# NTSB LAX00LA062: Cessna 172A, N7249T, Dos Palos, CA, January 2, 2000 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: January 2, 2000, 14:30 local (22:30 UTC) - Place: Dos Palos, CA - Coordinates: 37.070316, -120.630752 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.0703&lon=-120.6308&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 14, 2001 - Report: Approved by Office Director - ADs cited in the narratives: [AD 72-06-05 R2](https://openairdocs.org/ad/72-06-05-R2), [AD 93-19-04](https://openairdocs.org/ad/93-19-04), [AD 98-01-06](https://openairdocs.org/ad/98-01-06) (OpenAirDocs) - NTSB case key (mKey): 48427 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX00LA062 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/48427/pdf - Page: https://openairdocs.org/ntsb/LAX00LA062 ## Probable cause A partial loss of engine power due to the failure of maintenance personnel to properly install and safety the throttle arm to the carburetor throttle shaft. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - normal - fuel system,carburetor - throttle/power lever,linkage - loose part/bolt/nut/clamp/etc (cause) - maintenance,installation - improper, other maintenance personnel (cause) - Forced landing, emergency descent/landing - Nose over, landing - roll - terrain condition - rough/uneven - landing gear,nose gear - sheared ## Analysis While en route to the practice area, the student pilot performed several practice turns. She noted a loss of altitude, added throttle to regain altitude, but did not receive corresponding power indication. She checked the fuel selector to make sure it was in the on position, and then checked the engine gages. No discrepancies were noted. Carburetor heat was applied with no response and the rpm's continued to drop. She crosschecked the engine instruments, and reapplied carburetor heat with no change. With the rpm's continuing to drop, she made an emergency landing in a plowed dirt field. The engine was inspected, and it was noted that the retaining nut that attaches the serrated throttle lever to the serrated throttle shaft of the carburetor was loose, and the cotter pin was missing. The serrated portion of the throttle lever was unable to properly engage with the serrated stop of the throttle shaft. The carburetor had been replaced during the annual inspection on June 6, 1999, to comply with Airworthiness Directives. No further discrepancies were noted. ## Factual narrative On January 2, 2000, at 1430 hours Pacific standard time, a Cessna 172A, N7249T, experienced a partial loss of engine power and came to rest inverted after making an emergency landing in an open dirt field near Dos Palos, California. The airplane, owned and operated by the student pilot under 14 CFR Part 91, sustained substantial damage. The pilot received minor injuries. Visual meteorological conditions existed for the instructional flight that had departed the Merced, California, airport at 1400. No flight plan was filed. In an interview with a Federal Aviation Administration (FAA) inspector, the student pilot reported that she had refueled the airplane several weeks prior to the accident flight. The airplane was refueled with approximately 30 gallons, and she had not flown it since it had been refueled. The pilot stated that during the preflight she verified that she had "in excess of 15 gallons" of fuel in each wing by utilizing a graduated fuel gage. She then checked for fuel contamination by taking a sample from the port of each wing with no discrepancies noted. She reported that there were no problems encountered during the run-up or the departure from Merced. While en route to the practice area, she performed several practice turns. About 30 minutes into the flight, she noted a loss of altitude and added throttle to regain altitude, but did not receive a corresponding power indication. She noted the fuel selector was in the both position and attempted to troubleshoot the problem by switching to the left and then right fuel tank positions, and applying carburetor heat. She stated that there was no change and the rpm's continued to drop. The engine instruments were crosschecked and she reapplied carburetor heat with no change. The pilot reported that the engine was not running rough or sputtering, it was just not producing enough power to sustain flight. During the landing rollout, the nose gear dug into the plowed dirt field, collapsed, and the airplane nosed over and came to rest inverted. The student pilot indicated that she had purchased the airplane in June 1999, without the logbooks. The Airframe and Powerplant (A & P) mechanic who performed the annual inspection of the airplane sent a letter to the former owner requesting the logbooks. The former owner responded by indicating that the logbooks had been accidentally burned with the trash. In the last entry for the annual performed on June 6, 1999, the A & P mechanic indicates that the carburetor was replaced to comply with Airworthiness Directives 72-06-05, 93-19-04 and 98-01-06. An engine inspection was conducted at Plain Parts in Pleasant Grove, California, on February 9, 2000. It was noted that the retaining nut that holds in place the serrated throttle lever to the serrated stop of the throttle shaft of the carburetor did not have a cotter pin. The retaining nut was found loose on the shaft, allowing the serrated portion of the throttle lever to not engage properly with the serrated stop of the throttle shaft. ## Aircraft - Registration: [N7249T](https://openairdocs.org/deregistered/N7249T-2002-09-17), registration cancelled 2002-09-17, S/N 46849, built 1959 (OpenAirDocs) - Reported make and model: Cessna 172A - Registry model: [Cessna 172A](https://openairdocs.org/model/cessna-172a) (registry code 2072404) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 46849 - Airframe hours: 3177 - Engines: Continental O-300 145 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Lana L. Balatti - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 9, 1999, 10 hours before - Departed: MCE, MERCED, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; student; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 64 total ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 131 °F, dew point 86 °F - Altimeter: 30.00 inHg - Observed at: MCE, 21 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 20000102011429A](https://openairdocs.org/incident/20000102011429A), Jan 2, 2000: Cessna 172A, Dos Palos, CA, Substantial damage. (-23) On 1/2/2000, the student departed mce rw 30, climbed to 1500 MSL and at 80 IAS and 2200 RPM, made a left turn and departed in a southeasterly direction.… 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.