The First Simulator

Edwin A. Link's Flight Trainer

By William H. Geoghegan

Photographs by the author


The Link Trainer, also known as the "Blue Box," is arguably the best known of all the flight simulators that appeared in the last 70 years or so. It was the invention that launched what is now a multi-billion dollar atmospheric and spaceflight simulation industry. The original trainer was developed by Edwin A. Link, an inventor who was born in Indiana but grew up in the Binghamton area of upstate New York. As a youth he worked in his father's organ factory, and there learned about the pneumatic systems that would eventually power his invention. He developed an early interest in flying, and after going through the usual one-on-one training typical of the day, he decided to develop a means of simulating the learning experience on the ground.

He worked out a design for a simulator in the late 1920's, and built a model using bellows and air pumps to control simulated aircraft movement, based on what he had learned about pneumatics from his father's business. A patent was granted in 1931. With the advent of instrument flying, Link upgraded his invention for use as an instrument trainer. However, much of the interest shown in the '30s was for amusement parks and private pilot training.

It was not until the U.S. Army saw the Link Trainer as a potential means of avoiding the accidents that plagued primary flight training that Link's invention gained widespread acceptance. Over 10,000 copies of the "blue box" were delivered during the war, helping to train more than 500,000 pilots; and they continued in use for several decades thereafter. Edwin Link eventually went on to work on submersibles, oceanography, undersea archaeology, etc., until his death in 1981.

There are numerous pre-War and World War II era Link Trainers on display today in varying states of preservation and restoration. The One shown here is on display at the Elmira New York Wings of Eagles Air Museum. Other copies are on view at the Binghamton airport, the Roberson Museum and Science Center (Binghamton, New York), and (unrestored) at the Mid-Atlantic Air Museum, among others.

There is an excellent description of the Link Trainer (with additional detail on the Roberson Museum copy) on the American Society of Mechanical Engineers web site. Look for the link to a booklet in PDF format containing a wealth of technical detail, photos and diagrams of the trainer.


The photographs of a restored Type S.W. C-3 Instrument Flying Trainer (Link Trainer) were taken on July 3, 2004 at the Wings of Eagles Air Museum in Elmira, New York. The photo of an unrestored Trainer (in red paint) was taken on June 4, 2006 at the Mid-Atlantic Air Museum during their 16th annual World War II Weekend.

Overview of Link Trainer set-up, with the instructor's desk and course recorder in the foreground and the trainer itself in the background. View of the trainer's cockpit, with "flight information" clipped to the starboard side of the cabin. The control stick does not appear to be original; the trainer used a 3/4-round wheel rather than a joytstick.
The Link Trainer's instrument panel. I was consistently amazed at the accuracy of Ralph Currel's depiction of this subject. Profile view from the port side of the trainer.
View of the trainer from the tail. Note the elevator and rudder control cables. These are absent on the Currell model but could be added as part of a super-detailing project. Detailed view of the instructor's desk and "automatic recording device," which tracked the student's virtual flight path. A 1:24 model of the desk should be fairly easy to scratch-build in card, and would make a nice addition to a diorama based on Ralph Currell's model.
This is another Link instrument trainer, housed in the hangar of the Mid-Atlantic Air Museum in Reading, Pennsylvania. It's in need of some very serious restoration work!