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HomeAircraftHelicopterAerial Photography and Video › first crash with camera...
11-05-2004 05:55 PM  13 years agoPost 1
DANNO

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St. Petersburg, Florida

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hey guys....

well it was bound to happen. i was out taking pics for the website and while decending fairly rapidly, i added throttle at about 20 feet high to slow the decent....the heli started to slow then started falling faster again, with no drop in headspeed. then it was as if full left cyclic was applied and at bam, into to grass. this is my eco16, not the joker ..phew... but its still bad...will need new blades, boom, and shafts. camera seems ok though....

im not sure what caused this crash. it was a little windy but ive flown in windier and not had this happen...the heli was only about 50 feet away from me when it happened. all the ball joints popped off so i dont know if they were due to impact or happened before.....


well, time to break out the checkbook...

www.skypiximaging.com

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11-05-2004 06:37 PM  13 years agoPost 2
Torsten

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Germany

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sounds like you flew into your own downwash.

unless your absolutly positive that it happend while flying into the wind.

a decending aproach with the wind can be just like a vertical descend in no wind.

once you are in your own downwash adding power does not help it only makes it worse. you can only fly out of it, best into the wind.

I fly two logo 20 photohelis and with the cameragear they act pretty scale too.

better luck next time

t

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11-05-2004 07:31 PM  13 years agoPost 3
bell-230

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sonoma, ca (currently milano italy)

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you're flying camera gear on a eco 16?! i was flying a 2 1/2 lb camera gear and i thought i was over doing it...... i'am actually even getting a new camera the optio s5i( bring my camera weight down to 1 1/3eek: but back to topic! i have repeatedly gotten the downwash effect, i agree with torsten, what you're describing sounds exactly like downwash! i get it quite often some as i fly( without camera equip.) most commenly occurs when i transfer from forward flight in a vertical decent manner to my flare. it happens to me in all condtitions wind or not. it never seemed to be that big of a deal to me, but i did get quite a few close calls! whenever i expeirience downwash its basically like the helicopters pitch curve goes out(even though it isnt) and just falls through its own dirty air so it produces low/ no lift i noticed flying forward through it is the trick not trying to climb out

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11-05-2004 09:03 PM  13 years agoPost 4
DANNO

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St. Petersburg, Florida

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hmmm...the decent was more or less vertical with a tailwind. the area i was flying from was a small park with a many tall trees so not much room for forward flight...just striaght up to about 150 feet take the pics and back down...

im not sure i understand fully how the flying into your downwash causes rapid loss of altitude, could you explain this to me? also what measures do you take to prevent this/ get out of it?
thanks
danno

www.skypiximaging.com

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11-05-2004 09:09 PM  13 years agoPost 5
Torsten

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Germany

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jepp,

sounds like downwash to me.

picture your helicopter in a vertical wind tunnel with smoke in the air that is being pushed downwards by the rotor.

then lower the helicopter to a point were it is dropping so fast that it no longer takes in fresh/calm air from the top, but is already in the used/falling air it just pushed down.

there you go.

got it ?

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11-05-2004 09:17 PM  13 years agoPost 6
Torsten

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Germany

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and you can prevent this by "repelling" real slowly if it has to be a vertical descent, or by keeping some forward speed INTO the wind.

with the wind at the wrong speed leaves you moving over ground but not in relation to the sorounding air causing the problem again.

i try to go step by step if i have to do a vertical descent. slowly down 6 feet. pause (make sure the helicopter still "hangs" on the pitch stick) then another 6 feet etc.

always plan you flight in and out before takeoff and also say NO to a customer if you feel it is unsave. they understand. youré the pilot and responsible.

t

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11-05-2004 09:25 PM  13 years agoPost 7
DANNO

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St. Petersburg, Florida

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yes i think your right...thats what it was....ive noticed this happen before but never atributed it to downwash, and have always been high enough to get of it before...

anyway this is good to know....i learned something new....i hate crashes when you dont learn anything plus i can be realativlty assured it was not radio problems...

thanks

dan

www.skypiximaging.com

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11-05-2004 09:30 PM  13 years agoPost 8
Torsten

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Germany

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my pleasure.

i just checked your homepage and noticed youré in St. Pete.

i lived in cocoa beach during my high school days until 82´.

we had friends in St. Pete that we visited now an then.

t

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11-05-2004 10:30 PM  13 years agoPost 9
Clicky finger

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Christchurch, New Zealand

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Can relate to the comments about down-wash being a real killer. It was the cause of my first ever crash with my heli ship. Although I have occassionally been caught out since, it's never resulted again in the 'kiss-of-death.'

I was trying to photograph my sisters house in a strong breeze. Climbed out into wind, then turned back towards the house in forward flight, decending towards it. My forward speed was only relative to the ground however. Air speed nill. Lift.... nill. Oh bother! Hit the ground hard under full power still vainly looking to arrest the decent.

There are three factors involved. Airspeed, rate of decent, and power to weight ratio. The lower the power to weight, the more critical airspeed and rate of decent becomes. What we are all doing is basically lowering the power to weight ratio of our models because of the additional equipment we are carring.

In the early days, my reserves of power were so low, there were times I simply couldn't fly, (high altitude, no breeze, low barametric pressure, high temperatures) because once out of ground effect, under full power, the helicopter would only hover, it couldn't climb. And there were times the only way I could stay airborne after struggling into the air was to maintain translational lift. Stop and hover for a photo? No way!! I was originally carrying 1.2 kg (2.4 lbs) worth of transmitter, 12 volt gel cells to power it, and board camera. The present equipment shaves 1.0 kgs off that. That plus a greater lifting capacity makes for a much happier pilot! I do have sufficient reserves of power now with the equipment I commonly lift to break free of my own downwash, but it is still bad practise to be flying in a manner to find yourself in that situation to begin with.


The basic principle regarding flying style is if you are decending rapidly, you HAVE to maintain airspeed. If you are trying to decending straight down on a calm day, exercise extreme caution with the rate you come down at. SLOWLY does it.

Something to take note of is the sound the blades are making. It is a more unstable sound they make when running out of lift because of the above. If you do find yourself in that situation, applying power and forward stick to gain airspeed should sort the situation out.

DANNO, good luck with the rebuild. Hope you are airborne again soon.

Pete

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11-05-2004 10:54 PM  13 years agoPost 10
daggit

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Claremont, MN

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The downwash effect is definately a bigger factor on a heavy helicam.

In the beginning I was fooled by the effects of downwash. I thought there was something wrong and I was getting some kind of swash plate interaction. It took me while to realize that it only happended on the decent (yeah, I'm a little slow).

Ever notice that full-size heli's don't come straight down?

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11-05-2004 10:57 PM  13 years agoPost 11
Davo

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London, UK

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Are we talking vortex ring state/ turbulent wake state here? I thought r/c helis weren't susceptible to it.

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11-05-2004 10:58 PM  13 years agoPost 12
Torsten

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Germany

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thats what i meant by writing my photohelis handle pretty scale.

the power to weight ratio is almost as bad as the real thing.

we rc pilots are just spoiled with the ammount of power we have.

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11-05-2004 10:59 PM  13 years agoPost 13
Torsten

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Germany

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we be talking vortex donut dude !

i guess , have to read it up myself now.

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11-05-2004 11:08 PM  13 years agoPost 14
daggit

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Claremont, MN

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yeah.... vortex donut

If I descend slowly in the downwash my helicam will ride the "donut" like a surfer on the waves.

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11-05-2004 11:10 PM  13 years agoPost 15
Torsten

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Germany

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then check this here to fill your donut

thats what it looks like and what i tried to get across when i was talking about the smoke.

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11-05-2004 11:21 PM  13 years agoPost 16
DANNO

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St. Petersburg, Florida

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cool photos! its all pretty clear now....

yea thats what got me i think. bit it due to vortex donut....well, atleast i got a few good photos out of it

thanks guys!

www.skypiximaging.com

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11-06-2004 12:04 AM  13 years agoPost 17
bell-230

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sonoma, ca (currently milano italy)

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danno how long have you been flying? i was expeiriencing downwash since my first day (of forward flight/ ascending decending) where you self taught danno?

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11-06-2004 01:01 AM  13 years agoPost 18
waterskier

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Crosby, Texas

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I think the key is to not do a desending hover, treat each approach similar to an auto, plus that way if you have a power failure on the way down you are already set up for the auto. Pull the collective back to 0 deg or even -1, with transitional lift the heli will desend a a controable rate much like an auto, but not quite as fast. If you can do it into the wind you can come almost straight down, if you have to approach down wind, it will have to have more slope to it. This prevents the top of the disk from sucking in the "dirty" air.......Works for me....but if you have a tight space, no wind (or tailwind), and underpowered heli....don't do it.......

GOT POWER?

Greg

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11-06-2004 03:05 AM  13 years agoPost 19
tabbytabb

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seattle

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Yep, sounds like you settled with power.

I have done this a few times in similar circumstances with my Joker but luckily it has loads of extra power and can grunt its way out of my mistakes.

Best to fly to the landing site almost as you would an airplane to assure yourself a constant supply of "clean" air

Sorry to hear about the crash!

Tabb

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11-06-2004 05:25 AM  13 years agoPost 20
bell-230

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sonoma, ca (currently milano italy)

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how did the mount itself take it? or was it more of one of those roll over type incidents?

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