How to properly crap yourself

Lola · May 03, 2015, 10:57:26 AM

Morning all,

Sunday morning, wife and daughter still asleep, changes made to the Sh and off for an early morning test flight at the field.

I stuck the 808 on top of the pan and tilt but this time its powered using 1 cell of a proper lipo, the result is ok but a thousand times better than before.

vTx is in the wing with the inverted vee, two sBecs soldered in front of the powermodule, one for the minimosd and the other to power the back servo rail.

set up as usual, double checked and triple checked then off I went. Flying around for 5 mins got her all trimmed out, tested RTL and all was ok. So....what to do? I know, I´ll do some low level practice, nothing spectacular.

All is well and then I thought i know, i´ll push it a bit. Now normally this is the time when you should land, maybe pack up and go home. But no.... So out to 5k in stab mode, turn round to come home and then i think to myself...

how low can you go? Well, Video lost at 70 meters and this is what happened next....

Skip to 7 mins from the end.

http://youtu.be/29NsXKYEkT0

Jake Bullit · May 03, 2015, 11:05:40 AM

Brown pants moment,got it back though.

ASBO · May 03, 2015, 11:39:31 AM

I had a similar thing happen and was due to low voltage from BEC.
Scary when you loose control.....lol

BlueFlyer · May 03, 2015, 11:39:54 AM

i was just waiting for it to plough in lol

Lola · May 03, 2015, 11:46:47 AM

I just pulled up to hard. It stalled and then I lost video again. I gave it full throttle and counted to five, then hit RTL. After 10 seconds the video came back and started to breathe again. Stabilization pulled her out of the spin. APM to the ultimate test. Lol

BlueFlyer · May 03, 2015, 11:50:50 AM

it had five seconds on full throttle before you hit RTL? (counted to five)
your skills and knowledge is what saved you here, not the stabilisation. Sure the stabilisation is what returned the aircraft to level, but it wouldn't have been able to do that in a stall if it wasn't for you giving it the beans.

take some credit dude :)

Coyote · May 03, 2015, 11:58:29 AM

Nice brown trouser recovers Anthony. That was as close as it gets mate.

FPVSteve · May 03, 2015, 12:11:37 PM

Yep, fair play - most would have gone in at that point lol

Lola · May 03, 2015, 12:19:49 PM

Cheers guys for the nice replys :)

I was lucky. I should have paid more attention to the airspeed though, I normally just watch the apms. Thing is I broke my 2 blade prop at home yesterday and had to switch back to my 3 blade. That pulls two more amps traveling at the same speed.

I did wonder though as soon as saw nothing but blue sky...hang on...and then oh S**t! lol

Still, lives to see another day.

Rg´s
Anthony

skyscraper · May 03, 2015, 02:52:50 PM

Whats the fuss about? you had loads of height to spare :laugh:

Seriously though... Nice Catch! Well done.. Good old APM too :)

regards
Andy

Billy_boy_2010 · May 03, 2015, 06:28:10 PM

Do you generally fly it quite close to the stall speed?

I would have thought, even if you pulled up fairly harshly- it would have gained a fair bit of speed and momentum having descended fairly quickly?

Anyway- as others have said only experience can save you in that situation. I don't think I would have had the peace of mind to nail the throttle, pause, and then hit stab mode :s

Billy_boy_2010 · May 03, 2015, 06:30:03 PM

Also what made you lose video? Just quite far out and violating the fresnel zone?

Lola · May 03, 2015, 06:38:27 PM

Quote from: Billy_boy_2010 on May 03, 2015, 06:30:03 PM
Also what made you lose video? Just quite far out and violating the fresnel zone?

I was pushing the limit as I always do, I wanted to see how low I could go. The countryside here is very flat.

I pulled up because I lost video but obviously to harshly with only 40 % or so throttle. Then I had a camera full of blue sky and cloud and I quickly realized what was going on. Then the left wing dropped and I had to nail it. Then the video went again as she went earthbound but came back after 15 seconds or so as she was climbing again.

I was in stab all the time, just hit the RTL after I counted 5 seconds directly after the stall.

Billy_boy_2010 · May 03, 2015, 09:15:43 PM

Ah right.

I would have thought having stab mode on would have exacerbated the stall as it would have constantly tried to correct the stall before you had sufficient airspeed?

And wouldn't stab mode have sorted it out alone when the airspeed was sufficient? Without the need to RTH? It looks like the RTH was what righted it all of a sudden?

A good advert for apm as you say :)

I really must practice some stall recoveries. I'm always quite worried about stalling as I fly wings. A couple of batteries spent practicing stalls a few mistakes high would be terrifying but time well spent I expect. Even learning what a stall looks like in fpv would be handy instead of assuming it's God or a massive gust of wind.

Lola · May 03, 2015, 10:19:30 PM

Quote from: Billy_boy_2010 on May 03, 2015, 09:15:43 PM
Ah right.

I would have thought having stab mode on would have exacerbated the stall as it would have constantly tried to correct the stall before you had sufficient airspeed?

And wouldn't stab mode have sorted it out alone when the airspeed was sufficient? Without the need to RTH? It looks like the RTH was what righted it all of a sudden?

A good advert for apm as you say :)

I really must practice some stall recoveries. I'm always quite worried about stalling as I fly wings. A couple of batteries spent practicing stalls a few mistakes high would be terrifying but time well spent I expect. Even learning what a stall looks like in fpv would be handy instead of assuming it's God or a massive gust of wind.

Going back to my IC days I would practice stall turns, spins and so on but all that was in view. With FPV you don't have the view nor the rotation of the aircraft. What we need is a simulator seat which rolls and pitches to that of the aircraft. Imagine that! God I come up with some great ideas. Lol.

I've watch the video over and over again and counted the 5 seconds from the start of stall which is the same time I gave it full throttle. The SH has just recovered from the spin and is pulling up as the 5 seconds end and it's at that point I hit RTL. Don't forget from the moment of stall the video is gone.

The video then shows the SH turning and gaining height, still on full throttle. A few seconds later the video started coming back.

Normally when you spin you have to give opposite rudder as the ailerons have a limited effect but the SH as you know does not have rudders. Luckily the spin was not vicious and the stability mode did level the plane, I did not pull on the sticks as that would have been fatal. I knew the plane needed airspeed asap and the apm did a fine job.