# NTSB LAX95IA229: Boeing 737-200, N457TM, Elko, NV, June 29, 1995 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: June 29, 1995, 09:25 local (16:25 UTC) - Place: Elko, NV - Location: 40.8381° N, 115.7678° W: Placed by OpenAirDocs: center of Elko, NV, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=40.8381&lon=-115.7678&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 84 uninjured - Status: Completed, report November 25, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 28954 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX95IA229 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28954/pdf - Page: https://openairdocs.org/ntsb/LAX95IA229 ## Probable cause in-flight separation of the aileron as a result of inadequate bonding. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, descent - normal - flight control,aileron surface - debonded (cause) - maintenance,major repair - improper, other maintenance personnel (cause) ## Analysis THE CREW EXPERIENCED AN UNUSUAL VIBRATION WHILE DESCENDING THROUGH FL250. THEY REDUCED SPEED AND THE VIBRATION DECREASED. A FLIGHT ATTENDANT REPORTED THAT PART OF THE RIGHT WING WAS MISSING. THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. EXAMINATION OF THE AIRCRAFT INDICATED THAT 1.5 FEET OF THE RIGHT AILERON HAD SEPARATED IN FLIGHT. THIS AILERON UNDERWENT A MAJOR REPAIR IN 1990 INVOLVING SKIN AND CORE REPLACEMENT. IT WAS INSTALLED ON THE AIRCRAFT IN 1992 WITHOUT FURTHER WORK DONE ON IT. EXAMINATION OF THE AILERON REVEALED VERY LITTLE FLOW OF THE ADHESIVE BETWEEN THE SKIN AND THE CORE, POSSIBLY DUE TO USE OF AN ADHESIVE BEYOND ITS SHELF LIFE. ## Factual narrative On June 29, 1995, at 0925 hours Pacific daylight time, the crew of Casino Express, a Boeing 737-200, N457TM, from Portland, Oregon, experienced an unusual vibration during a descent through flight level 250 into Elko, Nevada. A flight attendant reported to the pilots that part of the right wing was missing. The first officer confirmed that a section of the right aileron had separated from the aircraft. The captain declared an emergency and the aircraft subsequently landed without further incident. There were no injuries to the 78 passengers or 6 crewmembers onboard. Visual meteorological conditions existed at the time with no in-flight turbulence reported. After experiencing the vibration, the captain slowed the aircraft from .76 Mach to 250 knots indicated airspeed and the vibration decreased. He determined that the aircraft was controllable and advised the cabin crew to prepare for a precautionary emergency landing. Examination of the aircraft afterwards revealed that 1.5 feet of the right outboard aileron had separated at the hinge point to the front spar. The aileron trim tab remained attached. Boeing has reported no previous occurrences similar to this to their knowledge. Casino Air reported that the aileron was last inspected on the daily walk-around, which is performed each day before flight, and no defects were noted at that time. The investigation revealed that the aileron underwent a major repair late in 1990 involving skin and core replacement. The aileron was installed on the aircraft in September, 1992. According to the operator, the aileron has not been repaired since the installation. Boeing examined the part and they indicated that there was very little "filleting" or flow of the adhesive between the skin and core. They believe one possible cause of the insufficient "filleting" could be the use of adhesive beyond it's shelf life. No other examinations were conducted. ## Aircraft - Registration: [N457TM](https://openairdocs.org/deregistered/N457TM-2013-11-08), registration cancelled 2013-11-08, S/N 20156, built 1969 (OpenAirDocs) - Reported make and model: Boeing 737-200 - Registry model: [Boeing 737-214](https://openairdocs.org/model/boeing-737-214) (registry code 138446R) (OpenAirDocs) - Registry engine: [Pratt & Whitney JT8D-9 series](https://openairdocs.org/engine/pratt-whitney-jt8d-9-series) (registry code 52048, turbo-jet) (OpenAirDocs) - Category: Airplane - Serial number: 20156 - Airframe hours: 48512 - Engines: P&W JT8D-9 14400 lbs thrust turbo jet - Damage: Minor damage - Flight: Part 121 - Registered owner: Tem Enterprises - Airworthiness certificate: Standard, Transport; Standard, Normal - Departed: PDX, PORTLAND, OR - Destination: EKO - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 11,000 total, 2,500 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 3 knots - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 63 °F - Altimeter: 30.00 inHg - Observed at: EKO ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 19950629023579I](https://openairdocs.org/incident/19950629023579I), Jun 29, 1995: Boeing 737214, Elko, NV, Minor damage. Vibrating flight controls on descent. Section right aileron separated. Landed safely. 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.