The A-1’s 12 outer wing stations were able to carry 500-lb class stores. The two Inboard Stations (commonly called stubs) carried up to 2000 lbs each and the Centerline Station could cope with up to 3600 lbs of ordnance.
Taken by former A-1 pilot Byron E Hukee (be sure to visit his Skyraider.org website. His ‘virtual’ book, the A-1 Combat Journal, on that website chronicles his one year tour flying the A-1 in combat with 1st Special Operations Squadron during the Vietnam War) the cool main image of this post features the typical Skyraider ordnance load for a Sandy mission.
As Hukee himself explains in his book USAF and VNAF A-1 Skyraider Units of the Vietnam War, the A-1’s 12 outer wing stations were able to carry 500-lb class stores. The two Inboard Stations (commonly called stubs) carried up to 2000 lbs each and the Centerline Station could cope with up to 3600 lbs of ordnance. Multiple ejector racks (MERs) could be fitted on the Inboard Stations to increase the number of munitions loaded. Ordnance carried by both USAF and VNAF Skyraiders can be grouped into the following categories – guns, bombs, napalm, rockets, cluster bombs (CBUs) and miscellaneous stores.
The four internal M3 guns carried 200 rounds of percussion-primed 20 mm ammunition each. The weapons were fired in pairs, inboards or outboards. The nominal rate-of-fire was 600-800 rounds per minute (10-14 rounds per second), which meant guns could be fired out in approximately ten seconds. There were two types of 20 mm rounds typically used for combat, the M95 Armor Piercing Tracer (APT) and the M97 High Explosive Incendiary (HET). Muzzle velocity for both rounds was 2730 ft per second.
The SUU-11 gun pod (known as the minigun) was also often carried on the Inboard Station(s). This was a six-barrel Gatling-type weapon that was rated at 6000 rounds per minute (100 rounds per second). The minigun, which carried 1500 rounds of 7.62 mm ammunition, was a very effective weapon for close-in work around friendly troops or a downed aviator during a SAR mission.
The A-1 carried three main types of bombs — general-purpose (GP) bombs, fragmentation bombs and white phosphorus bombs (WP).
The earliest GP bombs used by A-1s were those left over from Korean War stockpiles that in fact originated from World War 2. These were available in a variety of sizes, and could be used with either box or conical fins. The designations for the bombs that were most often carried on the A-1 were M30 (100-lb), M57 (250-lb), M64 (500-lb), M117 (750-lb) and M66 (1000-lb).
These older GP bombs of lower yield were very good for supporting friendly troops under close attack by enemy forces. They could be dropped within 100 ft of protected friendly troops against enemy forces in the open.
An improved family of GP bombs (referred to as low drag GP or LDGP) was developed by the US Navy in the late 1960s. Designated the Mark (Mk) 8X series, these were a big improvement over earlier GP bombs. The sizes available were Mk 81 (250-lb), Mk 82 (500-lb), Mk 83 (1000-lb) and Mk 84 (2000-lb).
All GP bombs required fuses — typically a nose and tail fuse for redundancy. The fuse was a timer that armed the weapon after it had fallen for a predetermined period following its release, allowing the aircraft to be safely away from the blast. Fuse extenders (referred to as ‘Daisy Cutters’) were often used to ensure that the bomb detonated before penetrating soft earth. The Skyraider pilots of the 1st ACS and 602nd Fighter Squadron Commando), pioneered the early use of ‘Daisy Cutters’. Initially, a non-serviceable 20 mm gun barrel was welded to the bomb nose plug that was then threaded back into the fuse well of the bomb. Later, an iron pipe was welded to the fuse plug instead. The problem with the extenders was that they were often not aligned to the longitudinal axis of the bomb, which resulted in diminished accuracy.
These early efforts got the attention of the munitions professionals, and before too long production fuse extenders were used not just by A-1s, but also by the entire force of both fighters and bombers from all services in Southeast Asia.
Early fragmentation bombs were used when enemy troops were the expected target. M81 and M88 fragmentation bombs were 250-lb class weapons that were essentially the same bar their slightly different construction. Their similarity allowed them to be fielded interchangeably. A more commonly used fragmentation bomb was the M1A frag cluster bomb. It consisted of a pre-built cluster of six 20-lb fragmentation bomblets banded together in a six-bomb cluster. The M1A was used throughout the war by A-1s of both services.
The final member of the bomb family was the M47 100-lb WP weapon. The favoured munition of many USAF A-1 pilots, it was used in the early stages of the conflict, as well as at the very end. The bomb’s white phosphorus filler, which burned at a higher temperature than napalm, spread on impact when the weapon was dropped armed. If dropped safe, the bomb would crack open on ground contact and the white phosphorus would provide a smoke marker visible from the air for more than an hour.
Napalm was often used, being expended in 500- and 750-lb versions. The smaller of these two was carried on the outer wing stations of the A-1, whilst the larger could only be carried on the Inboard Stations. Early napalm stores were mixed and loaded on base, but later versions were premixed off base and supplied to units ready to load. Once the weapon was attached to an aircraft, installation of the fuse was all that remained. Napalm came in finned and unfinned versions. Finned ‘nape’ allowed for better accuracy, but limited the weapon’s ‘splash’ pattern. Since the Skyraider was very accurate due to its low speed, unfinned napalm was preferred due to its wider burn pattern.
The A-1 also regularly used rockets, of which there were two different kinds (irrespective of the warhead) compatible with the aircraft. More common was the 2.75-in FFAR (Folding Fin Aerial Rocket), which was always carried in a launcher pod of either seven or 19 tubes. The seven-tube rocket pods were the LAU-59 and LAU-68, while the 19-tube pods were the LAU-19 and LAU-3. Rockets could be fired singly in the seven-tube launcher, but had to be fired in pairs (all bar the first rocket, which was a single shot) out of the 19-tube launchers.
Warheads for the 2.75-in FFARs could be white phosphorus (WP or `Willy Pete’), high explosive (HE), high-explosive anti-tank (HEAT) or flechette. The latter warhead contained approximately 2500 stamped darts that look like six-penny finishing nails with three circular shaped fins instead of a nail head. Normally, an entire pod would be loaded with a single type of warhead, rather than having them mixed.
The other, less common, type of rocket was the 5-in high velocity aerial rocket (HVAR), which was single-mounted to the outer wing station pylons. Thus, a maximum load of 12 could be carried on one sortie.
The cluster bomb units (CBUs) dropped from Skyraiders were different from those used by jet aircraft of the period. In 1964, William M Mogan and his team at the First Combat Applications Group at Hurlburt Field developed a new CBU dispenser specifically for the A-1, the SUU-14. Just over six feet in length, it consisted of six tubes arranged in a triangular shape held together by reinforcing metal. What was different with this dispenser was that it stayed attached to the A-1 and the bomblets were ejected out the back of it.
The first CBU munition to use the SUU-14 dispenser was the CBU-14, which worked fine against targets in the open but was inadequate in forested areas because the BLU-3 bomblet would detonate in the treetops, which may have been 100 ft or more above the enemy. Additionally, the dud rate for the BLU-3 was quite high, and provided the enemy with a supply of anti-personnel munitions for use against friendly troops in the form of booby traps.
Recognising the need for an improved CBU munition for the Skyraider, a second version was developed and fielded in September 1970. Still using the innovative SUU-14 dispenser, the CBU-25 contained 132 BLU-24 bomblets (22 per tube) with fusing that allowed them to penetrate the jungle canopy before they detonated. The CBU-25 proved to be a great improvement over its predecessor, the CBU-14. Indeed, it was used on nearly every load we carried during Hukee’s tour, and was featured on the `Sandy’ mission load.
Another CBU that used the SUU-14 dispenser was the CBU-22, which contained 72 BLU-17 white phosphorus smoke bomblets. The CBU-22 was used as an incendiary weapon, or to create a dense smoke screen to shield rescue helicopters from an enemy ground threat.
An interesting munition that was used when Skyraiders were in the `truck killing’ role over the Ho Chi Minh Trail was the M36 incendiary bomb, referred to by A-1 pilots who employed the weapon as the ‘funny bomb’. The M36 was developed during World War 2, which in fact it helped bring to an end. The bomb was one of the principal weapons used in the fire-bombing of Japanese cities that quickly led to the dropping of the atomic bomb and the surrender of Japan. Somewhere, somehow, stocks of these leftover munitions were located and shipped to Nakhon Phanom for use by A-26s and A-ls, which were the principal truck killers on the trail in 1969.
Although the M36 functioned much like a more modern CBU, technically it was not a CBU. Rather than bomblets being ejected from a dispenser, with the M36 its bomb casing split open and dispensed thermite grenades that consumed anything with which they came into contact, including trucks. It was the weapon of choice, with the grenades putting on quite a pyrotechnics show since the M36 was almost exclusively used at night. For that same reason very few photographs exist of this weapon.
Anti-personnel area denial munitions were occasionally used to prevent an approaching enemy from directly contacting friendly forces on the ground. These munitions were chemical (non-lethal) riot control agents that would incapacitate personnel for varying periods of time ranging from 15 minutes to two hours. This category of munition was not used by the VNAF.
These weapons could be delivered in two main ways by the A-1. The BLU-52 was actually a 750-lb napalm tank filled with CS agent in powderised form. No fuse was needed when employing this munition because the thin-walled case of the tank ruptured on impact with the ground, dispensing its powder over a wide area.
The CBU-19 and CBU-30 could also be used in conjunction with non-lethal CS agent, the latter being contained within small bomblets that were in turn packed into the CBU canister. The CBU dispensers were retained on the aircraft, with their contents being ejected out the bottom of the canisters. This method of delivery covered a wider area than the BLU-52. The CBU-19 was used in the early war years, before being replaced by the improved CBU-30.
One final store that was available to drop was the Madden Kit. This was not a weapon but rather a ‘survival kit’ that contained items — maps, a survival radio and/or batteries, signalling devices, water or food — that a downed airman needed to facilitate his rescue.
USAF and VNAF A-1 Skyraider Units of the Vietnam War is published by Osprey Publishing and is available to order here.
Photo credit: Byron E Hukee and U.S. Air Force