Cessna 402C N88TN

The pilot stated the airplane was about 5 miles north of Fort Lauderdale Executive Airport (FXE) and at approximately 4,000 feet mean sea level, when the airplane pitched sharply nose down, with an uncontrollable back and forth oscillation of the control yoke, lasting about 5 seconds. A loud shearing noise was heard from the right rear of the aircraft before pitch control was regained. He looked toward the right rear of the airplane to see sheet metal flapping in the wind near the elevator section. He declared an emergency and he was cleared for immediate landing at FXE; the landing was uneventful. An examination by NTSB revealed a section of about 16 inches was missing from the right elevator's outboard area; which was later recovered about 5 miles north of FXE in a residential area. The remaining outboard of the elevator up to the inboard attaching hinge was peeled up and aft. The attaching hardware connecting the elevator trim tab horn to the elevator trim actuator push-rod was missing. No abnormality was observed to the areas and surfaces of the trim tab horn and the push-rod attaching area. The pilot was asked to demonstrate all the steps accomplished during the preflight prior to the accident flight and what type of nut was securing the trim tab horn to the trim tab push rod, a self locking nut or one that has a cotter pin? He did recall a nut however could not recall observing a cotter pin. The accident airplane had undergone inspections and maintenance on February 21, 2005, which included the overhaul of the elevator trim tab actuator. The mechanic, whom performed the tasks, stated that after the installation of the elevator trim tab actuator, he attached the elevator trim tab actuator push- rod to the elevator trim horn using a new bolt, washer, nut and cotter pin from the shop stock in accordance with the maintenance manual. Another mechanic stated that he was present and actually handed the cotter pin to the mechanic who performed the installation. An FAA inspector examined the maintenance facility and interviewed the mechanics that were involved in the tasks and stated that he did not observe any discrepancy with the bins of cotter pins. During the interview with the mechanic, the one mechanic stated that he remembers installing the cotter pin however he could not remember the exact cotter pin he installed and added the cotter pin was given to him by another mechanic. The FAA inspector instructed the other mechanic, who retrieved the cotter pin, to demonstrate where he got the cotter pin from. The mechanic went to the bin area and opened two bins. One of the bins had the proper cotter pin. The mechanic said he believed that he took the proper cotter pin. The pilot who test flew the accident airplane after maintenance stated that a preflight was accomplished and no irregularities were noted. The pilot added that he personally completed two test flights. The airplane owner's pilot completed a preflight of the accident airplane in the facility's hanger prior to signing the delivery receipt and a least two more times, prior to and during his en route flight to Florida.

Quoted verbatim from the NTSB record.