Luscombe 11A N1606B

Summary

On 19 June 2010 at about 01:30 local time, a Luscombe 11A registered N1606B was involved in an accident near Merced, California, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 June 2010 at 01:30

Classification

Accident

Location

Merced, California, United States

Coordinates

37.3833, -120.6500

Aircraft

Luscombe 11A

Registration

N1606B

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Visalia → Vacaville

Aircraft damage

Substantial

Weather

VMC

Light

Dawn

NTSB number

WPR10LA306

Nobody was injured.

The pilot’s inability to maintain airplane control during cruise flight due to the failure of the elevator trim tab as a result of missing hardware for the elevator control cable bellcrank to elevator torque tube attachment bracket.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot reported that during cruise flight several minutes after departure he felt both the control yoke and airframe shake violently. The pilot looked out of his window toward the tail section and observed the elevator trim tab fluttering up and down with no corresponding movement to the trim wheel inside the cockpit. The pilot reduced engine power to slow the airplane and regain aircraft control. The airplane began to descend despite full aft elevator pressure. Realizing that he did not have elevator control, the pilot manually manipulated the throttle for pitch control and contacted air traffic control to report his situation. During the descent to a road, the left wing struck a heavy advertising sign and a fence post. After exiting the airplane, the pilot inspected the trim tab and stated that it had failed outboard of the trim cable control horn bracket attachment. He also reported that the upper bolt for the elevator control cable bellcrank to the elevator torque tube attachment bracket was missing. Further examination of the airframe revealed that bolts from the upper attachment and the aft attachment for the elevator control cable bellcrank to elevator torque tube attachment were missing. Damage to the airframe in the tail section included, on the right side torque tube, rub marks on the leading edge with corresponding damage to the adjacent airframe skin, and left side torque tube rub marks on the trailing edge with damage to the rudder skin behind it. What likely occurred was that the elevator attachment bolts on the elevator control cable bellcrank backed out, which then initiated flutter at the elevator, which transferred to the trim tab causing it to fail in overload. Maintenance records indicated that the applicable Airworthiness Directive for the inspection of the trim tab horn attachment was accomplished in December 1949. The airplane had flown 7 hours since its last annual inspection 6 months prior to the accident.

Quoted verbatim from the NTSB record.