and were nominally intended to help the aircraft stay aloft during in-flight emergencies or forced landings. However, it is unclear whether this feature was ever installed on a production aircraft or used in any instance other than test flights. Operational history The Twin Bonanza had trouble competing with the similarly capable but substantially lighter Cessna 310 and Piper PA-23, so Beechcraft used the basic single-engined Bonanza fuselage and many other Bonanza parts to create the Twin Bonanza's effective replacements: the Travel Air and the closely related Baron. The Twin Bonanza has been plagued by a reputation for slow cruise speed, poor fuel economy and high engine overhaul costs relative to other six to eight-seat light piston twins; this has historically kept resale values low, but many owners praise its reliability, good outwards visibility, stable flying qualities and generous interior space, particularly when the three-wide seats are not fully occupied. The Twin Bonanza is popularly known as the "Twin Bo" or the "T-Bone". In January 2012, the Australian Civil Aviation Safety Authority issued an airworthiness directive grounding all Bonanzas, Twin Bonanzas, and Debonairs equipped with a single pole-style yoke, having forward elevator control cables more than 15 years old, until they could be inspected. The AD was issued based on two aircraft found to have frayed cables, one of which suffered a cable failure just prior to takeoff, and resulting concerns about the age of the cables in fleet aircraft of this age. At the time of the grounding, some Bonanzas had reached 64 years in service. Aircraft with frayed cables were grounded until the cables were replaced, and those that passed inspection were required to have their cables replaced within 60 days regardless. The AD affected only Australian aircraft and was not adopted by the airworthiness authority responsible for the type certificate, the US Federal Aviation Administration. The FAA instead opted to issue a Special Airworthiness Information Bulletin (SAIB) requesting that the elevator control cables be inspected during the annual inspection. Variants Model 50 Initial production version powered by two Lycoming GO-435-C2 engines, 13 built (six for the US Army, remainder civilian versions, with the first two production numbers for factory evaluation). As of 2010, only one Model 50 is still registered and flying (serial number H-7). As of June 2016, Serial Number H-7 is owned by W. Hulsey Smith through his holding company Archangel Technologies, LLC, as part of