Forum: Drones

Hello. I was recently reading about the F-106 Delta Dart, and discovered that the vast majority of survivors ended up being used as QF-106 target drones. That led me to a question. How were these drones controlled?

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Remotely.

During takeoff and landing they were controlled by a van near the runway. Two controllers sat on top of the van, one controlling pitch and throttle and the other controlling roll and yaw. One second update rate on the control system displays which looked like Microsoft Flight Simulator by the way Very Happy

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I actually did a little flight testing on them when they started pitching out of control and crashing.

Wow, that's very interesting, thanks for sharing!

Same control features have been standard throughout the AF's FSAT program, beginning with the QF-102. Starting with the QF-106, FSATs began to incorporate GPS control, once the aircraft had taken off. The van controllers would pass the aircraft off to Range Control, which would initiate the GPS-controlled profile. On approach, as Roscoe stated, the van controllers would again take control of the aircraft, and land it with a barrier engagement.

Not a barrier, a beefed up tail hook and cable.

Right. I wasn't referring to a barrier in the Navy sense, where the jet hits a nylon barricade. I was referring to what the AF calls a "barrier", which is nothing more than a cable stretched across the runway, with a braking system on either side of the wire. If you catch the wire with the tail hook, and you are within the speed restriction (Re: IAF F-15 one-wing landing), you WILL come to a stop.

Last barrier engagement that I saw was at Lakenheath, about a month ago. C model Eagle came in IFE, and had to take the barrier instead of a roll out. His wingmen landed first, except for one chase aircraft, and then he and two Mudhens diverted to Mildenhall.

Roscoe wrote:

Two controllers sat on top of the van, one controlling pitch and throttle and the other controlling roll and yaw.

That sounds like a really screwy system to me... but I guess it worked.

gtg947h wrote:

Roscoe wrote:

Two controllers sat on top of the van, one controlling pitch and throttle and the other controlling roll and yaw.

That sounds like a really screwy system to me... but I guess it worked.

Indeed. Why couldn't they put it all in one controller, ala an RC plane?

I don't know, I asked the same question. Didn't get a good answer, but as they were busy I didn't press the issue.

As an aside, as I mentioned above the controller display had a 1 Hz refresh rate. As it turns out, the F-106 short period is about 2 Hz (the Short period is the natural frequency that the aircraft will demonstrate in pitch).

At one point in the spring of 1995 the QF-106 was experiencing a high crash rate do to loss of pitch control. Seems the drone control system used an OEM part called the turn rate transmitter (for yaw feedback and damping) and converted it to a pitch rate feedback gyro. Don't ask me why, probably seemed like a good idea at the time. Anyway, the gyro starting failing. Without the pitch feedback, the aircraft would start pitching up and down in a divergent manner. Eventually, it would pitch up so high it would stall, and then pitch up even more. That big old delta wing would basically come to dead stop and then slice off to one side. One time it nearly sliced into the manned wingman. He later asked the controllers what they were thinking. Because the display rate was 1 Hz (you were wondering when that was going to matter), and the pitch oscillations were at 2 Hz, the controllers thought the aircraft was flying straight and level...seems the display would "snap" the condition as the aircraft was passing through level in each direction and they never saw the pitch angle go crazy.

Rolling Eyes

I got to see them self destruct one at Holloman. Was spring of 96 though. Heard it take off when I was leaving my house. Hard lite burners were a pretty good indication a 106 was taking off. Got across base, looked up, and saw a large fireball trailing black smoke. Never heard what the problem was.

If the aircraft loses control, and is deemed to be a safety hazard, then the drone will be destructed. The destruct package utilizes a strategically placed AIM-9 warhead, which is designed to immediately terminate flight, i.e., the drone's wreckage will not be able to continue careening out of control. Rather, the warhead cuts through the aircraft at critical structural points, and renders what remains unflyable.

Also, when contact is lost with the drone, it will begin orbiting to 30,000 ft., where it will remain for a period of 30 minutes. If contact with the drone is not regained within that 30 minute window, then the drone will self destruct.

Forum: Drones

Target Drones