Page 27 - February 2015 Volume 19 Number 2

ircus Tricksdon’t have as obvious an application as crosswind takeoffs and landings, stall recognition and recovery, and engine failure procedures.One such checkride “circus trick” applicable to multiengine aircraft is the VMC Demonstration. VMC is the airspeed, determined during certification of a multiengine aircraft, below which directional control is not possible with one engine inoperative and the other engine operating at full power. Flight controls become less effective as airflow decreases. Consequently, as speed decreases the pilot must deflect the controls progressively further to compensate for asymmetric thrust. Loss of directional control occurs at the point when the pilot reaches full control deflection and the airplane decelerates further.The “VMC Demo” consists of climbing to a safe altitude and clearing the area, then establishing the demonstration configuration (flaps, power, gear andtrim) with the critical engine (if one engine is identified as critical by the manufacturer) at idle power and the other engine at takeoff power, with both propellers at takeoff RPM. While maintaining heading in a climb at approximately 10 knots above VSSE (minimum safe single engine speed as defined in the Pilot’s Operating Handbook), slow the airplane approximately one knot per second (a very gradual deceleration). Add rudder and aileron input as needed. Recover at the first sign of inability to maintain heading or the first indication of a wing stall, whichever occurs first. (see “VMC vs. VS” in the July 2014 Twin and Turbine).Recover by reducing power on the “operating” engine sufficiently to stop the heading change (generally to idle power, to quickly eliminate the asymmetry that causes the VMC effect), while simultaneously lowering the nose to increase airspeed and therefore airflow, making the controls more effective. Do so properly and•••S••E••ESS•WrWoooEEllllyyyEEaaafeeelleoolloooffeeecimmmuuur,,,SiisssoooSSttiiioteheeeooneecheeewcccnnwccuuuwwirrrrwwiooonnniaaaeeeaiiinrrretttnnnnnaaneerrroogggccclllolnnssseeelleeedddUUUnnndddeeerrrCCCooonnntttrrrooolll•••PPPrrreeeccssssssrr•Waaalllkkkttthrrrtttaaaiiillltttooowwwaaatttcccsshhhfffooorrrcccllleeeaaarrraaannnccceees••eeccctttrrriiicccwwwiiinnnccchhhfffooorrroaaadddiiinnngggaaannndddssseeecccuuurrriiinnngggrraaaiiirrrcccrrraaafffttt–––nnnooohhhaaannndddcccrrraaannnkkkiiinnnggg•••LLLooowwwppprrrooofififillleeefffooorrrsssiiinnngggllleeeeeennngggiiinnneeeppprrrooopppcccllleeeaaarr•leeeccctttrrriiiccchhhyyydddrrraaauuullliiicccllliiiffftttfffooorrreeeaaasssyyyllloooaaadddiiinnngggaaannndddaaaddddddeeedddgggrrrooouuunnndddcccllleeeaaarrraaannnccceeeSMARTech Industries, LLC15935 Assembly Loop, Suite D, Jupiter, FL 33478 P 734.277.5759 • F 561.624.2900SmarTug Half Page 4/C Adwww.SMARTug.comFEBRUARY 2015TWIN & TURBINE • 25C