Robinson R22 MARINER II N7183Y

Summary

On 3 December 1999 at about 22:00 local time, a Robinson R22 MARINER II registered N7183Y was involved in an accident near Minden, Nevada, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 December 1999 at 22:00

Classification

Accident

Location

Minden, Nevada, United States

Nearest airport

Minden (MEV)

Coordinates

39.0101, -119.7496

Aircraft

Robinson R22 MARINER II

Registration

N7183Y

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Susanville → Minden

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX00LA050

Nobody was injured.

the result of a foreign object contacting the tail rotor blade(s) while the aircraft was hover taxiing, which caused blade separation with subsequent loss of anti-torque (lateral) control.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

While hover-taxiing, the pilot experienced a sudden uncommanded right yaw. The aircraft was at a 5-foot hover when it spun 360 degrees (about the mast) to the right. The pilot attempted to stop the turn with full left pedal but the aircraft did not respond. After a full rotation, the lower horizontal stabilizer struck the ground. The aircraft had continued to spin an additional 180 degrees when the pilot rolled off the throttle, applied full up collective, and pressed the right pedal. The aircraft touched down abruptly next to the taxiway. The outboard 11 inches of one tail rotor blade had separated along with the outboard 6 inches from the second blade. Both separated blade sections were recovered with both showing similar leading edge damage near the blade tips. The geometric design of the vertical and horizontal stabilizer acts as a "stinger" or guard for the tail rotor. While there is evidence of ground contact with the lower horizontal stabilizer, it is indicative of lateral contact consistent with damage incurred during a right yaw. The damage to the vertical stabilizer shows evidence of mechanical loading originating from the movement of the lower horizontal stabilizer. The resultant loading produced left to right buckling of the vertical stabilizer just below the tail boom. This damage was also consistent with a right yaw. There was no evidence of contact between the either stabilizer and the tail rotor. The extent of damage to the stabilizers and geometric position of the tail rotor did not support the witness contention of contact between the tail rotor and the ground. The differential loading created by the unequal tail rotor blade separation resulted in an unbalanced system feeding back to the tail rotor gearbox.

Quoted verbatim from the NTSB record.