TM 1-1510-223-10 Change 3          3-19 plain/cipher mode and fill data and identifier to be de- leted. When the scratchpadded channel’s data has been successfully deleted, the box around the legend at L2 will be removed. Valid data consists of a valid hopset (HSET) channel (0 through 6 or an M). NOTE Several channels can be deleted by scratchpad- ding several channel numbers with a space be- tween them. Scratchpadding 1 4 and pressing L2 causes data in channels 1 and 4 to be de- leted.   Scratchpadding   1-4   and   pressing   L2 causes data in channels 1 thru 4 to be deleted. (3)    DEL  LSET.    This  key  provides  a  means  for deleting locksets. Scratchpadding valid data and press- ing  L3  causes  the  legend  at  L3  to  be  boxed  and  the hopset, plain/ciph mode and fill data and identifier to be deleted.  When  the  scratchpadded  channel’s  data  has successfully been deleted, the box around the legend at L3  is  removed.  Valid  data  consists  of  a  valid  lockset (LSET) channel (1-8). NOTE Several  channels  can  be  deleted  at  once  by scratchpadding several channel numbers with a space between them. Scratchpadding 1 4 and depressing L3 will cause data in channels 1 and 4  to  be  deleted.  Scratchpadding  1-4  and  de- pressing   L3   will   cause   data   in   channels   1 through 4 inclusive to be deleted. (4)    ADD.  When the VHF-FM transceiver is in the single channel mode, this key is used to add information to the single channel frequency list. Scratchpadding valid data and depressing R1 will cause the scratchpadded data to be entered into the frequency list. Valid data consists of a valid channel (1 through 20 or C or E) followed by a valid frequency (30.000 through 87.975  with  leading  and  trailing  zeroes  and  decimal points optional) and/or a valid plain/cipher command (a P or a space or C plus a 1 through 6) and/or a valid identi- fier  (1  through  6  alphanumeric  characters,  beginning with an alpha but excluding, E, C, C plus 1 through 6, and P). (5)    DEL.  This key is used to delete channel (pre- set) data from the frequency list. Scratchpadding valid data and depressing R2 will cause the frequency, plain/ cipher mode and fill data, and identifier for the scratch- padded channels to be deleted. Valid  channels  for  the  VHF-FM  transceiver  are  1 through 20 or C or E. NOTE Several  channels  can  be  deleted  at  once  by scratchpadding several channel numbers with a space between them. Scratchpadding 1 4 and depressing R2 will cause data channels 1 and 4 to be deleted. Scratchpadding 1-4 and depress- ing R2 will cause data in channels 1 through 4 inclusive to be deleted. 3-13.   EMERGENCY LOCATOR TRANSMITTER (ELT 110-4). a.   Description.  An automatic or manually activated emergency locator transmitter (ELT, fig. 3-6), is located in the left side of the aft fuselage. The associated anten- na is mounted on top of the aft fuselage. An access hole with spring-loaded cover is located in the fuselage skin adjacent to the transmitter, enabling a downed pilot to manually initiate or terminate operation, or reset the ELT to an armed mode. The transmitter contains a G switch which automatically activates the transmitter following a velocity change of 3.5 feet per second. When activated, the ELT will radiate omni-directional radio frequency sig- nals on the international distress frequencies of 121.5 and 243.0 MHz. The radiated signal is modulated with an audio swept tone. Internal batteries provide transmitter operation for a minimum of 50 hours at -20 C. b.   Remote Switch and Functions. The remote switch is accessible through a small (finger-size) spring loaded door,  located  on  the  left  side  of  the  aft  fuselage.  The remote switch is placarded ON - ARMED/RESET. (1)    ON.  Initiates emergency signal transmissions for test or for emergency purposes. (2)    ARMED/RESET.    Used  to  ARM  the  ELT  or reset it after an accidental activation. c.   Normal  Operation.  During  normal  operation  the remote switch is in the down (ARMED/RESET) position. d.   Emergency Operation. The ELT may be manually activated by moving the remote switch to the up (ON) position. e.   Resetting the ELT. If the ELT is activated accidently it will need to be reset. Do this by moving the remote switch up to the ON position and holding it there for one second, then immediately rocking it down to the ARMED/ RESET position, then releasing the switch.