Picture of the contraption:

enter image description here
Source: wikimedia.org

After a quick research, and Simon's link, it turns out to be a simulator for how different aircraft would handle. And was useful is simulating crosswind with the fins installed mid-wing.

If you already have the preliminary aerodynamic data (which won't change mid-testing) to simulate different planes, what's the point of taking that data in the air vs. a ground based simulator?


1 Answer 1


There's a detailed and very interesting Air Force paper on this: CAPABILITY OF THE TOTAL IN-FLIGHT SIMULATOR (TIFS). The main point it makes is that TIFS wasn't just about gathering aerodynamic data, it was about testing aircraft configurations (including cockpit layouts) in actual flight, and training pilots on them. Here are some extracts, but you can read the paper yourself for the full details.

Test different configurations:

It also surpasses the utility of past variable stability aircraft through the realism possible in its separate, new evaluation cockpit. The capabilities and features of this in-flight simulator considerably broaden the ability of the aircraft designer to deal with difficult trade-offs in flying qualities problems. A base configuration can be set up and then its stability and control characteristics can be systematically varied for investigations to gain research knowledge pertinent to flight vehicle and flight control system design.

Simulate a number of very different aircraft:

It has been designed to reproduce in actual flight the flying qualities of a wide range of large airplanes.

Test different cockpit configurations:

The simulation cockpit is removable, so that it can be replaced by other cockpits of different configurations.

Simulate a new design in flight, before the new design has even been built:

Flight evaluations of the flying qualities of new airplane configurations can be accomplished, such as investigation of the behavior of extremely large airplanes. This can be extended to investigating the flight control characteristics of entirely new types of designs, as for example, reproducing the landing approach flight characteristics of a large re-entry vehicle. [...] The flight characteristics of specific aircraft can be simulated in great detail, both to evaluate flying qualities in advance of the first flight of the actual airplane and to investigate difficulties that may arise during the airplane's flight test program.

Train pilots on new aircraft:

Finally, a well established and highly valuable use of in-flight simulation is pilot training. In-flight simulation of emergency conditions can be conducted safely because, if the evaluation pilot is having control problems, the safety pilot can switch the system off and resume control of the normal base airplane

  • 2
    $\begingroup$ @ymb1 If simulation was that good, we wouldn't need test pilots. But we do, even today. $\endgroup$
    – Pondlife
    Jun 28, 2016 at 16:07

You must log in to answer this question.