# NTSB FTW93LA236: Beech F35, N5064B, Mena, AR, August 11, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 10, 1993, 19:00 local (Aug 11, 1993, 00:00 UTC) - Place: Mena, AR - Coordinates: 34.579555, -94.230712 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.5796&lon=-94.2307&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 1, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 18813 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW93LA236 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18813/pdf - Page: https://openairdocs.org/ntsb/FTW93LA236 ## Probable cause THE INFLIGHT SEPARATION OF THE RUDDERVATOR AS RESULT OF IMPROPER BALANCING. ## 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,ruddervator - separation (cause) - maintenance,balancing - improper, other maintenance personnel (cause) ## Analysis A SEVERE VIBRATION DEVELOPED AS THE OUTER PORTION OF THE RIGHT RUDDERVATOR AND THE COUNTER WEIGHT FOR THE LEFT RUDDERVATOR SEPARATED FROM THE AIRFRAME ON THE DOWNWIND LEG AT AN ESTIMATED 155 MPH. TURBULENCE WAS NOT ENCOUNTERED AT ANY TIME DURING THE DESCENT OR THE APPROACH. THE PILOT CLOSED THE THROTTLE AND EXTENDED THE LANDING IN AN ATTEMPT TO SLOW DOWN THE AIRPLANE. AN UNEVENTFUL LANDING WAS MADE AT THE INTENDED AIRPORT. EXAMINATION OF THE RUDDERVATORS REVEALED THAT BOTH RUDDERVATORS WERE OUT OF BALANCE DUE TO A COMBINATION OF UNAUTHORIZED SHEET METAL REPAIRS, IMPROPER PAINT APPLICATION TECHNIQUES, AND THE USE OF A LOCALLY MANUFACTURED COUNTER WEIGHT. ## Factual narrative On August 10, 1993, at 1900 central daylight time, a Beech F35, N5064B, was substantially damaged during descent near Mena, Arkansas. The private pilot was not injured. Visual meteorological conditions prevailed for the personal flight. In a prepared written document and during a telephone interview, the pilot stated he initiated his descent from 4,500 feet, increasing his indicated airspeed to 180 mph. After announcing his position in the downwind leg at the Intermountain Airport at Mena, Arkansas, while at 155 mph, a severe vibration developed throughout the airframe. The pilot further stated that he closed the throttle and extended the landing gear in a attempt to slow down the airplane. The oscillations and vibration decreased as his airspeed decreased, and a normal landing was executed. No turbulence was encountered at any time during the descent or the approach. Examination of the airplane on the ramp revealed that the outer portion of the right ruddervator outboard of the center hinge, and the counter weight for the left ruddervator had separated from the airframe in flight. Substantial twisting, buckling, and skin tearing were also found in the aft section of the empennage. Both ruddervators (p/n 35-660040-607 and 608 respectively) were removed from the airplane and shipped to the manufacturer's lab for further evaluation and testing. All parts that separated from the airplane in flight were recovered, with the exception of the counter weight for the left ruddervator. A detailed examination and inspection was conducted by Beech engineers. The investigation concluded that both ruddervators were out of balance due to a combination of unauthorized sheet metal repairs, improper paint application techniques, and the use of a locally manufactured counter weight. A copy of the their examination report is enclosed in this report. ## Aircraft - Registration: [N5064B](https://openairdocs.org/deregistered/N5064B-2012-09-06), registration cancelled 2012-09-06, S/N D-4319, built 1955 (OpenAirDocs) - Reported make and model: BEECH F35 - Registry model: [Beech F35](https://openairdocs.org/model/beech-f35) (registry code 1151514) (OpenAirDocs) - Registry engine: [Continental E225 series](https://openairdocs.org/engine/continental-e225-series) (registry code 17015, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: D-4319 - Airframe hours: 4482 - Engines: CONTINENTAL E-225-8 225 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Donica, Dalton R. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 15, 1993, 6 hours before - Departed: LIT, LITTLE ROCK, AR - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 5,000 total, 1,100 in this make and model, 6 in the last 90 days, 6 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 6 knots - Visibility: 12 statute miles - Lowest ceiling: 25,000 ft overcast - Temperature: 91 °F, dew point 75 °F - Altimeter: 30.00 inHg - Observed at: HOT, 55 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 19930810029069A](https://openairdocs.org/incident/19930810029069A), Aug 10, 1993: Beech F35, Mena, AR, Substantial damage. Outer portion left ruddervator separated and right counter weight also. Vibration. Landed. Improper bogus repairs. 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.