DEN00FA084

NTSB accident investigation · Aerospatiale AS-350B · Blanding, UT · May 4, 2000

Accident · FatalField investigationFinal report
Date
May 4, 2000, 15:55 local (21:55 UTC)
Place
Blanding, UT
Injuries
3 fatal, 3 serious
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
CGPTTAerospatiale AS-350B
Weather
Visual (VMC) · Day
Status
Completed · report November 1, 2001
Report
Approved by Office Director
Case key
49127

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 loss of aircraft control due to abrupt flight maneuvering. Contributing factors were the high density altitude weather condition, the total loss of engine power due to the pilot manually introducing excessive fuel into the engine and over temping the turbine section, and the lack of suitable terrain for the ensuing 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 control - in flightManeuvering
Aircraft handling - abruptPilot in commandCause
Weather condition - high density altitudeFactor
Loss of engine power(total) - mech failure/malfDescent - uncontrolled
Emergency procedure - attemptedPilot in commandFactor
Turbine assembly - overtemperatureFactor
In flight collision with terrain/waterDescent - uncontrolled
Autorotation - attemptedPilot in command
Terrain condition - rough/uneven
Terrain condition - none suitableFactor

Analysis

The pilot was assigned to fly for a geophysical seismic team in rugged high desert conditions (elevation 5,366 feet). On his second day of flying, he was requested, by one of the team members, to "fly a little easier; less aggressively." On his third day of flying, he was assigned to pick up five team members and their equipment. Once airborne (density altitude was 8,908 feet), he had been briefed that he would receive GPS team distribution coordinates; instead, he was instructed to land and hold for a period of time. A witness observed the helicopter fly eastbound, and then make a 45 to 60 degree bank turn [180 degrees] back to the west. The witness then saw the helicopter turn southbound, lower its nose down almost vertically, and then reduce its nose low pitch to approximately 45 degrees as it disappeared from sight. Postaccident examination of the engine revealed that the manual throttle pointer on the fuel control was in the emergency position. The first and second stage turbine wheels were found with their blades 50 to 70 percent melted, indicating an engine that functioned for a time at a temperature level well above its limits.

Factual narrative

History of flight

On May 4, 2000, approximately 1555 mountain daylight time, an Aerospatiale AS-350B helicopter, Canadian registration CGPTT, was destroyed during impact with terrain while maneuvering near Blanding, Utah. The commercial pilot and two passengers were fatally injured, and the other three passengers were seriously injured. The helicopter was being operated by Peace Helicopters Ltd., Edmonton, Alberta, under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local flight that originated from landing zone 1 (LZ1) 10 minutes earlier. No flight plan had been filed.

The pilot arrived in Blanding, Utah, on May 1, 2000, to relieve the project pilot working for a geophysical seismic team. On May 2, 2000, he flew a familiarization flight with the previous project pilot, and was briefed on operational procedures and environmental concerns. The previous project pilot stated that "when you live with, and fly for a geophysical seismic crew for 3 or 4 weeks, they get used to you; a new guy has to prove himself." The operator stated that this was the first time that the pilot had been on assignment in the United States.

On May 3, 2000, the pilot flew his first day as the project pilot. In the afternoon, the Safety Officer of the geophysical project said that the pilot told him that this was "his first time to fly in the desert, and the [desert's unpredictable] winds." He also said that the pilot seemed "very brash."

On May 4, 2000, the helicopter mechanic said that the helicopter was fueled at the LZ1 staging area (landing zone 1; N37 degrees 22.77', W109 degrees 28.40'; elevation 4,702 feet) to its project maximum 40 percent of the 143 gallon tank, or 57 gallons. A geophysical team member, who operated the Kodiak system [a computerized ground based resource management system that displays and records the real-time helicopter location utilizing GPS technology] at the staging area, said that he briefed the pilot for the flight. He said that the briefing included a request that the pilot "fly a little easier; less aggressive." The Kodiak operator told the pilot that two other team members had spoken to him and requested that he talk to him about his "rough handling of the helicopter."

The helicopter departed at 1545 and flew 5.35 nautical miles (nm) direct to LZ4 (N37 degrees 20.56', W109 degrees 23.01'; elevation 4,586 feet) to pick up five geophysical team members. The helicopter's flight data stopped recording on the Kodiak, at 1547, due to the terrain masking characteristic of the line-of-sight system.

The passenger sitting in the left front seat said that when he boarded the helicopter at LZ4, the pilot was wearing a flight helmet and shoulder harness. Because of the anticipated short ride, the passenger secured himself with only the seat belt; he also put on a headset. At 1552, the Kodiak system once again started recording; the helicopter was recorded flying westbound. The estimated weight of the helicopter, with five passengers and equipment, was 4,076 pounds.

At this point, the Kodiak operator said that he was scheduled to transmit the team's multiple drop off points to the pilot. But instead, he transmitted a radio request for the pilot to land the helicopter so that a seismic shot could be fired [the helicopter's noise/vibration is picked up by the geophones, and recorded if the helicopter is airborne at the time of the shot]. According to the Kodiak operator, the pilot radioed back that he would set down "on top, up here" [on top of the mesa]. The helicopter was last recorded (2.6 nm of flight from LZ4) on the Kodiak as flying 065 degrees at 68 knots, at an altitude of 1,696 meters, or 5,565 feet. This would have placed him 199 feet above the mesa (elevation 5,366 feet).

The Safety Officer, located .74 nm east of the crash site, observed the helicopter flying eastbound towards him (this portion of the flight was not recorded on the Kodiak due to terrain blocking). He said that as it approached the eastern edge of the mesa, it made a "very hard left hand turn [180 degrees] back to the west." He later estimated that the helicopter's bank was 45 to 60 degrees. He then saw the helicopter turn southbound, lower its nose almost vertically down, and then reduce its nose low pitch to approximately 45 degrees as it disappeared from sight. Immediately he observed a cloud of dirt and dust. He got on the radio and reported that the helicopter was down; approximately 1 minute from the helicopter's disappearance, he observed smoke rising from the mesa top.

One of the surviving back seat passengers [who was on his first flight with the pilot] said that he remembered a hard left turn, followed by a loud pop, then a screaming whir," followed by a red light on the pilot's instrument panel. Another surviving passenger said that he heard a loud noise (sounded like something breaking), and then a loud Beep, Beep, Beep.... The third surviving back seat passenger said that he saw the pilot move his left hand quickly towards something near his left knee. He said that the pilot looked "upset," and then he heard a loud high pitch screaming sound. The passenger further reported that moments later the pilot pulled up (on the collective) with both hands, but nothing happened.

Personal information

The pilot was a Canadian citizen. According to the operator's records, the pilot had a commercial pilot certificate (helicopter) and private pilot certificate (single engine airplane). He was not instrument rated. The records further indicated that at the time of the accident, the pilot had approximately 2,900 hours total time in helicopters, with approximately 1,500 hours in this make and model. The records also indicated that the pilot had flown in a variety of environmental conditions, including desert conditions in Canada.

Aircraft information

The helicopter was a single engine, six seat aircraft, which was manufactured by Aerospatiale (now Eurocopter) in 1980. It was powered by an Turbomeca Arriel-1B turbo shaft engine rated at 641 horsepower at sea level. The engine (S/N 303) was installed in the aircraft on March 14, 2000, with a total time on it of 9,274 hours.

On March 21, 2000, the engine air-intake particle separator was removed, which reduced the helicopter's weight by 14.6 pounds. The last weight and balance measurement was performed on March 29, 2000; the helicopter's empty weight was determined to be 2,624.01 pounds. The aircraft's certificated maximum gross weight was 4,300 pounds, its in-ground-effect (IGE) maximum gross weight for the weather conditions at the accident site was 4,025 pounds, and its out-ground-effect (OGE) maximum gross weight for the weather conditions at the accident site was 3,725 pounds. Transitional lift speed was 15 knots.

The previous pilot assigned to the helicopter, departed Edmonton, Alberta, on March 31, 2000, in the helicopter and flew it to the project site. He arrived in Blanding on April 1, 2000; the total trip flight time was approximately 10 hours. He flew for the geophysical project until being relieved by the accident pilot on May 3, 2000. The previous pilot stated that he "felt very good about the aircraft," and he had very few problems with it. Maintenance performed on the aircraft during his tour of duty was confined to a tail-rotor change and an engine bleed value change. He said that he thought it was one of the operator's "better aircraft."

The maintenance person assigned to the helicopter said that he performed an annual inspection on April 22, 2000. The aircraft records indicated that the last daily inspection was performed on May 3, 2000; the maintenance person said an inspection was performed on May 4, but was never recorded in the aircraft logbooks. At the time of the accident, the helicopter had 11,221 hours of flight time and the engine had 9,427 hours since new.

The helicop

Aircraft

Registration
CGPTT
Reported as
Aerospatiale AS-350B
Category
Helicopter
Serial number
1317
Airframe hours
11,221
Engine
Turbomeca ARRIEL-1B, 641 horsepower, turbo shaft
Damage
Destroyed
Fire
On-Ground
Flight
Other work use · Part 91
Operator
Peace Helicopters Ltd.
Registered owner
Northern Mountain Helicopters
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · April 22, 2000 · 100 hours before
Departed
NONE

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
37
Certificates
Foreign, Commercial, Private
Airplane ratings
Single-engine land
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Right
Toxicology
Performed
Flight hours
3,000 total · 1,485 in this make and model · 2,800 as pilot in command · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
230° at 8 knots, gusting 16
Visibility
10 statute miles
Lowest ceiling
None
Temperature
203 °F, dew point 126 °F
Altimeter
30.00 inHg
Observed at
CEZ, 36 nm away

Docket · 32

The files NTSB released with the investigation on October 10, 2001, on NTSB’s docket system: statements, records, photos and specialists’ reports. 7.3 MB in all.

Supplement GItem 1 · .PDF · 96 KBSupplement SItem 2 · .PDF · 59 KBPilot/Operator Aircraft Accident Report, NTSB Form 6120.1Item 3 · .PDF · 413 KBWitness StatementsItem 4 · .PDF · 482 KBMaterials Laboratory 15 - Factual Report of Group ChairmanItem 5 · .PDF · 458 KBMaps or Charts of Accident Area, Wreckage DiagramsItem 6 · .PDF · 1.2 MBReports from Federal AgenciesItem 7 · .PDF · 420 KBReports from Local AgenciesItem 8 · .PDF · 139 KBReports from Parties to the InvestigationItem 9 · .PDF · 695 KBReports from Parties to the Investigation - TurbomecaItem 10 · .PDF · 566 KBOther Pertinent Forms and ReportsItem 11 · .PDF · 1.8 MBStatement of Party Representatives to NTSB InvestigationItem 12 · .PDF · 77 KBRelease of Aircraft Wreckage, NTSB Form 6120.15Item 13 · .PDF · 112 KBToxicological ReportItem 14 · .PDF · 156 KBPhoto 1: Accident scene of CGPTT looking south.Item 15 · .PDF · 39 KBPhoto 2: Accident scene of CGPTT looking east/ southeast.Item 16 · .PDF · 42 KBPhoto 3: This picture shows the molten metal of the fuselage on top of a main rotor blade.Item 17 · .PDF · 57 KBPhoto 4: CGPTT's engine. Note the damage on its right side and the molten aluminum. (Picture 8: exhaust pipe bending toward center from the right side.) - color copy photoItem 18 · .PDF · 30 KBPhoto 5: Accident scene looking east. Note tail rotor drive shaft section. - color copy photoItem 19 · .PDF · 39 KBPhoto 6: The tailboom of CGPTT. Note the horizontal stabilizers. - color copy photoItem 20 · .PDF · 48 KBPhoto 7: CGPTT's tailboom with ventral fin pushed up. The tail rotor wxhibits impact damage & broken at the cuff.Item 21 · .PDF · 41 KBPhoto 8: CGPTT's tailboom.Item 22 · .PDF · 41 KBPhoto 9: CGPTT's debris track. Note scars on the rock. - color copy photoItem 23 · .PDF · 43 KBPhoto 10: A close up of the scratches on the rock.Item 24 · .PDF · 32 KBPhoto 11: To the right and backwards from picture #10. The rock is scuffed with green paint transfer. The darker color may be black transfer.Item 25 · .PDF · 41 KBPhoto 12: The main ground scar with the right landing skid.Item 26 · .PDF · 48 KBPhoto 13: Right landing skid with bear paws attached.Item 27 · .PDF · 35 KBPhoto 14: Main ground scar with plexiglass and rubber seals. The arrow points to the rock with the scar on it.Item 28 · .PDF · 34 KBPhoto 15: The view from where the witness was standing looking west to the approximate location of the impact.Item 29 · .PDF · 31 KBPhoto 16: The number one turbine wheel. Note the thermal damage to the blades. - color copy photoItem 30 · .PDF · 36 KBPhoto 17: The number one turbine wheel. - color copy photoItem 31 · .PDF · 34 KBPhoto 18: The fuel control unit to the engine. Note the throttle pointer is at 71 degrees or in the emergency position.Item 32 · .PDF · 39 KB