C H A P T E R 1
I N T R O D U C T I O N
1-1. Scope. This manual is for your use in operating
and maintaining the aviation unit maintenance shop set
and equipment mounted in the portable shelter. It pro-
vides the necessary information about the shelter,
storage for the tools, equipment and working space for
personnel performing aviation unit maintenance of air-
1-2. Maintenance Forms and Records. Mainte-
nance forms and records which you are required to use
are listed and explained in DA PAM 738-751.
1-3. Administrative Storage. Refer to TM 740-90-1
for storage requirements.
1-4. Calibration. There are several items in the
AVUM No. 2 shop set which require periodic calibra-
tion, for example, torque wrenches, dial indicators, etc.
This equipment should be calibrated in accordance
with procedures and practices contained in TB 43-180.
1-5. Quality Assurance/Quality Control (QA/QC).
There are no quality assurance/quality control
manuals pertaining to this material.
1-6. Destruction of Material to Prevent Enemy Use.
Refer to TM 750-244-3 for procedures concerning
destruction of this material.
1-7. Reporting of Equipment Improvement Rec-
ommendations (EIR). If your tool set company size,
set No. 2 airmobile needs improvement, let us know.
Send us an EIR. You, the user, are the only one who
can tell us what you dont like about your equipment.
Let us know why you dont like the design or per-
formance. Put it on an SF 368 (Product Quality
Deficiency Report). Mail it to the address specified
in DA PAM 738-751.
Section Il. DESCRIPTION AND TABULATED DATA
a. Refer to TB 43-0124 for the basic description of
the portable S-280 shelter.
b. Each S-280 shelter is modified per drawing
4920-EG-056 (figure D-2) to a shelter suitable for avia-
tion unit maintenance.
c. Each 4920-EG-056 shelter (figure D-2) is further
modified per drawing 4920-EG-054 (figure D-1) to a
common AVUM No. 2 shelter.
d. The 4920-EG-054 AVUM No. 2 shelters (figure
D-1) are then finished per drawing 4920-EG-057 (figure
D-3) into three specific configurations which make up
the AVUM No. 2 complex.
1-9. Shelter Features.
a. A hook to assist in balancing tail rotors is
installed in the No. 1 shelter of each complex.
Loads exceeding 75 pounds should not
be applied to ceiling hook.
b. Mobilizer brackets are installed on all shelters
per drawing 4920-EG-080 (figure D-6) to allow ground
handling with the M-720 dolly set. Details on
the use of the M-720 dolly set can be found in
Assistance in troubleshooting the elec-
system is available by referring to drawings
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