donlynn
Key Veteran
Location: New Zealand
My Posts This: Topic Forum | maybe I'm the rare antique!
hopefully you folk may be able to help with my crash report
Kalt cyclone
Irvine 61 with os 7H carb -goes real sweetly
futaba
TX 8uhp
RX R129dp
3-9202 sevos-roll ,pitch,collective
1-3003 - throttle
1-3001 - tail
gyro G154
battery 4 of 1700mAhr sub C NiCd
multi led type batt monitor
all gear in new condition
I've had the radio gear since I got the jet ranger( approx 5yrs)Tx is the only bit out of the box and I'm a rank beginner on heli's.(been getting my fix on ridge soaring foamys) I was given the heli about one month ago
I have a never flown Hirobo Scale 60 jet ranger DDF SST that came with the RCFS and have been too scared to fly it as I could see the quality in engineering and not in me being heli current
Spent big hours on Dave Brown RCFS then realflight g2 a lot for the last 5yrs
1st flying session wind vrb 3kts
going awesome ,nothing marginal at all. Last flight of the day boom strike on bottom of landing as during session I had changed pitch curve at low stick from 0 to -4 as I wanted auto option as I could see foward flight looming. should of stopped as one doesn't Got tired , too fast a decent and dumped the collective on touchdown .Result new boom (local ali tube-more lead on nose,, few new links, rob the pitch change assy off the jet ranger(I'm not gonna stack it again!) Total fueled weight now ~ 5kg
2nd session wind 3kts
Awesome hover feeling nailed tried a few very successfull slow and gentle 100ft circuts
during very agressive transition to foward flight pirroutting level disk pole foward straightens up, circut and land adjust tail pitch center position,try again same doesn't realy make any difference,flag it ,got away with it this long. Check and tighten belt to 5mm max belt depression between main gear and entry to tail boom
third flying session
wind ~5 gusting 8 knots
either side on, nose in circuts all ok and not too stressfull at all.
I'd be more comfy calling it a loiter rather than a hover if I really try to stare the heli out then the hover seems a little more stable I guess in/out transitional lift,man this stuff is great!!
Previous flying session managed to get head speed a little more stable and control things a little tidier during and at bottom of decent so feeling a little cosier.
6 minutes flying sofar on first tank of the day still a couple of minutes easy, it had done one uncommanded pirrouette which I managed to recover from by poling foward a little circut and land.
I had just turned on the revo function trying to nail the tail during climb and decent phase,so figgured I had it set all wrong so turned revo off,deal with that later !
I can see it would be wise to get current quickly on auto's.
Established in a nice stable 3 foot hover ,full rudder input one way- ok other way -ok (my tail belt tension test) begin gentle climbout poling foward a wee bit entering foward flight -established nicely slowly add collective to full then approx 2-3 seconds later (may have been straight away) at approx 50 feet the wild pirrouetting begins again against the direction of main rotor,unable to stop by poling foward I'm not sure but I think maybe I had the tail gyro set the wrong way or the tail belt to loose
so it sensed yaw acceleration and put input in which increased the yaw
result-
uncontrollable pirouettes approx 2-3 per second at 50 feet
going downwind towards tall trees,with heli slowly rolling off to side impacting at a 90 degree from level attitude still pirouetting unable to establish autorotation( didn't even try as trying to figure out what the truck is going on) before getting heli all trucked up with the dirt.I couldn't see the impact but from flying buddy who did it was the ugliest he had witnessed, this from a person who wrote off/stacked a awesome scale extra.I guess that was supposed to make me feel better -didn't really do it for me.
audio-
waaaaaaaaaaaa wooooar wooar "buggar" wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar "the book didn't say anything about this" wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar wooar WUMMP burrr.that was a shame.
my guess-tail rotor failure or the previously mentioned gyro setting
A auto would have stopped drive to the tail and given a wee bit of yaw stability to enable a controlled landing (theoretically)
worst part was the beginning of it's death dance was in a fresh cow pat then it thrashed about for a wee bit,spending money furiously
similar sensation to being busted by the school principal.
Didn't look like a heli at all on the way home!
Belt tension checked before flight approx 5mm of squeeze ,after crash approx 8 mm but boom bent a wee bit.
Tail blade shaft severed on one half.
Grub screw on tail pitch control wire loose and wire bent ,grub screw checked before flight.
Gyro motor still operating after crash.
any thoughts on the cause will be greatly appreciatted and not taken personally even if the pilot did truck up.
regards Don |
