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View Full Version : OOOPS Blaming it on the AP2000i!


furyphoto
08-19-2008, 05:39 PM
Well, every crash is ultimately pilot error, I am pretty sure this wouldn't have happened if I was using an inertial stabilizer instead of an IR stabilizer.

Almost everywhere I have to fly is limited to taking off between tall dark trees, but flying above them in the bright sunlight. So I have to calibrate my AP2000 quite high in the sunlight so ti will remain steady while I shoot. Anyway, at the end of the shoot , about 4 feet from landing, the heli, now in the shade starts to drift quite strongly to one side, so much so that almost full right stick is not stopping it from drifting left towards the dark green shrubs, realizing what the problem is, I quickly lower the gain on the ap2000i to avoid hitting the shrubs (perhaps a bit too quickly), Since I was hold almost full right stick to correct for the drift, the heli immediately rolled 45° to the right. PANIC, over correct, over correct, slap the ap2000 gain back up to try to stabilize, nose in by this time, the heli shots off in the opposite direction, straight sideways, into the trees. Whole thing lasted about .6 seconds

http://www.helifreak.com/attachment.php?attachmentid=59593&stc=1&d=1219180370

:DOH

Hindsight: lots of things I could have done different to prevent the crash, and lessons learned, but I can't get over the thought that if I was using an inertial based stabilizer that this never would have happened. I think the AP2000i is fantastic is many conditions, especially in open spaces, Arizona, Saskatoon, Florida, etc, but I think that where I mostly fly, it might not be the best tool for the job.

Having said that, does anyone have an FMA sensor for sale so I can get it back in the air while I contemplate dropping $650 on a Helicommand Rigid?

Total Damage (So far)

1 Askman 360 mount leg (Askman, how much for a new one!)
1 rotor head (sheared off, probably saved a bunch more damage)
A few pitch links
1 blade grip
horoz fin
2 tail boom supports
tail boom (I'll put a new belt in too cause it was pinched pretty good, looks OK, but not worth the risk!)
FMA Sensor (80% M.I.A.)
RX antenna - Trisected, middle M.I.A. ( I could used some experienced advice on this one)

CF Blades, hardly damaged, probably saveable
Flybar, not even bent
Main Shaft (solid!) straight and true!

If you don't want to crash it, don't fly it right?

waiting for parts,
-A

Griffo
08-19-2008, 07:38 PM
Ouch! Sorry to see that Andrew. II feel your pain. Hopefully you'll have it back up there in no time.

I only ever have stabiliser gain on when I need to hover the heli at altitude and always reduce the gain back to zero when landing or close to the ground. There's no need to have it on for landing, especially below the tree line.

I had the AP2000i turn my fully laden AP Logo700 upside down at an altitude of about 100ft. I stupidly applied maximum gain after a rebuild and hadn't realised that I'd reversed the stabilser direction. It took half a second for the whole thing to rotate 180 upside down! Luckily I always have my finger on the gain lever and was able to switch off the gain and bring the heli back to a hover. The whole event took about 2 seconds and by that stage the heli was 10 ft off the ground... my heart rate was through the roof!

Rules I've learnt using the AP2000i:

1. ALWAYS recheck stabiliser after changing anything on heli.
2. Have gain on a slider and apply gain gradually
3. Only use stabilisation above roof/tree line (if you can't fly without it you shouldn't be flying)
4. It pays to cut out the crappy FMA plug and solder the connections directly to the FMA circuit board (Then apply hot glue).
5. Maximise distance between AP2000i unit and RFI emitting devices
6. Ensure that the FMA sensor is stuck down firmly and double up with a zip tie for insurance.
7. Have FUN!

Griffo

chris24g
08-25-2008, 12:19 AM
agree with griffo. you should only use the stabilizer when necessary. when taking off or landing, the heli should be under total pilot control.

aramsdell
08-25-2008, 06:03 PM
I commonly land with a low stabiliser gain. Just set your cyclic to high rates so you can easily override the AP2000. I find this tends to smooth out any jerky motion you might accidently impart to the heli. This could be useful for those not really comfortable with nose in up close .
I've also taken to using the default calibration on the 2000. It seems to work more consistantly than constantly(each flight) readjusting the cal.