After the war, competition from Curtiss-Wright stimulated Link to develop their own electronic simulators. Also at this time the value of the Link Trainer motion system was being called into question. The movements of the Link Trainer did not correctly simulate the forces experienced in flight, and in fact a ground-fixed trainer would more accurately locate the force vector in coordianted turning or level flight. Also, the axis of roll rotation was too far below the pilot to allow correct simulation of accelerations due to roll. It was argued that the modern pilot should not fly "by the seat of his pants", but by instruments. Ed Link disagreed and held the view that trainer motion was needed even if incorrect, since motion was present in flying. However, customer pressure caused Link to follow the trend to fixed base simulators. The company therefore developed their own electronic analogue computer which was used in their C-ll jet trainer. A contract was awarded by the U.S. Air Force in 1949, and eventually over a thousand of these types were sold.

Meanwhile, Curtiss-Wright had contracted to develop a full simulator
for the Boeing 377 Stratocruisers of Pan American Airways. The simulator was
installed in 1948 and was the first full aircraft simulator to be owned by an
airline. No motion or visual system were installed, but in all other respects
the simulator duplicated the appearance and behaviour of the Stratocruiser
cockpit. The trainer was found especially useful for the practice of procedures
involving the whole crew; emergency conditions could be readily introduced by the
instructor on his fault insertion panel. Complete routes could be flown, as in
real life, using the same navigational aids. This facility was used by other
airlines, and in the words of a BOAC Captain, "From start to finish we had
treated the whole exercise as if it were the real thing, and the cockpit was so
complete in every detail that we soon forgot that we were not in an aeroplane''
However, there were some reservations expressed about the lack of motion in a
fixed-base simulation, which caused it to feel unnatural and could even cause
control problems.
In 1947 B0AC decided to buy Boeing 377 Stratocruisers, and knowing of
Redifon's work on synthetic crew trainers, asked Mr Adorian if a simulator could
be built for this aircraft; the simulator was to be the same as that which
Curtiss-Wright were building for Pan American. In order to comply with the BOAC
requirement Redifon had to enter into an agreement with Curtiss-Wright and Dr.
Dehmel and obtain clearance from the U.S. State Department. Work commenced on
the construction of the simulator at Redifons Wandsworth works in January 1950.
The computation was analogue, using 60Hz (U.S. mains frequency) signals and servo
motors, contoured potentiometers and 400Hz synchros and magnesyns for aircraft
instrument drives. The control loading unit used variable levers, servo
controlled as a correctly computed function of air speed, with springs to produce
the necessary forces. The unit took the form of a separate frame running the
whole length of the fuselage and, as today, carried the flying controls, throttle
pedestal and pilot's panels and seats. The simulator was finally accepted in
October 1951 with the price to BOAC being £120,000.
Prior to the final acceptance of the Stratocruiser, BOAC gave another
simulator order to Redifon, this time for a Comet I. This was to become the
first jet transport simulator in the world, and was designed by A.E. Cutler.
Whereas the first simulator's servos had been manufactured by Curtiss, the Comet
servos and potentiometers were built by Redifon. This second simulator followed
similar principles to that of the first, except that a carrier frequency of 50Hz
was employed and no computed control loading was necessary as the aircraft used a
fixed spring-loaded control system.
The first Curtiss-Wright, Redifon and Link simulators used the a.c.
carrier method of analogue computer. Air Trainers Limited however, decided to
use the d.c. method - a more demanding technology, but one capable of superior
precision in simulation. Their first simulator using this technology was built
for the RAF's Meteor aircraft. The d.c. method was later adopted by Link in the
United States. Redifon, however, developed a system using a carrier frequency of
400Hz which was very successful. Also, at this time, mechanical analogue
computers were constructed for use in the simpler "type trainers" by Air Trainers
Limited.