After the failure of a third-party component, the crew of this experimental new aircraft design was able to walk away unscathed in the ultimate testament to the safety and strength of a breakthrough composite structural fuselage after a pants staining crash.
Using patented EvoStrength technology, Composite Helicopters Intl. has developed the world's first full monocoque helicopter fuselage fabricated entirely from rigid carbon-kevlar composite materials. They claim this provides unparalleled impact and fatigue resistance which has been unintentionally but vividly confirmed after this accident left the fuselage virtually undamaged and its occupants safe.
This incident comes with over 250 hours of flight testing performed already, and has proved to be stronger, safer and has the lowest operational costs in its class. Surprisingly the crash wasn't a result of an out of balance situation from the enormous weight of the test pilot's testicles. After a full investigation it was determined that loss of control was due to a failed rod end in a link connection to the upper rotating swash plate. A swashplate is a device that translates input from the helicopter controls of the non-rotating fuselage to the rotating rotor hub and main blades. This changes the pitch of the rotor blades as they rotate allowing the helicopter to pitch, bank, climb, or descend.
On advanced helicopter rotor systems, each blade is independently hinged to allow for flapping up and down as well as bending forward and back. This is done to compensate for certain aerodynamic effects. After the control link failed, phase control was lost creating a situation similar to extreme out of balance. A similar problem can happen on the ground that can literally tear the aircraft apart as demonstrated by this ground resonance test using a Chinook.
This particular helicopter appears to be equipped with a semi-rigid rotor blade system, which means that flapping of the rotor blades is accomplished strictly by their inherent ability to flex. This flexing of the blades and the rotor discs ability to rotate independent of the fuselage can lead to a potential strike of the blades with the tail during extreme maneuvering, especially at negative Gs.
It seems there were 3 key design characteristics that saved these pilot's lives in addition to their prompt action and skilled piloting. First, the rigidity of the rotor system and tail boom prevented a catastrophic inflight tail strike. Second, the inherent strength of the fuselage was able to withstand the tremendous vibration that would most likely have caused a traditional helicopter to break apart, and finally, the fact that the fuselage did not collapse upon impact with the ground. All these factors culminated into a successful crash landing during a routine test flight.
The composite fuselage design is impressive and I'm glad these guys survived the experience and are able to learn from it. This video will surely help sell their design, but that's a tough way to prove its worth. Kudos to the pilots and design engineers. Watch below as the pilots walk you through what went right and what went wrong, and how they managed to wrangle the crippled aircraft to earth after a crucial control element failed.