Typhoon H Pro pitches to the right when landing

[Joram Nevversan]

I am new to drones in general and the Typhoon H Pro is actually my 1st and only drone. I got it as a crashed unit that I repaired and it works great most of the time. Every once in a while when trying to land it it will pitch to the right just as it is touching down and the rotors will make contact with the ground and the whole unit will flip onto its back. I have gone through several rotors because of this. It has done this on multiple surfaces from rocks to dirt to grass. What could be causing this?

if this has been covered in other posts, please point me to them.

Thanks in advance,
Joram

 

[WTFDproject]

One suspicion might be you are trying to land with the rate slider in "turtle mode". A common misconception is turtle mode simply reduces controller response, giving the pilot "more control". That is an incomplete understanding. It keeps the power output closer to "neutral buoyancy", in both "up" and "down". Which means when you land, you are not really "landed", and the slightest thing can tip you over. To cure this, all you need to do is ensure the rate slider in full Rabbit Mode and keep the control stick in full down until the motors are stopped.

Another suspicion is a controller issue of some sort. We would need the flight logs to best evaluate this. Please refer to Typhoon H Flight Log Retrieval as needed for guidance on retrieving and posting the flight logs.

A less likely suspicion would be an IMU glitch, compounded with ground turbulence. That one seems unlikely, but IMU issues can sometimes be seen on the Typhoon H GUI. If there is no other anomalous flight behavior, this one seems even less likely.

 

[MountainDroneTN]

Post in thread 'Flipping while landing'
Flipping while landing

 

[h-elsner]

And check with HW monitor if all sticks are centered and values follow the stick movements immediately.

And do a accelerometer calibration. preventative. I do this from time to time and feel good with it.

 

[Steve Carr]

This is the main reason I'm an advocate of using the red button to land. Just hover 12-18" above the landing zone, press and hold the red button and the H will land and shut the motors off. In the rare event it does tip after touchdown the props won't break.

 

[Stephen1988]

This is the main reason I'm an advocate of using the red button to land. Just hover 12-18" above the landing zone, press and hold the red button and the H will land and shut the motors off. In the rare event it does tip after touchdown the props won't break.

Does this work on all models. I can’t recall but will the h480 power off if the button is held. On the h520 hplus will this work also.

 

[Enrico Jorysch]

Does this work on all models. I can’t recall but will the h480 power off if the button is held. On the h520 hplus will this work also.

With the Typhoon H, it only works with the latest firmware.
Bring the drone to knee height... Leave the sticks in the center position... Hold down the red start button.
The Typhoon H lands gently, without the usual bouncing, and automatically switches off the motors.
This has never been documented by Yuneec, but it works perfectly.

I have never tried this with the TH PLUS / TH 3 / H520 and H520E, as these land very gently
and the motors do not need to be switched off using the start button.

 

[Stephen1988]

With the Typhoon H, it only works with the latest firmware.
Bring the drone to knee height... Leave the sticks in the center position... Hold down the red start button.
The Typhoon H lands gently, without the usual bouncing, and automatically switches off the motors.
This has never been documented by Yuneec, but it works perfectly.

I have never tried this with the TH PLUS / TH 3 / H520 and H520E, as these land very gently
and the motors do not need to be switched off using the start button.

Excellent answer.
I’ve had the hex try and tip over after landing on a few of the models, luckily it never did. It’s scary at the time . Throttle fully down and held there but still the same results. It might be if I’m not landing on a perfectly level surface. I’ve read also something regarding the barometer if this could be linked. I’m mostly taking the models out from a warm house and flying straight away with temperatures outside being 0 degrees Celsius up to 5 degrees above freezing. So far luckily no tip over or broken props

 

[Steve Carr]

It might be if I’m not landing on a perfectly level surface.

Landing on an incline or in wind can cause the aircraft to tip. When it tips, the IMU senses the aircraft is tipping and tries to level it by adding power. But the landing gear drags on the ground forcing the tip over. If you can see it happening and immediately add full power you can take off before disaster. The flight controller seems to ignore all stick input when it's trying to correct instability with the exception of full throttle.

On the H, you can "bump" the red button to drop altitude in increments. That is handy when landing before the press and hold function. It also works on the H Plus but if you press red 3 times in a row it will shut off the motors regardless of the altitude. It's meant to be used for an emergency shutdown. I believe that to be true with the 520 also.

I call this "Big Red Landing". I've used it to land the Q500 many times since that model tends to be erratic when landing because of ground effect from the prop wash.

 

[h-elsner]

Technical background:
Typhoon H landing detection is not as good as it should be (PX4 based drones have a better one including the Thunderbird FW for H480). Remedy: Accelerometer calibration before flight day.

Throttle is not fully reduced to -100% due to:
- right slider not in rabbit mode or not calibrated to full rabbit mode,
- not calibrated or not clean throttle stick.
Remedy: ST16 calibration / "Big Red Landing".

When pressing red button motor cut off is delayed by 3 seconds to prevent unintentional shutdown. But the throttle goes down to zero (-150%) immediately what forces landing. You have 3s until the motors are cut off no matter how high the drone is.

 

[Stephen1988]

Landing on an incline or in wind can cause the aircraft to tip. When it tips, the IMU senses the aircraft is tipping and tries to level it by adding power. But the landing gear drags on the ground forcing the tip over. If you can see it happening and immediately add full power you can take off before disaster. The flight controller seems to ignore all stick input when it's trying to correct instability with the exception of full throttle.

On the H, you can "bump" the red button to drop altitude in increments. That is handy when landing before the press and hold function. It also works on the H Plus but if you press red 3 times in a row it will shut off the motors regardless of the altitude. It's meant to be used for an emergency shutdown. I believe that to be true with the 520 also.

I call this "Big Red Landing". I've used it to land the Q500 many times since that model tends to be erratic when landing because of ground effect from the prop wash.

Exactly the symptoms u have described here, I was wondering why it would try tip over instead of lifting of the ground again nice and level. The dragging landing gear holds the answer . I believe ur right the h520 and tapping the red button 3 times quickly. If I am about to tip over I keep holding throttle fully down and tap 3 times to kill the motors . Sometimes I’ll just hand catch the leg and tap 3times . I must try this now again with the h520 to confirm

 

[Stephen1988]

Technical background:
Typhoon H landing detection is not as good as it should be (PX4 based drones have a better one including the Thunderbird FW for H480). Remedy: Accelerometer calibration before flight day.

Throttle is not fully reduced to -100% due to:
- right slider not in rabbit mode or not calibrated to full rabbit mode,
- not calibrated or not clean throttle stick.
Remedy: ST16 calibration / "Big Red Landing".

When pressing red button motor cut off is delayed by 3 seconds to prevent unintentional shutdown. But the throttle goes down to zero (-150%) immediately what forces landing. You have 3s until the motors are cut off no matter how high the drone is.

U have a good knowledge of how the software behaves. The pilot might be unpredictable but having the information u mentioned above reduces the pilot error

 

[h-elsner]

This is the idea behind - better understanding makes us better pilots, especially when it comes to problems.

 

[Joram Nevversan]

This is the main reason I'm an advocate of using the red button to land. Just hover 12-18" above the landing zone, press and hold the red button and the H will land and shut the motors off. In the rare event it does tip after touchdown the props won't break.

I was unaware that you could do that. I will have to try that