I CRASHED THE GRIPEN 5 TIMES ✈️ Let's talk about WHY + other stuff too
36I crashed my Freewing JAS-39 Gripen 5 times in a row... at first I thought it was pilot error but... was it really? ...Watch the video to find out what really happened!
Further context: Haven't been flying much the Gripen this last year, and as a result I barely posted any video on it. Namely because the jet spent most of the time on the workbench undergoing repairs. Here's the chronology of the crashes (Spoiler alert: better read this after watching the video):
Flight 106th: Pilot error in depth perception, thrown plane into a tree.
Flight 113th: After repairs, replacing a few servos for more capable ones and adding a HE A3S3 gyro to replace the S8R one, the CG moved slightly back forward and the TV yaw nozzle servo was malfunctioning without me realizing. The combination caused me to misjudge the commands required for a maneuver I always do without problems but this time it ended with the plane banked over 90º of roll (which shouldn't have happened with my usual inputs, had all been fine and end parallel to the ground instead)... so when pulling up the jet went straight into yet another tree. Spent the entire evening up until 1 or 2 AM trimming the tree from the inside in order to be able to access and recover the jet, which had survived almost unscathed up until then but badly broke its nose on the fall when trying to bring it down.
Flight 115th: Low, mild high alpha (about 30º, usually a no brainer for the Gripen) suddenly developed severe oscillations (no wind that day) to the point it became uncontrollable and went straight into the ground, suffering the worst of the crashes. Canards damaged, canard horns broken and shaft bent, one wing ripped apart from the fuse, wing spar broken and pulled back THROUGH the foam of the fuselage causing quite a massive 'wound'... I wrongly attributed this crash to a different handling of the plane with new gyro and servos, and hence, pilot error for doing risky maneuvers before getting properly reaccustomed. But it obviously was the TV yaw servo malfunctioning that impeded me (and the gyro) from applying sensible corrections.
At this point I removed the wing spar for good after repairing the fuselage to experiment with a cleaner duct, hoping that the design would be robust enough to take the bending loads without breaking.
Flight 122nd: Similar story, only now it was a post stall maneuver executed higher up from which I couldn't properly recover due to the failing servo. Again, I wrongly attributed this exclusively to piloting error without realizing the underlying root cause. This time the crash was really not that bad, just a tough belly impact which took little time to fix.
Flight 125th: Yet again, after overshooting on a descending spiral, I applied my usual yaw correction (to the right in this case) but the nozzle was not only not responding but locked in a slightly-left-yawing position which made it impossible to exit the condition without sending the plane into the trees. Damage wasn't as bad as before, but still required quite some extensive repair work.
The plane has since been repaired (and the faulty servo replaced) and no more problems have arisen so far, so I'll soon post more flight videos of the repaired jet. After all this ordeal though, my CG is no longer 40mm aft of CG wing-marks, to my dismay. :'(
Anyway, "broken beat and scarred", but still kickin'! ;)
These were flights 104th to 106th, 112th, 113th, and 123rd to 125th on 'Jana'.
Pilot: RC4ever
Ground video: Luis Ibáñez
Airfield: Club Els Cards
Music: Metallica
PLZ, check my merch! ;)
airguardian.creator-spring.com
LINK to Arthur-RC's tail-heavy maiden of the Su-35:
https://www.youtube.com/watch?v=OoSzt_z1Iik
Chapters:
0:00 - Quick crash compilation
0:38 - Video presentation and context
1:39 - Plane before the recent crashes, talk about previous belly landing crashes
2:57 - Discussion about my aft CG setting and 'tail-heaviness'
4:15 - Shoutout to @Arthur-RC, commentary on his 'Su-35 tail-heavy maiden' video
5:55 - Closing thoughts on CG 40mm aft of the wing marks
6:45 - Insight about canards' pitch-down offset, CP shift
9:13 - Canards' pitch-up offset cons (Non exhaustive list)
10:33 - The CRASHES and their undesired consequences
12:40 - 1ST CRASH, the rebel-terrorist squirrel militia!
13:56 - 1st flight after the 1st crash
15:25 - Greaser landing!
15:42 - 2ND CRASH, Squirrels 2 - Gripen 0
(Here would go the 3rd and 4th crashes but we sadly didn't film those flights)
16:36 - 1st flight after the 4th crash. Wing spar removed, much nose heavier
18:40 - Comments on the two missing crashes
20:54 - Upgrade to HE A3S3 gyro and high refresh rate servos
22:22 - Another greaser landing
22:50 - The beauty of having video evidence
23:49 - 5TH CRASH, Squirrels 3 - Gripen 0
24:07 - The problem, REVEALED at last!
28:30 - Conclusions / Outro
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