LEVELING AND WEIGHING
**** Hidden Message ***** <P>LEVELING<BR>1. General<BR>A. The airplane can be leveled by using either a plumb bob, an attitude gage, or an engineer's<BR>transit.<BR>B. For an alignment check of the airplane structure following repair or modification, a more<BR>accurate means of leveling is needed, such as an engineer's transit. For complete details on<BR>alignment checking, refer to the Structural Repair Manual Chapter 51, Alignment Check<BR>Procedure.</P><P>LEVEL AIRPLANE USING PLUMB BOB<BR>1. General<BR>A. The plumb bob may be used for general airplane leveling, such as when the airplane is being<BR>jacked for weighing, general maintenance, gear retraction tests, etc.<BR>2. Equipment and Materials<BR>A. Plumb Bob and Cord<BR>3. Level Airplane (Fig. 201)<BR>A. Park airplane in most level position available.<BR>B. Hang plumb bob from bracket marked LEVEL HERE in the right main wheel well. The bracket<BR>is directly above the leveling scale.<BR>C. Check position of plumb bob after it has stopped swinging. If plumb bob is not over zero on the<BR>leveling scale, the airplane must be adjusted by jacking or oleo inflation until plumb bob is<BR>zeroed.<BR>(1) For minor leveling adjustments, the main and nose landing gear shock struts can be<BR>extended or retracted by inflation to normal service band limits or deflation as required<BR>(Ref Chapter 12, Main Landing Gear Shock Strut Servicing and Nose Landing Gear Shock<BR>Strut Servicing).<BR>WARNING: SHOCK STRUTS MUST NOT BE PRESSURIZED BEYOND NORMAL<BR>SERVICING LEVELS. TO DO SO CAN RESULT IN OVER<BR>PRESSURIZATION AND POSSIBLE INJURY TO PERSONNEL AND<BR>SERIOUS SHOCK STRUT DAMAGE.</P>
<P>(2) For major leveling adjustments, place appropriate jack pad adapters and jacks at jacking<BR>points A, B, and C. Refer to Airplane Jacking, Chapter 7.<BR>CAUTION: ALL JACKS MUST BE EQUIPPED WITH LOAD OR PRESSURE GAGES.<BR>JACK POINT LOAD LIMITS MUST NOT BE EXCEEDED.<BR>(3) Raise or lower appropriate jack until plumb bob is centered over zero on leveling scale.<BR>LEVEL AIRPLANE USING ATTITUDE GAGE<BR>1. General<BR>A. The primary purpose of the attitude gage is to determine the correct attitude of the airplane on<BR>the ground prior to a fuel quantity check. The pitch and roll readings combined with dripstick<BR>readings will give accurate fuel quantities in the tanks. Refer to Chapter 28, Fuel Quantity<BR>Indicating System, for further information on dripstick readings. In this chapter, the attitude<BR>gage will be used to level the airplane while jacking.<BR>2. Equipment and Materials<BR>A. Airplane Attitude Gage, F70043<BR>3. Level Airplane (Fig. 202)<BR>A. Park airplane in most level position available.<BR>B. Place both alignment tube tips of attitude gage against ceiling in main wheel well. Position gage<BR>parallel to airplane centerline to determine level of longitudinal axis and pitch of airplane (Fig.<BR>202)<BR>NOTE: Ensure that alignment tube tips are resting on a flat surface of the wheel well ceiling<BR>between the rows of rivets that attach the ceiling panel to the floor beams.<BR>C. Set screw adjuster on top of attitude gage until pointer is on zero. If bubble in level vial is not<BR>centered the airplane must be raised accordingly. The bubble will move toward the high end of<BR>the airplane.</P>
<P>D. Correct airplane attitude, proceeding until airplane is level along longitudinal axis.<BR>(1) For minor adjustments, the main and nose landing gear shock struts can be extended or<BR>retracted by inflation or deflation as required. Refer to Chapter 12, Main Landing Gear<BR>Shock Strut Servicing and Nose Landing Gear Shock Strut Servicing.<BR>WARNING: SHOCK STRUTS MUST NOT BE PRESSURIZED BEYOND NORMAL<BR>SERVICING LEVELS. TO DO SO CAN RESULT IN OVERPRESSURIZATION<BR>AND POSSIBLE INJURY TO PERSONNEL AND SERIOUS SHOCK STRUT<BR>DAMAGE. WITH SHOCK STRUT FULLY EXTENDED PRESSURE MUST NOT<BR>EXCEED 67 PSI IN MAIN GEAR (PART NO. 65-73761-1, -2, -3, -4) OR 78 PSI<BR>IN MAIN GEAR (PART NO. 65-73761-5, -6), OR 495 PSI IN NOSE GEAR.<BR>(2) For major adjustments place appropriate jack pad adapter and jack at jacking point C.<BR>Refer to Airplane Jacking, Chapter 7.<BR>CAUTION: JACK MUST BE EQUIPPED WITH LOAD OR PRESSURE GAGE. DO NOT<BR>EXCEED JACKING POINT LOAD LIMIT.<BR>(3) Raise or lower jack until bubble in level vial is centered.<BR>E. Place attitude gage in a position that is perpendicular to the airplane centerline. Ensure that<BR>both alignment tube tips are centered between the rows of rivets on the floor beams. The gage<BR>can now be used to measure the roll attitude of the airplane.<BR>F. With pointer on zero adjust airplane attitude until bubble is centered in level vial.<BR>(1) For minor adjustments, the main landing gear shock struts can be extended or retracted.<BR>Refer to NOTE and WARNING following step D.(1).<BR>(2) For major adjustments place appropriate jack pad adapters and jacks at jacking points A<BR>and B (Ref steps D.(2) and D.(3)).<BR>G. Repeat longitudinal and lateral leveling until level vial bubble is centered at both positions.</P> LEVELING AND WEIGHING
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