TM 1-1520-240-105-2-1SECTION II. SYSTEM LIMITS5-2-1. Instrument Markings.5-2-2. Instrument Marking Color Codes.Operating limitations and ranges are identified by thecolored markings on the dials of engine, flight and utilitydrive train system instruments. The RED markings on thedials of these instruments indicate the limit above or be-low which continued operation is likely to cause damageor shortened life, white background may be utilized tohighlight RED markings. The GREEN markings on in-struments indicate safe or normal range of operation.The YELLOW markings on instruments indicate the timelimited range or when special attention should be givento the operation covered by the instrument. Operation ispermissible in the yellow range, but should be avoided.BLUE is a maximum indication associated with sustainedoperation of the related aircraft system for a prescribedperiod of time. Limitations (fig. 5-2-1) which are markedon the various instruments are not necessarily repeatedin the subsequent text. When further explanation of cer-tain markings is required, refer to the specific area ofdiscussion.5-2-3. Instrument Glass Alignment.All instruments with range markings on the glass haveshort white alignment marks extending from the dialglass onto the rim of the indicator. These slippage marksappear as a single line when limitation markings on theglass properly align with the proper increments on thedial face. However, the slippage marks appear as sepa-rate radial lines when a dial glass has rotated5-2-4. Rotor Limitations.Refer to figure 5-2-1 for limitations. Should 108 percentpower off be inadvertently exceeded, no entry need bemade in DA Form 2408-13-1 unless the rotor systemaccelerates to 111 percent or above. Even though noaction is required when RPM exceed 108 percent poweroff but remains less than 111 percent, willful operationshould not be conducted in this range. Operation be-tween 96 and 92 percent is permitted when water taxiing.5-2-5. Inoperative Cruise Guide Indicator.Flight at or below 98 percent RRPM with an inoperativecruise guide indicator is prohibited.5-2-6. Starting and Shutdown Limits.The APU shall not be started with a tailwind in excess of25 knots. Main engines shall not be started with a tailwindin excess of 10 knots. The rotor blade start-up and shut-down limits of figure 5-7-1 shall be observed. if it be-comes necessary to shut down in conditions outside thelimits shown in figure 5-7-1, the following precautions arerecommended:a.Aircraft should be landed in an area which isclear, as level as possible, and at least 300 feet awayfrom any vertical obstructions, abrupt changes in groundterrain, trees, bushes, fences, etc.b.Aircraft should be oriented such that the windwould be coming in at the left side. If the pilot is unsureof the wind direction after landing, a crew member shouldbe dispatched beyond the rotorwash to make a true winddirection determination before engines are secured.
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