with the rudder full in there was but little skid, then a dip to the side on which rudder was applied. I don't believe anyone could get an accidental spin out of a rudder gliding turn. Ailerons give a satisfactory bank with a small amount of adverse yaw at the start; throwing in rudder gives a coordinated turn.

The glides were quite simple. With carburetor heat on, throttle closed, and a couple of twists to the over-head trim control, she glided nicely at 75 indicated. The nose attitude on my Plexiglas reference point was exactly the same as in level flight. Engineering tests have proved that the airplane could be flown blind right into the ground in this glide angle without damage to the structure.

Gliding turns were also easy. Just have to remember that "water pistol" reference point on changing course. Slow flight was accomplished at 65 m.p.h. indicated. At this speed I had full control, even full cross-control control.

Power-off stalls, flaps up, occurred at 55 to 60 m.p.h. As the nose slowly came up to the horizon line there was a series of steady thumps and down the nose went. There was no tendency for the airplane to fall off on either side. Holding the wheel back through a series of stalls without rudder produced the same results. There is no tendency to fall off into a spin in either direction. Flaps down, the same thing held true. This plane is positively spin resistant.

During the CAA test rides last summer, Inspector John Paul Jones in charge of tests forced the airplane into spins from every attitude possible, flaps up, and flaps down. More than 50 spins were executed. There was never more than one turn accomplished, because the plane built up flying speed during the first turn and came right out of it.

Wing-overs and chandelles are accomplished in a conventional manner. Lazy eights and all maneuvers needing coordination can be done without difficulty. However, it should be mentioned that the airplane is in the normal CAR 03 category and is therefore restricted against acrobatics.

My first landing was not very good. Usually a pilot can blame his bad landing on having to "feel for the ground" because he cannot see it. My excuse for a bad landing was too big a view of the ground. Anyone who has ridden a rollercoaster in the front seat can sympathize.

Consequently, as I flared out and pulled wheel full back, we got a heavy jolt. Hanging on for dear life, I fanned rudder, then grinned sheepishly at Greenwood. The airplane had dropped about three feet on two wheels, then lowered its front gear, and slowed down to an easy lope. We had landed.

My next landing was a good one. I became used to the extreme vision and was able to form a mental picture of the different attitudes of the plane's body in relation to the rough turf. Here my reference point of the Plexiglas window was important. Just before landing, I pulled the nose up slightly to let the two main wheels take the load. As the airplane settled on them, I simply left the wheel alone‹did nothing. The front end came down almost immediately. I had proved on my first landing that I couldn't get the booms to drag the ground with the wheel clear back. After the plane was rolling on final run, the wheel is pushed forward to bring the steerable nosewheel onto the ground so that directional control can be maintained. The AG-14 is literally a car on the ground, complete with single pedal brake and steering wheel. My foot was even feeling for the accelerator.

Approaches with full flaps pose the same problem. The nose is dumped almost to a 45 deg. angle. Too much vision throws you off for a moment.

A word on the flap proposition. Take-offs with and without flaps are about the same, so that they are not essential for take-off. On landing they are not necessary, save to come in short over power lines or other obstacles. A novice may easily forget they are there.

I measured the take-off and landing. One take-off solo into a 10 m.p.h. wind measured 390 feet. A braked landing measured 195 feet from point of touchdown. This was at sea-level elevation.

It is pretty hard to sum up this unconventional, conventional airplane. It is definitely new, safe, and different.

The twin booms are of unusual design, being long, lean, and rectangular. Attached to the top of the booms are twin fins and a smallish rudder. Anchoring the booms is the horizontal tail plane. The elevator is hinged to this. The airplane is all-metal without external bracing.

The wing span is about equally divided into ailerons and flaps. An unusual effect is obtained from the unusually thick airfoil and small chord, coupled with straight stub wings and definite dihedral on the panels.

The fuel load of 23 gallons is contained in each wing stub, and it might be noted that the fuel system is entirely gravity feed; no fuel pump whatsoever.

The engine and cabin of the "body" are built around a keel quite like a boat, which structurally permits a full-height door. A Hartzell propeller, ground adjustable, is mounted to the engine with a small spacer. It is a direct-drive rig. As the propeller rotates, it misses the boom side by some 10 inches and the ground by some 14.

The engine itself is a Continental C-90-12FP, 90 h.p. It is cooled through large curving air ducts which lead the cooling air in under each wing stub and circulate it around the engine.

The passenger portion of the "body" is entered on the right in front of the wing stub. A large door opens to reveal a 44inch wide seat and unlimited leg room. A very small rubber knob between the rudder pedals connects to an electric starter. A large pedal to the right of the rudder pedals connects to equalizing hydraulic brakes on the two main wheels.

Appointments are in two-tone flannel gray with an abundant amount of soundproofing. The dash and wheels are low and permit one to see the ground some 10 feet ahead of the plane. The back of the seat assembly folds forward and presents an eight-cubic feet baggage compartment. This holds up to a maximum of 250 pounds. Above and to the rear of the seat is a large deck for holding maps and small items.

The usual extras are obtainable, over and above a tentative list price of $4,200.

By way of personal objection to the airplane, there are some details which might be rectified. Coordination could be a little worrisome until one becomes used to it. Rudder control is soft and spongy. In contrast, the ailerons are not as yielding, and I could not use full aileron without a drastic change in flight attitude. It ought not to be a difficult matter to equalize these pressures and make the rudders a little more positive.

The splendid vision is not entirely without its drawback. Did you ever try to aim a rifle with the front sight only? That gives an idea of the problem of reference points and horizon line. The pitot tube on the nose is something of an aid, as is the top corner of the triangle vent. However, until the pilot masters this plane two small strips of colored scotch tape would be of value in gauging attitudes. These should be placed in front of the pilot's eyes on the plastic enclosure, and could be adjusted to height. A rate-of-climb indicator might profitably be installed in the panel as a cross-check in climbing and gliding.

Adequate ventilation in the "body" on the ground in hot weather is a typical problem in ships of this weight, and has not been successfully solved. Finally, from the careful pilot's point of view, the fuel strainer bowl has been stowed under the engine. It takes some time to remove a left bottom aluminum panel to check this item, and a plastic square or inspection plate might well be installed.

The AG-14 is functionally well adapted to farm and ranch observation, pipe line patrol, aerial photography, and military observation purposes. It has stability, safety, simplicity, and amazing vision. The complaints of pilots that airplanes haven't changed much in the past 15 years are definitely answered with the AG-14. END -------------

EDITOR'S NOTE
This series of articles is planned to help the pilot and prospective plane owner evaluate aircraft now on the market. Only aircraft holding a CAA Type Certificate are flown. The authors evaluate each aircraft though the eyes of the average private pilot who flies a plane for business or recreation.

Captions:

Photo 1
The AG-14 tops 120 m.p.h., cruises at 11O, and lands at 49. Rate of climb is 700 f.p.m. with Continental 90-h.p. engine. Tentative price: $4,200 to $4,500.

Photo 2
Author shows handy brake, starter; says AG-14 drives like car on ground.

Photo 3
Eight cubic-foot baggage space in back of 44-inch seat holds 250 pounds.

Photo 4
Woman passenger shows how easy it is to get into AG-14. Just sit down on seat and pull your legs in.

Photo 5
Builders Marvin Greenwood (left) and Ben Anderson decided on pusher design because it gives practically unlimited vision and eliminates propeller danger.

Photo 6
Author Hoadley, startled at first by wide-open vision, liked it better on second landing when he was used to it.


ANDERSON, GREENWOOD AG 14
( 1951 Model)
Approved Type Certificate 4A1
Engine, Continental
Wing span
Length
Height
Wing area (including fuselage)
Gross weight
Empty weight
Useful load
Wing loading
Power loading (per horse-power)
Fuel capacity
Top speed
Cruise
Landing Speed
Cruising range
Service ceiling
Rate of climb (sea level)
90 h.p.
34 ft. 7 in.
22 ft.
7 ft. 9 in.
120 sq. ft.
1,400 lbs.
850 Ibs.
550 Ibs.
11.7 Ibs.
15.5 Ibs.
23 gal.
over 120 m.p.h.
over 110 m.p.h.
49 m.p.h.
4 hrs.
16,500 ft.
over 700 f.p.m.
Source: Anderson, Greenwood and Co., Houston, Tex.