Page 215 - Challenges in Corrosion Costs Causes Consequences and Control(2015)

CORROSION PROBLEMS IN THE US DEPT. OF DEFENSE 193

In February 2000, the Army released a report indicating that 40% of the helicopter
fleet is not combat ready. In addition, these problems are experienced particularly with
aging equipment such as the Vietnam War–era Hueys and Cobras, which are assigned
mostly to the National Guard and the Army Reserve Units. In addition, newer heli-
copters, such as the Apaches and Chinooks, also suffer from combat-readiness prob-
lems. Approximately 8–22% of overhaul and repair costs are because of corrosion. In
fact, it was estimated that in 1998, approximately $4 billion was spent on the corro-
sion control of helicopters alone (J Argento, US Army TACOM-ARDEC, Picatinny
Arsenal, NJ, Personal Communication, 1999).

3.31.6 Air Force
As the fleet of military aircraft and support equipment ages, the damage caused by
corrosion becomes an increasing concern. The aircraft spend a longer time in depots
for maintenance and repair, which leads to a decrease in readiness and an increase in
cost to maintain the aircraft. Moreover, a possible loss of integrity of the structure is
possible if the corrosion goes undetected and becomes severe.
Recently, a study was done for the Air Force Corrosion Program Office to
determine the annual cost of direct maintenance to the Air Force (48). The Air Force
study examined the cost for the fiscal year 1996 and examined costs for all Air Force
systems and equipment, including all aircraft, aircraft subsystems, ground systems,
vehicles, missiles, munitions, ground support equipment, and space equipment.
Corrosion maintenance was defined as a comprehensive inspection for corrosion, all
repair maintenance because of corrosion, washing sealant application and removal,
and all coating applications and removal. Intangible or indirect costs, such as aircraft
downtime, and the depreciation effects that result from corrosion maintenance, such
as repeated grind-outs of skin and structure, were not addressed in the study. Other
intangible or indirect costs that were not addressed include the costs of building cor-
rosion control facilities; the cost of building and maintaining formal corrosion main-
tenance schools for training of maintenance technicians, and the cost to produce, dis-
tribute, and install specialized corrosion control equipment in corrosion control shops.
The total cost of direct corrosion maintenance to the US Air Force for fiscal year
1997 was estimated at approximately $800 million (48; Table 3.19).
The table clearly indicates that the major portion of the cost can be attributed to
aircraft repair and paint. Significant amounts are also spent on washing and vehicle
maintenance. In addition to the total cost findings, it was found that maintenance in
the depot accounted for 80% of the total cost of corrosion maintenance. While the
total number of aircraft in the fleet decreased by 20%, the costs decreased by only
10%, and the maintenance costs have increased.
The data presented in Table 3.20 show the effect of aging on weapon system costs.
The difference in age and size has an effect on the cost of aircraft.

3.31.7 KC-135 Stratotanker
This is a strategic air refracting tanker built by the Boeing Company, which can also
be used as a cargo carrier or troop transport. The first KC-135 entered the Air Force