Author Topic: Maiden Flight: 72 inch PICA 1/5th Scale WACO-YMF 08-05-18  (Read 13 times)

0 Members and 1 Guest are viewing this topic.

Offline Paul Lange

  • Moderator
  • *****
  • Posts: 547
Maiden Flight: 72 inch PICA 1/5th Scale WACO-YMF 08-05-18
« on: August 06, 2018, 11:32:26 am »
This airframe is spot on Gorgeous.....the only complaint I have is the access to the battery compartment which is from the bottom fuselage with a nice removable access hatch just forward of the landing gear....so the plane must be upside down to swap batteries.....a plane this size and heavy is a bit awkward to flip over.  I may build a special rotiserie for this effort?

Yesteray (08-05-18) I did my maiden:
Winds gusty out of the SE 10-13mph or better
At or about 7:15pm (Bob is my trim man, Jim is at the flight line videoing via his iPhone and Brian on hand to witness)
I had charged the 6v 2300mAh NiMh flight battery at .5amps for 4hrs total with a resting voltate at or near 6.9v on the test meter
The two 4s 40c 3600mAh LiPo were fully charged and inserted as designed in series for 8s motor power train
I noticed the airframe was not center trimmed when I bound the Spectrum AR6210 with external satellite antenna to my Spectrum DX6 transmitter - so I trimmed all control surfaces to neutral from the transmitter instead of physically setting control surfaces to neutral on the aircraft thinking it may trim back to what I witnessed at intial binding.
I have no manual for setting up COG but figured since the batteries that were left in the WACO seated full forward as possible from its last known flight (I suppose) that were still fully charged....my batteries of choice would work fine mounted same way forward as they are a tad bit heavier by 10grams.

After taxing out into the wind and adjusting a wheel pant....I slowly applied power and stabbed some rudder as she picked up the tail right away and rolled about 10yards where she litterally floated up like an elevator!!! Easy and ubra stable flat at about 50% throttle on the 18x10 APC prop.  The WACO was very easy to fly and was handling the wind as expected......it needed only a scoshe of down by a couple of transmitter clicks elevator down. On the 3rd pass Bob suggested I take it up into the wind at 45degrees and roll it over inverted to check COG.  It rested just fine inverted with (Maybe) a hint of upward tendancy.  If there was any tail heavy bias at all I ....could not tell  - as it was stable yet pretty nimble.  Since I had no bench mark set for battery load and flight duration....I had set a timer for a 5min flight.  So at 3:35 into the flight I wanted to start shooting landing approaches to learn the glide slope and decent rate.  My first pass was perfect and very slow but the wind blew it back up for an aborted landing.....the ensuing go around was excellent with no P-Factor or rolling tork as I applied power to climb out heading south.  Another smooth left turn in an aggressive bank she pointed back north down wind with ease.  As I boxed left again in the north east corner heading west.....she abrubtly rolled over on her back and I lost control.  It then snapped back right with nose to the sky as I was trying to counter transmitter sticks for level flight....I finally let go of the sticks for a second and blipped the throttle as it dipped nose down and rolled again...I continued pulling back the throttle where I was just able to get her flat winged for level flight and was able to point the nose toward us and center runway.  The airframe was still "Jittery" as it darted southward at or near 50% throttle.  Bob strongly suggested to get it down if at all possible on this pass....again the wind was picking it up so I kept pointing down while reducing throttle while keeping wings flat....she finally landed long and coasted into the rough with no damages what so ever.....but less than an inch from the right wheel dropping off into an irrigation inscpection hole cover (it might have rolled it over)

I was able to pull it back onto the runway green and taxi back without issue.  It sure as heck lost control in the North East corner of our field.  Triny who was watching from the pits thinks it was loss of flight battery voltage and suggest that I change to LIFE battery and toss the NiMh battery.  I did make a  range check after my maiden with no evidence of issue. 

Just for notes....I had warmed up this maiden with a flight of my FMS 1700mm P-47 on Spektrum radio system and Bryan had been flying his FMS Electric warbirds and jets just prior to my maiden.....all without issue. 

I am thinking to agree with Triny to lend fault to the flight battery....will replace with 6v Life battery with same form factor to fit the tray.

This aircraft will be pure joy to fly....and for the record.....is "Fully Acrobatic" as noted when all the monkeys came out during the control loss at our infamous GSWAM Trinity River Bottoms Netarian Nebulous Time Continuem Vortex North End Corner.

I should have the video uploaded later today for reference with smaller photos posting to this thread.

One last note....the 4s 40c 3600mAh LiPo batteries both had 3.95v left on each cell after the 4minute flight and long taxi from the south rough back into center gate.

https://youtu.be/Hl9iccRImWo

Paul H Lange
« Last Edit: August 06, 2018, 01:50:54 pm by Paul Lange »
Best Regards - Paul H Lange