NYC00MA048

After a 5-hour flight, the Westwind jet began its descent to the airport. Air traffic control instructed the flight crew to cross a VOR at 18,000 feet. The flight crew was then instructed to cross an intersection at 6,000 feet. The flight crew needed to descend the airplane 12,000 feet, in 36 nautical miles, to make the crossing restriction. The flight crew acknowledged the clearance, and no further transmissions were received from the airplane. The airplane struck treetops and impacted the ground in a wooded area. The accident flight was the airplane's first flight after maintenance. Work that was accomplished during the maintenance included disassembly and reassembly of the horizontal stabilizer trim actuator. Examination of the actuator at the accident site revealed that components of the actuator were separated and that they displayed no damage where they would have been attached. Examination of the actuator by the Safety Board revealed that the actuator had not been properly assembled in the airplane. A similar actuator was improperly assembled and installed in a static airplane for a ground test. When the actuator was run, the jackscrews of the actuator were observed backing out of the rod end caps within the first few actuations of the pitch trim toward the nose-down position. As the pitch trim continued to be actuated toward the nose-down position, the jackscrews became disconnected from the rod end caps, and the horizontal stabilizer became disconnected from the actuator.

History of flight

On December 12, 1999, about 1635 eastern standard time, an Israel Aircraft Industries (IAI) 1124A, N50PL, was destroyed after impacting terrain near Gouldsboro, Pennsylvania. The two certificated airline transport pilots and a passenger were fatally injured. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the personal flight conducted under 14 Code of Federal Regulations (CFR) Part 91.

The flight departed from the Boeing Field/King County International Airport (BFI), Seattle, Washington, and proceeded eastbound, destined for the Teterboro Airport (TEB), Teterboro, New Jersey. After a 5-hour flight, the airplane began its descent to TEB. Air traffic control (ATC) instructed the flight crew to cross the Wilkes-Barre (LVZ) VOR at 18,000 feet, which the flight crew acknowledged. The flight was then instructed to cross the MUGZY intersection at 6,000 feet. The flight crew acknowledged the clearance, and no further transmissions were received from the airplane.

Several witnesses stated that they observed the airplane before its impact. One witness, who was riding in the front passenger seat of her car heading southeast on Interstate 380 in Pennsylvania, stated that she saw an airplane in a near vertical climb level off, then begin a pattern of "twists, swoops, and turns." The witness also observed a fairly dark smoke trail but stated that it was "not a thick trail of smoke." Several other people in the same car thought that the airplane was performing acrobatic maneuvers. The witness added that the airplane's movements became more erratic as it made more "flips and turns" and that it went straight down "nose first, no spinning, twisting, or corkscrewing."

Another witness, who was standing in his yard at a mobile home complex, observed an airplane flying close to the treetops. The witness stated that he heard the sound of the engines being "fired up" and that the airplane went into a vertical climb. He added that the airplane completed one spiral, then "the nose came down" into the ground.

A third witness, who was also traveling southeast on Interstate 380, stated that she observed the airplane "dipping" toward the highway. She stated that it then ascended steeply, completed several spins, and made a final descent. The witness added that, at the time, she thought it was a model airplane performing acrobatic maneuvers.

A fourth witness, who was getting out of his car at a nearby rifle range, stated that the airplane came at him from the trees. He added that it then went straight up into the air, and "nose dived" to the ground. He then heard an explosion about 10 seconds later, and observed smoke rising from the trees.

A fifth witness, who was sitting on his porch, stated that he observed an airplane and heard a "pop" noise, like the engine had quit. According to the witness, the airplane then flew "tipsy" like it was in turbulence and then the engine sounded like it had started up again. The witness added that as the airplane passed low overhead, it sounded like something out of "Top Gun." He further added that the airplane was intact and that the engines were red. The witness stated that there was no fire or smoke emanating from the airplane prior to impact.

The airplane struck treetops and impacted the ground in a wooded area, which surrounded a mobile home complex.

The accident occurred during the hours of daylight approximately 42 degrees, 28 minutes north latitude, and 76 degrees, 8 minutes west longitude.

Flight crew information

Captain

The captain held an airline transport pilot certificate with a rating for airplane multi-engine land and commercial privileges for airplane single-engine land and sea. In addition, the captain was type rated in the Gulfstream G-1159, Israel Aircraft Industries IAI-Jet, and Lear Jet. The captain also held a flight instructor certificate for airplane single land.

The captain reported 9,700 hours of total flight experience on his last application for a medical certificate. The captain's pilot logbook was not recovered.

According to company records, the captain last attended recurrent training in the IAI-1124, on February 15, 1999.

The captain's most recent Federal Aviation Administration (FAA) first class medical certificate was issued on February 1, 1999.

First Officer

The first officer held an airline transport pilot certificate with a rating for airplane multi-engine land and commercial privileges for airplane single-engine land and sea. In addition, the first officer was type rated in the Israel Aircraft Industries IAI-Jet. He also held a flight instructor certificate for airplane single and multi-engine land.

According to the first officer's most recent pilot logbook entries, he recorded 4,413 hours of total flight experience.

According to company records, the first officer last attended recurrent training in the IAI-1124, on January 5, 1999.

The first officer's most recent FAA first class medical certificate was issued on January 29, 1999.

Aircraft information

Examination of the airplane maintenance records revealed that on February 20, 1998, the airplane's horizontal jackscrew actuator was overhauled and returned to service by Lucas Aerospace Power Equipment Corporation, Aurora, Ohio. The actuator was then installed in the airplane on February 26, 1998, and an entry was made in the airplane flight log describing the installation. The airplane flight log entry did not mention, however, that the installation of the new actuator would have terminated the repetitive inspections required by Airworthiness Directive (AD) 98-20-35, Amendment 39-10802.

On October 9, 1998, an "A" check was accomplished in accordance with the IAI inspection guide. The entries made in the airplane flight log did not mention compliance with AD 98-20-35 Amendment 39-10802, nor was it required.

The airplane maintenance records also revealed that on December 10, 1999, an "A" check was accomplished in accordance with the IAI inspection guide. Among the activities completed during the inspection, the left-hand elevator was removed from the airplane, painted, balanced per the maintenance manual, and reinstalled.

Examination of the airplane's flight log revealed stickers that were added to two pages of the log. The stickers were dated December 10, 1999, and described work that was accomplished during the "A" check. One of the stickers stated, "Complied with an "A" check in accordance with I.A.I. inspection guide. Complied with A.D. 98-20-35 Amendment 39-10802 on inspection of trim actuator. Actuator was replaced 3/98. This terminates the repetitive inspections I.A.W. Para. (2) (a) of this AD."

Review of the airplane's flight log revealed that the airplane had accumulated about 170 hours of total flight time in the previous year. The airplane's last flight prior to maintenance was on December 1, 1999. The airplane accumulated 3.6 hours of flight time and 3 cycles that day.

According to line service personnel at BFI, the airplane was last fueled on December 11, 1999, with about 958 gallons of Jet A fuel. A fuel additive was mixed with the fuel, as requested by the pilot.

Meteorological information

The weather reported at 1645, by the Wilkes-Barre Wyoming Valley Airport, Avoca, Pennsylvania, was calm winds, 10 statute miles of visibility, and clear skies.

Flight recorders

Cockpit Voice Recorder

The airplane was equipped with a B&D cockpit voice recorder (CVR). The CVR was transported to the Safety Board on December 13, 1999. The CVR group convened on December 20, 1999. A transcript was prepared for the entire 32 minute 50 second recording.

The following are excerpts of the CVR transcript:

1621:16, the first officer stated, "elevator up... my light just flashed on."

1621:22, the captain stated, "oh, your trim did?"

1621:22, the first