TM 1-1510-223-10 Change 3          5-1 CHAPTER 5 OPERATING LIMITS AND RESTRICTIONS Section  I. GENERAL 5-1. PURPOSE. This chapter identifies or refers to all important oper- ating limits and restrictions that shall be observed during ground and flight operations. 5-2. GENERAL. The operating limitations set forth in this chapter are the direct result of design analysis, tests, and operating experiences. Compliance with these limits will allow the pilot to safely perform the assigned missions and to de- rive maximum utility from the aircraft. Limits concerning maneuvers, weight, and center of gravity are also cov- ered in this chapter. 5-3. EXCEEDING OPERATIONAL LIMITS. Anytime an operational limit is exceeded, an appropri- ate entry shall be made on DA Form 2408-13. Entry shall state what limit or limits were exceeded, range, time be- yond limits, and any additional data that would aid main- tenance personnel in the maintenance action that may be required. 5-4. MINIMUM CREW REQUIREMENTS. The minimum crew required for aircraft operation is two pilots. Additional crewmembers as required, will be added at the discretion of the commander, in accordance with pertinent Department of the Army regulations. Section  II. SYSTEM LIMITS 5-5. INSTRUMENT MARKINGS. Instruments which display operating limitations are il- lustrated in figure 5-1. The operating limitations are color coded on the instrument faces. Color coding of each in- strument is explained in the illustration. 5-6. INSTRUMENT MARKING COLOR CODES. Operating limitations and ranges are illustrated by the colored markings which appear on the dial faces of en- gine, flight, and utility system instruments. Red markings indicate the limit above or below which continued opera- tion is likely to cause damage or shorten life. The green markings indicate the safe or normal range of operation. The yellow markings indicate the range of operation. The yellow markings indicate the range when special atten- tion should be given to the operation covered by the in- strument. Operation is permissible in the yellow range, but should be avoided. White markings on the airspeed indicator denote the flap operating range. The blue mark- ing on the airspeed indicator denotes best rate of climb with one engine inoperative, at maximum gross weight, maximum  forward  c.g.,  sea  level  standard  day  condi- tions. 5-7. PROPELLER LIMITATIONS. The maximum propeller overspeed limit is 1870 RPM (transient,   20   seconds   maximum).   Propeller  speeds above 1700 RPM indicate failure of the constant speed governor. Propeller speeds above 1802 RPM indicates failure of both the constant speed and overspeed gover- nors. 5-8. STARTER LIMITATIONS. The starters are limited to an operating period of 40 seconds ON, then 15 minutes OFF, 40 seconds ON, then 30 minutes OFF. Contact maintenance personnel for as- sistance if no engine start occurs during cycle noted in this paragraph. 5-9. AUTOPILOT LIMITATIONS. a.   An  autopilot  preflight  check  must  be  conducted and found satisfactory prior to each flight on which the autopilot is to be used. b.   A pilot must be seated at one set of flight controls with the seat belt fastened when the autopilot is in opera- tion. c.   Operation of the autopilot and yaw damper is pro- hibited during takeoff and landing, and below 200 feet above terrain. Maximum speed for autopilot operation is 248 KIAS to 11,500 feet, then 0.472 Mach to 35,000 feet. 5-10.   FUEL SYSTEM LIMITS. NOTE Aviation gasoline (AVGAS) contains a form of lead which has an accumulative adverse effect on gas turbine engines. The lowest octane AV- GAS  available  (less  lead  content)  should  be used. If any AVGAS is used, the operating time must be entered on DA Form 2408-13-1. Oper- ating time on AVGAS is computed on the basis of quantity used and average consumption.