# NTSB SEA06FA146: Spectrum Aeronautical 33, N322LA, Spanish Fork, UT, July 25, 2006 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: July 25, 2006, 16:06 local (22:06 UTC) - Place: Spanish Fork, UT - Coordinates: 40.141666, -111.661392 - Nearby events: https://openairdocs.org/map.md?lat=40.1417&lon=-111.6614&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report November 29, 2007 - Report: Approved by Office Director - Parties: Spectrum Aeronautical LLC, Rocky Mountain Composites, Williams International, FAA FSDO - NTSB case key (mKey): 64191 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA06FA146 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64191/pdf - Page: https://openairdocs.org/ntsb/SEA06FA146 ## Probable cause Incorrect installation by company maintenance personnel of the aft upper torque tube bell crank resulting in roll control that was opposite to that commanded in the cockpit. Contributing factors were the lack of maintenance documentation detailing the installation of the bell crank, the installing mechanic's incorrect assumption that the bell crank could only be installed in one position, and the failure of maintenance personnel and the flight crew to check the position of the control stick relative to the ailerons after the maintenance and during the preflight checks. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, standing - pre-flight - flt control syst,aileron control - reversed (cause) - expectancy, company maintenance personnel (contributing factor) - maintenance,installation - incorrect, company maintenance personnel (cause) - condition(s)/step(s) not listed, manufacturer (contributing factor) - maintenance,inspection - inadequate, company maintenance personnel (contributing factor) - aircraft preflight - inadequate, flightcrew (contributing factor) - Loss of control - in flight, takeoff - initial climb - aircraft control - not possible, pilot in command - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis The proto-type experimental light jet airplane was departing on a local maintenance test flight. Witnesses reported that the airplane entered a right roll almost immediately after liftoff. The roll continued to about 90 degrees right wing down at which point the right wingtip impacted the ground. During examination of the wreckage, the aileron control system was found connected such that the airplane rolled in the opposite direction to that commanded in the cockpit. The maintenance performed on the airplane before the accident flight included removal of the main landing gear (MLG) in order to stiffen the MLG struts. Interviews with the mechanics who performed the maintenance revealed that during re-installation and system testing of the MLG, it was discovered that the changes to the MLG struts impacted the V-bracket holding the aileron control system's upper torque tube. The V-bracket was removed and a redesigned V-bracket was installed in its place. This work required the disconnection of a portion of the aileron control system, including the removal of the aft upper torque tube bell crank from the torque tube. The mechanic who reinstalled the aft upper torque tube bell crank was under the incorrect assumption that there was only one way to install the bell crank on the torque tube. However, there are actually two positions in which the bell crank could be installed. The incorrect installation is accomplished by rotating the bell crank 180° about the axis of the torque tube and flipping it front to back, and this is the way the bell crank was found installed. With the bell crank installed incorrectly and the rest of the system installed as designed, there is binding in the system. This binding was noticed on the accident airplane during the inspection after initial installation. However, the mechanic did not recognize that the bell crank was improperly installed on the torque tube. Instead of fixing the problem by removing and correctly reinstalling the bell crank, he fixed the problem by disconnecting the necessary tie rods and rotating the upper torque tube so that the arm of the bell crank pointed up and to the left. This action reversed the movement of the ailerons. According to all of the personnel interviewed, there was no maintenance documentation to instruct mechanics how to perform the work since this was a proof-of-concept airplane. None of the mechanics who performed the work could recall if the position of the ailerons in relation to the position of the control stick was checked. Such a position check, if it had been performed by either the mechanics after the maintenance or by the flight crew during the preflight checks, would assuredly have indicated that the system was installed incorrectly. ## Factual narrative HISTORY OF FLIGHT On July 25, 2006, approximately 1606 mountain daylight time, a Spectrum 33 experimental twin-engine jet airplane, N322LA, collided with terrain following a loss of control during the initial climb after takeoff from runway 30 at Spanish Fork-Springville Airport, Spanish Fork, Utah. The airplane, which was registered to and operated by Spectrum Aeronautical LLC, was destroyed by impact forces. The two commercial pilots aboard received fatal injuries. Visual meteorological conditions prevailed and no flight plan was filed for the 14 CFR Part 91 local maintenance test flight. The flight was originating when the accident occurred. Witnesses reported that the airplane entered a right roll almost immediately after liftoff. The roll continued to about 90 degrees right wing down at which point the right wingtip impacted the ground. PERSONNEL INFORMATION The pilot-in-command (PIC), who was seated in the left front seat, held a commercial pilot certificate with airplane single engine land, multiengine land, and instrument ratings. Additionally, he held a mechanic certificate with airframe and powerplant ratings. He held a first class medical certificate dated February 14, 2006, with the limitation, must wear corrective lenses. On the application for this medical certificate, the PIC reported that he had accumulated 2,350 hours total flight time with 100 hours flown in the past six months. According to the operator, he had accumulated a total time of 22 hours in the Spectrum 33 of which 16 hours were as pilot-in-command. The co-pilot, who was seated in the right front seat, held a commercial pilot certificate with airplane single engine land, multiengine land, instrument and glider ratings. Additionally, he held a mechanic certificate with airframe and powerplant ratings and a flight instructor certificate with airplane single engine land, multiengine land, instrument and glider ratings. He held a first class medical certificate dated December 28, 2005, with the limitation, must wear corrective lenses. On the application for this medical certificate, the co-pilot reported that he had accumulated 3,000 hours total flight time with 220 hours flown in the past six months. According to the operator, he had accumulated a total time of 16 hours in the Spectrum 33 of which 13 hours were as pilot-in-command. AIRCRAFT INFORMATION The airplane was the prototype for a new all composite, light business jet aircraft. It was issued a special airworthiness certificate in the experimental category for the purpose of research and development by the FAA on November 7, 2005. According to information provided by the operator, the airplane had accumulated about 44 hours total flight time since its first flight on January 7, 2006. Prior to the accident flight, the airplane's most recent flight, flight number 46, had taken place on June 30, 2006. During the time between flight 46 and the accident flight, the airplane had been undergoing maintenance. The maintenance included removal of the main landing gear (MLG) in order to stiffen the MLG struts. Interviews with the mechanics who performed the maintenance revealed that during removal of the MLG, a portion of the roll control system located in the MLG wheel well and gearbox area was disconnected to facilitate the work. Roll control on the airplane was from the pilots' side sticks to the ailerons through a mechanical system of torque tubes and push-pull tubes. The left side stick was primary, and the right side stick was slaved to the left side stick. The roll control motion of the left side stick was linked through a quadrant below the cockpit floor to the lower torque tube. The lower torque tube ran from the quadrant to the aft pressure bulkhead. The translation linkage, the linkages and bell cranks that translated the rotational motion of the lower torque tube to a linear motion of the aileron push-pull tubes, was located on the aft side of the pressure bulkhead in the MLG gearbox area. The rotational motion of the lower torque tube was translated through the lower torque tube bell crank to a linear motion of the torque tube interconnect tie rod. The linear motion of the interconnect tie rod was then translated back to a rotational motion of the upper torque tube through the forward upper torque tube bell crank that was attached to the upper torque tube. The forward end of the upper torque tube was installed in a bearing on the pressure bulkhead and was supported in a V-bracket towards the aft end. At the aft end of the upper torque tube, the rotational motion of the torque tube was translated through the aft upper torque tube bell crank to a linear motion of the walking link drive tie rod. The walking link drive tie rod was connected to the left walking link. The left walking link was connected to the right walking link through the walking link interconnect tie rod. The walking link assembly translated the linear motion of the walking link drive tie rod to linear motion of the left and right aileron push-pull tubes. During re-installation and system testing of the MLG, it was discovered that the changes to the MLG struts impacted the V-bracket holding the upper torque tube. The V-bracket was removed and a redesigned V-bracket was installed in its place. The mechanics who performed the work stated that the tie rod bolts were removed from the aft upper torque tube bell crank and the lower torque tube bell crank and the bolts securing the V-bracket to the bulkhead were removed. The upper torque tube was then removed as an assembly with both the forward and aft upper torque tube bell cranks and V-bracket still attached. The aft upper torque tube bell crank was then removed to install the new V-bracket. Once the new V-bracket was installed the aft upper torque tube bell crank was reinstalled on the upper torque tube. The mechanic who reinstalled the aft upper torque tube bell crank on the torque tube stated that due to the tapered pin used to install the bell crank, he believed there was only one way to install it on the torque tube. The upper torque tube assembly was then reinstalled on the airplane. Following the reinstallation, a functional check of the roll control system revealed that there was only about 1/4-inch of side-to-side movement at the control stick. Visual examination of the system in the gearbox area by one of the mechanics revealed that the arm of the aft upper torque tube bell crank was pointed down and to the left. The tie rod bolts were removed from the aft upper torque tube bell crank and the lower torque tube bell crank. The upper torque tube was rotated so that the arm of the aft upper torque tube bell crank was pointed up and to the left and the tie rod bolts were reinstalled. The system was then re-rigged by centering the control stick and adjusting the various tie rod lengths so that the ailerons were faired with the wing. Motion of the system from stop to stop at the control stick and at the left and right ailerons was then verified. One of the pilots was asked to inspect the installation and found that the stick forces required were higher than previously. New washers were installed at the walking link-bulkhead interface that corrected the problem. The system rigging and motion was then checked again by the mechanics. None of the mechanics who performed the work could recall if the position of the ailerons in relation to the position of the control stick was checked. According to all of the personnel interviewed, there was no maintenance documentation to instruct mechanics how to perform the work since this was a proof-of-concept airplane. All of the work was performed based on experience. Two different pilot checklists for normal operation of the Spectrum 33 were recovered from the accident site. One checklist dated 7/25/2006 included the item "Flight Controls - CHECK" in both the PreStart and ## Aircraft - Registration: [N322LA](https://openairdocs.org/deregistered/N322LA-2008-11-19), registration cancelled 2008-11-19, S/N 0001, built 2005 (OpenAirDocs) - Reported make and model: Spectrum Aeronautical LLC 33 - Registry model: [Spectrum Aeronautical 33](https://openairdocs.org/model/spectrum-aeronautical-33) (registry code 056199J) (OpenAirDocs) - Registry engine: [Williams FJ33-4A-15](https://openairdocs.org/engine/williams-fj33-4a-15) (registry code 66008, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 0001 - Airframe hours: 44 - Engines: Williams International FJ33-4A-15 1562 lbs thrust turbo fan; Williams International FJ33-4A-15 1562 lbs thrust turbo fan - Damage: Destroyed - Flight: Flight test, Part 91 - Registered owner: Spectrum Aeronautical LLC - Airworthiness certificate: Special, Experimental (Special) - Last inspection: 100 hour, July 1, 2006, 0 hours before - Departed: U77, Spanish Fork, UT - Destination: U77 - Airport: U77, Spanish Fork - Springville, runway 30, 5,700 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; injuries: fatal; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: left; toxicology performed; flight hours: 2,300 total, 22 in this make and model - Co-pilot; age 25; injuries: fatal; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: right; toxicology performed; flight hours: 3,100 total, 16 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 4 knots - Visibility: 10 statute miles - Temperature: 86 °F, dew point 57 °F - Altimeter: 29.96 inHg - Observed at: PVU, 5 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 (OpenAirDocs). - [Accident 20060725013889A](https://openairdocs.org/incident/20060725013889A), Jul 25, 2006: Spectr 33, Spanish Fork, UT, Destroyed, 2 fatal. (-23) On July 25, 2006, at 16:06 mountain daylight time, a spectrum 33, N322LA, s/n 0001 collided with terrain following a loss of control during… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.