ERA10TA292

NTSB accident investigation · Bell 206B · Memphis, TN · May 30, 2010

Accident · No injuriesFinal report
Date
May 30, 2010, 12:45 local (17:45 UTC)
Place
Memphis, TN
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N6401XBell 206B
Defining event
Landing-flare/touchdown: Tailstrike
Weather
Visual (VMC) · Day
Status
Completed · report April 12, 2011
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20100530006099A
Case key
76179

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The pilot’s failure to maintain adequate rotor rpm and the certificated flight instructor’s delayed remedial action, which resulted in a hard landing.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Action: incorrect action performancePersonnel issues › Action/decision · CopilotBell 206B: 11 casesAll aircraft: 1,386 casesProbable cause
Performance/control parameters: prop/rotor parametersAircraft › Aircraft oper/perf/capability · Not attained/maintainedBell 206B: 11 casesAll aircraft: 182 casesProbable cause
Action: delayed actionPersonnel issues › Action/decision · Instructor/check pilotBell 206B: 4 casesAll aircraft: 894 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

During a public use training flight, the certificated flight instructor (CFI) simulated an engine failure as the helicopter was climbing through approximately 450 feet above ground level (agl). He then advised the pilot to terminate the maneuver with a power recovery. Approximately 100 feet agl the CFI told the pilot to increase the engine torque to full power. Shortly thereafter, the CFI heard the low rotor rpm warning and relayed to the pilot that he was assuming authority of the helicopter's controls. The CFI advanced the throttle to 100 percent power while both pilots remained on the controls. During the flare, the tail stinger struck the ground and the helicopter landed hard. The main rotor came into contact with the tail boom aft of the horizontal stabilizer and severed it. There was no evidence of any preimpact mechanical anomaly or malfunction with the helicopter.

Factual narrative

On May 30, 2010, about 1245 central daylight time, a Bell 206B, N6401X, operated by the City of Memphis Police Department, was substantially damaged during a practice autorotation at the Memphis Police Department Heliport (27TN), Memphis, Tennessee. The certificated flight instructor and certificated commercial pilot were not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The public use training flight was operating under the provisions of 14 Code of Federal Regulations Part 91. According to the flight instructor, after takeoff, they remained in the traffic pattern to conduct flight maneuvers. After about 20 minutes, as the commercial pilot was climbing the helicopter through approximately 450 feet, the flight instructor rolled the throttle back to flight idle to simulate an engine failure. He then advised the commercial pilot to terminate the maneuver with a power recovery. The commercial pilot immediately lowered the collective and entered an autorotation. Approximately 100 feet above the ground, the flight instructor advised the commercial pilot to increase the throttle to full power. Shortly thereafter, the flight instructor heard the low rotor warning signal, and “got on the controls with the pilot.” The flight instructor advanced the throttle to 100 percent power, as both pilots remained on the controls. During the flare, the tail stinger struck the ground and the helicopter landed hard. The main rotor came into contact with the tail boom aft of the horizontal stabilizer and severed it. Examination of the helicopter by a Federal Aviation Administration inspector revealed that the helicopter came to rest on the helipad, and that the tail boom was severed aft of the horizontal stabilizer. Examination of the airframe and flight control system components revealed no evidence of preimpact mechanical malfunctions, and neither pilot reported any flight control or engine anomalies.

Aircraft

Registration
N6401X
Reported as
Bell 206B
Category
Helicopter
Serial number
4522
Airframe hours
2,794
Engine
Rolls-Royc 250-C20J, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
Public aircraft - local · Public use
Operator
City Of Memphis
Registered owner
City Of Memphis
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · May 10, 2010 · 1,044 hours before
Departed
27TN · Memphis, TN
Destination
27TN · Memphis, TN
Airport
27TN · Memphis Police Heliport

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
38
Injuries
Minor
Certificate
Flight instructor
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 2, Without waivers/limitations
Last flight review
February 25, 2010
Seat
Left
Flight hours
4,199 total · 1,703 in this make and model · 3,825 as pilot in command
Role
Co-pilot
Age
46
Injuries
Minor
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Without waivers/limitations
Last flight review
September 23, 2008
Seat
Right
Flight hours
2,366 total · 1,918 in this make and model · 2,240 as pilot in command · 121 in the last 90 days · 40 in the last 30 days · 9 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Visibility
10 statute miles
Lowest ceiling
None
Temperature
84 °F, dew point 68 °F
Altimeter
29.92 inHg
Observed at
NQA, 10 nm away

Docket · 4

The files NTSB released with the investigation on November 3, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 933 KB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.