# NTSB LAX08LA221: Cessna 172RG, N9627B, Moorpark, CA, July 9, 2008 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 9, 2008, 16:46 local (23:46 UTC) - Place: Moorpark, CA - Coordinates: 34.251945, -118.845832 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.2519&lon=-118.8458&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report September 10, 2009 - Report: Approved by Office Director - Parties: American Flyers, Federal Aviation Administration - NTSB case key (mKey): 68414 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX08LA221 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68414/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=68414 - Page: https://openairdocs.org/ntsb/LAX08LA221 ## Probable cause A partial loss of engine power due to the disconnection of the throttle control cable from the throttle arm due to the operator's improper maintenance. Contributing to the accident was unsuitable terrain for a forced landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine controls](https://openairdocs.org/ntsb-findings/01057600): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-findings/01057600/cases.md?model=2072438), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/01057600/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=2072438), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [Cessna 172RG, 5 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=2072438), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=2072438), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) - [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-findings/03021017/cases.md?model=2072438), [All aircraft, 270 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=2072438), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Maneuvering: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 172RG, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072438), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Maneuvering: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 172RG, 10 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072438), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 172RG, 9 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072438), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis While performing air work during the instructional flight, the student attempted to increase engine power above idle, but upon pushing the throttle control knob forward, the engine's power did not increase. The certified flight instructor (CFI) verified that there was no change in engine power with movement of the throttle control, and he believed that the control had likely become disconnected from the carburetor. The CFI performed a forced landing on the nearby rough terrain. During landing, the airplane impacted a berm and nosed over. An examination of the airplane revealed the throttle control cable was in fact disconnected from its respective carburetor attachment fitting and undamaged. Also, the threaded portion of the cable's attachment end was found without damage. The jam nuts, which normally secure the throttle cable to the carburetor attachment fitting, were found tight against each other, but backed off from their designated location, and were not positioned close enough to the rod end to secure the cable to the carburetor throttle arm. The operator's mechanics were responsible for, and had performed, recent maintenance and inspections of the flight school's airplane. The accident airplane's last 100-hour inspection had been performed on July 3, 2008, 6 days prior to the accident. The security and condition of the engine control connections to the carburetor are part of this inspection. ## Factual narrative On July 9, 2008, about 1646 Pacific daylight time, a Cessna 172RG, N9627B, experienced a partial loss of engine power about 3 miles east-southeast of Moorpark, California. The certified flight instructor (CFI) acquired the airplane's controls from his student who had been maneuvering the airplane, and he made a forced landing. During landing, the airplane impacted rough terrain, nosed over, and was substantially damaged. Both pilots sustained minor injuries. American Flyers, Santa Monica, California, operated the airplane under the provisions of 14 Code of Federal Regulations Part 91. The CFI held a commercial pilot certificate, and he was the assistant chief instructor for the flight school. The student held a private pilot certificate. At the time of the accident, the private pilot was undergoing the final flight phase check for a commercial pilot certificate under the Federal Aviation Administration (FAA) approved school's Part 141 examination authority. Visual meteorological conditions prevailed, and no flight plan had been filed. The local area instructional flight commenced from Santa Monica Municipal Airport, Santa Monica, about 1515. The CFI reported to the National Transportation Safety Board investigator that he had directed the student to perform a ground reference maneuver (eights on pylons) over a field, and the student commenced a descent to 1,000 feet above ground level. When the student attempted to increase the engine's throttle to level out, the engine's power did not increase. The CFI verified the problem and decided to execute an emergency landing. He set the transponder to the 7700 squawk code and attempted to declare an emergency to a nearby air traffic control (ATC) facility. The CFI stated that due to the airplane's low altitude, the radio transmission was not heard by ATC, but another airplane's pilot relayed the distress call. As the airplane descended toward the CFI's chosen forced landing site, the CFI executed a 180-degree turn with full flaps and landing gear extended, and he entered a full slip. During this time, the engine continued to develop a minimum (idle) level of power. The airplane touched down on upsloping terrain and impacted a rocky berm. During an interview with the Safety Board investigator, the CFI opined that the throttle control had become dysfunctional, since it moved too freely, and it was obviously "disconnected" from the engine's carburetor. The student reported that they had moved the throttle control through its full range of operation (from its full forward to its full aft stops) without obtaining any noticeable change in the engine's power (rpm). The Safety Board investigator's subsequent examination of the accident airplane revealed that the throttle control cable was, in fact, disconnected at its carburetor rod end attachment fitting. The cable's threaded bolt end indicated no evidence of screw thread deformation, and there was no evidence of thread deformation in the carburetor's rod end attachment fitting. Investigators noted that the jam nuts on the control cable, which are used to secure the cable to the rod end, were tight against each other, but were not positioned close enough to the rod end to secure the cable to the carburetor. Additional assembly discrepancies were noted with the throttle cable's attachment to the carburetor. (See the Wreckage Examination report in the docket for additional details and photographs.) Investigators noted chordwise scratches on both propeller blades. No evidence of pre-impact oil leakage was noted in the engine compartment. All of the flight control surfaces were found with the airplane. Neither pilot reported having experienced any preimpact flight control malfunction. Following examination of the accident airplane, investigators examined the flight school operator's fleet of airplanes located in Santa Monica. According to the operator's representative, the flight school employed two fulltime mechanics. One mechanic, who was employed as the maintenance director, held an FAA airframe and power plant certificate with inspection authorization. The maintenance director had responsibility for oversight of the FAA certified airframe and power plant mechanic who had performed a majority of the maintenance on the flight school's fleet of airplanes, and who had performed the last two accident airplane inspections. The operator maintained its airplanes on a program of annual and 100-hour inspections. The accident airplane's last 100-hour inspection had been performed on July 3, 2008, 6 days prior to the accident. The Cessna Aircraft Company publishes a Service Manual that delineates the procedures to be followed in maintaining the accident model of airplane. In pertinent part, the manual specifically addresses how to attach and secure the throttle control cable to the carburetor. It also provides instructions regarding how to verify that the attachment is correctly accomplished. The operator's representative reported to the Safety Board investigator that the flight school utilized a record keeping system for pilots to log abnormal airplane conditions/discrepancies in the airplane's dispatch book and/or in the flight school's computerized tracking program. Discrepancies (squawks) logged in the computerized system were visible by all company management. At the time of the Safety Board investigator's fleet examination of the six Santa Monica-based airplanes, no logged discrepancies were found in the dispatch books, or in the computer system for any of the airplanes. A CFI-employee, who was not associated with the accident, reported to the Safety Board investigator that he worked for the operator on a full time basis. The CFI stated that he routinely does not write down squawks in the company's records. Rather, as the occasion necessitates and avails itself, he verbally informs staff of problems with the airplanes. Flight school management responded to this employee's disclosure by indicating to the Safety Board investigator that it was unaware of the lack of adherence to its policy to make a written record of squawks. During the Safety Board investigator's examination of the Santa Monica-based fleet of seven airplanes, maintenance-related anomalies were found with each airplane. For example, one airplane exhibited jam nuts on the throttle control cable that were not adjacent to each other. The Safety Board investigator turned the cockpit throttle control knob counterclockwise through 20 360-degree rotations, and the threaded bolt of the control cable correspondingly turned counterclockwise and completely disconnected itself from the rod end housing at the carburetor. (See the Fleet Examination report in the docket for additional details and other observed discrepancies including restricted movement of the cockpit fuel selector and mixture controls.) The operator participated in the Safety Board's accident investigation. As a result of this participation and the investigator-initiated fleet examination, the operator took immediate action to address the noted airworthiness-related maintenance abnormalities. The operator reinforced employee reporting squawk procedures, and enhanced management's oversight of both the flight and maintenance departments throughout its nationwide base of 50 airplanes and 300 employees. ## Aircraft - Registration: [N9627B](https://openairdocs.org/deregistered/N9627B-2018-01-24), registration cancelled 2018-01-24, S/N 172RG0928, built 1981 (OpenAirDocs) - Reported make and model: CESSNA 172RG - Registry model: [Cessna 172RG](https://openairdocs.org/model/cessna-172rg) (registry code 2072438) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 172RG0928 - Airframe hours: 15484 - Engines: Lycoming O-360-F1A6 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Ameriflyers of California, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 3, 2008 - Departed: SMO, SANTA MONICA, CA - Destination: SMO, Santa Monica, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 42; injuries: minor; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review July 1, 2008; seat: right; flight hours: 4,000 total, 800 in this make and model, 150 in the last 90 days, 13 in the last 30 days, 2 in the last 24 hours - Pilot; age 19; injuries: minor; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review May 16, 2008; seat: left; flight hours: 224 total, 16 in this make and model, 143 as pilot in command, 126 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 61 °F - Altimeter: 29.76 inHg - Observed at: KCMA, 13 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 20080709846009A](https://openairdocs.org/incident/20080709846009A), Jul 9, 2008: Cessna 172RG, Moorpark, CA, Substantial damage. (-23) While performing commercial maneuvers in the simi valley practice area on a dual lesson crew descended from 3500 ft to about 1000 ft to perform eights on… ## Docket (33 files) The files NTSB released with the investigation on July 14, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=68414. 22.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298154&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photo 1. Airplane, front view (item 2, .PDF, 170 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298773&FileExtension=.PDF&FileName=Photo%201.%20Airplane,%20front%20view-Master.PDF - Photo 2. Airplane, rear view (item 3, .PDF, 217 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298774&FileExtension=.PDF&FileName=Photo%202.%20Airplane,%20rear%20view-Master.PDF - Photo 3. Airplane, left side (item 4, .PDF, 182 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298775&FileExtension=.PDF&FileName=Photo%203.%20Airplane,%20left%20side-Master.PDF - Photo 4. Airplane, right side (item 5, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298776&FileExtension=.PDF&FileName=Photo%204.%20Airplane,%20right%20side-Master.PDF - Photo 5. Throttle control found disconnected (item 6, .PDF, 172 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298777&FileExtension=.PDF&FileName=Photo%205.%20Throttle%20control%20found%20disconnected-Master.PDF - Wreckage Exam Report (item 7, .PDF, 673 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298745&FileExtension=.PDF&FileName=Wreckage%20Exam%20Report-Redacted.PDF - Wreckage Exam - Attachment 1 - Photo 1 (item 8, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298759&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%201-Master.PDF - Wreckage Exam - Attachment 1 - Photo 2 (item 9, .PDF, 180 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298760&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%202-Master.PDF - Wreckage Exam - Attachment 1 - Photo 3 (item 10, .PDF, 135 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298761&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%203-Master.PDF - Wreckage Exam - Attachment 1 - Photo 4 (item 11, .PDF, 942 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298762&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%204-Master.PDF - Wreckage Exam - Attachment 1 - Photo 5 (item 12, .PDF, 171 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298763&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%205-Master.PDF - Wreckage Exam - Attachment 1 - Photo 6 (item 13, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298764&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%206-Master.PDF - Wreckage Exam - Attachment 1 - Photo 7 (item 14, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298765&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%207-Master.PDF - Wreckage Exam - Attachment 1 - Photo 8 (item 15, .PDF, 135 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298766&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%208-Master.PDF - Wreckage Exam - Attachment 1 - Photo 9 (item 16, .PDF, 166 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298767&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Attachment%201%20-%20Photo%209-Master.PDF - Wreckage Exam - Acft Maint Records (item 17, .PDF, 167 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298803&FileExtension=.PDF&FileName=Wreckage%20Exam%20-%20Acft%20Maint%20Records-Redacted.PDF - American Flyers Fleet Exam Report (item 18, .PDF, 468 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298758&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20Report-Redacted.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 1 (item 19, .PDF, 993 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298746&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%201-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 2 (item 20, .PDF, 834 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298747&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%202-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 3 (item 21, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298748&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%203-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 4 (item 22, .PDF, 966 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298749&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%204-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 5 (item 23, .PDF, 866 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298750&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%205-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 6 (item 24, .PDF, 796 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298751&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%206-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 7 (item 25, .PDF, 963 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298752&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%207-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 8 (item 26, .PDF, 903 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298753&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%208-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 9 (item 27, .PDF, 943 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298754&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%209-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 10 (item 28, .PDF, 925 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298755&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%2010-Master.PDF - American Flyers Fleet Exam - Attachment 1 - Photo 11 (item 29, .PDF, 842 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298756&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20-%20Attachment%201%20-%20Photo%2011-Master.PDF - American Flyers Fleet Exam Maint. Records - Attachment 2. (item 30, .PDF, 503 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298757&FileExtension=.PDF&FileName=American%20Flyers%20Fleet%20Exam%20Maint.%20Records%20%20-%20Attachment%202.-Redacted.PDF - Cessna Service Manual (Extract) (item 31, .PDF, 164 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298804&FileExtension=.PDF&FileName=Cessna%20Service%20Manual%20(Extract)-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 32, .PDF, 411 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40298772&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Letter from Bliss, American Flyers, to Pollack, NTSB (item 33, .PDF, 680 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40315003&FileExtension=.PDF&FileName=Letter%20from%20Bliss,%20American%20Flyers,%20to%20Pollack,%20NTSB-Redacted.PDF 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.