The 452nd Flight Test Squadron at Edwards Air Force Base operates a variety of
unique, highly modified C-135 and C-18 aircraft to plan and execute DoD, NASA, and
operational flight test programs. Missions supported include worldwide telemetry
gathering, international treaty verification, spacecraft launches, ballistic missile defense, electronic combat and vulnerability analysis, aircraft icing tests, and aerial refueling certification. The 452 FLTS accomplishes its primary mission using the Advanced Range Instrumentation Aircraft (ARIA) and the Cruise Missile Mission Control Aircraft (CMMCA).
The Advanced Range Instrumentation Aircraft (ARIA - pronounced Ah-RYE-ah) are EC-135E and EC-18B aircraft used as flexible airborne telemetry data recording and relay stations. These aircraft were designed and developed to supplement land and marine telemetry stations in support of DOD and NASA space and missile programs. The ARIA have the capability to acquire, track, record, and
retransmit telemetry signals, primarily in the S-band (2200-2400 MHz)
frequency range.
In the early 1960's, the National Aeronautics and Space Administration
(NASA) realized that the lunar missions of the Apollo program would require a
worldwide network of tracking and telemetry stations, many positioned in
remote regions of the world. The Department of Defense (DoD) was also
faced with similar considerations for its unmanned orbital and ballistic missile
reentry test programs. Since land stations are obviously limited by geographical
constraints, and instrumentation ships cannot be moved quickly enough to
cover different positions during the same mission, it soon became evident that
large gaps in coverage would occur. To fill these gaps, a new concept in
tracking stations was developed - a high-speed aircraft containing the
necessary instrumentation to assure spacecraft acquisition, tracking, and
telemetry data recording. The same aircraft could provide coverage of
translunar injection and recovery for NASA's manned space flight operations,
as well as events of interest in the DoD orbital or ballistic missile reentry tests.
To implement the concept, NASA and DoD jointly
funded the modification of eight C-135 jet transport/cargo aircraft. The Apollo/Range
Instrumentation Aircraft (A/RIA),
designated EC-135N, became operational in January 1968, having been
modified at the basic cost of $4.5 million per aircraft.
The Air Force Eastern Test Range (AFETR) was
selected to operate and maintain the system in support of the test and
evaluation (T&E) community. McDonnell-Douglas Corporation and Bendix
Corporation were the contractors for the design, aircraft modification, and
testing of the electronic equipment.
In December 1975, after 7 years of operation by the Eastern Test
Range, the ARIA (redesignated Advanced Range Instrumentation Aircraft
following completion of the Apollo program) were transferred to the 4950th
Test Wing, Wright-Patterson AFB, Ohio, as part of an Air Force consolidation
of large T&E aircraft. The 4950th Test Wing provided test support, personnel,
and resources for the operational use of, and modifications and improvement
to, the ARIA fleet. After arriving at Wright-Patterson AFB, the ARIA fleet underwent
numerous conversions, including re-engining of EC-135N ARIA to EC-135E
and the acquisition and conversion of used Boeing 707 commercial airliners to
ARIA.
In 1982, the Air Force bought eight used Boeing 707-320C's from American Airlines, modifying the jets to the ARIA configuration and dubbing them EC-18B's. The EC-18B, which is larger than the EC-135N, carries a bigger payload and operates on shorter runways, flew its first mission in January 1986 out of Kenya. In 1994, the ARIA fleet was relocated to Edwards AFB, California, as part of the 452d Flight Test Squadron, in the 412th Test Wing. The current ARIA fleet consists of three EC-135E and three EC-18B aircraft. On 10 February 1998 the annual Force Structure Announcement formalized adjustments to the aircraft fleet at Edwards, which included the loss of one EC-18 and one EC-135 aircraft. These changes were the result a continuation of the normal fleet adjustments which occur at Edwards as test programs change and the general test aircraft fleet is upgraded and modernized.
Aircraft 375 was one of the first Apollo Range Instrumentation Aircraft (ARIA) put into service. Aircraft 894 is one of two active ARIA with in flight refueling capabilities. This aircraft is a modified commercial Boeing 707, and is one of four ARIA that have been upgraded with 4 MHz Racal Storehorse recorders and Microdyne S-Band, C-Band, P-Band Superheterodyne receivers.
The ARIA deploy throughout the world to obtain telemetry data from orbital and reentry vehicles as well as air-to-air and cruise missile tests. This includes support of tests conducted at Cape Canaveral AFS, Vandenberg AFB, Hill AFB, Eglin AFB, and from ships and submarines. Normally, the telemetry data is obtained in locations such as broad ocean areas and remote land areas which are outside the coverage of ground stations. Selected portions of the data may be retransmitted in real time, via UHF satellite, to enable the launching agency to monitor system performance. All data is recorded on magnetic tape for post-mission analysis. The Cruise Missile Mission Control Aircraft (CMMCA) mission is different from both orbital and reentry mission types, primarily due to the mission duration which may involve continuous automatic tracking for more than five hours. Other differences include: the vehicle flies below the ARIA; real-time data is relayed via L-band transmitters directly to ground stations; and voice is relayed via ARIA UHF radios between mission aircraft (launch, chase, photo, etc.) and mission control. ARIA also flies as the primary remote command & control / flight termination system for these missions. On a typical mission, flown locally from Edwards AFB, a B-52 launch aircraft with the cruise missile departs its home base several hours prior to the ARIA takeoff. The ARIA joins the B-52 and acquires telemetry from the missile at about launch minus 90 minutes. The B-52 and the trailing ARIA then proceed to the launch area. At this point, mission control uses the ARIA telemetry data to evaluate the missile's status. Prior to launch, F-16 chase and photo aircraft join the B-52 launch aircraft. After final checks are completed, the cruise missile is launched and the B-52 departs the area. The ARIA continues to track the missile after launch, receives and relays telemetry data from the missile, and relays UHF voice from the chase planes to mission control. The ARIA tracks the cruise missile until termination of the mission. During most tests, ARIA supplies the primary remote command & control / flight termination system (RCC/FTS) signal to the missile. The Cruise Missile Mission Control Aircraft (CMMCA) Phase 0 modification provides real-time telemetry displays and redundant RCC/FTS systems. . The Advanced CMMCA, provides the same capabilities as the CMMCA Phase 0 plus a tracking/surveillance radar for stand-alone operations as well as real-time data processing and display. Each ARIA has both external and internal modifications. Externally the most obvious difference in appearance from a standard C-135 or C-18 aircraft is the large, bulbous, "droop snoot" nose, a ten-foot radome which houses a seven-foot steerable dish antenna. The ARIA also has a probe antenna on each wing tip and a trailing wire antenna on the bottom of the fuselage (EC-l35E only) used for high frequency (HF) radio transmission and reception. Further external modifications include antennas for data retransmission via UHF satellite. The internal modifications to the cargo compartment include all of the instrumentation subsystems (Prime Mission Electronic Equipment - PMEE) installed in the form of a 30,000 pound modular package. Also provided are facilities for the crew members who operate the PMEE. The Prime Mission Electronic Equipment (PMEE) is organized into eight functional subsystems to provide the ARIA mission support capability.
ARIA Prime Mission Electronic Equipment (PMEE)
|
| Antenna | 7 foot parabolic dish (auto/manual track); fixed horn antenna |
| RCC/FTS | Remote Command and Control / Flight Termination System |
| DSC | Data Separation Console (bit synchs, decoms, data processing) |
| RF | Radio Frequency (receivers) |
| MC | Mission Commander |
| HF | High Frequency (communications, data relay) |
| REC | Record (magnetic tape recorders) |
| SMILS | Sonobouy Missile Impact Location System |
The Advanced Range Instrumentation Aircraft needs technology development and advancement to support off-range flight tests of multiple simultaneous telemetry sources. The advanced weapons will continue to increase their launch ranges and payload complexity and to increase their test telemetry data requirements during future DT&E or OT&E flight tests. These airborne telemetry sources will have to be tracked from safe distances in spite of large hazard zones. The massive and multiple data streams from the targets will also have to be collected, retranslated, and recorded without sacrifice to the data quality. The physical size of current ARIA tracking antenna is not practical to increase because of the negative impact a larger radome would have to C-135 aircraft flying performance and qualities. The ARIA antenna is a dish design which does not lend itself to simultaneous tracking and telemetry from multiple data sources without severe penalty to data signal quality. The technology application/insertion necessary to provide low-cost high- performance telemetry-receivers must complement the ARIA antenna system. Large capacity data collection, processing and recording is necessary to complement the load created by the article's sources.
Specifications | ||
| Performance Factors | EC-135 | EC-18B |
| Max Takeoff Gross Wt (lb) | 300,500 | 326,000 |
| Normal Cruise Speed (kt TAS) | 430 | 450 |
| Max Cruise Speed (kt TAS) | 490 | 470 |
| Nominal Support Speed - 30kft (kt TAS) |
360/420 | 360/420 |
| Nominal Turning Radius - 30 kft, 30 deg bank (nm) |
3.3/4.5 | 3.3/4.5 |
| Minimum Turning Radius - 30 kft, 45 deg bank (nm) |
1.9/2.6 | 1.9/2.6 |
| Nominal Turn Time, 180 deg - 30 kft, 30 deg bank (min) |
1.7/1.8 | 1.7/1.8 |
| Minimum Turn Time, 180 deg - 30 kft, 45 deg bank (min) |
1.0/1.2 | 1.0/1.2 |
| Nominal Operating Altitude (ft MSL) | 30,000 | 30,000 |
| Maximum Operating Altitude (ft MSL) | 33,000 | 42,000 |
| Mission Operating Altitude (ft MSL) | 5,000 to 33,000 | 500 to 42,000 |
| Range |
The range capability of the ARIA is influenced by:
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| Navigation |
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