N8180H

Substantial
Fatal

Hiller UH-12AS/N: 180

Accident Details

Date
Saturday, February 24, 2007
NTSB Number
ATL07LA045
Location
Bethlehem, GA
Event ID
20070226X00225
Coordinates
33.756942, -83.651664
Aircraft Damage
Substantial
Highest Injury
Fatal
Fatalities
2
Serious Injuries
0
Minor Injuries
0
Uninjured
0
Total Aboard
2

Probable Cause and Findings

The pilot's failure to maintain adequate rotor rpm, which resulted in an attempted autorotation and in-flight collision with trees. Contributing to the severity of the accident was the pilot exceeding the helicopters takeoff capability.

Aircraft Information

Registration
Make
HILLER
Serial Number
180
Engine Type
Reciprocating
Year Built
1950
Model / ICAO
UH-12AUH12
Aircraft Type
Rotorcraft
No. of Engines
1
Seats
4
FAA Model
UH-12A

Registered Owner (Current)

Name
POCKRUS PAT B
Address
517 GRANT RD
City
MINERAL WELLS
State / Zip Code
TX 76067-8826
Country
United States

Analysis

On February 24, 2007, about 1508 eastern standard time, a Hiller UH-12A helicopter, N8180H, collided with the ground during takeoff from a private enclosed landing site, in Bethlehem, Georgia. The two pilots on board the helicopter, a commercial helicopter pilot, and a passenger, who was a certificated private helicopter pilot, were killed. The helicopter sustained substantial damage by impact forces. The flight was operated as an instructional flight under the provisions of Title 14 Code of Federal Regulations Part 91 with no flight plan filed. Visual Meteorological conditions prevailed at the time of the accident.

According to one witness, the helicopter was on its sixth takeoff. The witness stated that during the accident takeoff "the rotor sound which was normally loud seemed to subside. The engine did not sound as though it was turning as high a revolution per minute (RPM) as it usually did when you heard the helicopter after he cleared the trees. A brief moment later it sounded as though the engine stopped running and at the same time you could hear what sounded like tree limbs breaking and then a heavy thud."

Another witness in the local area and a friend of the private pilot, who also owns a UH-12 helicopter, stated that he had advised the private pilot not to attempt a takeoff without clearing woods several hundred more feet from his landing site. He stated that about a week before the accident the private pilot had topped several trees, which would allow the helicopter to clear the first two hundred feet. However, the witness stated that this still presented an extreme danger due to it being the only way in or out of the landing zone.

The witness further stated that the load capacity for this helicopter was around 500 pounds. This did not include the extra fuel tank that was recently installed by the owner. With full fuel and two people on board (the two pilots combined weight was 412 pounds) would have put the helicopter at its maximum gross weight of 2500 pounds. In the witness's experience, "if you do not at any time pay complete attention to the RPM running at 3100 under a load, you will loose power and have to descent if you are in a hover." "Because of this factor the helicopter can drop power on takeoff. It is not a difficult correction but the path of departure that" the private pilot had created made [it] impossible to recover," if this happened. According to the witness the commercial pilot had sold the helicopter to the private pilot and the purpose of the flight was for the commercial pilot to show the owner how to get the helicopter in and out of his enclosed landing site.

Examination of the helicopter by an FAA Inspector found the engine and transmission separated from their mounts and resting in the cockpit, with the tail boom resting against a tree. The tail rotor blades and main rotor blades had separated during the impact sequence. The throttle was observed closed and the throttle linkage was crushed in that position. The tail rotor drive-shaft was observed twisted and bowed aft of the tail rotor drive-shaft u-joint. Main rotor blades contacted the tail boom at the rear u-joint of the rear drive-shaft. The helicopter impacted the ground nose down and slightly to the right side. Examination of the cockpit found that the flight controls could be manipulated from either the center seat position or the left seat position. The flight controls could not be manipulated from the right seat. According to the FAA Inspector, the private pilot rated passenger was removed from the right side of the helicopter by rescue personal after cutting his restraint system.

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ATL07LA045