# NTSB ATL04IA138: Cessna 172RG, N6562V, Chamblee, GA, May 11, 2004 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: May 11, 2004, 16:30 local (20:30 UTC) - Place: Chamblee, GA - Coordinates: 33.875556, -84.30194 - Nearby events: https://openairdocs.org/map.md?lat=33.8756&lon=-84.3019&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 28, 2005 - Report: Approved by Office Director - Parties: Atlanta FSDO - 11 - ADs cited in the narratives: [AD 81-14-06](https://openairdocs.org/ad/81-14-06) (OpenAirDocs) - NTSB case key (mKey): 59483 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL04IA138 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59483/pdf - Page: https://openairdocs.org/ntsb/ATL04IA138 ## Probable cause The fatigue fracture of the nosewheel bungee assembly, which restricted the movement of the elevator control. A factor was the inadequate equipment from an unknown source/manufacturer. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - aircraft/equipment inadequate, unknown (contributing factor) - landing gear,nose gear assembly - fractured (cause) - landing gear,nose gear assembly - fatigue (cause) - flt control syst,elevator control - movement restricted ## Analysis The certified flight instructor reported full nose-down elevator deflection could not be achieved in cruise flight. The flight returned to the airport and landed without further incident. Examination revealed the threaded shaft of the nose gear steering bungee assembly was fractured, and the damaged component physically restricted the movement of the elevator control assembly. Metallurgical examination of the shaft revealed fatigue fractures in two locations with no evidence of hardness anomaly and no evidence of improper lubrication. Examination of the profile of the thread relief area of the shaft revealed the region was irregular and asymmetric, and a number of machining grooves were of smaller radii than the 0.050-inch radius specified in Cessna technical drawings. The shaft was absent of identifying markings or a part number, and maintenance logs for the airplane revealed no record of repair or replacement of the component. Federal Aviation Administration Airworthiness Directive (AD) 81-14-06 for the Cessna 172RG requires the replacement of part number 2467003-1 rudder trim/nose gear steering bungee with part number 2467003-6 rudder trim/nose gear steering bungee. Cessna Service Letter SE 80-99 states the new steering bungee part number 2467003-6 "includes a larger diameter jack screw shaft providing substantially greater unit strength and longer service life." Both the AD and the Service Letter are applicable to Cessna 172RG airplanes serial numbers 172RG0001 through 172RG0769. The incident airplane was serial number 172RG0775. ## Factual narrative On May 11, 2004, about 1630 eastern daylight time, a Cessna 172RG, N6562V, registered to and operated by Aviation Atlanta, Inc., exhibited limited elevator control during cruise flight in the vicinity of Chamblee, Georgia. The instructional flight was operated under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual meteorological conditions prevailed. The certificated flight instructor and the private pilot-rated student were not injured, and the airplane sustained no damage. The local flight departed Peachtree DeKalb Airport, Chamblee, Georgia, about 1600 on May 11, 2004. The certified flight instructor reported the airplane did not respond normally to elevator control inputs. He stated full nose-down elevator deflection could not be achieved, and the use of full nose-down elevator trim did not improve the condition. He stated that, when right rudder was applied, an increase in nose-down elevator deflection could be achieved. The flight returned to the airport and landed without further incident. Maintenance personnel examined the airplane and found the threaded shaft of the nose gear steering bungee assembly was fractured below the sprocket for the rudder trim chain. The fracture separated the upper portion of the shaft and sprocket from the bottom portion of the shaft and bungee assembly, which remained attached to the right rudder weld assembly. Maintenance personnel determined the damaged component physically restricted the movement of the elevator control assembly. The nose gear steering bungee assembly and fractured shaft were submitted to the National Transportation Safety Board, Materials Research Laboratory, Washington, D.C., for examination. Examination revealed the shaft was fractured at two locations. Examination of the upper fracture through the threaded region of the shaft revealed the fracture surface exhibited smooth crack arrest markings consistent with fatigue; the fatigue crack originated in a thread root. Additional cracks were observed in the two thread roots directly above the fatigue crack. Examination of the lower fracture through the thread relief area revealed the fracture surface exhibited smooth crack arrest markings consistent with fatigue emanating from the forward and aft surfaces of the shaft. The fatigue cracks extended through approximately 95 percent of the shaft radius, and the remaining fracture area exhibited ductile features consistent with overstress. Hardness measurements of the shaft metal and chemical examination of the lubricating grease revealed no evidence of anomaly and no evidence of improper lubrication. Examination of the profile of the thread relief area of the shaft revealed the region was irregular and asymmetric, and a number of machining grooves were of smaller radii than the 0.050-inch radius specified in Cessna technical drawings. The shaft was absent of identifying markings or a part number. Examination of the maintenance logs for the airplane revealed no record of repair or replacement of the component. Federal Aviation Administration Airworthiness Directive (AD) 81-14-06 for the Cessna 172RG requires the replacement of part number 2467003-1 rudder trim/nose gear steering bungee with part number 2467003-6 rudder trim/nose gear steering bungee. The AD states the purpose of the replacement is "to ensure the integrity of the rudder trim/nose gear steering bungee," and the AD states a limited elevator movement condition may be encountered, and "Cessna Single Engine Service Letter SE 80-99, Rev. 1, dated June 8, 1981, pertains to this subject." A review of the Cessna Service Letter SE 80-99 revealed the new steering bungee part number 2467003-6 "includes a larger diameter jack screw shaft providing substantially greater unit strength and longer service life." Both the AD and the Service Letter are applicable to Cessna 172RG airplanes serial numbers 172RG0001 through 172RG0769. The incident airplane was serial number 172RG0775. ## Aircraft - Registration: [N6562V](https://openairdocs.org/aircraft/N6562V), registered now, S/N 172RG0775, built 1980 (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: 172RG0775 - Airframe hours: 4999.1 - Engines: Lycoming O-360-F1A6 180 horsepower reciprocating - Damage: No damage - Flight: Instructional, Part 91 - Registered owner: Aviation Atlanta, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 31, 2004, 79.8 hours before - Departed: KPDK, Chamblee, GA - Destination: KPDK - Airport: KPDK, Peachtree DeKalb Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 32; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review June 21, 2003; seat: right; flight hours: 800 total, 50 in this make and model, 750 as pilot in command, 150 in the last 90 days, 50 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 4 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 55 °F - Altimeter: 30.18 inHg - Observed at: KLZU, 19 nm away ## Other investigations on N6562V (2) 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 MIA08LA053](https://openairdocs.org/ntsb/MIA08LA053), Feb 7, 2008: Cessna C-172RG (N6562V), Chamblee, GA, substantial damage. Probable cause: A cracked nose gear actuator o-ring resulting in hydraulic fluid exhaustion, and collapse of the main gear. - [NTSB MIA98LA165](https://openairdocs.org/ntsb/MIA98LA165), May 17, 1998: Cessna 172RG (N6562V), Roberta, GA, substantial damage. Probable cause: The pilot's inadequate compliance with the emergency procedures for his failure to completely pump the main landing gear into the down and locked position. Contributing to the accident was the… 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.