3.  The  aircraft  should  be  maneuvered  into  a favorable position so that the signaler can have an unobstructed view for as long a period as possible. 4. Accurate training of the light by the operator at all times is most important. Aircraft are called by the means of the prosign AA, the unknown station. Many aircraft cannot signal by flashing light, and an answer should not always be expected. If no answer is seen, the message is to be made through at least twice; repetitions are to be preceded by the prosign IMI. Receipt may be indicated by the aircraft rocking its wings. INFRARED  COMMUNICATIONS Infrared communications are divided into two forms:  directional  and  non-directional.  Directional  is the use of the standard searchlight fitted with the H hood. Nondirectional is the use of the AN/SAT 2 system located on the yardarm. Infrared communication between separate ships is generally directional. A station having traffic for wide distribution  will  normally  use  non-directional procedures. The OTC may prescribe calling periods during which infrared traffic may be passed without a special signal to attract attention. For example, stations may be  required  to  monitor  for  infrared  signaling  for  15 minutes  beginning  on  the  hour  and  half  hour.  Such instruction may be found in the operation orders, communications  plan,  or  message  traffic  calling periods.  At  the  beginning  of  the  calling  period,  the OTC  may  transmit  the  appropriate  operating  signal and the call signs of the stations the traffic is for. Stations not included in the traffic list may secure their equipment unless they have traffic for the OTC or other units in company. To transmit infrared traffic outside calling periods or when calling periods have not been prescribed, the stations may be alerted by the code word NANCY HANKS on voice radio, the appropriate signal from ATP 1, volume II, or an operating signal. The  point  of  train  (POT)  light  is  a  steady infrared light used to assist the sender in locating the receiving station and in keeping his/her light properly trained. It is turned on to indicate that a station is communicating  or  is  ready  to  communicate  with infrared. It is turned off at all other times. In the event of non-directional procedure, the originator's POT lights  will  become  its  Nancy  beacons,  and  the receiving stations will be able to train their receivers on the actual transmission. SEMAPHORE  PROCEDURES LEARNING  OBJECTIVES:  Explain  the procedure   for   calling,   receipting,   and requesting repetitions, interruptions, and relays by   semaphore.   Explain   procedure   for transmitting, rate of signaling, and the use of numerals.   List   special   characters   and semaphore  abbreviations. Semaphore   and   flashing   light   can   be   used interchangeably.  Semaphore  is  much  faster  and generally  more  secure  than  flashing  light  for short-distance   transmission   in   clear   daylight. Semaphore  may  be  used  to  transmit  messages  to several addressees at once if the sender is in a suitable position. Because of its speed, it is better adapted for long messages than other visual methods. Semaphore can be used at night with the use of wands attached to flashlights. See appendix II for semaphore drills and procedures. Semaphore signaling procedures are similar to those  used  in  flashing  light.  The  general  rules  of  visual responsibility apply; call signs are the same; and message parts are unchanged. Because of the different equipment used, some differences in procedure do exist. Care  is  to  be  exercised  in  selecting  a  good background from which to send a semaphore message. The better the background, the greater the signaling distance. The characters are to be formed in the same plane as  the  sender's  shoulders,  with  staffs  at  their  full extent, forefingers along the staff. When the sender is making the front sign, the flags should be crossed in front of the body. A distinct pause is to be made at each character according   to   the   rate   of   signaling.   When transmitting   prosigns,   operating   signals,   and abbreviations,  make  this  pause  of  double  duration. A double-duration pause is also recommended when sending  coded  messages. The front sign is made at the end of each word, group, prosign, or operating signal. Where double letters occur, the arms are to be dropped to the front 4-10