19 Apr 2010: BEECH B35 — Bogh Industries LLC

19 Apr 2010: BEECH B35 — Bogh Industries LLC

No fatalities • Burbank, CA, United States

Probable cause

The airplane's encounter with turbulence while at an airspeed above maneuvering airspeed, which exceeded the limit load of the stabilizers and ruddervators.

— NTSB Determination

Accident narrative

In the pilot's written statement to the Safety Board, he reported that he was traveling from Modesto, CA, to Burbank, CA. The pilot reported that during descent to Burbank at about 5,000 feet, the airplane was flying at 155-160 miles per hour when it hit slight turbulence while in a 15 degree left turn, and the tail started to flutter. The pilot quickly reduced power and smoothly raised the nose in accordance with the airplane's Pilot Information Manual. This stopped the vibration, which lasted about 3 to 5 seconds. The rest of the approach and landing at the airport was uneventful. During the post-flight inspection, the pilot noticed wrinkles in the left ruddervator. The airplane was inspected by a mechanic, who found that the left ruddervator had a cracked front spar, and the left stabilizer had wrinkled top skin and a cracked rear spar, which was bent up five inches. The pilot did not state if there were any mechanical problems with the airplane prior to the accident.

The airplane's maintenance records were reviewed. In January 2001, the airplane's two rear bulkheads were straightened and redoubled, short cracks were dressed, and new relief flanges were fabricated and installed. Also in January 2001, the empennage skins were redoubled. The airplane was painted as required, the flight controls and systems were reinstalled, and the static control balance was performed. The airplane was inspected for compliance with the pertinent Raytheon (Beechcraft) Service Bulletin. All work was done in accordance with the Service Bulletin, the appropriate Advisory Circular, and the Beechcraft 35 Shop Manual.

In April 2001, the airplane's ruddervators were rebuilt and painted. After the painting, the right ruddervator's static balance was 17.33 inch-pounds (in-lb) moment balance. The left ruddervator's static balance was 17.59 in-lb moment balance. Both static balances were within the Beechcraft Shop Manual's allowable balance parameters of 16.8 to 19.8 in-lb.

In February 2009, the airplane's fuselage and wings were repainted by the owner, then repainted by a certified mechanic shop. The control surfaces were not painted.

After the accident, a mechanic removed and replaced the spars, re-skinned the airplane, used doublers between the spar and the new skin, added a doubler to the center forward of the aft rib, and checked the ruddervator balance. The mechanic stated that the control surface balancing was "perfect."

The pilot reported that he was flying between 155-160 miles per hour (MPH) at the time of the turbulence encounter. The maximum structural cruising airspeed (Vno or Vc) is 161 MPH, and the maneuvering airspeed (Va) is 131 MPH. The pilot was flying above Va when the airplane encountered the turbulence; however, he was not flying above Vno and had no reason to believe that the airplane would encounter turbulence.

Contributing factors

  • cause Capability exceeded
  • cause Capability exceeded
  • cause Effect on equipment

Conditions

Weather
VMC, vis 10sm

Loading the flight search…

What you can do on Flight Finder

  • Search flights between any two airports with live fares.
  • By aircraft — pick a plane model (e.g. Boeing 787, Airbus A350) and see every route it flies from your origin.
  • Route map — click any airport worldwide to explore its destinations, or draw a radius to find nearby airports.
  • Global aviation safety — aviation accident database, 5,200+ records since 1980, with map and rankings by aircraft and operator.
  • NTSB safety feed — recent U.S. aviation accidents and incidents from the official NTSB CAROL database, updated daily.

Frequently asked questions

How do I search flights by aircraft type on FlightFinder?

Pick an aircraft model — Boeing 737, Airbus A320, A380, Boeing 787 Dreamliner and more — enter your origin airport, and FlightFinder shows every route that plane flies from there with live fares.

Which aircraft types can I filter by?

We support Boeing 737/747/757/767/777/787, the full Airbus A220/A319/A320/A321/A330/A340/A350/A380 family, Embraer E170/E175/E190/E195, Bombardier CRJ and Dash 8, and the ATR 42/72 turboprops.

Is FlightFinder free to use?

Search and schedules are free. Pro ($4.99/month, $39/year, or $99 one-time lifetime) unlocks the enriched flight card — on-time stats, CO₂ per passenger, amenities, live gate & weather — plus My Trips with push alerts.

Where does the route data come from?

Live schedules come from Amadeus, AeroDataBox and Travelpayouts. Observed routes (which aircraft actually flew a given city pair) are crowdsourced from adsb.lol ADS-B data under the Open Database License.