DFW07LA173

NTSB accident investigation · Bell 206B · Grand Prairie, TX · July 30, 2007

Accident · Serious injuriesLimited investigationFinal report
Date
July 30, 2007, 06:43 local (11:43 UTC)
Place
Grand Prairie, TX
Injuries
1 serious, 2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N4YJBell 206B
Weather
Visual (VMC) · Day
Status
Completed · report April 30, 2008
Report
Approved by Office Director
Parties
FAA
FAA report
20070730014219A
Case key
66320

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 loss of engine power as result of the failure of one or more of the compressor blades for the 5th stage compressor for undetermined reasons. A contributing factor was the lack of suitable terrain for the pilot to execute a successful autorotation.

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 powerCruise - normal
Compressor assembly,blade - failureCause
Forced landingEmergency descent/landing
Autorotation - initiatedPilot in command
In flight collision with terrain/waterDescent - emergency
Terrain condition - rough/uneven
Terrain condition - none suitableFactor
Roll overEmergency landing

Analysis

After departing their home base, the flight reported on the traffic and news for a local television and radio station for 42 minutes. While the helicopter was transiting from another location for an upcoming news story, the helicopter experienced a loss of engine power while in cruise flight at 800-feet above ground level. The pilot reported that he initiated a left 180-degree turn to a clear area. The autorotation was terminated over tall grass and during touchdown the helicopter rolled over and came to rest on its right side. The accident site was a wooded area with soft soil on rough and uneven terrain. The 8,000-hour helicopter pilot reported having accumulated approximately 7,000-hours in the Bell 206 helicopter, with 200-hours within the last 90 days and 50 hours in the last 30 days. The pilot reported that he did not perceive any anomalies or engine warnings prior to the loss of engine power. A preliminary examination of the helicopter was conducted under the supervision and control of the NTSB Investigator-in-Charge. Initial examination of the engine revealed that the compressor (N1) would not rotate. The engine was subsequently removed from the airframe and shipped to the engine manufacturer's facilities for further evaluation and teardown examination. The engine examination revealed that all of the blade airfoils for the 5th stage compressor had separated from the wheel, with no signs of distress on the first 4 stages of the compressor. Damage to the 6th stage of the compressor and compressor case assembly were considered to be secondary. A detailed metallurgical examination of the compressor revealed that the compressor failure was result of the separation of one or more of the 5th stage compressor blades. Some of the blade fragments were recovered during the engine examination; however they were heavily damaged precluding further analysis. The reason for the failure of the compressor blade(s) could not be determined due to the extensive secondary damage of the components involved.

Factual narrative

On July 30, 2007, at 0643 central daylight time, a single-engine Bell 206B helicopter, N4YJ, was substantially damaged during a forced landing following a reported loss of engine power while in cruise flight near Grand Prairie, Texas. The commercial pilot and one passenger were not injured. A second passenger was seriously injured. The helicopter was registered to Helicopters Inc., of Linden, New Jersey and was being operated by a local television station in Dallas, Texas. No flight plan was filed and visual meteorological conditions prevailed for the traffic and news gathering flight conducted under 14 Code of Federal Regulations Part 91. The local flight originated from the Dallas Love Field (DAL), near Dallas, Texas, at approximately 0600.

After departing DAL, the flight reported on the traffic and news for a local television and radio station in the Dallas-Fort Worth metropolitan area for about 42 minutes. While the helicopter was transiting from another location for an upcoming news story, the helicopter experienced a loss of engine power while in cruise flight at 800-feet above ground level. The pilot reported that he initiated a left 180-degree turn to a clear area. The autorotation was terminated over tall grass and during touchdown the helicopter rolled over and came to rest on its right side.

The pilot and the two passengers (news reporters) were able to egress the aircraft through the left side doors. Damage was sustained to the helicopter's blades, skids, tail boom, undercarriage, and cockpit. The accident site was a wooded area with soft soil on rough and uneven terrain. There were no reported eyewitness to the mishap on the ground.

The 8,000-hour helicopter pilot reported having accumulated approximately 7,000-hours in the Bell 206 helicopter, with 200-hours within the last 90 days and 50 hours in the last 30 days. The pilot reported that he did not perceive any anomalies or engine warnings prior to the loss of engine power.

The 1997-model helicopter, serial number 4463, was recovered to a secured location for a detailed examination. On July 31, 2007, a preliminary examination of the helicopter was conducted under the supervision and control of the NTSB Investigator-in-Charge. No evidence of an in-flight fire or post-impact fire was found. Aircraft control system and drive train continuity was confirmed and no airframe anomalies were identified. Examination of the fuel system revealed that the fuel cell was not breached and more than 15-gallons of fuel were removed from the fuel cell. Engine control continuity was established and there was no evidence of an uncontained engine failure. Initial examination of the engine revealed that the compressor (N1) would not rotate. The engine, a 420-horsepower Rolls Royce Model 250-C20J gas turbine engine, serial number CAE 272756, was subsequently removed from the from the airframe and shipped to the engine manufacturer's facility in Indianapolis, Indiana, for further evaluation and teardown examination.

Examination of the maintenance records for the engine revealed that the engine had been installed on the helicopter for 297.2 hours and had accumulated a total of 5,566.4 hours. Additionally, it was determined that the last 100 and 300 hour inspections on the engine were completed at 5,565.6 hours.

The engine inspection and teardown examination was completed at the engine manufacturer's facilities on 7 September 2007. The examination revealed that all of the blade airfoils for the 5th stage compressor were found separated from the wheel. No signs of distress were found on the first 4 stages of the compressor. A detailed metallurgical examination of the compressor revealed that the compressor failure was result of the separation of one or more of the 5th stage compressor blades. Damage to the 6th stage of the compressor and compressor case assembly were considered to be secondary. Some of the blade fragments were recovered during the engine examination; however they were heavily damaged precluding further analysis. The reason for the failure of the compressor blade(s) could not be determined due to the extensive secondary damage of the components involved.

At 650 local, the automated weather reporting facility at the Grand Prairie Airport (GPM), located approximately 4-nautical miles northwest from the accident site, reported calm winds, 10 statue miles visibility, few clouds at 13,000 feet, temperature 75 degrees, dew point 73 degrees, and barometric pressure of 29.91 inches of Mercury.

Aircraft

Registration
N4YJ
Reported as
Bell 206B
Category
Helicopter
Serial number
4463
Airframe hours
5,608
Engine
Rolls-Royce C250J, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
Aerial observation · Part 91
Registered owner
Helicopters, Inc
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · July 1, 2007 · 1 hours before
Departed
DAL · Dallas, TX
Destination
DAL · Dallas, TX

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
41
Injuries
None
Certificate
Commercial
Medical
Class 2, Without waivers/limitations
Last flight review
May 1, 2007
Seat
Right
Flight hours
8,000 total · 7,000 in this make and model · 7,850 as pilot in command · 200 in the last 90 days · 50 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
30,000 ft broken
Temperature
75 °F, dew point 73 °F
Altimeter
29.90 inHg
Observed at
KGPM

FAA reports on this event · 1

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