Aircraft Model. The model designation is entered in the first space at the top left of the card; for example, A-7E, F-14B, or F/A-18A. Bureau number (BUNO). Enter the six-digit BUNO assigned to that particular aircraft. Each aircraft is assigned a BUNO for identification and record purposes. This number remains with the same aircraft from acceptance by the Navy until the aircraft is retired or stricken from the Navy inventory. The number is not reused or reissued to another aircraft. Received From and Transferred To. These two blocks are self-explanatory. As long as the aircraft is in the custody of the reporting custodian that maintains the "A" card, only the “Received From” line is filled in. When the aircraft is transferred, the “Transferred To” line is completed, and the card is moved to the inactive "A" card file for 12 months. Permanent Unit Code (PUC). The second line at the right side shows the present reporting custodian and Permanent Unit Code. The next group of blocks provides data about the current aircraft operating service life. NOTE: When a new aircraft is accepted, it is known that the aircraft will go eventually to a depot maintenance activity for rework. This occurs after the aircraft has accumulated a predetermined number of operating service months (as opposed to calendar months) or flight hours (in some cases). This operating interval is known as the operating period. The period number is entered in the Period block. When the aircraft returns to an operating status after standard rework, it acquires a new period number. The new period number may be transcribed from the Monthly Flight Summary (MFS) form of the aircraft logbook. The PED is inserted in the space labeled PED. The PED can also be obtained from the MFS form, or computed by using procedures outlined in OPNAVINST 5442.2. The OPSERMOS accumulated as of the PED is entered in the space next to the PED. OPSERMOS should be computed by using procedures outlined in OPNAVINST 5442.2. A corresponding section (Planning Factors for Model for Period) is set aside to record operating serv- ice period planning factors as they relate to the period. The operating service period (OSP) is the specified length of a period either defined as months or flight hours. OSP, operating service life (OSL), and utilization rates (if applicable) for specific aircraft can be found in OPNAVINST 3110.11. The OSL is the specified length, in months, that an aircraft is programmed for total service with the Navy. NOTE: The interval between PEDs is regulated by the CNO and varies with different models of aircraft. Period lengths may also be changed as data on service experience accumulate. The data may indicate that a given aircraft model is so well constructed that it can operate for longer periods of time between SDLMs. The opposite is also true, and period lengths may be shortened as well. Aircraft are not operated after the last day of the month of their PED unless specific permission for an extension has been granted by higher authority. Refer to the latest edition of OPNAVINST 3110.11 for more information on OSL, OPSERMOS, and OSP for specific type/model/series aircraft. The lower left portion of the front side of the "A" card is used to record OPNAV XRAY reportable actions submitted on an aircraft. OPNAV XRAY reports that report change of location, fleet assignment, or operational status of an aircraft are NEVER recorded on the Aircraft Record “A” card. Reportable actions should be posted to the card as they occur. The following is a description of each block: The OPNAV XRAY serial number is entered in the first block. The OPNAV XRAY serial number is the same serial number as the serial number of the corresponding OPNAV XRAY report. The Date of Action is next. The date must appear exactly as it does in item "C" of the OPNAV XRAY report, that is as a six-digit month, day, and year date. The ACT block is a coded letter used to identify the type of action reported. Remember, Action codes fall into two separate categories—Action codes that report changes in custody and Action codes that report an ac- tion other than change in custody. At any rate, the Ac- tion code recorded here should match the same Action code reported in the applicable OPNAV XRAY report. The Status Code block contains the current aircraft status and indicates the classification of the use or condition of an aircraft. The PED block reflects the current projected PED of the aircraft. The EXT block is used for recording an extension to the present aircraft service period. Extensions are 7-19