Towed Survey Bird Project
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Towed Survey Bird Project
Building on a few years experience with developing and approving towed survey bird systems, and after a year of development, today I did the first flights of the newest system. The bird is about 12 feet by 16 feet, and weighs about 380 pounds. We did initial testing of a model under the wing of my C 150 last January, and that gave us the confidence to move forward with the full sized design. An amazing development project by a great team. It's nice to take off, and see the whole team on the ramp, watching us go by....
Careful attention has to be paid to not raising the nose too high during takeoff and landing...
Off to see how it stalls, before I have to come back and land it....
The second flight was the opportunity for the first deployments...
The second Caravan with the boss flying chase for me is very reassuring. The great photos are just a bonus!
The winch developer was also the operator, all I had to do was fly straight and steady, He did the hard part! Letting the "bird" out of the "nest" for the first time is a total commitment!
Initial model testing under my wing last January
With the model, we could design and refine the tail to provide the desired flight characteristics.
Over the next weeks, we'll be working on some details, then I'll be beginning the certification test flying, for Canadian STC approval.
Careful attention has to be paid to not raising the nose too high during takeoff and landing...
Off to see how it stalls, before I have to come back and land it....
The second flight was the opportunity for the first deployments...
The second Caravan with the boss flying chase for me is very reassuring. The great photos are just a bonus!
The winch developer was also the operator, all I had to do was fly straight and steady, He did the hard part! Letting the "bird" out of the "nest" for the first time is a total commitment!
Initial model testing under my wing last January
With the model, we could design and refine the tail to provide the desired flight characteristics.
Over the next weeks, we'll be working on some details, then I'll be beginning the certification test flying, for Canadian STC approval.
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As my job is the testing and STC approval elements of the project, I'm not able to offer too much information about the technical side of the survey equipment itself. I can offer that it uses magnetic fields for geological survey.
Strikes me as a lot more sensible than the twin wingtip mounted magnetometers / fatigue generators that were fitted to the BGS/FGS Twin Otter until recently.
Sounds like a fascinating project DAR, I envy you, and well done on the successful outcome.
G
Sounds like a fascinating project DAR, I envy you, and well done on the successful outcome.
G
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Thread Starter
We are making good progress on this. After a break over Christmas, and some redesign of the hydraulic system which operates the winch, we've got a lot more test flying done this week.
This has included the crosswind work yesterday. I found a nice 10,000 foot runway, with a direct crosswind at 18 G 25 (and lots of blowing snow). I expected some "keel effect" from the bird, and it's tails. The aircraft was manageable in this wind, but did require full rudder a few times.
Today was spins, first without the bird, to get familair with the plane, then with the bird strapped on tight. The Caravan is a magnificent spinning plane both ways! I could not hold it in for more that a turn in some cases, it was finding it's way out, even with full pro spin controls held in. A few times it did get up near Vne, with 2.5 -2.8 G force being applied in the pull out, so there is not much margin for a careless recovery! Spinning a Caravan without reference to an accelerometer, would have a very narrow margin of safety...
I've got video from two onboard cameras of the spinning, and will try to edit it to a postable size.
I hope to complete my Caravan testing this week. Then I've on to two different Piper Navajos with external mods....
This has included the crosswind work yesterday. I found a nice 10,000 foot runway, with a direct crosswind at 18 G 25 (and lots of blowing snow). I expected some "keel effect" from the bird, and it's tails. The aircraft was manageable in this wind, but did require full rudder a few times.
Today was spins, first without the bird, to get familair with the plane, then with the bird strapped on tight. The Caravan is a magnificent spinning plane both ways! I could not hold it in for more that a turn in some cases, it was finding it's way out, even with full pro spin controls held in. A few times it did get up near Vne, with 2.5 -2.8 G force being applied in the pull out, so there is not much margin for a careless recovery! Spinning a Caravan without reference to an accelerometer, would have a very narrow margin of safety...
I've got video from two onboard cameras of the spinning, and will try to edit it to a postable size.
I hope to complete my Caravan testing this week. Then I've on to two different Piper Navajos with external mods....
