OC-135 Open Skies

On 04 June 2021 OC-135B aircraft — known to crew members by its tail number, 61-2670 — retired, marking the end of one of the last vestiges of post-Cold War military cooperation between the U.S. and Russia. The other plane, bearing the tail number 61-2672, was retired in May 2021. The aircraft had been used since the mid-1990s for aerial photography missions over other countries as part of the 34-nation Open Skies Treaty.

"The United States regrets that the Treaty on Open Skies has been undermined by Russia's violations. In concluding its review of the treaty, the United States therefore does not intend to seek to rejoin it, given Russia's failure to take any actions to return to compliance. Further, Russia's behavior, including its recent actions with respect to Ukraine, is not that of a partner committed to confidence-building," a State Department spokesperson said 27 May 2021.

On 22 May 2020 candidate Joe Biden said "In announcing the intent to withdraw from the Open Skies Treaty, President Trump has doubled down on his short-sighted policy of going it alone and abandoning American leadership.... The transparency it provides is particularly important for countries that do not have their own satellite imaging capabilities. I supported the Open Skies Treaty as a Senator, because I understood that the United States and our allies would benefit from being able to observe — on short notice — what Russia and other countries in Europe were doing with their military forces. That has remained true for the nearly two decades the treaty has been in force....

"There are real concerns that Russia is not complying fully with the Treaty. It has improperly imposed restrictions on overflights over certain regions (Kaliningrad and the Russian-occupied regions of Abkhazia and South Ossetia in Georgia), to which the United States and other parties have objected. These Russian violations should be addressed not by withdrawing from the Treaty, but by seeking to resolve them through the Treaty’s implementation and dispute mechanism....

"Our allies have made clear they want us to remain in the Treaty, and to work together to address compliance issues with Russia. Without us, the Treaty could crumble. Withdrawal will exacerbate growing tensions between the West and Russia, and increase the risks of miscalculation and conflict."

Senate Foreign Relations Committee Ranking Member Bob Menendez (D-N.J.) was joined by Senate Democratic Leader Chuck Schumer (D-N.Y.), Ranking Member of the Senate Armed Services Committee Jack Reed (D-R.I.) and Vice Chairman of the Senate Select Committee on Intelligence Mark Warner (D-Va.) in sending a strong rebuke to the Trump Administration for the President’s decision to unilaterally withdraw the United States from the Open Skies Treaty. “The timing of your decision — less than five months before an election — is also suspect. Beginning the U.S. withdrawal from the Open Skies Treaty, without complying with U.S. domestic law or constitutional practice, is an obvious political maneuver in an attempt to bind a future administration,” wrote the Senators in a letter addressed to Secretary of State Mike Pompeo and Secretary of Defense Mark Esper. “As such, we demand that you immediately discontinue your efforts to initiate the withdrawal process until Congress is provided with the requisite notification under the NDAA, and the Senate has had an opportunity to weigh in on the withdrawal.”

On 21 May 2020 the United States submitted notice of its decision to withdraw from the Treaty on Open Skies to the Treaty. US Secretary of State Mike Pompeo said "Russia’s implementation and violation of Open Skies, however, has undermined this central confidence-building function of the Treaty – and has, in fact, fueled distrust and threats to our national security – making continued U.S. participation untenable.... Russia has flagrantly and continuously violated the Treaty in various ways for years.... Russia has refused access to observation flights within a 10-kilometer corridor along its border with the Russian-occupied Georgian regions of Abkhazia and South Ossetia, thereby attempting to advance false Russian claims that these occupied territories are independent states. Russia’s designation of an Open Skies refueling airfield in Crimea, Ukraine, is similarly an attempt to advance its claim of purported annexation of the peninsula, which the United States does not and will never accept. Russia has also illegally placed a restriction on flight distance over Kaliningrad, despite the fact that this enclave has become the location of a significant military build-up that Russian officials have suggested includes short-range nuclear-tipped missiles targeting NATO. In 2019, Russia unjustifiably denied a shared United States and Canada observation flight over a large Russian military exercise.

"These problems, moreover, follow on years of different Russian violations of the Treaty at various points since the Treaty entered into force, such as Russia’s violation, up until 2017, of improperly declaring force majeure to impose airspace restrictions related to VIP ground movements. These periodic and shifting violations highlight Russia’s willingness for many years now, to restrict or deny overflights whenever it desires. This strikes at the heart of the Treaty’s confidence-building purpose....

"Moscow has increasingly used Open Skies as a tool to facilitate military coercion. Moscow appears to use Open Skies imagery in support of an aggressive new Russian doctrine of targeting critical infrastructure in the United States and Europe with precision-guided conventional munitions...."

The US left the Open Skies Treaty on 23 November 2020, leaving the pair of Offutt AFB based OC-135 aircraft and crews without a mission. The Open Skies Treaty permited unarmed overflight of the sovereign territory of 34 signatory nations. The Treaty enhances mutual understanding and confidence by giving all participants, regardless of size, a direct role in gathering information through aerial imaging on military forces and activities of concern. Open Skies was one of the most wide-ranging international arms control efforts to date to promote openness and transparency in military forces and activities.

The Treaty permits specific categories of sensors to be used on observation flights to include: optical panoramic and framing cameras (30 cm maximum resolution); video cameras with real-time display (30 cm maximum resolution); infrared line-scanning devices (50 cm maximum resolution); and, sideways-looking synthetic aperture radar (3m maximum resolution). To date, no treaty nation had installed infrared line-scanning devices or sideways-looking synthetic aperture radar into their aircraft. The USAF used two OC-135Bs to fulfill US Treaty requirements. They are equipped with three KS-87 framing cameras and one KA-91 panoramic camera to accomplish Treaty observation missions. The aircraft is also equipped with a non-Treaty certified Hitachi video camera used for situational awareness. A mission suite consists of a Digital Camera Control Panel (DCCP) and an Integrated Data Annotation, Recording and Mapping System (IDARMS). By 2017 an acquisition program known as the Digital Visual Imaging System (DVIS) was underway to replace the KS-87 and KA-91 cameras with a digital electro-optical video camera system.

The Department of Defense was responsible for oversight, implementation of, and compliance with, arms control agreements, including the Open Skies Treaty. The United States Air Force has a requirement to execute missions under the Open Skies Treaty and utilizes two OC-135B aircraft as the observation aircraft. All roles and responsibilities were called out in Presidential Policy Directive 15, "Implementation of the Treaty on Open Skies, Mar 1, 2012.

The Open Skies Treaty, signed on 24 March 1992, provides for nearly unrestricted aerial data collection reconnaissance flights over the entire territories of the U.S. and the 26 other signatory countries. Flights are intended to enhance mutual understanding and confidence. The only restrictions on an Open Skies mission are sensor resolution, distance of the data collection flight, and safety of flight considerations. Signatories include all NATO countries, Russia, Ukraine, Belarus, Hungary, Poland, Romania, Czech Republic, Slovakia, Bulgaria, and Kirgizstan. To date, Japan, South Korea, Australia, and several Middle Eastern nations have expressed interest.

Winston Churchill eloquently described an Iron Curtain which, as it descended around the USSR and its satellites, effectively hid Soviet activities from the eyes of former wartime partners. It appeared that as Soviet expansionism became increasingly aggressive, Soviet homeland activities were becoming increasingly secretive. And the "balance of knowing" tilted alarmingly as the Soviets continued to enjoy access to worldwide current events, even as they concealed their own activities.

The Open Skies Treaty was first proposed by President Dwight Eisenhower to Soviet Premier Nikita Krushchev at the Geneva Conference of 1955. In 1955 the President made the Geneva “Open Skies” proposal.1 At that time aerial inspection coupled with an “exchange of military blueprints” and the most rudimentary form of ground inspection could have provided an effective safeguard against a surprise attack. Furthermore, if such an inspection system had been implemented, it would have tested inspection techniques that, if successful, could have formed the framework for monitoring future phases of disarmament.

The proposal was attractive to the US country for three quite different secondary reasons. First, by making such a proposal the US was in a position to test Soviet intentions in the disarmament field. Secondly, the proposal provided an excellent propaganda move for the US, indicating good faith and a sincere desire for peace. Finally, it was realized that if an inspection system were implemented, it would provide a means for raising the Iron Curtain and increasing the chances for hard intelligence from USSR. But advances in weapon technology in the follwoing years - notably advent of the ICBM and the greatly increased readiness capability of manned bombers - substantially reduced the value of an inspection system as a safeguard against surprise attack.

The Soviets shot down the concept and it lay dormant for a generation. In any event, the United States went on to implement part of the Open Skies proposal by U-2 overflights of the Soviet Union, which continued until Gary Powers was shot down.

In May 1989, the US 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.

Three OC-135Bs were modified to perform the Open Skies mission; two PAA and one BAI. The first OC-135 was first assigned to the 24th Reconnaissance Squadron, at Offutt AFB, NE in October 1993. Two more OC-135Bs were delivered by the end of 1996.

The OC-135B Open Skies Observation Aircraft supports the Open Skies Treaty. The aircraft flies unarmed observation flights over participating parties of the treaty. The aircraft was 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 acquire imagery, most of the installed equipment and systems provide direct support to the cameras and the camera operator. Modifications also included installing an auxiliary power unit, crew luggage compartment, sensor operator console, flight following console and upgraded avionics.

Because some of the countries use non-directional beacons (NDBs) to define navigation routes or as primary or backup instrument approaches to their airfields, the OC-135s require more reliable and accurate ADFs than are currently on board to ensure safe operations. The existing ADF (DFA-70) is rapidly becoming no longer reliable and maintainable. In fact, the other aircraft at Offutt have long since had their FDFA-70s replaced. Accurate and reliable ADFs are absolutely essential to the safe operation of the OC-135. Without them, a significant risk of Air Traffic Control violations with resultant diplomatic embarrasment, and potential loss of aircraft and crew exist.

By December 2011 ARINC Engineering Services LLC engineers, under contract with Rockwell Collins, had upgraded the navigation systems and advanced communications equipment on two OC-135B “Open Skies” observation aircraft. ARINC engineers installed the Rockwell Collins Block 40 Global Air Traffic Management (GATM) navigational upgrade and multiple new communications systems on both planes. With GATM navigational capability, the OC-135B meets worldwide Communications, Navigation, Surveillance, and Air Traffic Management (CNS/ATM) mandates. ARINC engineers finished the work on schedule at its expanded Aircraft Modification and Operations Center (AMOC) in Oklahoma City, Okla. Work on the first OC-135B aircraft was completed earlier this year, and the second was delivered to the Air Force 30 September 2011.

The OC-135B fleet experienced decreasing mission reliability due to age, difficulties with out-of-production parts, and increased operating costs. This is a particular problem for low failure rate parts that may not be readily available and require fabrication or extraction from another aircraft. When these types of failures occur, they leave an aircraft grounded for an extended time for part sourcing and installation. If a US aircraft is not available to fly when scheduled, there is a high probability the opportunity to execute the Treaty quota will be lost.

Open Skies missions averaged a 65% mission completion rate over the ten-year period from 2007 to 2017 with leading non-mission capable drivers being the engines, fuel system, landing gear, generators, and airframe. Additionally, the OC-135B aircraft's 6,500km range is insufficient to fully execute mission options within the 96-hour in-country Treaty observation time constraint permitted under Treaty.

The OC-135B fleet experienced decreasing mission reliability due to age, difficulties with out-of-production parts, and increased operating costs. Open Skies missions averaged a 65% mission completion rate over the ten-year period from 2007 to 2017 with leading non-mission capable drivers being the engines, fuel system, landing gear, generators, and airframe. Additionally, the OC-135B aircraft's 6,500 km range was insufficient to fully execute mission options within the time constraints of the 96-hour in-country Treaty observation time constraint permitted under Treaty.

The Department of Defense, motivated by operational limitations of the OC-135B experienced during Open Skies missions combined with declining mission capability, prompted program officials to request a Capabilities-Based Assessment in July 2015 to study aircraft issues. The effort which completed in June 2016 indicated that key requirements within the 1992 Open Skies Operational Requirements Document were no longer current, and that the OC-135B had known capability performance gaps in range and mission completion.

In October 2016, the Air Force secured permission to develop a Doctrine, Organization, Training, materiel, Leadership and Education, Personnel, Facilities and Policy Change Recommendation for the Open Skies Treaty Aircraft. The process used a multi-disciplinary High Performance Team to create and validate a series of required capabilities for an Open Skies aircraft, evaluate aircraft that could satisfy the required capabilities, and then consider each of the Doctrine, Organization, Training, materiel, Leadership and Education, Personnel, Facilities and Policy elements as part of a recommended solution.

The effort accomplished two main purposes. First, it updated operational requirements and replaced the 1992 Operational Requirements Document to reflect both operational experience and expected Open Skies program needs for the foreseeable future. Second, it recommend an Air Force solution that best satisfied required capabilities within existing materiel solutions. The Joint Capabilities Board adopted the Air Force recommendation directed acquisition of two small airliner class aircraft for the Open Skies Treaty mission to be acquired in a method consistent with the Federal Acquisition Regulation and other applicable guidance, training using existing contractor training facilities, equipment, and curriculum, and a maintenance concept with military personnel performing unit-level maintenance actions with contractor support for parts supply, and supply chain management, performed under a Low Utilization Maintenance Program.

Joe Biden — then a candidate, now president-elect — pointed to widespread support for the treaty among European allies and said withdrawing from it would harm their interests while further poisoning relations with Russia. “Instead of tearing up treaties that make us and our allies more secure, President Trump … should remain in the Open Skies Treaty and work with allies to confront and resolve problems regarding Russia’s compliance,” Biden said in a statement in May 2020.

Equipment Rack

Sensor Controls

Sensor Display

Sensor Window

KA-91C Panoramic Camera

KS-87E Panoramic Camera

Red Filter Set

Yellow Filter Set