CEN13LA523

NTSB accident investigation · Bell-Transworld Helicopter Cor 47G-2 · Wichita Falls, TX · August 28, 2013

Accident · No injuriesLimited investigationFinal report
Date
August 28, 2013, 08:45 local (13:45 UTC)
Place
Wichita Falls, TX
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N8051EBell-Transworld Helicopter Cor 47G-2
Defining event
Landing-flare/touchdown: Hard landing
Weather
Visual (VMC) · Day
Status
Completed · report April 23, 2014
Report
Approved by Office Director
NTSB office
Central Region
FAA report
20130828018289A
Case key
87965

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 delayed remedial action by the flight instructor during a simulated autorotation, 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.

Performance/control parameters: descent rateAircraft › Aircraft oper/perf/capability · Not attained/maintainedBell-Transworld Helicopter Cor 47G-2: 1 caseAll aircraft: 242 casesProbable cause
Action: delayed actionPersonnel issues › Action/decision · Instructor/check pilotBell-Transworld Helicopter Cor 47G-2: 1 caseAll 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

After the flight instructor initiated a simulated autorotation during an instructional flight, he instructed the student pilot to perform a power recovery. However, the student pilot delayed increasing the power, and the rotor rpm decayed. The flight instructor realized that it was too late to make a full recovery, so he took the flight controls and leveled the helicopter for touchdown and pulled the collective. The helicopter landed hard in a soft field, which resulted in damage to the tail rotor and main rotor blades. The flight instructor stated that he deviated from his normal procedure for recovery from a simulated forced landing and that, if he had used the procedure, the accident may not have happened.

Factual narrative

On August 28, 2013, at 0845 central daylight time, a Bell-Transworld Helicopter Corp. 47G-2, N8051E, impacted terrain during a simulated autorotation to a field near Wichita Falls, Texas. The helicopter received substantial damage to the main rotor blades. The flight instructor and student pilot were uninjured. The helicopter was registered to and operated by the student pilot under 14 Code of Federal Regulations Part 91 as an instructional flight that was not operating on a flight plan. Visual meteorological conditions prevailed at the time of the accident. The flight originated from Wichita Falls, Texas, about 0830. According to the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report that was received from the flight instructor, he and the student pilot departed from the student's hangar area for an instructional flight. Upon climbing to 500 feet above ground level, they flew to a private airstrip called Danaher, which was near the southwest end of Lake Wichita. After a normal approach and hovering practice, they flew toward the west to a small pinnacle to practice landings. At 500 feet above ground level, over a clear area, they initiated a simulated forced landing. The flight instructor reduced the throttle and announced a forced landing and that the student was to perform a power recovery. The flight instructor realized that it was too late to make a full recovery, and he leveled the helicopter for touchdown and pulled collective. The touchdown was slightly tail low, and the ground was soft and level. The full fuel load caused the skid heels to sink a few inches causing the tail rotor guard to break, allowing the tail rotor blades to contact the ground. The tail rotor guard contacted and damaged both main rotor blades. The flight instructor stated he deviated from his normal procedure for recovery from a simulated forced landing. That procedure was: 1. After lowering the engine rpm and announcing forced landing. 2. Ensuring collective is in full down position and rotor rpm was stable and in the green arc. 3. Return engine rpm to a near operating rpm. 4. Ensure that the airspeed for autorotations is established and maintained to landing flare. The student pilot held a private pilot certificate with an airplane single-engine land rating. He accumulated a total flight time of about 330 hours, of which 269 hours were in single-engine airplanes and 61 hours were in rotorcraft. The 61 hours of rotorcraft were all in the make and model of the accident helicopter.

Aircraft

Registration
N8051E
Reported as
Bell-Transworld Helicopter Cor 47G-2
Category
Helicopter
Serial number
TWH-15
Built
1979
Airframe hours
2,665
Engine
Lycoming VO435A1F, 265 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · July 8, 2013
Departed
PVT · Wichita Falls, TX
Destination
Wichita Falls, TX

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
77
Injuries
None
Certificates
Flight engineer, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 3, With waivers/limitations
Last flight review
July 10, 2012
Seat
Right
Restraint
Lap only
Flight hours
7,500 total · 500 in this make and model · 7,200 as pilot in command · 40 in the last 90 days · 20 in the last 30 days · 2 in the last 24 hours
Role
Student pilot
Age
66
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Last flight review
October 10, 2012
Seat
Left
Restraint
Lap only
Flight hours
330 total · 61 in this make and model · 221 as pilot in command · 21 in the last 90 days · 13 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
170° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
75 °F, dew point 68 °F
Altimeter
30.10 inHg
Observed at
CWC, 4 nm away

Docket · 1

The files NTSB released with the investigation on December 20, 2013, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.0 MB 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.