Anatomy of a 301 km Flight

Today I flew my Cyclops EPO for an incredible 7 hours and 8 minutes, covering 301 km (301 km !!!) in one flight.

After flying my Maja for 126km I decided 200km would be my next challenge. I got the Cyclops with that in mind, it was very very efficient straight out of the box and after my first flight test I realised it was capable of much more.

I did 5 flight testing sessions where I tested different speeds, C of G positions and propellers. The data from my last two sessions suggested 300km was possible with good conditions so that became my goal.

I planned my mission with a couple of waypoint path options that I could switch between using do_jump. After a hand launch I switched to auto for a very gentle climb reaching 50m of altitude over about 2km. I flew a few laps of a 2.5km lap, before switching to a 3km lap and then a 3.5km one which used a do_jump command to fly continuous laps at 60m altitude.

To monitor my progress I’d made battery consumption schedules for 250, 280 and 300 km. My calculations said that I would need to run my batteries down to 10% remaining to reach 300 km. The first half of the flight was very calm and I was ahead of schedule. But the wind picked up in the afternoon and it became apparent that I might finish with less than 10%. I tried to help the situation in the last hour by varying my speed around the lap. I flew at 14 m/s for the head and cross wind sections, and dropped to 13 m/s when I had a tail wind. I hadn't done any calculations to support that, it just seemed that I could make the most of the tailwind section by dropping my power there a little.

I’d decided in advance to end the flight when the battery dropped to 12 V (3.0 V per cell) and I could see as I passed the 280 km and 290 km milestones that it really was going to be tight. The voltage was hovering either side of 12 V as I approached the 300 km mark so I knew it was time to bring it in, but I also knew that Mission Planner can underestimate the distance compared to the GPS log. I decided to fly to 303 km to be safe. The way the laps worked out it was 305 km when I hit the ground, and just as well because the GPS log came up as 301 km. If I’d come in when Mission Planner told me 303 I would have been member of the 299 club.


The telemetry log file is 47 MB (linked below) and Mission Planner crashed when I tried to create the KML file (I tried on three different machines). It did manage the GPX file thankfully.
Key specs:

  • Cyclops E with V-tail
  • APM 2.5
  • Panasonic 18650B Li Ion batteries. 4S7P, 23,800 mAh
  • Aeronaut 11x9 prop
  • Hobbyking telemetry
  • Distance covered: 301km (according to GPS log file, 305 km according to Mission Planner)
  • Flight duration: 7 hr 8 min 10 sec
  • Average groundspeed 41.7 km/hr

Log File (47MB)

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  • Panasonic NCR18650 batteries from this supplier provides then wrapped in a variety of configurations from this

    eBay store (Free Shipping too) hunk_lee (Excellent eBay ratings)

  • What does a liion 4S7P pack of 23800mah even look like?
    I've seen many configurations of them but with that many cells, I'm curious to know what it will look like.
  • MR60

    I might test the Talon as I built a liion 4S7P pack for my 1h15min quad flight (23800mah). I'll post some results.

  • 300km

    I'd love to know. I've heard that the Talon is quite versatile. I've looked at it myself, but I don't think it wing is high aspect enough for real high efficiency flight. The cyclops by comparison has 2.6m wing.

  • MR60

    Very impressive. How do you think a XUAV Talon frame, with wing extensions (2m wingspan) , same type of 700Kv motor, 12" prop, same battery (LiIon 4S7P) would perform versus this cyclops frame you flew?

  • 300km

    They were LiIon batteries not LiPo, and they are fine, I'm still using them.

  • Congratulations.
    In the end, did the LiPos survived or got busted?

  • Excellent work and really great reading mogios, do you have another record planned ? 

  • moglos can you provide the motocalc air frame numbers or saved file for me so I can begin testing?

  • Awesome, would you be able to send me your Cyclops motocalc file with all the CL and CG info and that stuff? al.creigh@yahoo.com.

    I do think they have a 6s delux version.

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