14-08-2023, 11:53 AM
When flying my 3D planes I like to include 1-2 blenders in each flight. Essentially this is a blender:
vertical climb on full power
cut power, enter vertical dive
full R aileron to commence vertical spin
after a while, apply full L rudder to achieve a wobbly spin
wait 1-2 sec before apply down ele
when its time to recover, release aileron and rudder, and increase down ele till plane levels, then exit maneouvre in level inverted flight
On Sunday there was an unfortunate outcome of a blender with a 1m 3D plane, which happened to be documented with my Edgetx/Radiomaster flight log that allows a full black box investigation. In the preliminary analysis I monitored the radio signal (using RSSI, RQly, radio signal to noise and more), which ruled out a failure of the radio signal as the cause of the crash. The attached plot shows the position of the flight controls and reveals pilot actions/mistakes during the short flight.
A red arrow marks the start of the blender. At 68 seconds the plane is in vertical climb on full throttle at a great height, when throttle is cut.
Between 68 and 69.5 sec the aileron, rudder and elevator are in neutral position and throttle remains cut, as the plane tips over into a vertical dive.
At 69.5 sec full right aileron is applied, followed by full left rudder at 70 sec. The plane starts spinning (clockwise) in its vertical dive. Throttle is increased to full between 70 and 70.5 sec, along with down elevator whose purpose is to convert the vertical spin into a flat inverted spin.
Between 72 and 74 sec the vertical spin did not flatten out, and the spin rate increased. At 72.5 sec the pilot sensed a problem developing, and put aileron to zero. However down elevator, full throttle and left rudder were still applied and this remained the case till 75 sec when the plane - still in a fast vertical spin - struck the ground. Around 74 sec there was a brief application of left aileron (which is not really advisable ... it might have helped reduce spin if the plane had height and if rudder and elevator had been released).
The official report notes the pilot - when the time came to exit the blender at a safe height - failed to apply the recommended methods to exit. The pilot should have been aware that releasing (centering) the aileron, elevator and rudder controls and reducing throttle causes the fast spin to stop, and then down (or up) elevator is applied to fly out in an inverted (or level) flight.
Damage was surprisingly light as the plane came down in long grass. Unfortunately no explanation has come to light how the pilot - who routinely performs safe blenders - on this particular flight came to totally lose the plot.
For a more detailed anaysis of a blender, check out this excellent video:
https://www.youtube.com/watch?v=T798zEZCSxA&t=3s
vertical climb on full power
cut power, enter vertical dive
full R aileron to commence vertical spin
after a while, apply full L rudder to achieve a wobbly spin
wait 1-2 sec before apply down ele
when its time to recover, release aileron and rudder, and increase down ele till plane levels, then exit maneouvre in level inverted flight
On Sunday there was an unfortunate outcome of a blender with a 1m 3D plane, which happened to be documented with my Edgetx/Radiomaster flight log that allows a full black box investigation. In the preliminary analysis I monitored the radio signal (using RSSI, RQly, radio signal to noise and more), which ruled out a failure of the radio signal as the cause of the crash. The attached plot shows the position of the flight controls and reveals pilot actions/mistakes during the short flight.
A red arrow marks the start of the blender. At 68 seconds the plane is in vertical climb on full throttle at a great height, when throttle is cut.
Between 68 and 69.5 sec the aileron, rudder and elevator are in neutral position and throttle remains cut, as the plane tips over into a vertical dive.
At 69.5 sec full right aileron is applied, followed by full left rudder at 70 sec. The plane starts spinning (clockwise) in its vertical dive. Throttle is increased to full between 70 and 70.5 sec, along with down elevator whose purpose is to convert the vertical spin into a flat inverted spin.
Between 72 and 74 sec the vertical spin did not flatten out, and the spin rate increased. At 72.5 sec the pilot sensed a problem developing, and put aileron to zero. However down elevator, full throttle and left rudder were still applied and this remained the case till 75 sec when the plane - still in a fast vertical spin - struck the ground. Around 74 sec there was a brief application of left aileron (which is not really advisable ... it might have helped reduce spin if the plane had height and if rudder and elevator had been released).
The official report notes the pilot - when the time came to exit the blender at a safe height - failed to apply the recommended methods to exit. The pilot should have been aware that releasing (centering) the aileron, elevator and rudder controls and reducing throttle causes the fast spin to stop, and then down (or up) elevator is applied to fly out in an inverted (or level) flight.
Damage was surprisingly light as the plane came down in long grass. Unfortunately no explanation has come to light how the pilot - who routinely performs safe blenders - on this particular flight came to totally lose the plot.
For a more detailed anaysis of a blender, check out this excellent video:
https://www.youtube.com/watch?v=T798zEZCSxA&t=3s
