less frequently scheduled requirements are divided equally between the odd and even inspections, when practical, to provide a balanced calendar inspection workload. Normally, the first calendar inspection performed on a new aircraft or the first inspection performed after SDLM is an odd calendar inspection. The second inspection performed is an even calendar inspection. Subsequent calendar inspections repeat the same odd-even cycle.

PHASED INSPECTION. - The concept of this inspection is to divide the total scheduled maintenance requirements into small packages (phases) of approximately the same work content. These phases are accomplished sequentially (in order) at specified intervals. The completion of all the required phases at their specified interval completes the phased inspection cycle. The cycle is repetitive for the service life of the aircraft and is not interrupted during SDLM.

ZONAL INSPECTION. - This inspection is a general inspection of a specific area of an aircraft at a scheduled interval. During a zonal inspection, the aircraft is inspected for obvious defects such as leaks, frayed cables, cracks, corrosion, or physical damage. These inspections are normally performed in conjunction with other scheduled maintenance tasks by the rating assigned.

AIRCRAFT SERVICE PERIOD ADJUSTMENT (ASPA) EVALUATION. - This is a conditional maintenance action that is a depot-level evaluation of an aircraft's general material condition. The evaluation is performed by a certified ASPA evaluator and consists of record/logbook analysis and a physical aircraft examination. Upon completion of the inspection, the ASPA evaluator may recommend the following.

The aircraft period end date/operating service months (PED/OSM) be adjusted 12 months (or equipment flight hours) beyond the current PED or 18 OSM from the date of the ASPA inspection, whichever is less.

The aircraft be inducted for rework or preservation not later than 90 days after the current PED.

The aircraft be inducted into rework immediately, and the service tour be terminated.

NOTE: OPNAVINST 3110.11 requires an ASPA evaluation between 6 months prior to and 3 months after the PED of each ASPA aircraft. The 3-month window after the PED can only be allowed when no depot-level structural life-limited items will expire during that period.

DEVIATIONS TO INSPECTIONS. - It may not always be possible to perform a given inspection on the exact date or at the exact number of hours for which the inspection is scheduled. To meet these situations and to aid in workload scheduling, the following inspection deviations may be applied:

1. For inspections (except calendar) performed in increments of calendar days, a deviation of plus or minus 3 days maybe applied to the authorized inspection interval. The next inspection due is scheduled as if NO deviation had occurred.

2. For inspections performed in increments of flying hours, operating hours, cycles, or events, a deviation of plus or minus 10 percent (or any portion of 10 percent) may be applied to the authorized inspection interval. The next inspection is scheduled as if NO deviation had occurred.

3. A deviation of plus or minus 1 week (or a portion of the week) may be applied to the authorized calendar inspection interval. The next calendar inspection is scheduled as if NO deviation had occurred.

4. If it becomes necessary to accomplish an inspection earlier than the allowed deviations, the next inspection is due based on the date/hour/ cycles that the inspection began, and a logbook entry is required.

5. If it is necessary to exceed the deviations listed above because of priority operational commitments, a request should be submitted to the ACC. If this type of deviation is authorized, the next inspection is scheduled as if NO deviations had occurred, and a logbook entry is required.

FUNCTIONAL CHECK FLIGHT (FCF) RECORDS

After a calendar inspection has been performed on a Navy aircraft, a functional check flight is required to verify the maintenance performed. The check flight must be accomplished after all of the necessary ground checks are completed, and before the aircraft is released for operational use. A functional check flight is