Aircraft design in which the propeller is mounted on the front and pulls the craft forward
The
Cessna 172
, a tractor configuration aircraft, and the most popular airplane ever produced
A
Britten-Norman Trislander
aircraft (with an unusual 3rd tractor engine on the tail) at
Guernsey Airport
, Channel Islands
The
Royal Aircraft Factory FE2
is an example of a pusher configuration
In
aviation
, the term
tractor configuration
refers to an
aircraft
constructed in the standard configuration with its
engine
mounted with the
propeller
in front of it so that the aircraft is "pulled" through the air. Oppositely, the
pusher configuration
places the airscrew behind and propels the aircraft forward. Through common usage, the word "propeller" has come to mean any airscrew, whether it actually propels or pulls the plane.
In the
early years of powered aviation
both tractor and pusher designs were common. However, by the midpoint of the
First World War
, interest in pushers declined and the tractor configuration dominated. Today, propeller-driven aircraft are assumed to be tractors unless it is stated otherwise.
[
citation needed
]
Origins
[
edit
]
The first airplane to have a "tractor" configuration was the
Goupy No.2
(first flight on 11 March 1909) designed by
Mario Calderara
and financed by
Ambroise Goupy
at the French firm
Bleriot Aeronautique
.
[1]
When it was constructed, it was the fastest airplane in existence.
[2]
At that time a distinction was made between a propeller ("pushes the machine", akin to a ship's propeller) and a tractor-[air]screw ("pulls the machine through the air").
[3]
[
non-primary source needed
]
The
Royal Flying Corps
called the tractors "Bleriot type" after
Louis Bleriot
to distinguish them from pushers, or "Farman type".
World War I military aviation
[
edit
]
The downside of a single-engine tractor aircraft was that it was initially impossible to fire a gun through the propeller arc without striking the propeller blades. Early solutions included mounting guns (
rifles
or
machine guns
) to fire around the propeller arc, either at an angle to the side ? which made aiming difficult ? or on the top wing of a
biplane
so that the bullets passed over the propeller arc.
[
citation needed
]
The first system to fire through the propeller was developed by French engineer
Eugene Gilbert
for
Morane-Saulnier
, and involved fitting metal "deflector wedges" to the propeller blades of a
Morane-Saulnier L
monoplane
. It was employed with immediate success by French
aviator
Roland Garros
and was also used on at least one
Sopwith Tabloid
of the
Royal Naval Air Service
.
[
citation needed
]
A more workable solution was a
gun synchronizer
, which utilized a
synchronization gear
developed by aircraft pioneer
Anthony Fokker
and fitted to the
Fokker E.I
monoplane in
1915
. The first British "tractor" to be specifically designed to be fitted with synchronization gear was the
Sopwith 1½ Strutter
which did not enter service until early 1916.
[
citation needed
]
Other solutions to avoiding the propeller arc include passing the gun's barrel through the propeller's hub or spinner ? first used in production military aircraft with the World War I French
SPAD S.XII
? or mounting guns in the wings. The latter solution was generally used from the early 1930s until the beginning of the
jet age
.
[
citation needed
]
References
[
edit
]
See also
[
edit
]