All  alterations  are  managed  through  the  fleet modernization  program. Modifications Most  changes  to  electronic  equipment  are modifications  called  electronic  field  changes  (FC) (previously  called  electronic  alterations).  The  basic purpose of a field change is to improve performance, reliability,  maintenance,  operational  characteristics,  or safety. The type designator indicates how complete the change  package  is.  Some  packages  contain  all  necessary instructions,  parts,  and  tools.  Other  packages  contain only instructions. The four types are defined below: Type  I. Requires parts, all of which are included in the FC kit. Also included in the kit are the publication package changes and the materials  and  special  tools  required  to change  one  equipment  and  to  revise existing   equipment   nameplates, publications,  and  charts. Type  II. May require parts, none of which are included with the field change. This type of   FC   usually   affects   only   the publications package. If parts and tools are   required,   they   are   considered standard stock items and are available as bench spares (for example, wire, lugs, soldering irons, and so on). Type  III.    Requires  parts,  some,  but  not  all,  of which are included in the field change kit.   The   parts   not   included   are considered standard stock items. Type  IV.    Does  not  require  parts  or  use  of  any special tools. This type of FC is usually published in an EIB article and consists of only a publications change. There  are  three  classes  of  field  changes.  The  class designator indicates who is responsible for the funding and installing of the FC. Class A. Modification  may  be  made  by  forces afloat   or   station   personnel;   no installation   funding   is   required. Approval of Class A field changes to be made by forces afloat indicates only that the  work  content  is  within  their technical   capability.   The   Class   A designation  does  not  require  the modification,  nor  does  it  require  forces afloat  to  make  the  modification.  The decision of when and how to make the modification is considered to be a forces afloat   prerogative. Class B. Requires fleet funding for and work by naval  shipyards,  tenders,  and  so  on, when   authorized   by   the   TYCOM. Except   for   Class   B   field   changes presently  under  way  or  in  the  fleet planning  stage,  this  type  of  field  change will no longer be issued. Class C. Normally requires industrial assistance and requires the appropriate systems command installation funding. SAFETY Most  accidents  are  preventable.  However,  through ignorance  or  misunderstanding,  there  is  a  common belief   that   accidents   are   the   inevitable   result   of unchangeable circumstances or fate. This belief fails to consider  the  basic  law  of  cause  and  effect.  In  other words, accidents do not occur without a cause; most accidents are the direct result of some deviation from prescribed  safe  operating  procedures. A  preventable  accident  may  be  traced  to  an ingrained belief or work habit of an individual. This belief or work habit may cause the individual to perform an unsafe act or permit a hazardous condition to exist; when an accident occurs, the cause-and-effect sequence is  completed. One purpose of safety rules is to remind personnel of the dangers inherent in their work. Training in the observance   of   safety   precautions   can   help   avoid preventable  accidents  and  encourage  the  maintenance of   an   accident-free   work   environment.   Operating procedures and work methods should stress hazard prevention  so  that  personnel  do  not  expose  themselves unnecessarily to injury or occupational health hazards. You  can  prevent  accidents  that  are  about  to  happen  if you  are  alert  to  causes  and  take  appropriate  remedial action. SAFETY  TRAINING As  a  leading  ET,  you  have  safety-related responsibilities that may be grouped into three general areas as follows: 1.   Responsibilities   concerning   the   electronics division.  These  responsibilities  include  ensuring that all personnel in the division are aware of and observe  all  shipboard  safety  precautions, 2-23