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plthijinx · 10-03-2005, 05:08 PM

that's a loaded question of sorts. you have the value Va, or maneuvering speed, to which the airspeed actually lowers as weight is reduced. Va is loosely defined as an airspeed at which abrupt or full control deflection can be done without over stressing the airframe. why does this speed decrease as weight is decreased? simple, the lighter the object, the easier it is to through it around. take my trip back from paragould a few weeks ago. ATC (air traffic control) had me fly through a towering cumulous cloud that was not yet cumulonimbus. i got thrown around, badly. in an airframe that was built circa 1958. i remember looking at my airspeed upon entering the turbulence and immediately reaching for the throttles. right when i grabbed the throttle levers i got jolted again but thankfully i caused me to bring the throttles to idle as to get my speed around 120. i was doing 140 but when i closed the throttles at the same time i pitched up as best i could and quickly slowed down. back to the question in a way, the aircraft has a gross takeoff weight of 3800 lbs. would it be easier or harder to throw that plane around fully loaded or half loaded. it's all about inertia. your more apt to overstress the frame at a lighter weight because it's easier for the airplane to react to an abrupt or full deflection or both. in that one instance ATC asked me my on course heading to which i replied 210ish but that i couldn't hold it (with a stressed voice due to the situation, it's not easy talking on the radio whilst being bounced around) so she asked if i wanted another altitude and i said i couldn't do anything about it at the moment because i was along for the ride.

clear as mud?

10-03-2005, 05:08 PM	#75
plthijinx Master Dwellar Join Date: Aug 2003 Posts: 4,197	that's a loaded question of sorts. you have the value Va, or maneuvering speed, to which the airspeed actually lowers as weight is reduced. Va is loosely defined as an airspeed at which abrupt or full control deflection can be done without over stressing the airframe. why does this speed decrease as weight is decreased? simple, the lighter the object, the easier it is to through it around. take my trip back from paragould a few weeks ago. ATC (air traffic control) had me fly through a towering cumulous cloud that was not yet cumulonimbus. i got thrown around, badly. in an airframe that was built circa 1958. i remember looking at my airspeed upon entering the turbulence and immediately reaching for the throttles. right when i grabbed the throttle levers i got jolted again but thankfully i caused me to bring the throttles to idle as to get my speed around 120. i was doing 140 but when i closed the throttles at the same time i pitched up as best i could and quickly slowed down. back to the question in a way, the aircraft has a gross takeoff weight of 3800 lbs. would it be easier or harder to throw that plane around fully loaded or half loaded. it's all about inertia. your more apt to overstress the frame at a lighter weight because it's easier for the airplane to react to an abrupt or full deflection or both. in that one instance ATC asked me my on course heading to which i replied 210ish but that i couldn't hold it (with a stressed voice due to the situation, it's not easy talking on the radio whilst being bounced around) so she asked if i wanted another altitude and i said i couldn't do anything about it at the moment because i was along for the ride. clear as mud? __________________ For your dreams to come true, you must first have a dream.