Effects of Depleted Uranium Weapons
Federal Aviation Administration Circular
(Text version see below)
                                                  Avoiding or Minimizing Encounters with Aircraft Equipped with
    Depleted Uranium Balance Weights During Accident Investigations

Depleted Uranium Weapons


AC 20-123
Avoiding or Minimizing Encounters with Aircraft Equipped with
Depleted Uranium Balance Weights During Accident Investigations

DATE: Dec 20, 1984

Initiated: AWS-330

1. PURPOSE. This advisory circular provides information and guidance to
individuals who come in contact with depleted uranium contained in aircraft
control surfaces during accident investigations.

2. RELATED READING MATERIAL. Additional information on depleted uranium may
be found in the maintenance manual of each affected aircraft and also in
service information provided by the aircraft manufacturer.

3. DISCUSSION. For many years, aircraft manufacturers have used "depleted"
uranium to balance ailerons, rudders, and elevators on certain jet aircraft
and rotor blades on certain helicopters. Uranium is 1 1/2 times as dense as
lead and is the heaviest naturally occurring metal. According to a 1983
McDonnell Douglas Customer Service First Quarter publication, only
"depleted" uranium is used, which means it has been processed to remove most
of its uranium 235, the most highly radioactive form used in nuclear
powerplants. The remaining uranium 238 emits only low-level alpha radiation.
While the depleted uranium normally poses no danger, it is to be handled
with caution. The main hazard associated with depleted uranium is the
harmful effect the material could have if it enters the body. If particles
are inhaled or digested, they can be chemically toxic and cause a
significant and long lasting irradiation
of internal tissue. Depleted uranium is slightly radioactive. To minimize
radiation hazards, depleted uranium balance weights are 100 percent cadmium
plated during the manufacturing process. If the cadmium plating is intact,
normal handling of the parts is considered to be non-hazardous and no
special precautions are recommended. The use of radioactive materials in
many every day applications is not at all unusual. For example, tritium, a
radioactive form
of hydrogen, is used in self-luminous signs, such as exit signs, and
watches. Thorium, which has a radiation activity level comparable to
depleted uranium, is used in making gas mantels for lanterns, electronic
equipment, and high quality optical lenses for cameras and overhead
projectors. Also, smoke detectors contain americium 241, a radioactive
material.

4. PRECAUTIONS.

a. Avoid contact with balance weights using depleted uranium. On arrival at
accident scenes
of aircraft suspected of containing balance weights made of depleted
uranium, determine if balance weights have been damaged or lost their
cadmium plating coating. Request specialized assistance if balance weights
have been damaged or lost their cadmium plating. No penetration of the
plating is allowed.

b. Avoid breathing or swallowing particles of balance weights found damaged
or with cadmium plating damaged or lost.

c. If it becomes necessary to handle balance weights, the following
precautions should be observed:

(1) Personnel handling the balance weight should wear gloves.

(2) Industrial eye protection should be worn.

(3) Respirator mask should be worn to ensure no radioactive dust particle
ingestion.

d. Gloves, wrapping material, wiping cloths, respirator filters, or any
other articles used in the handling of damaged balance weights should be
discarded and appropriately labeled as radioactive waste and disposed of
accordingly.

M.C. Beard
Director of Airworthiness


Issues on the Use and Effects of Depleted Uranium Weapons