DEPARTMENT OF THE NAVY
NAVAL AIR SYSTEMS COMMAND
WASHINGTON, D.C. 20361

Canc frp: Jul 77

IN REPLY REFER TO
NAVAIRNOTE 13100
AIR-5304

1 Nov 1976

NAVAIR NOTICE 13100

From: Commander, Naval Air Systems Command

Subj: Definition of terms for aircraft modification and life extension; promulgation of

1. Purpose. To. establish categories of effort with corresponding definitions, so that ambiguities of terms, when discussing aircraft life extension, can be eliminated.

2. Background. Because of continuing fiscal constraints on procurement of new aircraft, the need to extend the lives of Navy aircraft is becoming an increasingly common alternative towards attaining operational aircraft inventories to meet OPNAV force level/threat requirements. In many cases this has required extraordinary action, including extensive fatigue testing, to insure that adequate safe structural life can be made available for the intended additional years the aircraft is required for service. Originally, life extension was predicated solely on fatigue life, which is a first consideration. In many cases, however, due to the environment to which the aircraft is exposed, the material condition may be the life limiting factor since it could significantly reduce the structural integrity of the aircraft. Two terms, Service Life Extension Program (SLEP), and Conversion in Lieu of Procurement (CILOP) have been identified with the ever-increasing process of life extension. These terms continue to be used interchangeably in some areas, and in others, the meanings are expanded or contracted to meet a particular situation.

3. Policy. To establish definitions which have been accepted both at the Congressional and D0D level for the two recognized life extension processes, the following definitions are set forth:

a. CILOP -- Conversion in Lieu of Procurement. CILOP is any conversion, service life extension, update, expansion/change of mission capability, improvement of combat capability or combination of the foregoing. CILOP is performed on existing aircraft for the primary purpose of providing a reasonably acceptable, modernized aircraft, as an alternative to procuring new aircraft, to meet or maintain force levels.

b. SLEP - Service Life Extension Program. SLEP, as one element of a CILOP, is the restoration and/or replacement of primary aircraft structure which has reached its life limit. SLEP is performed for the express purpose of establishing an increased service life. The Naval Air Systems Command (NAVAIR) will determine the duration of the service life extension that will be attained by accomplishment of the SLEP.

4. Action. When budgeting and programming actions are taken relative to extending programmed lives of aircraft or increasing their operational capability, the definitions herein established will be used. This should eliminate most ambiguity as to what action is required and where the ultimate responsibility lies.

5. Cancellation Contingency. This notice may be retained for reference purposes.

/S/
F. H. BAUGHMAN
Vice Commander

Distribution : (2 copies each)

(The Distribution List was not OCRed due to it being irrelevant.)