TM 1-1520-253-23
1.1.3 Inspection item Code. When inspection items, due to their proximity, are grouped in. one illustration, the figure
will be indexed using the inspection item code. This code consists of digits separated by dashes.
In the text, the inspection item is identified as follows:
a.
The first digit refers to the section of the manual in which the item appears. Example: Paragraph 2.5 is
found in Section II.
b.
The second digit refers to the item number or order that the part procedure occurs in the manual section.
Example: Paragraph 2. 5 refers to item or procedure 5.
1.1.4 Use of NDI Symbols. Nondestructive Inspection symbols and their application to detail inspection figures are
shown in Figure 1-1. In the main figures of each section, NDI symbols representing the type of inspection associated
with a part will appear next to the item number on the figure.
The technician shall be responsible for using the applicable referenced TM for the helicopter being inspected.
1.1.7 Description. The CH/MH-47 is a tandem rotor helicopter. It is powered by two T55 engines in nacelles on the aft
fuselage and pylon section of the helicopter. Torque from the engines is transmitted to the rotary-wing blades through a
series of mechanical transmissions. These transmissions are interconnected by a system of synchronizing driveshafts.
Each rotor system consists of a rotary-wing head and three rotary-wing blades. Rotor systems are controllable from the
cockpit by both pilot and copilot through dual, hydraulic-boosted control systems. The helicopter is equipped with four
landing < gear, with dual wheels on each forward landing gear, and a single wheel on each aft landing gear.
Each aft gear can swivel 360 degrees. Power steering is connected to the right aft gear. A hydraulically operated cargo
ramp and door is incorporated in the aft end of the fuselage. A hydraulically operated rescue and cargo handling winch is
located in the forward cabin area.
1.1.8 Configuration. The general configuration of the CH/MH-47 helicopter series is shown in Figure 1-2.
1.1.9 Stations. Water Lines. and Butt Lines (Figure 1-3). Stations, water lines, and butt lines provide an accurate
method of locating or installing parts and/or equipment in the airframe.
a.
CH/MH-47 helicopter length is divided into stations (STA) 1 inch apart along the longitudinal plane of the
helicopter. They begin with station 21. 50 at the most forward part of the nose section, and end at station
630. 50 at the aft end of the fuselage.
b.
Helicopter height is divided into water lines (WL) 1 inch apart along the vertical plane of the helicopter.
Water line 0.0 is marked at each side of the cabin along a beam below the windows.
c.
Helicopter butt lines (BL) are 1 inch apart starting at the helicopter center line (CL) and extending outward,
left and right, to the extreme outsides of the fuel tanks.