CEN10LA036

NTSB accident investigation · Bell 206 · High Island A-442A · November 1, 2009

Accident · Serious injuriesLimited investigationFinal report
Date
November 1, 2009, 10:40 local (16:40 UTC)
Place
High Island A-442A
Injuries
1 serious, 1 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N272MBell 206
Defining event
Initial climb: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report May 6, 2010
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA Flight Standards District Office
FAA report
20091101021479A
Case key
74996

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

A total loss of engine power due to maintenance personnel's failure to correctly torque the Pc line following removal and reinstallation of the turbine module.

Findings · 2

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.

Engine (turbine/turboprop)Aircraft › Aircraft power plant · Incorrect service/maintenanceBell Helicopter Textron 206L-1: 1 caseAll aircraft: 67 casesProbable cause
Maintenance: installationPersonnel issues › Task performance · Maintenance personnelBell Helicopter Textron 206L-1: 2 casesAll aircraft: 371 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 helicopter had landed on an off-shore oil platform and was refueled. It then took off with one passenger. Shortly after lifting off, the pilot "heard a loud pop as the nose of the aircraft passed over the edge of the helideck. The noise was simultaneously accompanied by illumination of the engine out warning light and a needle split indication was observed on the engine and rotor tachometer gauge. As the aircraft yawed and lost climb performance, the pilot lowered the collective pitch full down and activated the floats. Upon landing on the water, the aircraft rolled left until inverted. The helicopter was later recovered and the engine disassembled and examined. The only anomaly noted was a loose Pc line, which would cause a loss of fuel flow and subsequent loss of engine power down to or below idle. It was determined that the torque required to realign the B-nut would be between hand-tight and 27 inch-pounds. The required torque is 80 to 120 inch-pounds. Torque values on the other air line fittings between the power turbine governor and the fuel control were found to range from 55 to 85 inch-pounds. A review of the engine maintenance records revealed that 36.7 hours prior to the accident, the turbine module was completely disassembled and overhauled. This would have required the removal and re-installation of the Pc line.

Factual narrative

On November 1, 2009, approximately 1040 central standard time, a Bell 206L-1, N272M, registered to and operated by Rotorcraft Leasing Company LLC, was substantially damaged when it impacted water following a loss of engine power shortly after lifting off from an oil drilling platform. Visual meteorological conditions prevailed at the time of the accident. The non-scheduled domestic passenger flight was being conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 135. The pilot was seriously injured and the passenger received minor injuries. The flight had just originated from platform High Island A442A, and was en route to platform High Island A515, both in the Gulf of Mexico. According to the company accident report, the helicopter had landed on the platform and was refueled. It then took off with one passenger. Shortly after lifting off, the pilot "heard a loud pop as the nose of the aircraft passed over the edge of the helideck. The noise was simultaneously accompanied by illumination of the engine out warning light and a needle split indication was observed on the engine and rotor tachometer gauge. As the aircraft yawed and lost climb performance, the pilot lowered the collective pitch full down and activated the floats. Upon landing on the water, the aircraft rolled left until inverted. The pilot and the only passenger exited the aircraft and inflated their life vests and crawled onto the belly of the aircraft and inflated the life rafts. The pilot and the passenger hung on to the side of one of the inflated life rafts until a nearby crew boat arrived and pulled them out of the water." The helicopter was later recovered and taken to the operator's base in Broussard, Louisiana, where, on November 19, 2009, the engine was disassembled and examined under the supervision of an FAA inspector. The only anomaly noted was a loose Pc line. According to Rolls Royce, a loose Pc line would cause a loss of fuel flow and subsequent loss of engine power down to or below idle. Using a picture taken during the on-site engine examination, the position of the B-nut on the fuel control when torque paint was last applied was approximated. Re-connecting the B-nut to the fuel control fitting, the torque required to realign the B-nut was between hand-tight and 27 inch-pounds. The required torque is 80 to 120 inch-pounds. Torque values on the other air line fittings between the power turbine governor and the fuel control were found to range from 55 to 85 inch-pounds. The turbine wheels and nozzles exhibited signs of corrosion from salt water immersion. The engine controls were intact with no apparent damage. A review of the engine maintenance records revealed that 36.7 hours prior to the accident, the turbine module had been completely disassembled and overhauled. This work would have required removal and re-installation of the Pc line.

Aircraft

Registration
N272M
Reported as
Bell 206 (L1)
Category
Helicopter
Serial number
45365
Airframe hours
13,668
Engine
Allison 250-C30P, 650 horsepower, turbo shaft
Damage
Substantial damage
Flight
Part 135
Operator
Rotorcraft Leasing Company LLC
Registered owner
Rotorcraft Leasing Company LLC
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · October 10, 2009 · 85 hours before
Departed
Hi-A442, GM
Destination
Hi-A515, GM
Flight plan
Company VFR
Airport
A442 · High Island A442A

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
27
Injuries
Serious
Certificate
Commercial
Instrument ratings
Helicopter
Medical
Class 2, Without waivers/limitations
Last flight review
November 18, 2008
Seat
Right
Toxicology
Performed
Flight hours
1,874 total · 1,549 in this make and model · 1,874 as pilot in command · 139 in the last 90 days · 39 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
45° at 11 knots
Visibility
6 statute miles
Lowest ceiling
None
Temperature
61 °F, dew point 48 °F
Altimeter
30.20 inHg
Observed at
BPT, 95 nm away

Docket · 8

The files NTSB released with the investigation on December 14, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 9.1 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.

Other investigations on N272M · 1

Matched to the same aircraft by N-number and date.