Flightdeck Friday – A3J/A5A Vigilante

It is late 1960 in America – 13 December to be exact. Across the country the mood is reflective and restive. The prosperity of the fifties had netted Americans a bewildering array of choices in everything from products for the home to the cars they drove and sealed American dominion across the globe. The recently concluded Presidential election saw a close finish with a relative newcomer, challenging Americans to a New Frontier which could be found in areas as disparate as the African continent or the reaches of space. “Change” was the watchword for the new decade – be it a new Administration’s intent to implement Keynesian economics to “get America moving again” or Harold Macmillan’s Winds of Change speech that would light the fuse for the final dismemberment of the British Empire; “change” was the order of the day for the new decade. Change was also in evidence in the form of a volubly demonstrative Soviet presence, given an inflated persona courtesy new regimes led by Communist revolutionaries and closely managed demonstrations of missile prowess.

In the far western US, change was also present on the ramps of a sprawling complex that occupied the dried Muroc lakebed – Edwards AFB. There the collective scientific, engineering and industrial genius of the previous decade was taking form. A collection of aircraft were to be found there that were both a tour de force and broke new ground. Whether it was speed, altitude, methods of propulsion, construction materials, or control technology, they all had one thing in common for all their differences – to a plane, they all sought to push the edge of the envelope out a little more.

Some, like those that sported a “USAF” on their flanks, found it via dramatic lines – needle sharp forms held aloft on impossibly small wings, meant to violently pierce and peel away clinging air molecules in the quest for speed. Others, commonly found with a USN on the side, seemed to seduce the wind with their graceful curves, in some cases assuming an almost manta-ray like form in the sky. And yet, there was one that was different. Broad of shoulder, with a long, almost needle-like nose and a vertical tail that soared like some prehistoric shark’s above the other offerings – this one was different.

It was built by a company who emerged from the war mists of a decade and a half ago with a classic design and who again in the skies over Korea, had provided a swept wing fighter that earned a reputation as a killer of MiGs in the frozen spaces over the Yalu River. The same company with a reputation for innovation that provided the Navy with its first nuclear bomber designed to operate off a carrier and whose jet-black winged rocket was bringing Americans to the very edge of space.

This was the North American A5A Vigilante and it was poised on this day to set a world altitude record that would stand until the following decade.

As far back as 1953, North American Aviation sought to build an aircraft capable of delivering a nuclear weapon at supersonic speeds – a far cry from the slower, prop-driven AJ Savage that was its first offering, and taking on the A3D Skywarrior and A4D Skyhawk being built by rival Douglas Aircraft.

Under the head-scratching acronym of NAGPAW (North American General Purpose Attack Weapon), a company funded proposal began to take form. With twin GE J79 turbojets, delivering 17,000 lbs of thrust – each, in afterburner, the design incorporated such radical concepts as boundary layer control, variable inlet ramps, aluminum-lithium alloy for wing surfaces and titanium alloy for strength and lightweight in critical structural areas. The crew of two (pilot & BN) would have an integrated weapons system that included a HUD, multi-mode radar, inertial navigation system (from the company’s Navajo cruise missile)and an early digital computer to run the show. The Navy liked what it saw and, after some modifications (like moving to a single vice dual vertical stabilizer), awarded NAA a contract in 1956.

First flight was in 1958 and carrier trials conducted aboard USS Saratoga (CV 60) in July 1960 and by June 1961 it was equipping the RAG (VAH-3) by 1960 and made its first operational deployment aboard USS Enterprise (CVAN 65) in 1962 with VAH-7.

So how was the operational record of the aircraft? Not quite what was anticipated. Like many aircraft of the period, it suffered from frequent mission computer failures (one source notes MTBF – Mean Time Between Failures, was measured at a mere 15 minutes in the early production run). There were other issues as well – the fact that it was a challenging aircraft to fly around the ship and the primary weapon system, a “train” that was launched out of the internal weapons bay via a shot from the ejection gun, worked so poorly it was not used in the fleet. This train was comprised of a Mk 28 nuclear weapon and two fuel tanks – the CONOPS being that the weapon would be ejected with the two (empty) fuel tanks which would stabilize it. Instead what they found was the “package” did not perform as advertised and had a nasty habit of “drafting” with the rapidly accelerating drop aircraft. These and other concerns led the Navy to limit production runs of the A3J-1 and -2 (which would later be turned into the A5A vi McNamara’s renaming scheme in 1963). All was not lost, however, as we will see next week.

And the record breaking crew? The crew, consisting of LCDRs Leroy Heath (Pilot) and Lieutenant Larry Monroe (Bombardier/Navigator) established a world altitude record of 91,450.8 ft while carrying a 1,000 kilogram payload, besting the previous record by over four miles. This new record held for over 13 years. See for yourself.

General characteristics

* Crew: 2
* Length: 76 ft 6 in (23.32 m)
* Wingspan: 53 ft 0 in (16.15 m)
* Height: 19 ft 5 in (5.9 m)
* Wing area: 754 ft² (70 m²)
* Empty weight: 32,700 lb (14,800 kg)
* Loaded weight: 47,530 lb (21,580 kg)
* Useful load: 30,250 lb (13,730 kg)
* Max takeoff weight: 62,950 lb (28,580 kg)
* Powerplant: 2× General Electric J79-GE-8 afterburning turbojets
o Dry thrust: 10,900 lbf (48 kN) each
o Thrust with afterburner: 17,000 lbf (76 kN) each

Performance

* Maximum speed: Mach 2.0 (1,320 mph, 2,123 km/h) at altitude
* Range: 1,290 mi (2,075 km)
* Service ceiling 52,100 ft (15,880 m)
* Rate of climb: 8,000 ft/min (40.6 m/s)
* Wing loading: 80.4 lb/ft² (308.3 kg/m²)
* Thrust/weight: 0.72

Armament

* Bombs:
o 1— B28 or B43 freefall nuclear bomb in internal weapons bay
o 2— B43, Mark 83, or Mark 84 bombs on two external hardpoints