MIA01LA055

NTSB accident investigation · Hiller UH-12E · Cleveland, TN · January 5, 2001

Accident · No injuriesLimited investigationFinal report
Date
January 5, 2001, 15:00 local (21:00 UTC)
Place
Cleveland, TN
Injuries
1 uninjured
Damage
Destroyed
Phase of flight
Standing
Aircraft
N112ECHiller UH-12E
Weather
Visual (VMC) · Day
Status
Completed · report July 30, 2001
Report
Approved by Office Director
Parties
FAA FSDO
FAA report
20010105000479A
Case key
50884

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 PIC's failure to follow safe operating procedures for the maintenance of the rotorcraft's external aerial application equipment, resulting in inadvertent activation of collective as he egressed the rotorcraft, causing unmanned flight, in-flight break-up, and collision with terrain.

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.

Miscellaneous/otherStanding - engine(s) operating
Unsafe/hazardous condition - usedPilot in commandCause
Collective - inadvertent activationPilot in command
Miscellaneous/otherHover
In flight collision with terrain/waterDescent - uncontrolled

Analysis

According to the pilot, the externally slung, hydraulically operated fertilizer bucket stopped dispensing. With no ground handling crewman available, the pilot set the rotorcraft down to troubleshoot the problem. With engine rpm near maximum to run the hydraulic pump to its maximum output, the pilot climbed out of the left seat, onto the left skid to read the externally mounted hydraulic pressure gage. While egressing the cockpit, the pilot accidentally bumped the collective control to the "increase rotor pitch" position, and the rotorcraft became airborne without him aboard. The rotorcraft climbed to about 500 feet agl, in circling flight until the loaded fertilizer bucket began swinging in ever-divergent oscillations causing rotorcraft instability and eventual main rotor-to-boom strike and crash.

Factual narrative

On January 5, 2001, about 1500 central standard time, a Hiller UH-12E, N112EC, registered to B and S Air, Inc., operating as a Title 14 CFR Part 137 aerial application flight, crashed in the vicinity of Cleveland, Tennessee. Visual meteorological conditions prevailed and no flight plan was filed. The rotorcraft was destroyed, and the commercially-rated pilot, was not injured. The flight originated about 15 minutes before the accident.

According to the pilot, he was applying fertilizer to pine trees from a hydraulically operated Simplex bucket on a 25-foot external sling when the bucket stopped dispensing. He landed the rotorcraft to try and determine if the malfunction was hydraulic or mechanical. To do so, since he was the sole occupant aboard, and the ground handler was running an errand, he had to set the craft down, keep operating power on the engine, step out of the cockpit onto the skid, and read the externally mounted hydraulic pressure gage. As he exited the cockpit, he slipped and somehow during the fall, he bumped or grabbed the collective. As the unmanned rotorcraft lifted off, the left landing skid struck him in the face, and by the time he could react, the rotorcraft was at 100 feet agl, and climbing. The craft stayed airborne for about 30 to 45 seconds while attaining an altitude of about 500 feet agl, in a right spin before the main rotor collided with and severed the tail boom.

According to an FAA inspector, the engine power had to be near 100 percent operating rpm to effectively check hydraulic pump output. As the left-seated pilot swung his right leg over the cyclic, he tripped and fell. While falling, his left hand, which was positioned aft of the collective's pivot point, somehow engaged the collective control column to the full up position. Once the rotorcraft was airborne and climbing in right circling flight, the loaded fertilizer bucket began ever-diverging oscillatory motions until it caused the main rotor to severe the tail boom and the rotorcraft crashed about 1,500 feet from its liftoff point.

Aircraft

Registration
N112EC
Reported as
Hiller UH-12E
Category
Helicopter
Serial number
HA3012
Airframe hours
2,728
Engine
Allied Signal 250C20B, 420 horsepower, turbo shaft
Damage
Destroyed
Flight
Aerial application · Part 137
Registered owner
B and S Air, Inc.
Airworthiness certificate
Special, Restricted (Special)
Departed
Cleveland, TN

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
53
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
16,742 total · 3,000 in this make and model · 16,371 as pilot in command · 33 in the last 90 days · 3 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
260° at 9 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
52 °F, dew point 25 °F
Altimeter
29.80 inHg
Observed at
CHA, 21 nm away

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 N112EC · 1

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