Mayday! Mayday! I tested the FPV system on the Raptor140B, with nearly disastrous results. Luckily, the APM was onboard to save the day!

I added the 400mw 1.3Ghz FPV transmitter to the 140B, and took it for a test flight. Right after take off I had significant control issues, and barely recovered the airplane. Thinking it may have been the flight controller, and wanting to determine the cause while the same circumstances were available, I double checked all connections and systems, and flew the aircraft again.

Again, it had significant control issues, even in manual modes. Luckily, the APM flight controller was able to safely loiter the airplane overhead while I determined that indeed the Turnigy 9x transmitter was no longer able to safely control the airplane.

This required me to create a mission mid flight, update the mission, update flight parameters, and attempt an autolanding, the first time I've tried this feature.

Watch the find out the results!


Safety Statement: To maintain safety, I prepared by doing many thing things including:
-obtaining personal permission from a vast majority of property owners (I couldn't reach all of them)
-maintained a continues watch for full scale aircraft, and;
-maintained direct control of the aircraft for the majority of the flight
-this airplane and system has OVER 1,000 MILES of perfect performance, with 90% of it autonomous with this exact set up. It has been tried and proven many, many times, including over 200km of cross country flights
-the autopilot was programmed to continue to fly after a signal loss, which has been tested and proven to perform many, many times
-the flight was over a very open and low populated area, with 99%+ of the area being open fields or trees
-the altitude read over 120m, but elevation increased during flight as I took off out of a low valley. True AGL for the flight is 100-120m. 
-avoided all airports and populated areas.
-I've flown at this location 3-5 times a week for the last year. I know it very, very well.
-I conducted test flights with the new set up that I did not show during the video to confirm stable performance

Raptor 140b+ Stats:
Weight: 2280g
Max Flight Time: 70min
Max Range: 97km
Stall Speed: 35kph
Cruise Speed: 90kph
Max Speed: 135kph
Radio Range: 1.5km
Energy Carried: 167wh (15,000mAh at 11.1v)
Drive Power: 850w
Total Flight Time on Craft: 7.0 hours
Total Flight Distance on Craft: 498km

The equipment used---
Raptor 140 airplane:

Radio Tx: ParkeFlyer Turnigy 9x Tx:
Telemtry: 915mhz 100mW 3DR
Laptop: Compaq Presario CG57
GPS Dongle:

Flight Controller: APM2.6
Reciever: 6ch FlySky
Telemtry: 915mhz 100mW 3DR
Battery: (3) 5.0Ah 20C Lipo:
ESC: 60A Brushless
Motor: 3542 1450kv brushless
Prop: 10x7 Carbon Fiber Folding
Servos: 11g digital
Onboard camera:

Learn More:
Raptor Details:
USA Trip Details:

Follow the Show:
Skype: MyGeekShow

Filmed, Edited, Produced and Published by Trent in Arkansas, USA

Views: 2972

Comment by Thomas J Coyle III on April 16, 2014 at 7:23am


Since you have quite a bit of money tied up in your aircraft systems, why not spend the money and buy a quality Spektrum or other major brand transmitter/receiver combo.

I have yet to have an issue with my DX7/DX8 transmitters.


TCIII ArduRover2 Developer

Comment by UAS_Pilot on April 16, 2014 at 7:46am

I did the same thing with my JR9303 and lost my plane. So it shows that swapping to the more expensive radio will not fix the issue. The 900mhz video and 1.2/1.3 video systems interfere with 2.4ghz period. I would recomend the use of a low pass filter. 

Comment by Trent at MyGeekShow on April 16, 2014 at 7:48am

Thomas: I'm sure a better Tx/Rx would handle it better! We'll see if the budget is there before the USA trip : ) I think some distance and filters addition should improve it as well. 

Dave: Oh yes. I've never had to 100% rely on the the APM and telemetry like that. I've always had the Tx in the background to help as needed. So happy that I've tested it extensively (except autoland!) and have confidence in it's functionality.

Comment by Thomas J Coyle III on April 16, 2014 at 7:52am


I use this low pass filter on my 900MHz video transmitter: Filter


TCIII ArduRover2 Developer 

Comment by Mustafa TULU on April 16, 2014 at 8:55am

No need to change 9x, just buy a frsky module for 50 USD. I remember i saw one of your videos that you are using 9x stock module and i said "wow, this guy is a serious risk taker":) We are using 9x sstock module to control the gimbal on our sUAV, the range is not over 20 meters and we had problems like it going nuts. That's exactly what happened to you. By the way one of the best episodes.

Comment by Crady von Pawlak on April 16, 2014 at 9:07am

Awesome save, Trent!  Congrats on setting up your APM so well! Without seeing your rig first-hand it's hard to speculate what went wrong but some of the suggestions being posted here are definitely worth considering.

I have 9X myself but switched to FrSky modules with diversity. They have double the power over the stock 9X (60mW vs. 30mW) and seem more reliable.

Antenna positioning and low-pass filters are worth a look as is a band-pass or high pass filter for your RC Rx.

One of the things that struck me was the confining of your RC antenna to the vehicle interior. I've seen some pretty slick in-vehicle ground stations and one of the things they had in common was they all had there antennas remotely placed on the roof.

Just a thought.

Look forward to seeing another video when you get it sorted.


Comment by UAS_Pilot on April 16, 2014 at 9:08am

I agree, I use the Turnigy 9X with the Frsky module and it is great. I have yet to have any issues...

Comment by Stephen Carlson on April 16, 2014 at 9:08am

Due to the nature of your goal, you may want to invest in a LRS. That would ensure that lost link would be very rare, unless something on the plane or in the area spits out a lot of 430 MHz noise.

Comment by Gary Mortimer on April 16, 2014 at 9:14am

+1 on FrSky they are great. Separate all your antennas put some in the wingtips Trent its what all the big platforms do. Well done on returning home in time for tea and medals.

Comment by Graham Dyer on April 16, 2014 at 9:23am

Cool stuff, never heard anyone get so excited that their plane landed safely, lol

Trent, on a Hitec Aurora 9 I get about 2.4km (7800ft) range without my 1.3GHz VTx (on 1040MHz), about 800m (2600ft) with the VTx on and with a lowpass filter and about 300m (980ft) without the lowpass filter.


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