What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
1966 Hughes 269B helicopter experienced engine problems after take-off, came back down, and landed hard, the acft then spun around and came to rest on its side, other circumstances are unknown. (-23) at approx. 1130 local time N44KH impacted the earth. The PIC stated that during a practice autorotation terminating with power, the power source failed upon reducing the collective and throttle. The a/c continued autorotation and during the deceleration phase of the autorotation the a/c impacted the earth in a straight, nose high position. The evidence indicated the a/c impacted the earth at a higher than normal rate of descent. With the sudden excessive earth impact, the main rotor blades flexed down, severingthe tail boom approx. two feet forward of the ninty degree gear box.. The a/c spun left approx. 160 degrees coming to rest in an upright position. An engine run was completed with no duplication of failure. The engine, with rapid throttle reduction, idled erratically.
As the FAA filed it
1966 HUGHES 269B HELICOPTER EXPERIENCED ENGINE PROBLEMS AFTER TAKE-OFF, CAME BACK DOWN, AND LANDED HARD, THE ACFT THEN SPUN AROUND AND CAME TO REST ON ITS SIDE, OTHER CIRCUMSTANCES ARE UNKNOWN. (-23) AT APPROX. 1130 LOCAL TIME N44KH IMPACTED THE EARTH. THE PIC STATED THAT DURING A PRACTICE AUTOROTATION TERMINATING WITH POWER, THE POWER SOURCE FAILED UPON REDUCING THE COLLECTIVE AND THROTTLE. THE A/C CONTINUED AUTOROTATION AND DURING THE DECELERATION PHASE OF THE AUTOROTATION THE A/C IMPACTED THE EARTH IN A STRAIGHT, NOSE HIGH POSITION. THE EVIDENCE INDICATED THE A/C IMPACTED THE EARTH AT A HIGHER THAN NORMAL RATE OF DESCENT. WITH THE SUDDEN EXCESSIVE EARTH IMPACT, THE MAIN ROTOR BLADES FLEXED DOWN, SEVERINGTHE TAIL BOOM APPROX. TWO FEET FORWARD OF THE NINTY DEGREE GEAR BOX.. THE A/C SPUN LEFT APPROX. 160 DEGREES COMING TO REST IN AN UPRIGHT POSITION. AN ENGINE RUN WAS COMPLETED WITH NO DUPLICATION OF FAILURE. THE ENGINE, WITH RAPID THROTTLE REDUCTION, IDLED ERRATICALLY.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.