Not long ago I was talking with a friend who produces gorgeous aerial videos with a Tarot Iron Man he had built. He’d fitted it with a NAZA M V2 flight controller and I was intrigued with his description of the NAZA’s inherent stability and simplicity to setup, and the fact that he’d never experienced any issues with his flight controller.

With my confidence in the NAZA boosted I decided to take a gamble and replace the APM 2.6 flight controller in my XuGong 10 with a NAZA M V2. The results were phenomenal! Even after many hours of tweaking and PID tuning on the APM it never approached the dialed-in stability that the NAZA exhibited straight out of the box. I was so impressed with the results that [in my hubris] I decided to swap out the aging APM 2.6 on my large hexacopter and install a similar setup.

It was shortly after the accident that I discovered descriptions of ‘flyaways’ associated with DJI products show up disturbingly often in RC forums. In fact, a poll on RCGroups indicates that 1-in-3 pilots flying with DJI-made controllers have lost control of their aircraft to flyaways and half of them never recovered their machines.

Flyaway

The doomed flight began with nothing appearing out of the ordinary and came on the heels of two uneventful flights I had made that same morning, both in GPS mode. This wasn’t the first time I had flown this setup — I’d made 10 or 12 flights since the install two weeks earlier, all of which had gone extremely well with the hex feeling very locked-in.

I was flying LOS and waited until the NAZA’s status LED was flashing all-green for at least 30 seconds before takeoff, indicating that I had a good GPS lock. The NAZA was in GPS mode on liftoff and it ascended to 200 feet where I began a slow 360-degree rotation while hovering. It’s also worth noting that I had geofence limits in place with the altitude set to a maximum of 200 ft., the radius set to a maximum of 50 ft., and I had performed both an advanced calibration and compass calibration just a few days before the last flight.

When you watch video you there is a moment about three quarters of the way through the rotation when the hex begins drifting badly and — even though my indicated RSSI was very strong — it was completely unresponsive to my inputs.

Tried Atti mode and it wouldn’t respond.
Tried Home Lock and it wouldn’t respond.
Tried Failsafe and it headed in the opposite direction.

Within a minute I lost sight of it and all I could do was hope it maintained its altitude as I monitored the telemetry and prayed.

Several minutes passed and the altitude suddenly went into negative numbers and I presumed the copter had crashed. I did a disarm, grabbed my Tx, and headed out in the car hoping the RSSI signal would lead me to the crash site. After driving around a while I eventually came to a spot where the signal was at its strongest and parked the car to head off on foot. As soon as I stepped out I could hear the faint beeping of the motor beacons which lead me to the wreckage (thank you BlHeli).

What should have been a few minutes of safe hovering had quickly turned into a terrifying nightmare, but I got lucky. Very lucky. I found the hex crashed in some tall grass by the side of a road. It was utterly destroyed but it didn’t do any property damage and it didn’t injure anyone. Thank God.

I'm rebuilding the hex with a Pixhawk flight controller direct from 3D Robotics because NEVER AGAIN NAZA.

---

Relevant Stats

The Machine

• NAZA M V2
• Firmware: 4.02
• GPS
• 4S 8000mAh 30C LiPo with full charge
• Failsafe set to return to home
• Props and motors finely balanced
• FrSky X8R receiver
• Battery and altitude telemetry
• FrSky Taranis Plus transmitter
  

Weather

• Cloudy
• 65F / 18C
• 73% Relative humidity
• Winds avg. 12 MPH / 19 KPH
  

Not long ago I was talking with a friend who produces gorgeous aerial videos with a Tarot Iron Man he had built. He’d fitted it with a NAZA M V2 flight controller and I was intrigued with his description of the NAZA’s inherent stability and simplicity to setup, and the fact that he’d never experienced any issues with his flight controller.

With my confidence in the NAZA boosted I decided to take a gamble and replace the APM 2.6 flight controller in my XuGong 10 with a NAZA M V2. The results were phenomenal! Even after many hours of tweaking and PID tuning on the APM it never approached the dialed-in stability that the NAZA exhibited straight out of the box. I was so impressed with the results that [in my hubris] I decided to swap out the aging APM 2.6 on my large hexacopter and install a similar setup.

It was shortly after the accident that I discovered descriptions of ‘flyaways’ associated with DJI products show up disturbingly often in RC forums. In fact, a poll on RCGroups indicates that 1-in-3 pilots flying with DJI-made controllers have lost control of their aircraft to flyaways and half of them never recovered their machines.

Flyaway

The doomed flight began with nothing appearing out of the ordinary and came on the heels of two uneventful flights I had made that same morning, both in GPS mode. This wasn’t the first time I had flown this setup — I’d made 10 or 12 flights since the install two weeks earlier, all of which had gone extremely well with the hex feeling very locked-in.

I was flying LOS and waited until the NAZA’s status LED was flashing all-green for at least 30 seconds before takeoff, indicating that I had a good GPS lock. The NAZA was in GPS mode on liftoff and it ascended to 200 feet where I began a slow 360-degree rotation while hovering. It’s also worth noting that I had geofence limits in place with the altitude set to a maximum of 200 ft., the radius set to a maximum of 50 ft., and I had performed both an advanced calibration and compass calibration just a few days before the last flight.

When you watch video you there is a moment about three quarters of the way through the rotation when the hex begins drifting badly and — even though my indicated RSSI was very strong — it was completely unresponsive to my inputs.

Tried Atti mode and it wouldn’t respond.
Tried Home Lock and it wouldn’t respond.
Tried Failsafe and it headed in the opposite direction.

Within a minute I lost sight of it and all I could do was hope it maintained its altitude as I monitored the telemetry and prayed.

Several minutes passed and the altitude suddenly went into negative numbers and I presumed the copter had crashed. I did a disarm, grabbed my Tx, and headed out in the car hoping the RSSI signal would lead me to the crash site. After driving around a while I eventually came to a spot where the signal was at its strongest and parked the car to head off on foot. As soon as I stepped out I could hear the faint beeping of the motor beacons which lead me to the wreckage (thank you BlHeli).

What should have been a few minutes of safe hovering had quickly turned into a terrifying nightmare, but I got lucky. Very lucky. I found the hex crashed in some tall grass by the side of a road. It was utterly destroyed but it didn’t do any property damage and it didn’t injure anyone. Thank God.

I'm rebuilding the hex with a Pixhawk flight controller direct from 3D Robotics because NEVER AGAIN NAZA.

---

Relevant Stats

The Machine

• NAZA M V2
• Firmware: 4.02
• GPS
• 4S 8000mAh 30C LiPo with full charge
• Failsafe set to return to home
• Props and motors finely balanced
• FrSky X8R receiver
• Battery and altitude telemetry
• FrSky Taranis Plus transmitter
  

Weather

• Cloudy
• 65F / 18C
• 73% Relative humidity
• Winds avg. 12 MPH / 19 KPH