Siemens-Powered Extra 330LE Makes a Great Tow Plane

Dean Sigler Batteries, Electric Powerplants, Sustainable Aviation 1 Comment

Already proving its ability to climb at a great rate on its own, the Siemens-powered Extra 330LE towed an LS-8 sailplane to 600 meters (1.968 feet) in a mere 76 seconds.  This alone could be a gift to soaring. Sitting at the controls of a sailplane being towed aloft behind a conventionally-powered tow plane proves taxing, for the many minutes it takes to gain a release height of 2,000 or 3,000 feet can seem somewhat endless.  It’s also expensive for the gliding club or commercial operation.  The soaring club in which your editor was a member calculated the average tow for a Piper Pawnee or Cessna AgWagon consumed around 2.7 gallons to 3.0 gallons of $5.00 a gallon avgas.  Twenty or thirty tows a day make for significant operational costs. It’s also the most dangerous part of the flight.  A wrong move by a student (or experienced pilot) on tow can put two airplanes and their occupants into the dirt.  …

Record for Siemens, Extra Electric Time-to-Climb

Dean Sigler Batteries, Electric Powerplants Leave a Comment

Time-to-Climb is a tough record to beat, requiring an airplane with an excess of power, a skilled pilot, and just the right weather.  Your editor was supremely lucky a few years ago to meet Bruce Bohannon, holder of 25 records, including altitude and TTC marks to 20,000, 30,000 and 40,000 feet.  He managed these records in a modified Van’s RV-4 with a Lycoming IO-540 engine pumping out a nitrous-oxide assisted 425 horsepower.  The normal gross weight of an RV-4 is 1,500 pounds, for a power loading of 8.33 pounds per horsepower with a 180-horsepower engine. Since the RV-4 normally flies with 180 to 200 horsepower, the additional 225 ponies helped Bohannon achieve some big numbers.  His rate of climb to 3,000 meters (9,842 feet) was 4,407 feet per minute, besting the P-51D’s 3,600 feet per minute or the F-8-F Bearcat’s 4,500 feet per minute. An IO-540 weighs 199 kilograms, or 438 pounds (depending on configuration and accessories.  An O-360 with 200 …