CEN12TA004

NTSB accident investigation · Eurocopter EC120B · McAllen, TX · October 4, 2011

Accident · Minor injuriesFinal report
Date
October 4, 2011, 12:52 local (17:52 UTC)
Place
McAllen, TX
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N3925AEurocopter EC120B
Defining event
Landing: Loss of control on ground
Weather
Visual (VMC) · Day
Status
Completed · report December 11, 2012
Report
Approved by Office Director
NTSB office
Central Region
Parties
CBP, FAA/FSDO, Eurocopter
FAA report
20111004029759A
Case key
81984

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 pilot's improper use of the collective while landing, which resulted in an unrecoverable forward pitching moment. Contributing to the accident was the pilot's improper decision not to go-around.

Findings · 4

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 · PilotEurocopter EC120B: 1 caseAll aircraft: 1,386 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotEurocopter EC120B: 3 casesAll aircraft: 9,295 casesProbable cause
Performance/control parameters: pitch controlAircraft › Aircraft oper/perf/capability · Not attained/maintainedEurocopter EC120B: 1 caseAll aircraft: 526 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

The pilot and the supplemental crewmember were dispatched to provide aerial support for an on-going border patrol mission. The mission was delayed, so the pilot decided to make a no-hover landing to an unfamiliar grass field and sit idle (to conserve fuel) until needed. On approach, the pilot had too much forward speed for the no-hover landing and transitioned to a slow, running landing. Upon touchdown, the pilot said he used full aft cyclic to control the maneuver but did not remember what he did with the collective. The helicopter slid about 34 feet then pitched forward causing the helicopter's lower wire strike protection system and the main rotor blades to strike the ground. According to the operator's aircraft standardization manual, during a running landing, the pilot has to hold the collective stationary after ground contact to avoid any rapid pitch reductions. The pilot reported that there were no mechanical problems prior to the accident. He said the accident could have been avoided if he had conducted an approach to hover followed by a vertical landing or executed a go-around and re-attempted a no-hover landing.

Factual narrative

On October 4, 2011, approximately 1250 central daylight time, N3925A, a Eurocopter EC120B, sustained substantial damage while making a running landing to an unprepared grass field ten miles east of McAllen Miller International Airport (MFE), McAllen, Texas. The air interdiction agent (AIA) (the pilot) and the supplemental aircrew member (SAM) sustained minor injuries. The helicopter was registered to and operated by the Department of Homeland Security, Washington, DC. Visual meteorological conditions prevailed and no flight plan was filed for the Public Use flight conducted under 14 Code of Federal Regulations Part 91. The AIA and the SAM were dispatched to provide aerial support for an on-going border patrol mission. When the AIA realized there would be a delay in the mission, he decided to make a no-hover landing in an unfamiliar grass field and sit idle (to conserve fuel) until needed. The AIA said he carried too much forward speed for the no-hover landing and transitioned to a slow, running landing instead. He said this was to avoid brown-out conditions. The helicopter touched down between 16 and 24 knots, and slid forward approximately 34-feet before the helicopter began a forward pitching moment. The helicopter's wire strike protection system (WSPS) and the main rotor blades struck the ground. As the helicopter continued to pitch over it began a counter-clockwise rotation and came to rest on its right side, severing the tail boom. The skids and main rotor blades were also damaged. The pilot stated that during the landing he pulled the cyclic full aft but could not recall what he did with the collective. According to the operator’s aircraft standardization manual (ASM), during a running landing, the pilot should begin a slow deceleration by applying aft cyclic to approximately five degrees nose up and slightly lowering the collective to maintain a constant approach angle. The pilot should decelerate and arrive at an airspeed slightly above effective translational lift (ETL) and a height of ten feet above ground level simultaneously. After ground contact, the pilot must ensure the helicopter remains stable and the collective is held stationary (to avoid any rapid pitch reductions) until the termination of the ground run. The AIA reported there were no mechanical problems prior to the accident. He said that the accident could have been prevented if he conducted an approach to hover followed by a vertical landing or made a go-around and re-attempted a no-hover landing. The AIA held a commercial pilot certificate for airplane single-engine land and rotorcraft-helicopter. He reported a total of 4,517 total flight hours; of which 4,370 hours were in helicopters and 403 hours were in the same make/model as the accident helicopter. His last Federal Aviation Administration (FAA) Second Class medical was issued on January 31, 2011.

Aircraft

Registration
N3925A
Reported as
Eurocopter EC120B
Category
Helicopter
Serial number
1594
Airframe hours
994
Engine
Turbomeca ARRIUS 2F, 432 horsepower, turbo shaft
Damage
Substantial damage
Flight
Public aircraft - state · Part 91
Operator
Department Of Homeland Security
Registered owner
Department Of Homeland Security
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · May 19, 2011
Departed
MFE · McAllen, TX
Destination
MFE · McAllen, 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
Pilot
Age
39
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Helicopter
Medical
Class 2, Without waivers/limitations
Last flight review
April 30, 2011
Seat
Right
Flight hours
4,517 total · 403 in this make and model · 3,664 as pilot in command · 101 in the last 90 days · 31 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Variable at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
86 °F, dew point 59 °F
Altimeter
30.12 inHg
Observed at
MFE, 10 nm away

Docket · 5

The files NTSB released with the investigation on October 15, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.9 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.