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Reeves AN/MSQ-77 Bomb Directing Central

Reeves AN/MSQ-77 Bomb Directing Central
Combat Skyspot/Combat Proof radar beacon[1]
colloq: Radar Bomb Directing Central
An AN/MSQ-77 at Lima Site 85
Country of originUnited States
ManufacturerReeves Instrument Corporation
TypeSite area
Frequency8500 to 9600 MHz (X band)
PRF600 pulses/second or 300 pulses/second[citation needed]
Pulsewidth.25 microsecond
RPM30 cycles/second feedhorn rotation
→20 pulses/cycle conical scan signal
Range 200 nmi (370 km; 230 mi) beacon track[2]
135 nmi (250 km; 155 mi) skin track
130 nmi (150 mi) UHF radio reliability[3]
Diameter8 ft (2.4 m) Cassegrain antenna
Precisiontbd in range
tbd degrees (radar track)
tbd degrees (computer track w/
   joystick alignment on CCTV image)
          GDB ACCURACY
<680 ft CEP @ 200 nmi (specification)[4]
486 ft CEP @ 44 nmi (1965 testing)[5]
300-350 ft ave @ ≤100 nmi (1967 ops)[2]

The Reeves AN/MSQ-77 Bomb Directing Central, Radar[6] (nickname "Miscue 77") was a United States Air Force automatic tracking radar/computer system for command guidance of aircraft. It was often used during Vietnam War bomb runs at nighttime and during bad weather. Developed from the Reeves AN/MSQ-35,[citation needed] the AN/MSQ-77 reversed the process of Radar Bomb Scoring by continually estimating the bomb impact point before bomb release[7] with a vacuum tube ballistic computer. Unlike "Course Directing Central" systems which guided aircraft to a predetermined release point, the AN/MSQ-77 algorithm continuously predicted bomb impact points during the radar track while the AN/MSQ-77's control commands adjusted the aircraft course. A close air support regulation prohibited AN/MSQ-77 Combat Skyspot bombing within 1,000 yd (910 m) of friendly forces unless authorized by a Forward Air Controller,[8]: 135  and "on several occasions" strikes were as close as 273 yd (250 m).[5]

Post-war the MSQ-77 was used on US and other training ranges for Radar Bomb Scoring (RBS). The AN/MSQ-77 was also periodically used for post-Vietnam commanding of bombers during simulated ground directed bombing to maintain aircrew and radar crew GDB proficiency (RBS could be used to score the simulated GDB mission). Most AN/MSQ-77s were replaced by solid-state equipment near the end of the Cold War.

  1. ^ Cite error: The named reference Lake was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Wheeler was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Schlight2003 was invoked but never defined (see the help page).
  4. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2013-06-06. Retrieved 2013-09-01.{{cite web}}: CS1 maint: archived copy as title (link)
  5. ^ a b Cite error: The named reference Wolk1969 was invoked but never defined (see the help page).
  6. ^ Department of Defense Provisioning and Other Preprocurement Screening Manual (PDF), November 1983, p. 222 (Table 66), retrieved August 27, 2024
  7. ^ Cite error: The named reference Rowley was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Schlight was invoked but never defined (see the help page).

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