# NTSB MIA96LA171: Beech B35, N5136C, Kissimmee, FL, June 29, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 29, 1996, 09:30 local (13:30 UTC) - Place: Kissimmee, FL - Coordinates: 28.300111, -81.409408 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.3001&lon=-81.4094&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 10, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 38039 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA96LA171 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/38039/pdf - Page: https://openairdocs.org/ntsb/MIA96LA171 ## Probable cause the pilot was operating the airplane at an indicated airspeed that exceeded the design speed for maximum gust intensity (VB), when clear air turbulence was encountered. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, descent - normal - weather condition - turbulence,clear air (cause) - Airframe/component/system failure/malfunction, descent - normal - flight control,ruddervator - overload - airspeed - excessive, pilot in command (cause) ## Analysis The pilot stated that while descending at an indicated airspeed of 170 miles per hour (mph), the flight encountered moderate to severe clear air turbulence. He then felt a momentary vibration through the airframe and reduced power. He continued toward the planned destination and made an uneventful landing. Postlanding inspection of the airframe revealed that the rear bulkhead was cracked and that both stabilators and both ruddervators were damaged. The ruddervators were removed and found to be within prescribed limits for static balance checks. Regarding airspeed, the flight manual for the airplane indicated that the beginning of the caution range (VB) was 164 mph. ## Factual narrative On June 29, 1996, about 0930 eastern daylight time, a Beech B35, N5136C, registered to West Fair, Inc., encountered clear air turbulence while descending near Kissimmee, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged and the commercial-rated pilot, the sole occupant, was not injured. The flight originated about 0830 from the Fort Lauderdale-Hollywood International Airport, Fort Lauderdale, Florida. The pilot stated that while descending from 2,000 to 1,500 feet in an area of unstable air with the power set to 24 inches manifold pressure, and at an indicated airspeed of 170 miles per hour, the flight encountered "moderate to severe turbulence." He then felt a vibration through the airframe and immediately reduced power. The vibration only lasted "a couple of seconds" and he elected to continue and landed uneventfully at his planned destination. Post landing inspection of the airplane revealed that the rear bulkhead was cracked and both stabilators and both rudders/elevators were damaged. The flight manual for the airplane indicates that the beginning of the caution range is 164 miles-per-hour. Both rudders/elevators with attach hardware were removed from the airplane and found to be within prescribed limits for static balance tests. ## Aircraft - Registration: [N5136C](https://openairdocs.org/deregistered/N5136C-2000-05-10), registration cancelled 2000-05-10, S/N D-2421 (OpenAirDocs) - Reported make and model: Beech B35 - Registry model: [Beech B35](https://openairdocs.org/model/beech-b35) (registry code 1151506) (OpenAirDocs) - Category: Airplane - Serial number: D-2421 - Airframe hours: 2890 - Engines: Continental E-185-8 196 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: West Fair, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 7, 1995, 30 hours before - Departed: KFLL, FORT LAUDERDALE, FL - Destination: KLEE, LEESBURG, FL ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; flight instructor, commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 13,000 total, 1,600 in this make and model, 12,900 as pilot in command, 150 in the last 90 days, 45 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 60° at 13 knots - Visibility: 10 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 82 °F, dew point 72 °F - Altimeter: 30.00 inHg - Observed at: MCO, 18 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 19960629019919A](https://openairdocs.org/incident/19960629019919A), Jun 29, 1996: Beech B35, Kissimmee, FL, Substantial damage. Encountered severe air turbulence while descending above manuevering speed rear bulkhead and ruddervators damaged. 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.