Pacer CRAG 
Command's KC-135s receiving 
avionics, navigation upgrades 

Citizen Airman February 1999

By Master Sgt. Patrick E. Clarke 

     A desire to improve safety is the driving force behind a program to modernize the avionics and navigation systems on all Air Force KC-135 Stratotankers, including the approximately 70 in the Air Force Reserve Command inventory.
     Called Pacer CRAG, the project provides for a major overhaul of the KC-135 cockpit to improve the reliability and maintainability of the aircraft’s compass and radar systems. In addition, the program meets the congressionally mandated requirement to install the global positioning system in all Defense Department aircraft by the turn of the century. CRAG stands for compass, radar and GPS. 
     As an added safety measure for formation flying, a traffic collision avoidance system will be installed. TCAS will give pilots the ability to see other aircraft and will provide advance warning of possible mid-air collisions. 
      “In early 1997, the military decided that TCAS was needed and added it to the Pacer CRAG contract as part of an engineering change proposal,” said James Dean, a program analyst at AFRC headquarters, Robins Air Force Base, Ga. 
     “TCAS was added to Pacer CRAG because in the test phase the radar failed to adequately detect other aircraft during formation flying,” said Lt. Col. Craig Branning, AFRC’s chief of tanker programs. “It was a measure to improve safety.” 
     “Both systems (the radar and TCAS) use off-the-shelf products, so there aren’t a lot of modifications required,” Dean said. “That makes this program unique compared to many acquisition programs in that we’re taking existing commercial hardware and adapting it for military use.” 
     Although Pacer CRAG is good news for KC-135 pilots, giving them increased capability, the story is not the same for navigators. 
     The heart of the overall system is a state-of-the-art flight management system. Using this, pilots have the added ability to plot their courses in the training facility, download the information to a data card and then upload it into the aircraft. This capability, combined with the others, eliminates the navigator position. 
     “This affects approximately 102 reservists and 14 air reserve technician positions,” Branning said. “Navigators are being allowed to cross-train either into pilot positions, with waivers up to the age of 33, or non-flying slots with the units.” 
     Branning estimates that Pacer CRAG will save the Reserve about  $2.5 million a year in manpower costs. 
     He said that before deciding to acquire the system, some AFRC officials expressed a concern about overloading KC-135 pilots with too many tasks. 
     But the results of 45 air refueling test flights, as well as the system’s benefits, put these concerns to rest. 
     One of the biggest benefits is the system allows pilots to view several functions through multifunction glass displays. As a result, pilots can concentrate on one area to view certain functions rather than looking at a number of instruments to get the same information. 
     Using the improved radar, pilots can detect cloud formations, wind shear and other weather hazards. With GPS, pilots can identify their position anywhere in the world within a few meters. The system provides exact aircraft positioning by using satellites and also calculates the speed, bearing and altitude of the aircraft. 
     Another benefit of the upgrade is decreased maintenance costs. In 1994 the Air Force collected maintenance data to use in a comparison between the old system and Pacer CRAG. Data was collected in three areas: mean time between failures, mean time to repair and maintenance costs. The comparison was based on a fleet of 600 aircraft with 175,000 cumulative flight hours and 245,000 operational hours. 
      Using Pacer CRAG, aircraft flew 538 more hours before experiencing any type of failure, and crews spent an average of 30 minutes on each repair, compared to 168 minutes with the old system. The annual maintenance cost using Pacer CRAG was $10.2 million less. 
     The Air Force has set up six sites where its approximately 550 KC-135s are undergoing modifications. One modification site is at March Air Reserve Base, Calif. 
     “We’re the only joint Guard and Reserve effort involved in Pacer CRAG,” said Chief Master Sgt. Bruce Hanke of the 163rd Air Refueling Wing. Hanke serves as the Air National Guard’s Pacer CRAG project officer at March. 
     “We’ll convert approximately 232 aircraft,” said Tony Scherer, 452nd Logistics Group, Pacer CRAG project officer for the Reserve. “We work on six aircraft at a time and have about 119 people working at this site on shifts to cover 6:30 a.m. to 11:00 p.m. Monday through Friday.” 
     The 11-step conversion process is complicated, and workers are improving as they go. 
     “Our first airplane took 200 days to convert,” said Scherer. “We’ve gotten the process down to 79 days, and we’ll be trying for 45 days from now on.” 
     Modification of the KC-135 fleet is expected to be completed in 2001. 
     “Communication has been one of our most difficult problems,” said Hanke. “We’ve had to interface with Air Mobility Command headquarters at Scott AFB, Ill., the system program office at Tinker AFB, Okla., AFRC headquarters, the National Guard Bureau and the administrative contract office, plus every unit commander. You’re talking a lot of hands in the pot.” 
     Despite the difficulties, Hanke said he is pleased with the everyone’s cooperation so far. 
     “We call ourselves Team March, which signifies one effort. Our hangar is called the PRIDE hangar, as in Professional Results in Daily Efforts.” 
     (Sergeant Clarke is a public affairs specialist with the 940th Air Refueling Wing at Beale AFB Calif. Some information in this article is taken from a story written by Senior Airman Chuck Widener, 97th Air Mobility Wing Office of Public Affairs, Altus Air Force Base, Okla.)