CHI98LA047

NTSB accident investigation · Hall RV-6 · Blair, NE · November 25, 1997

Accident · No injuriesLimited investigationFinal report
Date
November 25, 1997, 15:00 local (21:00 UTC)
Place
Blair, NE
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N36AHHall RV-6
Weather
Visual (VMC) · Day
Status
Completed · report April 24, 1998
Report
Approved by Office Director
FAA report
19971125035789A
Case key
10791

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

a fatigue failure of the torque tube outside of the weld and the fractured pilot's side left rudder pedal.

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 flightTakeoff - initial climb
Flt control syst,rudder control attach points - fatigueCause
Flt control syst,rudder control - fracturedCause
Forced landingEmergency descent/landing
In flight collision with terrain/waterEmergency descent/landing

Analysis

The pilot said that during the initial takeoff, as the tail wheel came off the ground, the airplane began to 'fishtail.' When the pilot made rudder corrections, the airplane's directional control got worse. The airplane became airborne entering an uncontrolled left turn. The pilot said that he did not have 'positive response' when he turned back parallel to the runway. The pilot reduced power to land. The nose of the airplane tracked right away from the runway heading. The pilot tried to turn back to the left, but the airplane's controls would not respond. The pilot reduced the power to idle and impacted the ground in a left nose down slip approximately 20 feet left of the runway. Examination of the airplane's rudder controls revealed a fracture outside of the weld attaching the base of a T-shaped bar beneath the pilot's left rudder pedal to the torque tube connecting the left rudder pedals to the left and right seats. Further examination of the broken parts revealed a fatigue crack on the torque tube, originating on the rear outside portion of the fracture.

Factual narrative

On November 25, 1997, at 1500 central standard time (cst), a Hall RV-6, N36AH, operated by a commercial pilot, sustained substantial damage when on takeoff the airplane made an uncontrolled left turn. Subsequently, the pilot reduced power and the airplane impacted on the runway. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91. No flight plan was on file. The pilot reported no injuries. The flight was originating at Blair, Nebraska, when the accident occurred.

In his written statement, the pilot said that during the initial takeoff as the tail wheel came off the ground, the airplane began to "fishtail." When the pilot made rudder corrections, the airplane's directional control got worse. The airplane became airborne entering an uncontrolled left turn. The pilot said that he did not have "positive response" when he turned back parallel to the runway. The pilot reduced power to land. The nose of the airplane tracked right, away from the runway heading. The pilot tried to turn back to the left, but the airplane's controls would not respond. The pilot reduced the power to idle and impacted the ground in a left nose down slip approximately 20 feet left of the runway. The airplane skidded across the ground and came to rest in the center of the runway.

A Federal Aviation Administration (FAA) inspector examined the airplane at the accident site. The spinner and lower cowling were crushed inward. The firewall showed buckling at the bottom. The left side of the fuselage from the cowling, through the cockpit and aft to the empennage showed heavy skin wrinkling. The left main landing gear was bent aft and embedded in the bottom fuselage skin. The left wing tip was crushed inward and broken aft. The left forward wing spar was broken aft. The wood propeller was broken aft and split. Examination of the engine and engine controls revealed no anomalies. Examination of the airplane's rudder controls revealed that a fracture had occurred outside of the weld attaching the base of a T-shaped bar, forming the foot rest of the pilot's left rudder pedal, to the torque tube connecting the left and right seat left rudder pedals.

Further examination of the broken parts revealed a fatigue crack on the torque tube, originating on the rear outside portion of the fracture.

Aircraft

Registration
N36AH
Reported as
Hall RV-6
Category
Airplane, amateur-built
Serial number
20814
Airframe hours
439
Engine
Lycoming O-320-D1A, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Aaron Lee Hall
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · May 5, 1997 · 61 hours before
Departed
K46
Airport
K46 · Eagle Field, runway 31, 3,450 × 50 ft, asphalt

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
72
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
3,890 total · 429 in this make and model · 3,530 as pilot in command · 15 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 8 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
63 °F, dew point 41 °F
Altimeter
29.00 inHg
Observed at
OMA, 20 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.