DFW05CA142

NTSB accident investigation · Westland Wasp · Denison, TX · May 30, 2005

Accident · No injuriesData collectionFinal report
Date
May 30, 2005, 12:05 local (17:05 UTC)
Place
Denison, TX
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N108RAWestland Wasp
Weather
Visual (VMC) · Day
Status
Completed · report September 13, 2005
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20050530008539A
Case key
61596

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

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Probable cause

The NTSB’s determination of the probable cause, and any contributing factors.

The partial loss of engine power for undetermined reasons. A contributing factor was the lack of suitable terrain for the forced landing.

Analysis

During initial climb-out on a southwesterly direction, while at an estimated altitude of 90 feet above the ground, and an estimated airspeed of 25 knots, the helicopter experienced an un-commanded reduction of engine power to flight idle. The 358-hour student pilot turned the helicopter 180 degrees, put the collective down, and applied right anti-torque pedal. The helicopter landed hard on a street, impacting on all four landing gear before bouncing back into the air. During the second ground impact, the left rear landing gear collapsed and the main rotor blades and tail rotor made contact with the ground. The winds at the time of the mishap were reported from 040 degrees at 8 knots. The reason for the reported loss of engine power could not be determined.

Factual narrative

The factual narrative400 words

On May 30, 2005, about 1205 central daylight time, a Westland Wasp turboshaft powered helicopter, N108RA, was substantially damaged following a partial loss of engine power during takeoff from private property near Denison, Texas. The student pilot and his passenger were not injured. The helicopter, for which an airworthiness certificate had not been issued, was registered to and operated by the pilot. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight.

According to the 358-hour student pilot, during the initial climb-out in a southwesterly heading, at an altitude of approximately 90 feet above the ground, while at an estimated airspeed of 25 knots, the helicopter experienced an un-commanded reduction of engine power to flight idle. The pilot added that he turned the helicopter 180 degrees, placed the collective down, and applied right anti-torque pedal.

The helicopter settled hard into a street, impacting on all four landing gear before bouncing back into the air. During the second ground impact, the left rear landing gear collapsed and the main rotor blades and tail rotor made contact with the ground.

The pilot, who reports that he was operating the helicopter as a "public use" aircraft, reported to have accumulated all of his flight time in rotorcraft, with a total of 16.2 hours in the accident helicopter.

The helicopter was manufactured in the United Kingdom by Westland Helicopter in 1965. The design consisted of an all-metal monocoque fuselage supported by four separate gear legs, each with a single wheel. Powering the four blade main rotor was a single 1,050 shaft horse power Rolls-Royce Nimbus 103 turboshaft engine. The helicopter was designed to carry one pilot and four passengers. N108RA was imported into the United States at an unknown date.

A Federal Aviation Administration (FAA) inspector examined the wreckage. The inspector reported that the helicopter sustained structural damage to the fuselage. The reason for the reported uncommanded loss of engine power could not be determined.

At 1145, the weather observation facility at Grayson County Airport (GYI), near Denison, Texas, located approximately 8 nautical miles southwest from the accident site, reported winds from 040 degrees at 8 knots, visibility 10 statute miles, scattered clouds at 2,200 feet and 3,100 feet, clouds broken at 3,800 feet, temperature 77 degrees Fahrenheit, dew point 66 degrees Fahrenheit, and barometric pressure setting of 29.88 inches of Mercury.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine powerTakeoff - initial climb
Reason for occurrence undeterminedCause
Forced landingEmergency landing after takeoff
Hard landingEmergency landing after takeoff
Terrain condition - none suitableFactor
Gear collapsedEmergency landing after takeoff

Aircraft

Registration
N108RA
Reported as
Westland Wasp
Category
Helicopter
Serial number
0001
Engine
Rolls-Royce Nimbus 103, turbo shaft
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Roger D Avery
Airworthiness certificate
Special, Restricted (Special)
Departed
Denison, TX
Destination
Denison, 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

As NTSB recorded them. NTSB leaves out names.

Role
Student pilot
Age
37
Injuries
None
Certificate
Student
Medical
Class 3
Flight hours
358 total · 16 in this make and model · 16 in the last 90 days · 5 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
40° at 8 knots
Visibility
10 statute miles
Lowest ceiling
3,800 ft broken
Temperature
77 °F, dew point 66 °F
Altimeter
29.87 inHg

FAA reports on this event · 1

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