TM 1-1520-240-102-14-1SECTION XIV. FLIGHT INSTRUMENTS2-14-1. General.The following paragraphs contain information on theflight instruments. Information on the navigation instru-ments will be found in Chapter 3. Avionics. All other in-struments directly related to one of the helicopter sys-tems are found under the appropriate system heading inthis chapter. Refer to fig. 2-1-5, 2-1-6, 2-1-7, 2-1-8, 2-1-9,and 2-1-10 for illustrations of the instrument panels,canted and center consoles, and overhead switch panel.2-14-2. Cruise Guide indicator System.The cruise guide indicator (CGI) system gives the pilot avisual indication of actual loads imposed on critical com-ponents of the helicopter dynamic system. The systemallows the pilot to achieve maximum helicopter utilizationunder various conditions of payload, altitude, airspeed,ambient temperature, and center-of-gravity. The systemconsists of strain gages bonded to fixed links in the for-ward and aft rotor controls, an indicator, a signal proces-sor unit in the aft pylon, a signal conditioner unit in theforward pylon, and interconnecting wiring. The systemmeasures alternating stress loads at each rotor and dis-plays the larger of the two signals. Power to operate thecruise guide indicator system is supplied by No. 2 DC busthrough the CRUISE GUIDE circuit breaker on the No. 2PDP.2-14-3. CRUISE GUIDE Indicator.The CRUISE GUIDE indicator is on the pilot instrumentpanel (fig. 2-14-1). Three bands are colored green, yel-low, and striped red-and-yellow. Refer to figure 5-2-1 forlimitations. Immediate corrective action must be taken toreduce stress when in the red-and-yellow striped band.This can be accomplished by lowering THRUST CONTlever, reducing airspeed, releasing back pressure on thecyclic stick, or by reducing the severity of the maneuver.NOTEDo not test the cruise guide system with rotorsturning. False indications will result.When the switch is placed from the center position toeach test position, the pointer on the indicator shouldindicate within the white test band. The white test bandindicates proper system operation.When the test function is activated, circuits from thestrain gages to the indicator are tested. However, sepa-ration of the bond of the strain gage to a link will not bedetected by the test function. The narrow white line to-wards the high end of the striped red-and-yellow band isused for calibrating the indicator during bench test.Figure 2-14-1. Cruise Guide Indicator2-14-4. CGI TEST Switch.The CGI TEST switch is on the pilot instrument panel, onthe left side of the indicator (fig. 2-14-1). It is a three-posi-tion switch spring loaded to center off position labeledFWD and AFT.2-14-5. Airspeed Indicator.There are two airspeed indicators located on the upperleft portion of the copilot and pilot instrument panel (fig.2-1-7 and 2-1-9). The difference between dynamic pres-sure and static pressure as measured by the pitot staticsystem is introduced into these instruments. Indicatedairspeed is shown in knots.2-14-6. Altimeter.An AIMS altimeter is provided for the pilot (fig. 2-14-2).In the term AIMS, the A stands for Air Traffic ControlRadar Beacon System (ATCRBS), the I stands for identi-fication friend or foe (IFF), the M represents the Mark XIIidentification system, and the S means system. A pneu-matic counter-drum-pointer type altimeter is installed forthe copilot. The pilots altimeter is a pneumatic counter-drum-pointer type which is a self-contained unit consist-ing of precision pressure altimeter combined with an alti-tude encoder.Simultaneously, the display indicates and the encodertransmits through the transponder the altitude of the heli-copter. Altitude is displayed on the altimeter by a10,000-foot counter, and a 100-foot drum. A single point-er indicates hundreds of feet on a circular scale with50-foot center markings. Below 10,000 feet a diagonal
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
