Bird on a Wire ( How Spock's Johnson Avoided Landing in a Tree or a Pond )

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kjhambrick

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Thanks to a few volunteers at ARRG, there was an "Extra Launch" yesterday, 2023-12-30 from 14:00 to 16:00 at the AARG Hutto, TX launch site.

This was a high power only launch with two pads.

It was a beautiful day -- no clouds and the wind gradually diminished below the earlier 7 -or- 8 mph and blowing toward the 'Impenetrable Thicket"

@JimJarvis50 set up one of the pads farther south than normal for those of us without an active guidance system so we could land safely away from the Thicket.

Well ... I still found a way to find a different hazard or three :)

I flew "Spock's Johnson" my nearly 30-year old LOC Vulcanite, on an Aerotech I225FJ because it sim'd under 4000 ft and I thought it would have weathercocked enough to miss the trees and ponds.

Black Jack is my second favorite propellant after White Lightning but I've never seen Black Max propellant in person so I gave it a shot.

Beautiful !

sj-C31230-i225-launch-VideoCapture_20231231-013452.jpg

Not as loud and crackly as I remember Black Jack but then again, I am old and forgetful and I was wearing my Walston headphones too :)

I flew a Blue Raven in Dual Deploy mode with the main at 500 ft and it reported Apogee at 3,896 ft with Max Velocity at 661.96 ft/sec.

It worked as expected riding on my 'AltAcc style plywood plank', but I had to take other flier's word for it because not only am I losing my memory, but my eyesight is not that it used to be either -- I lost 'SJ' soon after burn-out.

Lucky for me, I brought my trusty old Walston Tracker and my brand new Comspec transmitter so I never lost contact with SJ so I knew where it was even without seeing it ( more feedback on @Brainstormz123's For Sale Custom Comspec Receiver Compatible Beacons thread later but the punch line is: it worked great ).

So when the range opened I walked the line across the field toward those distant trees behind the pad.

I didn't realize it until yesterday but there is a rise and then a dip where the trees are.

This is what I saw when I crossed the rise:
sj-C31230-i225-landing-20231230_33816PMByGPSMapCamera.jpg

Oops !

Lucky for me, all I had to do was cut the shock cord and SJ dropped off the line and down to the soft field.

And even more lucky for me that it did snag the power line !

That scraggly little tree's big ole daddy and mommy and uncles and aunts and siblings are just off the image to the right ( south ).

And then I also learned that there is also an irrigation pond ( bog ) down in that dip !
GoogleMap-sj-i225-c31230-Screenshot_20231231_064029.png
Anyhow ... whew !

It was a great day !

These are 20-sec of axial inertial data from the Blue Raven, re-integrated after the flight:
sj-C31230-i225-inertial-20-sec.png

And these are Altitudes IAlt ( Inertial Altitude ), PAlt ( raw Pressure Altitude from the Blue Raven ) and DAlt ( Density Altiture = raw Pressure Altitude corrected for the site temperature ( 68 F) and Pressure ( 997 mb ):
sj-C31230-i225-ipd-alt.png
Note that IAlt is invalid after drogue ejection at 17.5 sec.

I've got a little more launch rail data for @Zeta's Off the rail velocity POLL thread and if I can figure out how to get a huge video off my phone, I'll post that too :)

Whee !

A BIG THANK YOU to the core group at AARG who worked so hard to make this launch happen !

-- kjh
 
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