Identify the hoisting requirements for naval
calibrated accuracy, the scale should be repaired. Enter
aircraft.
the tare on the Aircraft Weighing Record, DD Form
365-2. Stow the equipment.
There are three main conditions that might require
you to hoist an aircraft or its components. They are
All aircraft must be weighed and balanced upon
aircraft mechanical problems, ship mechanical
completion of standard depot-level maintenance
problems, and aircraft mishap afloat or ashore. Aircraft
(SDLM). Aircraft should also be weighed and balanced
lifting slings are specialized items of support
under the following conditions:
equipment whose function is to aid in the hoisting of
1. When service changes, modifications, or
aircraft and aircraft components. Each airframe has
repairs are accomplished and calculated, or actual
structural lifting points for the attachment of a sling
weight and moment data for these changes are not
designed to lift that aircraft or aircraft subassembly.
available
Slings are used to hoist aircraft from the pier to carrier
2. When recorded weight and balance data is
deck, clear crash-damaged aircraft, and to remove and
suspected of being in error
install engines and other components during
3. When unsatisfactory flight characteristics are
maintenance operations. In general, slings are hand
reported by the pilot that cannot be traced to a flight
portable and attach to a single suspension hook of a
control system malfunction or improper aircraft
crane or other hoisting equipment.
loading
4. When the "Weight and Data" handbook has
LIFTING SLINGS IDENTIFICATION
been lost or damaged
Aircraft lifting slings are constructed in accordance
BALANCE
with Military Specification MIL-S-5944, and can be
classified under four types of construction or
An aircraft is said to be in balance, or balanced,
combinations of type. The four types are the wire rope,
when all weight items in, on, or of the aircraft are
the fabric or webbing type, the structural steel or
distributed so that the longitudinal center of gravity (cg)
aluminum type, and the chain.
of the aircraft lies within a predetermined cg range.
This range is defined by the most forward and aft
Wire Rope
permissible cg locations, which are called the forward
and aft cg limits, respectively. To determine if an
Slings of this type employ wire rope or cable. The
aircraft is balanced, the aircraft cg must be calculated
wire rope sling is the most common type, and it
and compared to the forward and aft cg limits for that
combines high strength, ease of manufacture, and a
particular configuration and gross weight.
great deal of flexibility for compact storage. There are
two basic types of wire rope slings. The simplest is a
Q1-28.
What characteristics of an aircraft are
multi-legged wire rope sling with an apex-lifting link.
directly dependent upon its weight and
The other is one built with structural steel or aluminum
balance condition?
in combination with wire rope supports. See figure
Q1-29.
What technical manual covers weight and
1-19.
balance?
Q1-30.
What is the standard method used by the Navy
for weighing aircraft?
Q1-31.
How often must heavy-duty portable scales
and MEWS scales be calibrated?
Q1-32.
What is the minimum time required for an
electronic scale to warm up?
Q1-33.
What actions must be accomplished if the
Weight and Data Handbook is lost?
AIRCRAFT HOISTING SLINGS
LEARNING OBJECTIVE: Recognize the
different types of aircraft hoisting slings.
Figure 1-19.--Wire rope slings.
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