Mission The United States of America Open Skies OC-135B
Observation Aircraft supports the Open Skies Treaty. The aircraft flies
unarmed observation flights over participating parties of the treaty.
Features
The aircraft is a modified WC-135B. The OC-135B modifications center
around four cameras installed in the rear of the aircraft. Since its
primary mission is to take pictures, most of the installed equipment and
systems provide direct support to the cameras and the camera operator.
Work on the aircraft also included installing an auxiliary power unit,
crew luggage compartment, sensor operator console, flight following
console and upgraded avionics.
The interior seats 35 people, including the cockpit crew, aircraft
maintenance crew, foreign country representatives and crew members from
the Department of Defense's Defense Threat Reduction Agency.
Cameras installed include one vertical and two oblique KS-87E framing
cameras used for low-altitude photography (approximately 3,000 feet above
the ground), and one KA-91C panoramic camera, which scans from side to
side to provide a wide sweep for each picture (used for high altitude
photography at approximately 35,000 feet).
The data annotation and recording system (DARMS) processes navigational,
altitude, time and camera signals to annotate each picture with correct
position, altitude, time, roll angle and other information. In addition,
this system records every picture taken according to camera, frame and
navigational position and downloads this data to a 3.5-inch floppy disk. A
keyboard with trackball is the input device for operation of this system.
Two Barco 12-inch VGA color monitors display camera annotation and other
camera data on screen for the sensor operator and observer use.
Camera control, located in the sensor operator's console, operates and
adjusts individual cameras for cloud cover, frame overlap and other
functions. The sensor operator console seats four and has all the
equipment listed above plus camera bay heating control, chronometers,
emergency oxygen, interphone and individual lighting. The flight following
console also seats four and includes most of the equipment listed above
except for DARMS and camera controls.
Seven commercial Norcoid Tek II coolers with individual refrigeration
units maintain temperature and humidity control to maintain peak film
performance. The units can be removed, if necessary, from the aircraft in
order to transport film. The coolers are capable of storing 40,000 feet of
film.
The aircraft flies on its intended flight path throughout the entire
mission with no reliance on ground-based navigation devices. A
top-of-the-line commercial system, Litton 92 INS/GPS, which is an
integrated inertial navigation system (INS) with a global positioning
system (GPS), provides continuous updates. The GPS updates the INS several
times per second to correct any deviations in the flight path. The INS
also feeds precise latitude, longitude, time, roll angle and barometric
altitude to the DARMS and camera systems. A true airspeed computer feeds
true airspeed data to the INS.
A combined altitude radar altimeter provides precise height above ground
information to the pilot for navigational purposes as well as a signal to
DARMS for film annotation. It is accurate from 0 to 50,000 feet above the
ground level. Plus, a metric altimeter is installed on the pilot's
instrument panel for altitude reference when flying in countries that use
meters for altitude reference.
The aircraft are being upgraded with the Block 30 Pacer Crag Navigational
System upgrade, a first step in making them compliant with ICAO mandated
Global Air Traffic Management and Global Air Navigation Standards
guidelines.
Other modifications support the aircrew. A gaseous oxygen system replaced
the liquid oxygen system to be more compatible with foreign airfields, and
fluorescent lighting system was added throughout the cabin to provide
adequate lighting for operation and inspections. Four upgraded seats with
a conference table, interphone, lighting and oxygen comprise the mission
commanders' station for both countries mission commanders. A four channel
interph
Background
The Open Skies Treaty was first proposed by President Dwight Eisenhower to
Soviet Premier Nikita Krushchev at the Geneva Conference of 1955. The
Soviets rejected the concept and it lay dormant for a generation. In May
1989, the U.S. reintroduced the idea of Open Skies as an instrument of
confidence building.
The Treaty enhances mutual understanding and confidence by giving all
participating countries, regardless of size, a direct role in gathering
information about military forces and activities of concern to them. It
permits short-notice, unrestricted aerial observation flights over the
territory of each signatory.
The aircraft are assigned to Air Combat Command at the 55 Wing, 45th
Reconnaissance Squadron, Offutt Air Force Base, Neb., for operations,
training and maintenance. When tasked, ACC 's role is to transport a DTRA
observation team to an Open Skies point of entry airport, and conduct the
observation flight, then return the team to the continental United States.
Three OC-135B were modified by the Aeronautical Systems Center's 4950th
Test Wing at Wright-Patterson AFB, Ohio. The first initial operational
capability OC-135B was assigned to the 24th Reconnaissance Squadron, at
Offutt AFB, Neb. in October 1993. It is now fitted with a basic set of
navigational and sensor equipment, and placed in inviolate storage at
Aircraft Maintenance and Regeneration Center at Davis Monthan AFB, Ariz.
Two fully operational OC-135B aircraft were delivered in 1996 with the
full complement of treaty allowed sensors, which includes an infrared line
scanner, synthetic aperture radar and video scanning sensors.
General Characteristics Primary Function: Support Open Skies Treaty Contractor: Boeing Military Airplanes Div. Power Plant: Four Pratt & Whitney TF33-P-5 Turbofans with
thrust reversers Thrust: 16,050 pounds (7,222.5 kilograms) each engine Speed: 500+ miles per hour (Mach.66) Unrefueled Range: 3,900 miles (6,500 kilometers) Length: 135 feet
(41.1 meters) Height: 42 feet (12.8 meters) Maximum Takeoff Weight: 297,000 pounds (133,633 kilograms) Wingspan: 131 feet (39.9 meters) Crew: Flight: Seven (Augmented crew) - three pilots, two
navigators, and two sensor maintenance technicians
DTRA mission flight crew: one mission commander, one deputy mission
commander, two sensor operators and one flight follower Date Deployed: June 1993 Inventory: Active force, 3 (1 in flyable storage); Reserve, 0;
Guard, 0
