Brad330l

My Feedback: (1)

Sundays flying didnt go too well for one of our members today.
More details later.

http://www.youtube.com/watch?v=UYxGWrBgZBs

Cheers,

Brad

ByLoudDesign

OUCH!!!!

Lnewqban

Very nice last flight, though.

AA5BY

Stretching the flight envelope will sometimes stretch the structure, eh.

Ih82crash

Man I didnt see anything in that video that would have been too much for the airframe. based on that flight alone that should have never happened. Good job on the video though!!

AA5BY

It looked to me that he had come from altitude at full bore and gave it a hard pull up. At 3:45 the plane pitches up but the wing is still in position so the pitch up is most likely elevator driven. There is no roll moment until well after the pitch, which further evidences that the wing failure came after the pitch up. The hard pitch up is what buckles the spar.

Is it your contention that most planes can handle hard pitch ups at full power after a dive? If so... then your flight envelope is more able than the planes I fly. I sometimes do full power snap rolls but only on uplines and even then I worry a little and I'd argue that a snap roll probably produces less spar stress than a hard elevator pitch because the plane is immediately rolled to a position where the wing knifes into the air stream rather than presenting a full force shear load on it.

Dick T.

My Feedback: (243)

Actually there were a number full throttle abrupt maneuvers that indicate how this model was flown that led to the failure. The powered abrupt pitch up around 41 second mark and the repeat near the end which caused the spar failure. The flying style caused the failure. Giant models cannot be tossed around like a 40 size acrobat. It will bite you as the video illustrated.

Tough loss but hope a lesson was learned.

nitro wing

My Feedback: (1)

When watching the big 3D/free style events, most guys are producing much wilder manouvers.

I think in this case the owner is carrying too much airspeed to enter big G stuff.
That flying field ( if it is one) looks awfully close to traffick, that tumbling wreck could have been serious/fatal to the public had it been further out.

zacharyR

My Feedback: (5)

that sucks

SukhoiKid

My Feedback: (15)

These bigger models (def Krill) are not made to fly that fast for extended periods of times. I could tell what was about to happen right before the crash even happen. Hate to see that though.

MetallicaJunkie

Ive seen Krill's number one pilot Gernot Bruckman really wring out an airframe , what this pilot did was elementary compared to what it should be able to withstand... definitely a defect

http://www.youtube.com/watch?v=O7BxukD4CTo


http://www.youtube.com/watch?feature...BYr2IcXY#t=15s

nitro wing

My Feedback: (1)

I would asume the Bruckman team, really goes thru this airframe prior to competition, perhaps even modifying a few things.
Vid #1 was mellow with little heading changes, and airspeed was low, mostly.
Vid # 2 had some agressive pitch changes, most done at low speed, but a few hard kickers in there for sure.

It would be advisable to recheck or reglue some structure items if pushing the very limit.

I cracked all the inner wing tuberibs/sheeting on one wing on an EF Yak on a fast downline/ Parachute, I had noticable dihedral [X(]
It fixed fine. Other have abused this much more without this occurance. Always check the structure no matter if its great planes or Krill.

I doubt any compensation is suitable for the owner, too bad so much other damage beside airframe was done.

Ih82crash

I do maneuvers with my wild hare 35% giles that make flight that look like basic Imac flight. If that is all of the stress a Krill can take, then I am definitely out. Maybe that is why they began making planes with wing tubes rather than spars.

Dick T.

My Feedback: (243)

The top line factory and sponsored pilots generally fly and discard airframes under 100 demo flights. One usually sees them for sale at various times. Also the top pilots usually understand aerial dynamics and fly accordingly within limits of the airframe. They rarely destroy one in the air.

I have watched an analyzed many demo routines for my own education. I see smooth use of power, speed and controls. It is easy to evaluate if one isn't watching in an open mouth, wow-wee state.

Too many wannabe 3D'ers lack the knowledge to understand the dynamics involved but only want to impress. When the expensive toy breaks it is never their fault.

speedracerntrixie

My Feedback: (29)

A 26 lb 35% airplane is not going to generate the same stress levels as a 40lb 40% airplane. IMO the pilot overstressed the airplane over a period of time and it was this one high G pitch up and roll that finally did him in. A composite airplane can suffer some structual damage and not fail right away like a wood airplane. I would not be pointing a finger at Krill on this one.

nitro wing

My Feedback: (1)

I somewhat agree to the above and want to add that we dont have a background on the plane, was it new, used, damaged and used? new assembled and checked or not??, Most of us are able to damage an airframe in flight.

TimBle

I agree not enough background to even view this video as anything other than interesting

MetallicaJunkie

so true

rc_buster

Hi Dick ,


I agree with the part that experienced pilots knows the limit of each and each airframe.

from the video I can only see a over G's from faulty Snap after a very(very) long dive , at very high speed .



About the life time of the airframe , I average on my last two Krill models (YAK55M , SU29) around 250 flights , most of them aggressive.


Its very hard to know what hapend , I have a lot of ideas why this heppend , but non of them because faulty spar , or any manufacturing defects.


for full disclosure , I fly KRILL AIRCRAFT airplanes as team pilots for the past 6 years .


Safe flying ,
Ido

MetallicaJunkie

Ido Segev! http://www.youtube.com/watch?v=LpWyn_mjkds nice!

Revy

My Feedback: (1)

100+ mph into a "wall"...what did you expect?

Dick T.

My Feedback: (243)

Thanks for the comments and good to know about your personal airframe's longevity. Obviously you maintain and fly it with care.

I know several sponsored pilots stateside and they part with their demo planes under 100 flights to avoid potential embarassment of a failure during a demo. They are excellent pilots who understand the limitations and have never pushed a plane to a point of failure. Their planes are readily purchased by other flyers who get varied milage from them.

Continue the success you have with Krill Aircraft, it is a positive testament to your skills and validates the manufacturers quality.

thepamster

I only noticed an actual throttle control when he taxied and took off. After that it seemed to be full throttle the entire flight. This was pilot error in my opinion.

The Pamster

mrbigg

My Feedback: (21)

Seen a cool video of Jesky a while back doing a nice IMAC style flight with very smooth snaps. Sounded like he was at full throttle and would pull it back, snap, back to full throttle and be back on his way. Very impressive and smooth. Still working on it myself.......

TimBle

I've seen Goldwing, Pilot-Rc and Slipstream ARF's put through worse and survive.
I don't think the flying style was an immediate issue.

It's likely repeated overloading of the airframe or a defect.
But hangar rash can also create problems.

It was a beautiful airplane though