Page 14 - Volume 16 Number 8

A Fg e sFFFTSeSeSSTTTFttttsFFFurgrrruuusaaaafor the Cessna 340For many years, Aircraft Performance Modifications, Inc. of Colorado Springs, Colorado, has been supplying and installing stability-enhancing strake kits for Cessna cabin-class airplanes. Until March of 2012, the Cessna 340/340A wasn’t on APM’s STC list, but now the 340 has joined its 400-series siblings with an STC approval for installation of strakes under the aft fuselage.Airflow-controlling afterbody strakes are a common fix for business jets, adding yaw stability and improving handling. Steve Hinckley,by LeRoy CookAPM’s CEO, owns a Cessna 421C andknew his aircraft could benefit from the addition of strakes. Accordingly, he founded Aircraft Performance Modifications in 2005 to develop and market such an improvement for the 400-series Cessnas. The STC list has expanded steadily over the years and now includes approvals from the 401 to the 425, along with the 404 and 441, and now the 340/340A. EASA approval for the European community has been obtained for all Cessna 400 series aircraft and, pending FAA approval of the 335 and 303T, EASA approval of the strakes will soon be in hand for allCessna 300-series aircraft, with the exception of the 310 and 337.In addition to performing installations at its facility, Aircraft Performance Modifications has a list of experienced installers for the strake kits in various locations. The two formed-aluminum attachments are placed on the lower aft fuselage, between the wing’s trailing edge and the horizontal stabilizer’s leading edge, at roughly the five o’clock and seven o’clock orientations. For the Cessna 340, strakes can actually bring a four to seven knot increase, according to owner reports of before-and-after testing.sssekkkkeeellllaeeaaaggss12 • TWIN & TURBINEAUGUST 2012