TM l-1500-328-23
(2) The tolerance window for flying hour inspections with an
interval of 50 hours or more is 5 hours.
For example, if an
inspection has an interval of 75 hours and is due at 1609.4 aircraft
hours the tolerance window starts at 1604.4 hours and ends at 1614.4
hours.
If the inspection is completed anywhere in that hour range
(1604.4 -- 1614.4) the next inspection due time will be 1684.4 (1609.4
+ 75 = 1684.4) aircraft hours.
(3) Flying hour special inspections completed outside of the
tolerance window are out of scheduled sequence for that specific
period.
If the inspection is completed outside of the tolerance
window the next inspection due time will be obtained by adding the
inspection interval to the hours on the aircraft when the inspection
was completed.
For example, if an inspection with a 50-flight hour
interval is due at 1306.4 (tolerance window of 1301.4 to 1311.4 hours)
and the inspection is completed at 1299.9, the next inspection due
time will be 1349.9 (1299.9 + 50 = 1349.9) aircraft hours.
b.
Tolerance window for calendar based special inspections
(inspection due dates entered in block 8 of a DA Form 2408-18 must
include the day, month and year for all calendar inspections):
(1) The tolerance window for inspections with an interval of less
than 12 months (300 days) is obtained by multiplying the number of
days in the inspection interval by 10 per cent.
For example, the
tolerance for a six-month interval would be plus or minus 18 days (180
Therefore, if the inspection due date is 31 January
days X 10% = 18).
1999 the tolerance window starts on 13 January 1999 and ends 18
If the inspection is completed anywhere in that time
February 1999.
frame (13 Jan -- 18 Feb) the next inspection due date will be 31 July
1999.
(2) The tolerance window for inspections with an interval of 12
months or more (over 300 days) is 30 days.
For example, an inspection
with an interval of 12 months and is due on 6 February 1999 the
tolerance window starts on 7 January 1999 and ends 8 March 1999. If
the inspection is completed anywhere in that time frame (7 Jan -- 8
Mar) the next inspection due date will be 6 February 2000.
(3) Calendar inspections completed outside of the tolerance
If the
window are out of scheduled sequence for that specific period.
inspection is completed outside of the tolerance window the next
inspection due date is obtained by adding the inspection interval to
For example, if an inspection
the date the inspection was completed.
with a six-month interval is due on 31 January 1999 (tolerance window
of 13 Jan to 18 Feb) and the inspection is completed 11 January 1999,
the next inspection due date will be 11 July 1999.
Tolerance window for special inspections on a dual criteria
The same guidelines apply when
hours/calendar time).
inspections, checks, or services, are scheduled using the dual
