TB 1-1520-238-20-102
(2) Ferry Status.
(a) Same as paragraph 1.a.
(b) Those aircraft that have a DD 250 and are at the Boeing Mesa facility will be inspected prior to ferry
to final destination.
e. Maintenance Trainers (Category A and B). Same as paragraph 1.a.
f. Component/Parts in Stock Including War Reserves at All Levels (Depot and Others). Upon receipt of this
message, the material condition tags of all items in all condition codes listed in paragraph 7 shall be annotated to read
"TB 1-1520-238-20-102, AH-64A/D Inspection of BUCS Servocylinders for Application of Sealant Not Complied With."
(1) Wholesale Stock. Same as paragraph 1.f.
(2) Retail Stock. Same as paragraph 1.f.
g. Aircraft at the Boeing Mesa production facility will be inspected by the contractor.
2. Task/Inspection Suspense Date . Five working days from receipt of this message.
3. Reporting Compliance Suspense Date . No later than 15 working days from the date of this message, per paragraph
4. Summary of the Problem.
a. Investigation into a BUCS activation in-flight has revealed a suspect condition in the BUCS AH-64A and AH-64D
servocylinders. The servocylinder contains a linear variable differential transducer (LVDT) which may move out of an
electrical null position. The LVDT transmits the position of the piston to the digital automatic stabilization equipment
computer (DASEC) or flight management computer (FMC). If the LVDT probe moves out of the null condition, this will
cause a BUCS system activation. Application of sealant to the LVDT threads eliminates this condition.
b. For manpower/downtime and funding impacts, see paragraph 12.
c. The purpose of this TB is to direct that sealant be applied to AH-64A and AH-64D BUCS servocylinders which do
not have the sealant.
5. End Items To Be Inspected. All AH-64 series BUCS active aircraft.
6. Assembly Components To Be Inspected. N/A.
7. Parts To Be Inspected.
a. Lateral/Collective Servocylinder.
PARKER HANNIFIN PART
MDHS PART NUMBER
NATIONAL STOCK NUMBER
NUMBER
289300-1019
7-311820011-13
289300-1017
7-311820011-11
289300-1015
7-311820011-9
289300-1009
7-311820011-7
289300-1007
7-311820011-5
2
