The Visual–Aural Radio Range (VAR)
History, Technology & Australia’s 30-Year Adoption

Part I — The LFRR Family Tree: From Radio Beams to VAR

The Low-Frequency Radio Range (LFRR) — The Root System

To understand VAR, one must first understand its ancestor, the Low-Frequency Radio Range (LFRR), sometimes called the “Four-Course Range” or “Adcock Range.” Inspired by a 1907 patent by German engineer Otto Scheller, the LFRR was deployed by the United States from 1927 as the first widespread aerial radio navigation system. It operated in the MF band, typically 200–400 kHz, using a four-antenna Adcock array that produced two overlapping figure-eight radiation patterns.

One pattern was keyed with the Morse letter “A” (dot-dash) and the other with “N” (dash-dot). These two letters interlock perfectly — the dash of “N” fills the gap in “A,” and vice versa — so that at the exact boundary between the two patterns, the aural signal merged into a continuous tone. Flying precisely along one of the four on-course beams, the pilot heard a steady note in his headphones. Drifting left or right, the letters A or N would emerge from the continuous tone, telling him which way to correct. Four beams radiated at roughly 90° to each other from each station, defining airways in four directions.

Australia’s VHF Advantage — The Lorenz Aeradio Network

Australia took a different path from the United States. Rather than adopting LFRR, Australian civil aviation authorities preferred the German Lorenz beam system, which operated at approximately 33 MHz VHF — already well above the static-prone MF band used by LFRR. This made Australia the first country in the world to adopt a VHF navigation system on a national scale.

The catalyst was the Kyeema disaster of 1938. On 25 October 1938, an Australian National Airways DC-2 named Kyeema flew into Mount Dandenong near Melbourne in instrument conditions, killing all 18 on board. The crash exposed the absence of adequate en-route radio navigation aids in Australia. The response was decisive: the Department of Civil Aviation (DCA) contracted Standard Telephone and Cable (the Australian subsidiary of ITT, which owned Lorenz) to build an “Aeradio” network of 15 Lorenz beam stations across the populous south-east, growing over time to cover the major trunk routes.¹

The Lorenz system worked on the same interlocking A-N principle as LFRR, but at 33 MHz VHF, it was far less susceptible to atmospheric static, “night effect,” and sky-wave contamination. It could also be equipped with a visual needle indicator — a feature LFRR entirely lacked. By the early 1950s, Australia had accumulated nearly two decades of experience with VHF radio navigation, which smoothed the path to VAR considerably.

Part II — The Visual-Aural Radio Range: How It Worked

Development History

The Visual–Aural Radio Range was developed by the US Bureau of Air Commerce (later the Civil Aeronautics Authority, or CAA) starting in the mid-1930s. Engineers recognised that moving LFRR’s frequency into the VHF band would largely eliminate its atmospheric noise problems, and that adding a visual cockpit indicator would address the headphone workload burden. A demonstration VAR system was built in 1937 at an Indianapolis research centre, and an experimental airway between Chicago and New York was established in 1941.²

World War II intervened. Wartime shortages of VHF components prevented the large-scale deployment that had been planned, and in the meantime, the far more capable VOR (VHF Omnidirectional Range) was advancing rapidly with wartime electronics development. By 1943, VOR was already “deemed practical,” and by 1946 it was being deployed in the United States. The CAA pressed ahead with 70 VAR stations in the US between 1944 and 1950, but VOR — offering 360 radials instead of VAR’s four courses — made the older system obsolete almost immediately. The last American VAR was decommissioned in 1960.

The Ground Station

A VAR ground station was physically compact compared to LFRR: the shorter VHF wavelength allowed antenna arrays that fit on top of a modest transmitter building, rather than the multi-acre Adcock arrays required for MF. The station produced a composite signal pattern:

The Cockpit Indicator — Blue and Yellow

The critical human-factors improvement of VAR over LFRR was the cross-pointer indicator (also called the “cross-pointer instrument” or simply the “VAR indicator”). The receiver’s circuitry compared the relative strength of the 90 Hz and 150 Hz tones and fed the result to a vertical needle that moved left or right in a dial face divided into blue and yellow sectors.

  VAR CROSS-POINTER INDICATOR — HOW TO READ IT

  ┌─────────────────────────────────────┐
  │                  ┃                  │
  │    BLUE   ◄══════┃══════►   YELLOW  │
  │  (150 Hz)        ┃         (90 Hz)  │
  │                  ┃                  │
  │              ON COURSE              │
  └─────────────────────────────────────┘

  Needle centred → ON COURSE on visual track
  Needle right → aircraft in YELLOW sector (90 Hz dominant) → fly LEFT
  Needle left  → aircraft in BLUE sector (150 Hz dominant) → fly RIGHT

  Full scale deflection at ~10° off track (±10° range)
  Progressive deflection proportional to deviation

  QUADRANT IDENTIFICATION (combined visual + aural):
  Blue + Morse "A"  = one quadrant (unique combination)
  Blue + Morse "N"  = another quadrant
  Yellow + Morse "A" = another quadrant
  Yellow + Morse "N" = another quadrant
  No combination is repeated — immediate position awareness

The visual indicator meant the pilot no longer had to maintain continuous headphone attention to navigate. The needle provided instant, unambiguous deviation information — the same principle used in the ILS localizer (which shared both the frequency band and the 90/150 Hz tones). When the pilot did listen on the audio, the combined quadrant information (a colour plus a Morse letter) gave an unambiguous indication of which of the four sectors of the station he was in — no two quadrants shared the same audio-visual combination.

Part III — Australia: The World’s Last VAR Nation

Why Australia Chose VAR — and Kept It

Australia’s decision to build a VAR network was logical given its history. The country already operated a 33 MHz Lorenz Aeradio network with pilot familiarity built up over nearly two decades. The Lorenz system used a single beam with a back course; VAR offered two visual plus two aural courses with a proper cockpit indicator — a meaningful upgrade using the same basic concept pilots already understood. As Flying the Beams notes, the operational similarity between Lorenz and VAR made the transition straightforward for Australian aircrew.

Construction of the Australian VAR network began in 1947 and the initial 30 stations were commissioned by January 1953, when the DCA published Publication No. 19: Operational Notes on Visual-Aural Radio Range and Associated Marker Beacons — the document Jan SP5XZG identified.³ That initial network fully superseded the old Lorenz Aeradio system.

The network eventually grew to approximately 50 VAR stations covering Australia’s major airways — a network second in scale globally only to the 70-station US deployment, and proportionally far more significant given Australia’s flying geography. Unlike the Americans, who had already pivoted to VOR before the VAR network was fully built, Australia had no incentive to rush the transition: the country’s vast distances and relatively sparse traffic made a staged modernisation entirely rational. The Australian VAR network remained in full operational service until 1980, when VOR (accompanied by its essential companion, DME) finally replaced it.

The Frequency Band: An Important Correction for Jan

Jan’s enquiry describes VAR as operating at 108–118 MHz. This is the correct US specification. In Australia, the band was slightly different: the DCA 1953 publication specifies that Australian VAR stations operated at 112–118 MHz, with channels designated A through E assigned for range use and channel Z reserved for ILS localiser compatibility. This 112–118 MHz sub-band within the VHF navigation spectrum ensured airborne receivers tuned for Australian VAR were also compatible with ILS localisers using the standard VHF navigation frequency range.

Part IV — Airborne Equipment: Receivers and Indicators

The Four Basic Components

Every aircraft operating on VAR routes in Australia needed four basic airborne components: a VAR receiver, a control panel, a cross-pointer indicator, and an appropriate VHF antenna. The DCA 1953 publication specifies that typical Australian VAR airborne receivers provided reception on six selectable channels, designated by letters matching the ground station channel assignments.

Aircraft Radio Corporation (ARC) — Type 16

Jan SP5XZG identifies the ARC Type 16 as a dedicated VAR receiver. The Aircraft Radio Corporation (ARC) of Boonton, New Jersey was one of the founding names in American avionics. Its history is extraordinary: it was ARC equipment that Jimmy Doolittle used for the world’s first completely “blind” flight in 1929, and ARC manufactured the AN/ARC-5 command set family that was ubiquitous in Allied military aircraft throughout World War II.⁴

In the postwar period, ARC moved into the civil aviation market with a series of VHF receivers and navigation equipment. Their Type 12 series, for example, covered 0.2–1.5 MHz and 118–148 MHz and was fitted to US Army helicopters and observation aircraft from around 1950. The ARC Type 16 was their dedicated VAR airborne receiver, covering the 112–118 MHz VAR band with the appropriate circuitry to separate and compare the 90 Hz and 150 Hz visual sector tones. ARC was eventually acquired by Cessna Aircraft Company in 1959, who found the avionics business a natural complement to their general aviation airframe manufacturing.

Collins Radio — The Early VHF NAV Equipment

Jan asks directly whether Collins supplied airborne VAR equipment to Australia, and the answer is almost certainly yes. Collins Radio entered the airborne VHF navigation market in the early 1950s and was a dominant force by the mid-decade. Several pieces of evidence support Collins’ presence in the Australian VAR network:

• Collins’ 51V-2 was a dedicated VHF aviation navigation receiver covering the 108–136 MHz range, directly applicable to VAR. It appears in Collins’ airborne equipment line from the early-to-mid 1950s and is known from surviving examples (including eBay listings with the part number 3R35-1).
• The Collins 618M VHF communication transceivers — the same family Jan researched in the context of the SSS avionics suite — were introduced from January 1963 and could tune the VAR frequency band for communication in addition to navigation functions.
• Collins’ broader penetration of the Australian aviation market through the 1950s and 1960s is confirmed by the later adoption of Collins SSS avionics for the airframe configurations discussed in our avionics correspondence series.
• The DCA 1953 specification requires six-channel selectable receivers; Collins was one of very few manufacturers in the world in 1953 capable of supplying certified VHF navigation receivers meeting this specification for the Australian market.

The Weston Instruments Cross-Pointer Indicator

Jan correctly identifies Weston Instruments as the principal supplier of the VAR cockpit indicator in the United States, with the Model 888 as the primary type. The Weston Model 888 was known by several designations depending on context: it appears in US military records as the ID-48/ARN course indicator (marked “Weston Model 888 Type 3Y2” on surviving examples), and in civil use as the Glide Path LOC Indicator Model 888 — the same instrument serving both VAR visual track and ILS localizer functions, as the 90/150 Hz tone comparison principle is identical in both systems.⁵

Variants of the Model 888 include the Type 3P1 (glide slope and LOC, used with ILS) and the Type 3Y2 (course indicator, used for VAR and LOC). The Weston Model 1172 that Jan mentions was a later version of the same instrument, updating the Model 888’s design for improved reliability and reduced maintenance. The Model 888 series is now a collector’s item, found at aircraft parts salvage dealers and occasionally at airshow autojumbles.

In Australia, the DCA 1953 specification describes the cross-pointer indicator’s blue and yellow sector arrangement in considerable detail. Whether Australian operators used Weston instruments specifically, or equivalent types from other manufacturers, is again a question best resolved by the Airways Museum at Essendon. The DCA publication does note that “usability and warning indicator” modifications were made to the horizontal pointer in some Australian installations — suggesting that Australian operators occasionally adapted the standard US equipment to local DCA requirements.

Part V — VAR Timeline: From Invention to Retirement

Part VI — Direct Answers to Jan’s Questions

1. Had I heard of VAR?

Yes — it is a well-documented piece of aviation navigation history, though not commonly known outside of serious aviation history circles and those with an interest in early avionics. The system was essentially forgotten in the United States after 1960, but it remained very much alive in Australia for another two decades.

2. Was VAR popular in Australia during the Cold War?

It was not merely popular — it was the backbone of instrument flying in Australia from 1953 to 1980. Every instrument-rated pilot on the trunk routes between Sydney, Melbourne, Brisbane, Adelaide, and Perth flew VAR approaches and en-route tracks. Ansett Airlines, Trans-Australia Airlines (TAA), and all IFR general aviation operators depended on it. The Australian VAR network of approximately 50 stations was the most extensive outside the United States and the longest-lived anywhere in the world.

The “Cold War” framing is apt: Australia’s VAR network was a 1953 construction and remained in full service into the OPEC-crisis era. The pilots who trained on it and flew it every day worked in a Cold War world, and the system represented a technically conservative but entirely reliable approach that suited Australian conditions.

3. Which vendor of VAR equipment was most popular in Australia? Was it Collins?

The definitive answer to market share by manufacturer would require access to DCA/CASA historical equipment certification records, which are held at the Airways Museum at Essendon Airport, Melbourne. However, the weight of evidence strongly suggests:

• Collins Radio was certainly a significant supplier of airborne VHF NAV equipment to the Australian market, particularly after the mid-1950s when Collins had established itself as the dominant name in professional avionics for airline and corporate aviation. The 51V-2 and its successors covered the VAR band.
• ARC (Aircraft Radio Corporation) supplied the dedicated Type 16 VAR receiver and was a major early supplier, particularly before Collins’ complete dominance of the market. ARC’s Type 12 and Type 16 sets were widely used in US-sourced aircraft that came to Australia during and after WWII.
• Weston Instruments Model 888 indicators were the standard cross-pointer instrument across the industry, used regardless of which receiver manufacturer was chosen. They would have been fitted in most Australian VAR-equipped aircraft.
• For general aviation (light aircraft), King Radio VHF NAV receivers were popular from the late 1950s onwards, feeding the same Weston-type indicators.

References & Sources

1. Flying the Beams — “VAR: An Interim Step” — flyingthebeams.com/its-fate. Comprehensive history of the VAR system in the US and Australia, including station counts and the Lorenz–VAR transition. The primary web source for VAR history.
2. DCA Publication No. 19 (January 1953) — Operational Notes on Visual-Aural Radio Range and Associated Marker Beacons. Commonwealth of Australia, Department of Civil Aviation. Reproduced at: airwaysmuseum.com and chingchic.com. The definitive primary source for the Australian VAR network at commissioning.
3. Wikipedia — Visual Aural Radio Range — en.wikipedia.org/wiki/Visual_Aural_Radio_Range. References the 1953 DCA Publication No. 19 as a primary source.
4. Wikipedia — Aircraft Radio Corporation — en.wikipedia.org/wiki/Aircraft_Radio_Corporation. History of ARC from 1924; Doolittle blind flight connection; acquisition by Cessna 1959.
5. Weston Model 888 — US military designation ID-48/ARN — eBay item 127025585440 (Army aircraft ID-48/ARN course indicator, Weston Model 888 Type 3Y2); Automatic Aerospace parts listing; BAS Airplane Parts. Confirms Weston 888 as the standard VAR/ILS localiser cross-pointer instrument.
6. Australian Civil Aviation Historical Society & Airways Museum — airwaysmuseum.com. Essendon Airport, Victoria. Holds original DCA records, Lorenz beam documentation, VAR network records, and operating-era photographs. Recommended for primary source research on Australian VAR equipment specifics.
7. 1938 Kyeema crash — en.wikipedia.org/wiki/1938_Kyeema_crash. The catalyst for Australia’s Lorenz Aeradio network, the direct predecessor to VAR.
8. Collins Aerospace Museum Products Database — collinsaerospacemuseum.org/products/. Collins product line including 51V-2 airborne VHF NAV receiver.
9. Jan SP5XZG — enquiry email, 28 March 2026. Identified the 1967 Australian DCA reference document; ARC Type 16; Weston Model 888 and 1172; Collins early VHF NAV equipment; raised question of Australian market dominance.