Link Trainer and X-Plane

EAA Chapter 44 in Rochester NY owns a 1960’s Link General Aviation Trainer (GAT-1.) It is currently INOP and our Chapter electrician has been trying to get it running on the old electronics for several years. If and when he does, we want to try to marry it with X-Plane, to have them communicate with each other and to work together to provide a full-motion, 3-axis experience with either 3-monitors in the cockpit or an Occulus Rift headset. That’s the goal.

But first we have to get it running. So I have two questions: Does anyone out there have experience with Link Trainers and getting them running? And, does anyone know if these two CAN be married or if they already HAVE been joined in Holy Simlock. Chapter 44 would appreciate any leads. Thanks.

Bob Nelligan-Barrett
EAA Chapter 44
Rochester NY

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Originally Posted by Trailbossbob

EAA Chapter 44 in Rochester NY owns a 1960’s Link General Aviation Trainer (GAT-1.) It is currently INOP and our Chapter electrician has been trying to get it running on the old electronics for several years. If and when he does, we want to try to marry it with X-Plane, to have them communicate with each other and to work together to provide a full-motion, 3-axis experience with either 3-monitors in the cockpit or an Occulus Rift headset. That’s the goal.

But first we have to get it running. So I have two questions: Does anyone out there have experience with Link Trainers and getting them running? And, does anyone know if these two CAN be married or if they already HAVE been joined in Holy Simlock. Chapter 44 would appreciate any leads. Thanks.

Bob Nelligan-Barrett
EAA Chapter 44
Rochester NY

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These people in Australia have been working on a Link Trainer project which was well on the way when I saw it a year ago.
Nhill Aviation Heritage Centre
Location: Nhill Aerodrome, VIC, 3418

P: +61 490 657 770
E: nahc3418@gmail.com

I've got experience with a Link ANT-18, the WWII model, but that wouldn't apply much, here. The ANT-18 was, basically, an analog computer using vacuum instead of electronics.

When you say, "get it running," what's the state, now? When you power up, does it just sit there, or....?

From NASA report NASA-CR-86294, it appears that the aircraft information such as pitch, roll, rate of climb, etc. is available at the slip rings under the cabin.

https://ntrs.nasa.gov/search.jsp?R=19700005776

Page 15 has a signals list; don't think it's a complete one, though. You would need something to do the Analog to Digital conversion and the appropriate port into the X-plane world.

Ron Wanttaja

The museum I work for part-time has a WWII vintage link trainer. They worked with some local group to restore it to (mostly) working order.

Responding to the original thread; I know a guy who worked on newer Link trainers for the military, T37, C130, Chinook, etc. I can get in touch and see if the GAT-1 is something he might be able to help with.

Sure I'd appreciate it. I'm not the member directly working on this but I am one who wants to see it "fly." Thanks for your help.

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Originally Posted by Tench745

The museum I work for part-time has a WWII vintage link trainer. They worked with some local group to restore it to (mostly) working order.

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WWII Link Trainers are completely different from the GAT-1. The WWII link (ANT-18) is an analog computer working in vacuum instead of electricity. There's an "altitude" tank that has air drawn out when the plane climbs, there's a manifold that "stores" your airspeed, which gets bled off or added to by throttle position, valves hooked to the aircraft pitch, etc. Yes, there's lots of electronics, but it's mostly to aid monitoring the aircraft status.

Led a team of CAP cadets, restoring one, almost 50 years ago. Great fun.

Ron Wanttaja

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Originally Posted by rwanttaja

WWII Link Trainers are completely different from the GAT-1. The WWII link (ANT-18) is an analog computer working in vacuum instead of electricity. There's an "altitude" tank that has air drawn out when the plane climbs, there's a manifold that "stores" your airspeed, which gets bled off or added to by throttle position, valves hooked to the aircraft pitch, etc. Yes, there's lots of electronics, but it's mostly to aid monitoring the aircraft status.

Led a team of CAP cadets, restoring one, almost 50 years ago. Great fun.

Ron Wanttaja

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Thanks for the extra info, Ron.

I've been neck deep in our WWII link trainer. It's a spaghetti of hoses and really neat pneumatic/mechanical features. Sadly, they removed all the original instruments for fear of the radium dials.

I've mentioned the GAT-1 project to my friend and will let you know what he says.

I've talked to my friend. Sadly, it's just a bit too far away for him to bite. Say's he's never worked on a civilian model anyway.

I was there thh day that Mr. MAC at McDonnell decided to stop bidding on Simulator business after they finished the C-5 and A-7 simulators they were late and over budget on or was it just unprofitable? At the time they had just digested CONDUCTRON who built the gantry travelling type interface TPQ-10 Radar Bomb Simulator for teh B-52. Years later in 1981 when I ha finished with my efforts with real airplanes I got a call from Jack Morgan saying GPL-Singer-LINK wanted me to come to Houston to work on a B-52 simulator. I negotiated. I pondered, then I took a turn at the drawbrige over the InterCoastal Water way #0007 and "got the girl." Paul Garabedian in Tampa had bought GPL-Singer LINK and after it went bankrupt he sold it to the Candian's who gobbled up most of the other simlator companies. I think what you are looking for is not called "Analog" but rather "Hardware-in-Loop which I saw in Orlando at Naval Training Device Center in the form of a EWO panel taken out of a EA3 and an adjacent large projector TV set up with a SONY 13 inch Black matrix mounted upside down and a console for a technician to "Fly" to create the scenario for the EWO aspect. Analog would be like what was in the ACES hybrid digital/analog simulator that Jack Simpson built at Huntington Beach MDAC-W with a Honeywell digital computer as supervisor and a lot of transistor amplifiers (I don't think OpAMPs yet) to fly QUICKTURN, vectored nozzle missiles against simple target in plane maneuvers. This in 1969-74. Me, I only did adversarial flights 1-on-1 with everything code, data,tactics, physics, autopilot, scoring and output. CDC-6500,6400,6600 and IBM 360/85, 370/75, IBM 2250 vector display, SC-4020, SD 4460 film recording display, Gerber plotter of control values of a 6-DOF module that was never incorporated into the overall when the programmer moved to Seattle.

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Analog would be like what was in the ACES hybrid digital/analog simulator that Jack Simpson built at Huntington Beach MDAC-W with a Honeywell digital computer as supervisor and a lot of transistor amplifiers (I don't think OpAMPs yet) to fly QUICKTURN, vectored nozzle missiles against simple target in plane maneuvers.

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Analog would be like the MA-6A/MA-7A Bomb-Nav (Bombing/Navigation) system used on the B-47 and B-52 in the '50s and '60s, which operated on servo mechanisms, gear trains, 3 dimensional cams, and even a few vacuum tubes. They were surprisingly decent computers, but very large, heavy and expensive, not to mention maintenance intensive.

We have to distinguish between the system in the actual airplane and reproducing that interface with some means of adding an atmosphere and the physics of the airplane. Hardware in the loop is still what you have described. What is your favorite atmosphere? ICAO plus 15 degrees or NACA Tropical? https://www.sciencedirect.com/topics/physics-and-astronomy/reference-atmospheres