R22 helicopter pilot reported empennage and tail rotor assembly separated from aircraft.

Attributes
ACN	1760314
Time
Date	202009
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Robinson R22
Operating Under FAR Part	Part 91
Flight Phase	Parked
Route In Use	Direct
Flight Plan	None
Component
Aircraft Component	Airframe
Person 1
Function	Instructor
Qualification	Flight Crew Rotorcraft Flight Crew Flight Instructor Flight Crew Commercial Flight Crew Instrument
Experience	Flight Crew Last 90 Days 250 Flight Crew Total 1900 Flight Crew Type 476
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

I had just completed all run-up checks and was increasing the throttle to operating RPM. I heard a thud from behind. My initial thought was that a drive belt had broken. When I looked out the door I saw the entire empennage and tail rotor assembly hanging by the rear position light wire. After inspection the tail rotor gear box mounting bracket had broken in half and the aluminum of the tail cone had ripped and completely separated. The tail rotor blades struck the bottom of the vertical fin and separated from the aircraft. No one was injured. The aircraft owner was notified and came to pick the helicopter up with a trailer.

Original NASA ASRS Text

Title: R22 helicopter pilot reported empennage and tail rotor assembly separated from aircraft.

Narrative: I had just completed all run-up checks and was increasing the throttle to operating RPM. I heard a thud from behind. My initial thought was that a drive belt had broken. When I looked out the door I saw the entire empennage and tail rotor assembly hanging by the rear position light wire. After inspection the tail rotor gear box mounting bracket had broken in half and the aluminum of the tail cone had ripped and completely separated. The tail rotor blades struck the bottom of the vertical fin and separated from the aircraft. No one was injured. The aircraft owner was notified and came to pick the helicopter up with a trailer.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.