Meanwhile, Hawker Beechcraft has re-invigorated its Xtra program to upgrade Bonanzas. It encompasses all Bonanza models from -35 V-tails, -33 straight-tails, through the -36 Series. Available options on the factory demonstrator -36 include: Garmin G500 retrofit glass panel avionics and GTN750 touchscreen navigator; 300-hp Continental IO-550 engine upgrade; Hartzell Scimitar prop; D'Shannon 40-gallon tip tanks (with gross-weight increase to 3,833 pounds); and the Cabin Comfort Plus environmental control – an automotive-style set-and-forget temperature control that mixes heat and air conditioning to maintain the desired levels. It also saves 40 pounds compared with factory air conditioning and eliminates the belly scoop for a net increase of three to five knots. Accessory packages from the Beech factory range from $10,000 to $100,000 and carry factory warranties.