Reader Enquiry

0. Collins Radio Company — Avionics Timeline

Collins Radio Company, founded by Arthur A. Collins in 1933 in Cedar Rapids, Iowa, became a world leader in avionics during the 1950s and 1960s. The company’s avionics work grew from airline HF communications (the 618T HF transceiver was a mainstay for the airlines in the 1950s) into a full integrated navigation and communications suite for commercial and corporate aviation.³

Two distinct avionics product generations define the equipment Jan is enquiring about:

• Solid State System (SSS), 1963: Collins’ first all-solid-state integrated avionics suite for airlines and business aircraft. The 618M-1 VHF COM was the flagship. A solid-state DME (the 860E) was planned for late 1963, completing the suite.
• Pro Line I, c.1970–1972: Collins’ second-generation integrated avionics suite, launched in the early years of the Rockwell ownership. The 51R-7A, VIR-30, DME-40, and 51RV all belong to this generation.

North American Rockwell acquired Collins Radio Company and the merger was completed on 2 November 1973.⁴ Rockwell International (renamed from North American Rockwell in February 1973) retained the Collins name for its avionics products. Rockwell Collins was spun off from Rockwell International in 2001, and was ultimately acquired by United Technologies Corporation on 27 November 2018, operating today as Collins Aerospace, a subsidiary of RTX Corporation.

  COLLINS RADIO AVIONICS — PRODUCT GENERATION TIMELINE
  ─────────────────────────────────────────────────────────────────────────
  1933  Collins Radio Company founded, Cedar Rapids IA
  1950s Collins 618T HF transceiver — airline and military standard
  ────────────────────────────────────────────────────────── SSS ERA ──────
  1962  Solid State System (SSS) announced in trade press
  Jan 1963  618M-1 VHF COM transceiver — CONFIRMED ★
  Late 1963  860E DME — FORECAST (1962 article); SSS completion
  1963-65   860E solid-state DME enters production — ESTIMATED
  1966-70   618M-2/2B/2D variants — ESTIMATED
  ─────────────────────────────────────────────── ROCKWELL TRANSITION ────
  Nov 2, 1973  Merger: Collins Radio → Rockwell International
  ──────────────────────────────────────────────────── PRO LINE I ERA ────
  c. 1970-72  Pro Line I launch:
              51R-7A VHF NAV receiver ★★
              VIR-30 / VIR-30A VOR receiver ★★
              DME-40 DME transceiver ★★
  c. 1972-75  51R-8A VHF NAV receiver ★★
              51RV-1/-2/-4 Combined NAV receiver ★★
  c. 1970-80s 618M-3 through 618M-5A variants
  ─────────────────────────────────────────────────────────────────────────
  ★  High confidence (contemporary trade press confirmation)
  ★★ Moderate confidence (Pro Line I era confirmed; exact year uncertain)

Figure 1. Collins Radio avionics product generation timeline. Lines marked ★ indicate dates confirmed from primary sources; ★★ indicates Pro Line I era assignment confirmed, exact year estimated.

1. 618M — VHF COM Transceiver Series

Introduction Date: January 1963

A 1962 aviation equipment survey, accessible via the prc68.com Collins HSI archive, documented the pre-announcement of Collins’ Solid State System:

The Radiomuseum.org entry for the 618M-1 independently records the build date as 1963.⁵ The 618M-1 was certified to TSO-C37b (VHF communication transmitter) and TSO-C38b (VHF communication receiver), the FAA Technical Standard Orders applicable at the time of its certification.

The 618M was Collins’ primary VHF airborne communication transceiver for airline and corporate aviation from 1963 into the 1980s. It covered 118.000–135.975 MHz (later variants extending to 151.975 MHz) and was installed widely on the Boeing 707, 727, and early 737, the Douglas DC-8 and DC-9, and numerous business jets including the Learjet and Cessna Citation families of the era.

2. 51R-7A — VHF NAV Receiver

Introduction Date: c. 1970–1972 (Pro Line I)

The 51R-7A is a VHF navigation receiver forming part of Collins’ Pro Line I avionics suite. Southeast Aerospace, a Collins specialist dealer, states in their product notes for all Pro Line I components: “Most of the Collins Pro Line I components were originally manufactured in the early 1970s… Most of the Collins Pro Line I product lines incorporates 1960s and 70s analog technology.”²

The 51R-7A is a single-conversion VHF NAV receiver covering the VOR and ILS localizer bands (108.000–117.950 MHz in 50 kHz steps). It was typically installed as a paired unit with the 618M VHF COM in Pro Line I Collins-equipped aircraft.

3. 51R-8A — VHF NAV Receiver

Introduction Date: c. 1972–1975 (Pro Line I, second generation)

The 51R-8A is an updated member of the 51R NAV receiver family. It covers the same VHF navigation band (108.000–117.950 MHz) and serves the same function as the 51R-7A but represents a significant enough revision to warrant its own model designation rather than a simple letter suffix.

The -8A suffix (versus the -7A) in Collins avionics numbering conventions indicates a design generation increment. The -8A is therefore a later Pro Line I variant, most likely c. 1972–1975. Both the 51R-7A and 51R-8A remain in common use on surviving Pro Line I aircraft, and both are readily available on the used avionics market through dealers such as Southeast Aerospace.

4. VIR-30 — VOR Navigation Receiver

Introduction Date: c. 1970–1972 (Pro Line I)

The VIR-30 is Collins’ dedicated VOR navigation receiver from the Pro Line I generation. VIR stands for VHF Instrument Receiver; the unit covers VOR bearing (108.000–117.950 MHz) and ILS localizer functions. Unlike the 51R-7A/8A, which are combined NAV/COM receivers, the VIR-30 is a dedicated NAV-only unit, making it particularly suitable for twin-NAV installations where two independent VOR receivers are required.

The IND-40 DME indicator and VIR-30 were complementary Pro Line I units, often installed together in twin-NAV configurations on business jets and regional airliners of the early 1970s.

5. 860E — DME Transceiver Series

Introduction Date: c. 1963–1965 (Solid State System era)

The 860E is historically the most interesting of Jan’s list, because the 1962 trade press article quoted in section 1 above specifically forecast a solid-state DME for Collins’ Solid State System alongside the 618M-1:

The 860E therefore predates the Pro Line I launch by approximately seven years, placing it contemporary with the original 618M-1 rather than in the 1970s generation. It continued in production and was updated through at least three variants.

6. DME-40 — DME Navigation Transceiver

Introduction Date: c. 1970–1972 (Pro Line I)

The DME-40 is the dedicated DME transceiver of the Pro Line I suite and the successor to the 860E in new aircraft installations from around 1970. Southeast Aerospace states: “Most of the Collins Pro Line I components were originally manufactured in the early 1970s.” The DME-40 replaced the 860E in new-installation Pro Line I avionics, offering improved integration with the VIR-30, 51R-7A, and 618M through standardised ARINC interconnections.

The DME-40 operates on the standard ICAO DME band (962–1213 MHz) and provides slant-range distance, groundspeed, and time-to-station readout. The companion IND-40 DME indicator (also Pro Line I) displays this information on the instrument panel. The DME-40 remained in widespread use on business aircraft and smaller airliners through the 1980s and 1990s, long after Pro Line I production ended in the early 1970s.

7. 51RV — Combined VOR / GS / DME / MB Receiver

Introduction Date: c. 1970–1975 (Pro Line I to early Pro Line II transition)

The 51RV series is Collins’ integrated navigation receiver combining VOR, glideslope (GS), DME, and marker beacon (MB) functions in a single Line Replaceable Unit (LRU). The “RV” suffix denotes the combined receiver function; the base “51” series number connects it to the 51R NAV receiver family.

The 51RV represents a significant packaging evolution: it consolidates what previously required separate 51R NAV, glideslope, and marker beacon receiver units into one chassis, reducing weight and panel space. This integration philosophy became increasingly important as cockpit space and weight constraints tightened on business jets in the early 1970s.

Summary Timeline — All Seven Units

Confidence key: HIGH = confirmed from contemporary primary source.   MODERATE = generation era confirmed; exact year estimated.   LOW = relative dating only; no primary date found.

Resolving the Remaining Uncertainties

The dates rated LOW above could potentially be pinned down precisely through the following research avenues:

• 1 Collins Collectors Association (CCA) — collinsradio.org — maintains an extensive archive of Collins avionics brochures, manuals, and product files. Their technical archive at collinsradio.org/cca-collins-technical-archives/ holds many Collins avionics manuals. The earliest-dated edition of any 51R-7A, VIR-30, DME-40, or 51RV-1 manual would give a precise lower bound on the introduction date.
• 2 Collins Aerospace Museum — collinsaerospacemuseum.org — maintains a Signal Index (A–Z listing) which may include original product announcement dates and brochure dates for Pro Line I equipment.
• 3 FAA TSO certification records — The FAA maintains historical records of Technical Standard Order (TSO) approvals through the Aircraft Certification Service (AIR-100). Each Collins variant would have a TSO approval date, typically within one to two years of market introduction. Relevant TSOs: TSO-C37b/C38b (VHF COM), TSO-C34 (ILS), TSO-C36 (VOR), TSO-C66 (DME), TSO-C35 (marker beacon).
• 4 Aviation Week & Space Technology archives, 1962–1975 — The contemporary trade press of this period published detailed product announcements. The 1962 article that confirmed the 618M-1 and 860E dates was exactly this type of source; a systematic search of Aviation Week from 1963–1975 would likely yield specific introduction announcements for the 51R series, DME-40, VIR-30, and 51RV. Available through ProQuest Historical Newspapers at major research libraries.
• 5 Collins Radio Company Records, University of Iowa Libraries — The Collins Radio Company corporate archive held at the University of Iowa Special Collections includes product files, advertisements, and instruction manuals from CRC’s corporate existence. These records may contain original product introduction dates for all Pro Line I components.

Notes on Collins Avionics Numbering Conventions

Collins avionics of this era follow consistent numbering patterns that assist in establishing family relationships and relative dating:

References & Sources

• prc68.com Collins HSI page — prc68.com/I/CollinsHSI.html — Primary source for the January 1963 618M-1 and late-1963 860E DME introduction dates. Reproduces text from a 1962 aviation equipment survey article documenting the Collins SSS pre-announcement and January 1963 availability of the 618M-1.
• Radiomuseum.org — Collins 618M-1 — radiomuseum.org/r/collins_618m_1.html — Build date recorded as 1963; independently corroborates the trade press announcement.
• Southeast Aerospace (Pro Line I product notes) — seaerospace.com — DME-40; VIR-30A; 51R-7A — Pro Line I product notes confirming “early 1970s” original manufacture for all Pro Line I components. Primary source for the Pro Line I generation era assignment across this document.
• Rockwell Collins — Wikipedia — en.wikipedia.org/wiki/Rockwell_Collins — Corporate history; merger date 2 November 1973; spin-off 2001; UTC acquisition 2018.
• Arthur A. Collins — Wikipedia — en.wikipedia.org/wiki/Arthur_A._Collins — Avionics history context; 618T HF transceiver; HSI development.
• Collins Radio Company Records — University of Iowa Libraries — lib.uiowa.edu — Collins Radio Company Records — Corporate archive including product files, advertisements, and instruction manuals; potential primary source for precise Pro Line I introduction dates.
• Collins Collectors Association (CCA) — collinsradio.org — Technical archive of Collins manuals and brochures; recommended first port of call for further primary source research.
• Southeast Aerospace — 860E-2 — seaerospace.com — 860E-2 — Parts database entry confirming production and availability of 860E-2 variant.
• Southeast Aerospace — 860E-3 — seaerospace.com — 860E-3 “DME R/T” — Parts database entry for the 860E-3 variant, designated DME R/T.
• Essco Aircraft — Collins 618M-2B/2D Overhaul Manual, 1986 — esscoaircraft.com — 1986 overhaul manual for 618M-2B/2D; confirms the -2 family remained in active overhaul support at least to 1986.