bimoadiprakoso
The Lockheed SR-71 "Blackbird" is a long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft that was operated by the United States Air Force. It was developed as a black project from the Lockheed A-12 reconnaissance aircraft in the 1960s by Lockheed and its Skunk Works division. American aerospace engineer Clarence "Kelly" Johnson was responsible for many of the design's innovative concepts. During aerial reconnaissance missions, the SR-71 operated at high speeds and altitudes (85,000 feet, 25,900 meters) to allow it to outrace threats. If a surface-to-air missile launch was detected, the standard evasive action was simply to accelerate and outfly the missile. The shape of the SR-71 was based on that of the A-12, which was one of the first aircraft to be designed with a reduced radar cross-section. The SR-71 served with the U.S. Air Force from 1964 to 1998. A total of 32 aircraft were built; 12 were lost in accidents with none lost to enemy action. The SR-71 has been given several nicknames, including "Blackbird" and "Habu". As of 2020, it still holds the world record it set in 1976 for the fastest air-breathing manned aircraft, previously held by the related Lockheed YF-12.

sr-71_blackbird_and_f-16xl.jpg  55-61375-pappas1-1430169855.jpg  SR-71 Blackbird Wallpaper.jpg 
This PI SR-71 project was delayed due to the size consideration. However, this year, we made a choice to finally started the project. With 1.5m in length, this is the longest PI parkjet's record, beating the T-38 by far.

As all PI parkjet designs, modelling and designing was done in Rhinoceros 6. The goal of this project was a simple built. But in order to make the structures strong enough, we needed to throw in many slots and registers to the design. It also requires 3 sheets of A0 size 6mm depron.

Eventhough this design carries true airfoil, it would be quite easy to construct.

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More to come.

      "Hungry for better accomplishments in every way"
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Wildthing
Flew the new proto type PI SR-71 Blackbird today and I would call it successful. the cg has to be move back slightly as it felt tail heavy and I need to add a little expo to the elevators and maybe even tune them down slightly. Roll seemed good but pitch was touchy. Going against the wind the nose would go up and that didn't help landing because I came in soft but a little gust of wind came in and made it go vertical and it came down on it's butt, minor damage .

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jimbosflyin
Wildthing wrote:
Flew the new proto type PI SR-71 Blackbird today and I would call it successful. the cg has to be move back slightly as it felt tail heavy and I need to add a little expo to the elevators and maybe even tune them down slightly. Roll seemed good but pitch was touchy. Going against the wind the nose would go up and that didn't help landing because I came in soft but a little gust of wind came in and made it go vertical and it came down on it's butt, minor damage .

Good going Jeff,I guess your club is back in the swing of things with all it's new bells and whistles.👌
Parkflyers International 
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Wildthing
jimbosflyin wrote:
Good going Jeff,I guess your club is back in the swing of things with all it's new bells and whistles.👌

Limit of 10 but up and going. I forgot to take pictures of the new clubhouse 🙂 
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Sterling101
Wasn't too bad Jeff - just a bit tail heavy and maybe lost a bit too much speed on the way in hence it just dropped it's tail and fell on it's arse 😉
I know the SR-71 is a bit of a bugger to control if you're not careful so wouldn't be too worried about the handling just yet.
Looks nice in the air though!

Hopefully I'll be having my first flight since January this week as long as the weather gods behave!!
Whoever said nothing is impossible had obviously never tried slamming a revolving door...
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Wildthing
Sterling101 wrote:
Wasn't too bad Jeff - just a bit tail heavy and maybe lost a bit too much speed on the way in hence it just dropped it's tail and fell on it's arse 😉
I know the SR-71 is a bit of a bugger to control if you're not careful so wouldn't be too worried about the handling just yet.
Looks nice in the air though!

Hopefully I'll be having my first flight since January this week as long as the weather gods behave!!


It definitely keeps you on your toes, it has so much surface and even just turning into the wind it wanted to go vertical. She is all stitched up again but now the winds have gone stupid . Feels good to be able to go to the field even though there is a limit of people. 
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Sterling101
Hopefully it'll be a good one tomorrow - time to throw some cheap foam board into the air and see what happens! 😉
Whoever said nothing is impossible had obviously never tried slamming a revolving door...
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Wildthing
Very short little flight with the SR-71. After the maiden I had adjusted my rates down a bit and moved the battery just slightly further ahead. Not sure if I was just to nose heavy now or I just simply stalled. Few more bandaids required before it's next attempt. Tried to get as much land speed going before lift off and not really sure if I banked or it did it on it's own, will get her patched up and give it another whirl 🙂 
[MEDIA=youtube]6_ZxGrItYS8[/MEDIA]
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Dodgy Crasher
watched your youtube clip, it did behave like a tail heavy model, after the first attempt to land against the wind I'd have landed wind at the tail, however you did really well to land that in one piece ðŸ‘
I would have crashed  ðŸ˜œ probably unfixable ðŸ˜–
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Sidewayskiwi
from the video the plane is "phugoiding" which is pitch instability around the longitudinal axis (repetitive sine wave if you will) 
i would remove rear motor completely  and test fly again with slightly bigger counter rotating props on the front 
as i believe the the 3 thrust lines are not coexisting peacefully or playing well together 
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Dodgy Crasher
I agree with Sidewayskiwi, just disconnect the rear motor and try the model using only the front 2 motors.
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Wildthing
My only problem with that is the first flight went good other then the landing, but it still might be worth a shot. 
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Wildthing
Couple pieces grafted in and some new bandaids, third time is a charm they say 🙂 

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