TM 1-1520-238-10 2-77 c. Free Air Temperature (FAT) Indicator. The FAT indicator (fig 2-11) is a self-contained unit mounted to the bulkhead adjacent to, and left of, the pilot PWR quadrant. A probe extends through the airframe to sense outside free air temperature. The dial, marked FREE AIR, indi- cates in degrees Celsius (C). d. Accelerometer. The accelerometer measures the g-forces during flight. e. Radar Altimeter. For description refer to para- graph 3.18. 2.50.3 CPG Flight Instruments. The flight instru- ments unique to the CPG instrument panel (fig 2-10) are the radio magnetic indicator, airspeed indicator, and altim- eter. a. Radio Magnetic Indicator (RMI). The RMI, lo- cated at the bottom center of the CPG right instrument cluster, displays magnetic heading and ADF bearing to a selected station. The ADF will be discussed in Chapter 3 in conjunction with direction finder set AN/ARN-89 or the AN/ARN-149. Magnetic heading is provided through a synchro signal from the heading/attitude reference set (HARS) to a heading servo that positions the heading compass card within the instrument. When the HARS is aligning or failed, a heading warning signal will cause the OFF flag (right center on the instrument face) to appear. Internal power to the RMI is provided by 115 vac 400 Hz input power. 2.51 PITOT-STATIC SYSTEM. Electrically-heated pitot tubes are installed at the out- board leading edge of both wings. Two associated static ports are installed flush with the fuselage: one on the right, and one on the left. The right wing pitot tube supplies ram air to the pilot airspeed indicator, and the left wing pitot tube supplies ram air to the CPG airspeed indicator. The static port on the right side of the fuselage provides static air pressure to the pilot barometric altimeter, rapid re- sponse vertical speed indicator, air speed indicator, No. 2 airspeed transducer, and the air data processor. The stat- ic port on the left side of the fuselage provides static air pressure to the CPG barometric altimeter, rapid response vertical speed indicator, airspeed indicator, and No. 1 air- speed transducer. 2.52 PILOT AND CPG MASTER CAUTION PANEL. The master caution panels (fig 2-43), located at the center of the pilot and right center of the CPG glareshield (fig 2-9 and 2-10), are identical. When the PRESS TO TEST pushbutton is pressed, all caution/warning lights in that crew station illuminate. All segments have two lamps so that failure of a single lamp will produce only a dimming effect. If a segment fails to light, it indicates either the fail- ure of both lamps or a defective circuit. The MASTER CAUTION display is also pushbutton operated; it is the only amber light on the master caution panel. Initially, when a caution/warning panel segment illuminates, it will flash. Simultaneously, the MASTER CAUTION will flash. Pressing the MASTER CAUTION light segment will extin- guish the lamp and convert the illuminated fault segment to steady on. The MASTER CAUTION lights are individu- ally reset in each crew station. and will remain on until the fault or condition is corrected. Warning lights are red, and when lighted, require immediate crewmember attention. The master caution panel segments are described in table 2-3. MASTER CAUTION LOW RPM ROTOR FIRE APU ENGINE 1 OUT ENGINE 2 OUT ENGINE CHOP HIGH RPM ROTOR BUCS FAIL PRESS TO TEST M01-121 Figure 2-43. Pilot and CPG Master Caution Panel