Originally Posted by
megan
Question for you Ace. What aerodynamic phenomena caused the aircraft to go from your stated negative "g" with your failure of the tailplane to 8.3 positive?
Also what aerodynamic phenomena would cause the tailplane to fail upwards?
The aircraft entered a climb, at a velocity higher than allowed.
The aerodynamic surfaces were overloaded.
The tail in climb pitches the tail Down, to provide nose up.
Overloaded as it was, the tail at fuselage snapped.
The tail, In failing to provide consistent nose up, caused the aircraft to react nose down.
In addition to the already extreme positive load on the wings, the aircraft fuselage increased its moment down, and away from the wings. This unsustainable additional load failed the wings, which then separated in the chaotic drag induced by the flapping tail assembly and the loss of aerodynamic flight.....
The failure was in the tail; had the tail remained sound, it is arguable the flight may have survived.
An overloaded tailplane in climb fails “up”, but you knew that, right? It doesn’t look like “up”, but the tail lifts in opposite direction to the wings.
addendum. Notice, megan, the left HS fails first, the aircraft quits the climb, and the pitch down is evident. Our pilot “preloaded” the left side elevator with NU Trim, then trimmed out the NU trim with forward stick. Level, with NU Trim, when he released ND and pulled NU, the tail broke. The left wing also failed, just milliseconds post Max NU. Note yaw right after loss of left wing. The wings did not fail “at exactly the same moment”.....
Don’t try this at home, skipper.