ettled into the left seat at our final cruise altitude of 26,000 feet, we were showing a true airspeed of 304 knots and burning about 700 pounds of jet-A per hour. As the lush rolling landscape of central Pennsylvania slid by far below, a nagging question had entered my mind. What is it about the Beechcraft King Air family of twin turboprops, I asked myself, that keeps these airplanes rolling out of the factory in Wichita, Kansas, more than 53 years after the first one emerged? I always thought I knew the answer to that question, but there in the confines of the King Air 250’s cockpit a quiet crisis of confidence was beginning to bubble up in my mind. Who, precisely, should be buying this airplane anyway? I wondered. Beech conceived of the original King Air 90 in the turbulent period in history that coincided with the JFK assassination, Martin Luther King Jr.’s “I Have a Dream” speech and the dawn of Beatlemania. The models that followed in the ensuing years — the King Air 100, 200 and 300 series — constitute the best-selling business-aircraft family in aviation history, with well over 7,000 produced and delivered. Still, I asked, how can a decades-old design like the King Air possibly continue to keep pace with the latest business aircraft making their debuts in the era of Uber and Usher? The T-tail Super King Air 200, introduced in 1973 and superseded by the upgraded versions that followed, including the King Air 250 that emerged in 2010, holds its own special place of distinction as the most successful business-airplane model bar none, with more than 2,400 in service across the globe. Clearly, people have always had their reasons for buying this airplane. Still, I couldn’t quite get over the sticker price. At $6 million, a new King Air 250 sells for a million dollars more than a HondaJet, 2 million more than a TBM 910 and 4 million more than a Cirrus Vision Jet.