- Date
- October 3, 2005, 17:10 local (Oct 4, 2005, 00:10 UTC)
- Place
- Grand Canyon, AZ
- Injuries
- 7 uninjured
- Damage
- Substantial damage
- Phase of flight
- Landing
- Aircraft
- N31MHAerospatiale AS350B
- Weather
- Visual (VMC) · Day
- Status
- Completed · report February 28, 2006
- Report
- Approved by Office Director
- Parties
- Federal Aviation Administration
- FAA report
- 20051003022499A
- Case key
- 62602
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
the pilot's failure to maintain control of the helicopter during landing in gusty wind conditions, which resulted in a hard landing and ground resonance.
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.
Analysis
The helicopter encountered a ground resonance event following a hard landing in gusty wind conditions. The pilot reported that the winds were from the south at 18 knots with gusts to 36 knots. He hover-taxied to the helipad for landing following a sightseeing tour and had established the helicopter in a 3-foot hover in preparation for landing. A gust of wind disrupted the helicopter and brought it to a 6-foot hover. The pilot regained control and stabilized it back in a 3-foot hover. Another gust of wind "slammed" the helicopter onto the helipad and a ground resonance event began. The pilot lifted the helicopter back into the air upon noticing the increasing vibrations. After the vibrations dissipated, the pilot set it back onto the helipad.
Factual narrative
On October 3, 2005, at 1710 Pacific daylight time, an Aerospatiale AS350B, N31MH, encountered a ground resonance event following a hard landing at the Grand Canyon Airport (GCN), Grand Canyon, Arizona. The commercial rotorcraft pilot and six passengers were not injured; the helicopter sustained substantial damage. The helicopter was registered to, and operated by, Maverick Helicopters, Las Vegas, Nevada, as a sightseeing flight under the provisions of 14 CFR Part 135. The tour flight originated from GCN at 1647, and was terminating at the time of the accident. Visual meteorological conditions prevailed, and a company visual flight rules flight plan had been filed.
According to the pilot's written statement, he established the helicopter in a 3-foot hover and taxied to the helipad. As the helicopter neared the helipad, a "gust of wind lifted the aircraft into a 5- to 6-foot hover." The pilot regained control and reestablished the helicopter in a 3-foot hover and began lowering the collective to land. At 1.5 feet above the ground, another gust of wind "slammed" the helicopter onto the ground, impacting the terrain with the right front skid. A "violent vibration" began, and the pilot pulled the helicopter up in the air after realizing he was in a ground resonance situation. The vibrations dissipated, and the pilot set the helicopter down and shut off the engine.
The helicopter sustained substantial damage to its tail boom. Post accident examination of the landing skid system revealed that the spring-steel extensions were within limits and the dampers were in serviceable condition. The pilot did not report any anomalies with the helicopter prior to the event.
The pilot reported that the winds were from the south at 18 knots with gusts to 36 knots.
Aircraft
- Registration
- N31MH
- Reported as
- Aerospatiale AS350B
- Category
- Helicopter
- Serial number
- 2141
- Airframe hours
- 8,933
- Engine
- Turbomeca Arial 1D1, 700 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Part 135
- Registered owner
- Maverick Helicopters Inc.
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · September 1, 2005 · 92.3 hours before
- Departed
- GCN · Grand Canyon, AZ
- Flight plan
- Company VFR
- Airport
- GCN · Grand Canyon National Park
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 22
- Injuries
- None
- Certificates
- Flight instructor, Commercial
- Instrument ratings
- Helicopter
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- July 1, 2005
- Seat
- Left
- Flight hours
- 1,790 total · 240 in this make and model · 240 in the last 90 days · 50 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 180° at 18 knots, gusting 36
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 73 °F
- Altimeter
- 30.02 inHg
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.