CLASSIFICATION: UNCLASSIFIED// 
ROUTINE 
R 012058Z MAR 23 MID200080774560U 
FM CNO WASHINGTON DC 
TO NAVADMIN 
INFO CNO WASHINGTON DC 
BT 
UNCLAS 
 
NAVADMIN 061/23 
 
MSGID/NAVADMIN/CNO WASHINGTON DC/N4/MAR// 
 
SUBJ/READINESS BASED SPARING - INTERIM CHANGE (CORRECTED COPY)// 
 
REF/A/DOC/OPNAV/17NOV2022// 
NARR/REF A IS OPNAVINST 4442.5B, READINESS BASED SPARING// 
 
POC/CAPT ANDREW OSWALD/OPNAV N4L/CNO WASHINGTON DC/TEL: (703) 695-4758/EMAIL: 
ANDREW.J.OSWALD2.MIL@US.NAVY.MIL// 
 
RMKS/1.  Purpose.  Pending formal amendment to reference (a), this interim 
change adds a new readiness threshold to reference (a).  This interim change 
is effective upon the release of this message. 
 
2.  Background.  Endurance supply measures the days a system remains fully 
operational without an off ship requisition. 
 
3.  Changes.  Endurance supply (Es) is added to amend reference (a), 
subparagraph 3a.  Reference (a), subparagraph 3a is hereby amended and will 
read as follows: 
    a.  This instruction describes the application of readiness based sparing 
(RBS) methodology to spares and repair parts allowance determination to 
ensure that prescribed readiness thresholds and objectives at the lowest 
possible cost. RBS thresholds are expressed as operational availability (Ao); 
or full mission-capable (FMC) and/or mission capable rates.  Per reference 
(a), the term RBS applies to single echelon and single indenture systems, as 
well as their multi-echelon and multi-indenture extensions, where applicable. 
RBS applies to all methods of product support whether by organic or 
commercially provided practices.  In addition to these measures, Es may be 
used for the systems listed below and will use readiness thresholds to 
include Es RBS: 
        (1) AG9140 Ship Service Gas Turbine Generator (SSGTG) 
        (2) AN/SLQ-32(V)6 and SLQ-32(V)7 Electronic Warfare Suites 
        (3) AN/SPG-62 Fire Control Radar (Illuminators) 
        (4) AN/SPQ-9B Radar 
        (5) AN/SPS-73(V)18 Radar 
        (6) AN/SPS-75 Search Radar 
        (7) AN/SPS-77 Search Radar 
        (8) AN/SPY-1D and SPY1D(V) Radars 
        (9) AN/SQQ-89 Naval Anti-submarine Warfare (ASW) System 
        (10) AN/WSC-9A(V)3 Satellite Comms (Navy Multi-Band Terminal, NMT) 
        (11) Fairbanks Morse Ship Self Service Generators (SSDGs), all 
variants 
        (12) High Pressure Air Compressors (HPACs), all variants 
        (13) LCS-2 Class Waterjets, all variants 
        (14) LM2500 Gas Turbine Module (GTM) 
        (15) LPD-17 Class Electrical and Machinery Control Systems (ECS-MCS) 
ECS-MCS 
        (16) LPD-17 Class Main Propulsion Diesel Engines (MPDEs), all types 
        (17) Mk 110 57mm Gun 
        (18) Mk 15 Phalanx CIWS SeaRAM Variant 
        (19) Mk 15 Phalanx Close-in Weapon Systems (CIWS) 
        (20) Mk 41 Vertical Launching System (Mk 41 VLS) 
        (21) Mk 57 NATO SEASPARROW Missile System (NSSM) 
        (22) MT30 (LCS-1 Class GTM) 
        (23) MTU 20V 8000 Series (LCS-2 Class MPDEs) 
        (24) Ship Self-Defense System (SSDS) 
        (25) Shipboard Air Conditioning Plants, all variants 
        (26) Shipboard Refrigeration Systems, all variants 
        (27) Ships Signal Exploitation Equipment Increment Echo & Foxtrot 
(SSEE INC E & F) 
        (28) Unmanned Aerial Vehicle (UAV) Common Automatic Recovery System 
(UCARS) 
 
4.  This interim change will be incorporated into the next revision of 
reference (a). 
 
5.  Released by VADM R. L. Williamson, CNO N4.// 
 
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