Beechcraft C-12C Operator And Technical Reference Manual

Contents

Beechcraft C-12C Operator And Technical Reference Manual Manual pdf 851 page image

TM 1-1510-218-10NOTEDue to possible precession error, the pitchsteering bar may slightly lower duringacceleration, causing the pitch attitude toappear higher than actual pitch attitude.To avoid lowering the nose prematurely,crosscheck the vertical velocity andaltimeter to ensure proper climbperformance. The erection system willautomatically remove the error after theacceleration ceases.8-50. INSTRUMENT CLIMB.Instrument climb procedures are the same asthose for visual climb. En route instrument climbs arenormally performed at cruise climb airspeeds.8-51. INSTRUMENT CRUISE.There are no unusual flight characteristics duringcruise in instrument meteorological conditions.8-52. INSTRUMENT DESCENT.When a descent at slower than recommendedspeed is desired, slow the aircraft to the desired speedbefore initiating the descent. Normal descent toapproach altitude can be made using cruise airspeed.Normally, descent will be made with the aircraft in acruise configuration, maintaining desired speed byreducing power as required. The aircraft is completelycontrollable in a high rate descent.8-53. INSTRUMENT APPROACHES.There are no unusual preparations or controltechniques required for instrument approaches. Theapproaches are normally flown at an airspeed of Vref toVref + 20 KIAS until transitioning to visual flight.Approach speeds are increased appropriately forpotential wind shear and gusty wind conditions IAWthe ATM.8-54. AUTOPILOT COUPLED APPROACHES.There are no special preparations required forplacing the aircraft under autopilot control. Refer toChapter 3 for procedures to be followed for coupledapproaches.NOTEThe ILS localizer and glideslope warningflags indicate insufficient signal strength tothe receiver. Certain electrical mechanicalmalfunctions between the receiver andindicators may result in erroneous localizer/glideslope information without a warningflag. It is recommended that ILSinformation be cross-checked with otherflight instruments prior to and during finalapproach. Utilization of NAV TEST prior tothe final approach fix may detect certainmalfunctions not indicated by the warningflags.Section IV. FLIGHT CHARACTERISTICS8-55. STALLS.A pre-stall warning in the form of a very lightbuffeting can be felt when a stall is approached. Amechanical warning is also provided by a warninghorn. The warning horn starts to alarm approximately5 to 10 knots above stall speed with the aircraft in anyconfiguration. If correct stall recovery technique isused, very little altitude will be lost during the stallrecovery. For the purpose of this section, the term"power-on" means that both engines and propellers ofthe aircraft are operating normally and are responsiveto pilot control. The term "power-off" means that bothengines are operating at idle power. Landing gearposition has no effect on stall speed.a. Power-On Stalls. The power-on stallattitude is very steep and, unless this high-pitchattitude is maintained, the aircraft will generally "settle"or "mush" instead of stall. It is difficult to stall theaircraft inadvertently in any normal maneuver. A lightbuffet precedes most stalls and the first indication ofapproaching stall is generally a decrease in controleffectiveness, accompanied by a "chirping" tone fromthe stall warning horn. The stall itself is characterizedby a rolling tendency if the aircraft is allowed to yaw.The proper use of rudder will prevent the tendency toroll. A slight pitching tendency will develop if theaircraft is held in the stall, resulting in the nosedropping sharply, then pitching up toward the horizon;this cycle is repeated until recovery is made. Controlis regained very quickly with little altitude loss,providing the nose is not lowered excessively. Beginrecovery with forward movement of the control wheeland a gradual return to level flight. The roll tendencycaused by yaw is more pronounced in power-on stalls,as is the pitching tendency; however, both are easilycontrolled after the initial entry. Power-on stallcharacteristics are not greatly affected by wing flapposition, except that stalling speed is reduced inproportion to the degree of wing flap extension.b. Power-Off Stalls. The roll tendency isconsiderably less pronounced in power-off stalls, in8-25