# NTSB LAX05LA085: Air Tractor AT-401, N4530L, Calexico, CA, February 4, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 4, 2005, 13:15 local (21:15 UTC) - Place: Calexico, CA - Coordinates: 32.673332, -115.558891 - Nearby events: https://openairdocs.org/map.md?lat=32.6733&lon=-115.5589&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 28, 2006 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 60965 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX05LA085 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/60965/pdf - Page: https://openairdocs.org/ntsb/LAX05LA085 ## Probable cause a loss of directional control due to a jammed rudder pedal, which prevented the pilot from exercising full rudder control authority. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - flare/touchdown - miscellaneous,dowel/pin - binding(mechanical) (cause) - flt control syst,rudder control - jammed (cause) - directional control - not possible, pilot in command (cause) - ground loop/swerve - encountered, pilot in command - On ground/water encounter with terrain/water, landing - roll - terrain condition - berm ## Analysis The airplane veered off the runway, collided with a berm, and came to rest in a ditch following a loss of control during landing. During the landing flare the pilot encountered a left crosswind and he input right rudder to compensate for the crosswind, but the pedal would not move. After the accident the pilot noticed that he was still depressing the right rudder pedal. He looked down and saw that the rudder pedal adjusting pin was caught on the aft edge of the hopper. When he relaxed pressure on the rudder pedal, the pedal moved to the left and was free of the hopper. Post accident examination by a Federal Aviation Administration (FAA) inspector revealed a groove the pin had carved into the side wall of the hopper over time. The groove began at a radius in the hopper wall where the wall turned 90 degrees from a cross cockpit orientation to a longitudinal direction. When he depressed the rudder pedal, he noted that the adjusting pin contacted the groove the entire length of travel. He further noted that despite the contact of the pin in the groove, there was no restriction of movement of the rudder pedal. A gouge dimensionally identical in shape and size to the pin was observed in the hopper just to the right of where the adjusting pin contacted the groove. The FAA inspector noted no groove or gouge on the left side of the hopper. ## Factual narrative On February 4, 2005, at 1315 Pacific standard time, an Air Tractor AT-401, N4530L, came to rest in a ditch after experiencing a rudder pedal control malfunction on touchdown at Johnson Brothers Airport (61CL), a private dirt strip in Calexico, California. Frontier Agricultural Service, Inc., operated the airplane under the provisions of 14 CFR Part 137, as an agricultural spraying operation. The airplane sustained substantial damage. The commercial rated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed for the local area flight, and no flight plan had been filed. The flight departed 61CL about 1300. In the pilot's written statement he reported that he had started operations out of 61CL about 1100. He was returning to pick up his sixth load of the day when the accident occurred. On the first flight of the day he performed the standard walk-around preflight. After startup, he taxied for takeoff and verified the flight controls were "free and easy." He flew to Johnson Brothers Airport for his first load, and returned for four subsequent loads. While on short final, the airplane encountered a left crosswind condition. He immediately applied pressure to the right rudder pedal to correct for the crosswind, but the pedal would not move. The airplane touched down on the runway, veered to the left exiting the runway, collided with a berm, and came to rest in a ditch. During the accident sequence, the left wing dragged on the ground displacing the fuselage about 60 degrees along its lateral axis. After the airplane came to a stop the pilot noticed he was still applying pressure to the right rudder pedal. He looked down and saw the rudder pedal adjusting pin contacting the aft edge of the hopper. When he released pressure on the pedal, the entire pedal assembly, to include the adjusting pin, moved to the left and returned to its normal position. The pilot further reported that a 100-hour inspection had been completed on February 1, 2005, 3 days prior to the accident. In the post examination of the wreckage, an inspector from the Federal Aviation Administration (FAA) discovered a groove in the right side of the hopper wall. The groove began at a radius in the hopper wall where the wall turned 90 degrees from a cross cockpit orientation to a longitudinal direction. When he depressed the rudder pedal, he noted that the adjusting pin contacted the groove the entire length of travel. He further noted that despite the contact of the pin in the groove, there was no restriction of movement of the rudder pedal. A gouge dimensionally identical in shape and size to the pin was observed in the hopper just to the right of where the adjusting pin contacted the groove. See photograph 2 in the docket materials for this accident. The FAA inspector noted no groove or gouge on the left side of the hopper. ADDITIONAL INFORMATION The closest official weather observation station was Imperial, California (IPL), located 10 nautical miles (nm) north of the accident site. The elevation of the weather observation station was -56 feet mean sea level. An aviation routine weather report (METAR) for IPL was issued at 1253. It stated: winds from 330 degrees at 11 knots; skies clear; temperature 22 degrees Celsius; dew point -02 degrees Celsius; altimeter 29.99 inHg. The Airport/ Facility Directory, Southwest U. S., indicated the runway was 2,500 feet long and 50 feet wide; the runway surface was dirt. ## Aircraft - Registration: [N4530L](https://openairdocs.org/deregistered/N4530L-2012-01-25), registration cancelled 2012-01-25, S/N 401-0761 (OpenAirDocs) - Reported make and model: Air Tractor AT-401 - Registry model: [Air Tractor AT-401](https://openairdocs.org/model/air-tractor-at-401) (registry code 0390204) (OpenAirDocs) - Category: Airplane - Serial number: 401-0761 - Airframe hours: 7154 - Engines: Garrett TPE-331 715 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Frontier Agricultural Service, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, February 1, 2005, 101 hours before - Departed: 61CL, Calexico, CA - Destination: 61CL - Airport: 61CL, Johnson Brothers Airport, runway 9, 2,500 × 50 ft, dirt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; injuries: minor; commercial; airplane ratings: single-engine land; medical: class 2; last flight review April 1, 2004; seat: center; flight hours: 4,800 total, 1,200 in this make and model, 4,700 as pilot in command, 150 in the last 90 days, 50 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 28 °F - Altimeter: 29.98 inHg - Observed at: IPL, 10 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 20050204007329A](https://openairdocs.org/incident/20050204007329A), Feb 4, 2005: Airtrc AT401, Calexico, CA, Substantial damage. (-23) On feb. 4, 2005, at 1300 PST, an air tractor AT-401, N4530L, attempted to land at johnsons Brothers airport (61CL). The aircraft was empty. As the acft… ## Other investigations on N4530L (1) 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. - [NTSB CEN10LA503](https://openairdocs.org/ntsb/CEN10LA503), Aug 26, 2010: Air Tractor AT-401 (N4530L), Castroville, TX, substantial damage. Probable cause: A loss of engine power due to the failure of the torque sensor bearing. 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.