TM 1-1510-218-10 2-9 2-5.  MAXIMUM WEIGHTS. a.   Operations At or Below 12,500 Pounds.  (1)   Takeoff.  Maximum Gross Takeoff Weight (GTOW) is 12,500 pounds. (2)   Landing.  Maximum gross landing weight is 12,500 pounds. (3)   Maximum Ramp Weight.  Maximum ramp weight is 12,590 pounds. (4)   Maximum  Zero  Fuel  Weight.    Maximum zero fuel weight is 11,000 pounds. (5)   Altitude. (a)  At least 75% of total missions shall be flown at altitudes above 5,000 feet above ground level when operating at or below 12,500 pounds GTOW. (b)  At least 50% of total missions shall be flown   at   altitudes   above   10,000   feet   above   ground level    when    operating    at    or    below    12,500    pounds GTOW. b.  Operations    Over    12,500    Pounds    Gross Takeoff Weight  C D1. (1)   Requirements. (a)  Takeoffs.      Takeoff   should   only   be performed   on   a   smooth   paved   runway.      Takeoffs should not be performed with a tailwind. (b)  Landing.  Maximum landing weight is 12,500 pounds, unless required by an emergency.  If it is necessary to land with a weight over 12,500 pounds, the landing shall be made on a smooth, paved runway at a sink rate of 500 feet per minute or less, if possible. (c)  Flight   Duration.      All   missions   with over   12,500   pounds   GTOW   shall   be   planned   and flown at or above 10,000 feet above ground level and be    a    minimum    of    60    minutes    in    duration    unless restricted  by  Air  Traffic  Control,  turbulence,  or  other weather conditions, or emergencies. (d)  Takeoff.        All     missions     with     over 12,500  pounds  GTOW  shall  be  flown  on  a  smooth, paved runway.  Takeoffs shall not be performed with a tailwind. (e)  Center  of  Gravity  (CG)  Limits.     The CG limits shall be IAW with Figure 6-7. 1   The    aft    CG    limit    above    12,500 pounds is 196.4 ARM inches. 2   The    forward    CG    limit    at    13,500 pounds is 188.3 ARM inches.  Intermediate values to 12,500 vary linearly to 185.0 ARM inches. (f)   Wing Spar.    Authorization  to  operate above  12,500  is  applicable  to  the  following  aircraft, only after the original wing spars have been replaced after 10,000 hours of service. C12C 73-22250 73-22252 Through 73-22264 73-22267 Through 73-22269 (2)   Maximum Weight Operation. (a)  Takeoff.   Maximum GTOW is 13,500 pounds. (b)  Landing.      Maximum    gross    landing weight is 12,500 pounds. (c)  Maximum  Ramp  Weight.     Maximum ramp weight is 13,590 pounds. (d)  Maximum Zero Fuel Weight.   Maximum zero fuel weight is 11,000 pounds. c.   Operations    Over    12,500    Pounds    Gross Takeoff Weight  D2  T . (1)   Requirements. Artificial  stall  warning  systems  may  only provide a 1 to 5 knot stall warning. Maximum   GTOW   charts   must   be   strictly followed  to  ensure  climb  capability  in  the event of an engine failure. (a)  Aircraft shall be equipped with Raisbeck    Engineering    dual    aft    body    strakes    and engine ram air recovery system with PT6A-42 engines. (b)  Landing.  Maximum landing weight is 12,500 pounds, unless required by an emergency.  If it is necessary to land with a weight over 12,500 pounds, the landing shall be made on a smooth, paved runway at a sink rate of 500 feet per minute or less, if possible. (c)  Flight   Duration.      All   missions   with over   12,500   pounds   GTOW   shall   be   planned   and flown at or above  10,000  feet  above  ground  level  and WARNING