Anacortes, WA – In the past quarter-century, Micro AeroDynamics has sold over nearly 20,000 Vortex Generator kits to the owners of over 700 models of GA aircraft. The company, through its extensive flight tests has accumulated extensive documentation about the enhanced effects VGs have on stall speed and slow flight control. They have learned recently that there seems to be an added
benefit they never sought to validate: vortex generators will increase the service ceiling of an aircraft by 15 to 18 percent.
Dick Britton, a CFI, was climbing over icing conditions in a Cessna Skylane and topped the clouds at 22,000 feet, 3,100 feet above the service ceiling number in the POH. Jim Price went for an altitude record in his Long EZ. He got to 31,000 feet the first time, then installed VGs and made it to 35,027 feet, breaking the earlier record of 33,600 feet for his class. There was a similar story recounted by a Luscombe pilot.
The belief held by Micro AeroDynamics is that the service ceiling of an aircraft is reached when the available power has diminished to the point that the ensuing angle of attack breaks up the boundary layer, preventing any more lift. With vortex generators attached, the angle of attack remains below the critical point for an additional several thousand feet. This would be due to the effect the VGs have on keeping the boundary layer intact. "It's a benefit we hadn't researched," said Anni Brogan, President of Micro AeroDynamics. "However, it does appear to be valid
and as we saw in the case of Mr. Britton, it could be a tremendous asset in trying to rise above bad weather systems. We are not recommending that pilots take off to challenge the service ceiling of their aircraft, but it's useful to know you may have a little more in the bank than you thought."