This is once again a work in progress, last updated on 6 December in the AM. I'm on the road so I don't have access to all my files. There may therefore be more errors and misstatements in the following than usual. Even then, it will pale beside the information available at Bob Jellison's website.
When the first pictures of the A3J-1 were published in Aviation Week, I thought it was the most beautiful airplane that I had ever seen. It was intended to replace the carrier-based, long-range atomic bomb delivery capability then provided by the Douglas A3D Skywarrior, except it was supersonic with a unique weapon delivery system. As it happened, only 59 were built, including the two prototypes, since it was the victim of a budget battle won by the proponents of the submarine-launched Polaris missile.
The nuclear bomb was carried internally but not dropped. Instead it was propelled rearward, attached to empty fuel tanks, out the back of the airplane at about 30 knots, not at the same speed as the aircraft as is sometimes stated and the store also did not get sucked along, affecting bombing accuracy as is frequently reported; it worked as advertised. However development of satisfactory accuracy and reliability of the bombing system was not achieved by the time it was apparent that Polaris was the better alternative for the requirement.
Before the bomber version was cancelled, however, the range of the Vigilante was to be improved with the A3J-2. Additional fuel was added by increasing the height of the fuselage over the wing and adding two additional external stores pylons. The extra weight was accommodated with a bigger wing and flaps and the addition of boundary layer control to the leading edge flaps. The engine inlet was also modified. Note that in the -2 prototype, the bleed air piping for the leading edge slats ran forward in the armpit of the wing.
The Navy ordered 18 -2s but only two were completed as such. The next four were built to aerodynamically represent a reconnaissance version, the A3J-3P, and used for transition training in the replacement air group squadron. (The leading edge BLC piping was relocated to above the wing and integrated with the overwing fairing.) The last 12 became the first RA-5Cs, the redesignation of the A3J-3P in November 1962.
These two pictures illustrate the difference in wing planform between the A3J-1 and the RA-5C.
If you look closely at the pictures (click on them first) you'll see two different positions of the unusual A3J/RA-5 lateral control system, one to roll left and the other to roll right. There were two sets of spoiler/slot/deflector controls on each wing, one to raise it and the other to lower it. The spoilers were hinged at the leading edge and the deflectors at the trailing edge to direct air flow through the slot.
All four sets were opened simultaneously to function as a speed brake.
The RA-5C was probably the best, certainly the most capable, reconnaissance airplane the Navy ever operated from carriers. It has never been replaced with anything comparable. It was fast, with good range/endurance, and big enough to carry an internal equipment pallet and a belly pod that could be fitted with cameras, side-looking radar, and electronic signal detectors. It retained the weapon delivery capability using the stores pylons but it is unlikely that it was ever used as an attack airplane, considering the RA-5C's value as a reconnaissance platform and that relatively few were assigned to each carrier air wing.
Counting the 12 A3J-2s that were completed as RA-5Cs, 91 RA-5Cs were built for a total of 156 aircraft:
2 XA3J-1s BuNos 145157/8
57 A3J-1s (A-5As) BuNos 146694/708, 147850/863, 148924/933, 149276/299
2 A3J-2 prototypes BuNos 149300/1
4 YRA-5C (YA3J-3P) BuNos 149302/5
12 RA-5C (A3J-3P) BuNos 149306/17
43 RA-5C (J79-GE-8) BuNos 150823/842, 151615/634, 151726/151728
36 RA-5C (J79-GE-10) BuNos 156608/653
The nomenclature above is not precise in all cases since it is intended to differentiate between the various contracts, initial intentions, etc. Note that -3 is not a typo.
The 91 RA-5Cs built were augmented by conversions of earlier production. Not all sources agree, but Joe Baugher's website provides a list of conversions by BuNo. According to his tally, there were 43 A-5As converted including one of the A3J-1 prototypes. In addition, the first six of the original order of 18 A3J-2s were rebuilt to the RA-5C configuration, for a total fleet of 140. Some sources state 134, with the difference likely being the omission of the two A3J-2 prototypes and the four YA3J-3Ps. Of course, due to attrition (almost half of the A-5s built were destroyed in accidents and combat), the fleet never totaled 140 aircraft at any time. In fact, the production line was restarted, a very rare event, to build the last block of aircraft in order to bring the numbers back up to a satisfactory level.
The last new-build RA-5Cs were slightly different in addition to being powered by the J79-GE-10, which had a notably different afterburner nozzle.
Also see http://tailspintopics.blogspot.com/2012/12/j79-exhaust-nozzles.html
The engine inlet of the last new-build aircraft had a different outboard shape, being straight instead of curved, and a small leading-edge extension was added along the side of the nacelle.
Early RA-5C inlet:
Late RA-5C inlet and leading edge extension:
There were, of course, detail changes over time to the ECM antennas, tail cone, etc. It also appears that some of the conversions from A-5As (and a couple of early build RA-5Cs) were to the later build inlet configuration with the leading-edge extension like BuNo 146702 shown here. Note that the RA-5C vertical fin tip slopes downward from front to back due to the addition of an IFF antenna.
From photographs, Craig Kaston has identified the following BuNos as receiving the late-build configuration: 146702, 149276, 149287, 149299, 149301, 150831, and 151630. Note that the last two were originally delivered as RA-5Cs in the early configuration.
Trumpeter has produced both 1/72nd and 1/48th kits of the RA-5C. It is reportedly a mix of features of the early and late configurations, but the major knock on the kit is the shape of the forward fuselage and vertical fin. For comparison, here are Rockwell drawings. (The first one shows the tip of the vertical fin as being roughly straight across, which is incorrect for almost all, if not all, of the RA-5Cs.)
As usual, Steve Ginter offers one of the best monographs on the subject, North American A-5A/RA-5C Vigilante Naval Fighters Number 64. It is also generally available from Sprue Brothers, along with lots of other Vigilante kits and stuff.
To be continued...
When the first pictures of the A3J-1 were published in Aviation Week, I thought it was the most beautiful airplane that I had ever seen. It was intended to replace the carrier-based, long-range atomic bomb delivery capability then provided by the Douglas A3D Skywarrior, except it was supersonic with a unique weapon delivery system. As it happened, only 59 were built, including the two prototypes, since it was the victim of a budget battle won by the proponents of the submarine-launched Polaris missile.
The nuclear bomb was carried internally but not dropped. Instead it was propelled rearward, attached to empty fuel tanks, out the back of the airplane at about 30 knots, not at the same speed as the aircraft as is sometimes stated and the store also did not get sucked along, affecting bombing accuracy as is frequently reported; it worked as advertised. However development of satisfactory accuracy and reliability of the bombing system was not achieved by the time it was apparent that Polaris was the better alternative for the requirement.
These two pictures illustrate the difference in wing planform between the A3J-1 and the RA-5C.
The RA-5C was probably the best, certainly the most capable, reconnaissance airplane the Navy ever operated from carriers. It has never been replaced with anything comparable. It was fast, with good range/endurance, and big enough to carry an internal equipment pallet and a belly pod that could be fitted with cameras, side-looking radar, and electronic signal detectors. It retained the weapon delivery capability using the stores pylons but it is unlikely that it was ever used as an attack airplane, considering the RA-5C's value as a reconnaissance platform and that relatively few were assigned to each carrier air wing.
Counting the 12 A3J-2s that were completed as RA-5Cs, 91 RA-5Cs were built for a total of 156 aircraft:
2 XA3J-1s BuNos 145157/8
57 A3J-1s (A-5As) BuNos 146694/708, 147850/863, 148924/933, 149276/299
2 A3J-2 prototypes BuNos 149300/1
4 YRA-5C (YA3J-3P) BuNos 149302/5
12 RA-5C (A3J-3P) BuNos 149306/17
43 RA-5C (J79-GE-8) BuNos 150823/842, 151615/634, 151726/151728
36 RA-5C (J79-GE-10) BuNos 156608/653
The nomenclature above is not precise in all cases since it is intended to differentiate between the various contracts, initial intentions, etc. Note that -3 is not a typo.
The 91 RA-5Cs built were augmented by conversions of earlier production. Not all sources agree, but Joe Baugher's website provides a list of conversions by BuNo. According to his tally, there were 43 A-5As converted including one of the A3J-1 prototypes. In addition, the first six of the original order of 18 A3J-2s were rebuilt to the RA-5C configuration, for a total fleet of 140. Some sources state 134, with the difference likely being the omission of the two A3J-2 prototypes and the four YA3J-3Ps. Of course, due to attrition (almost half of the A-5s built were destroyed in accidents and combat), the fleet never totaled 140 aircraft at any time. In fact, the production line was restarted, a very rare event, to build the last block of aircraft in order to bring the numbers back up to a satisfactory level.
The last new-build RA-5Cs were slightly different in addition to being powered by the J79-GE-10, which had a notably different afterburner nozzle.
The engine inlet of the last new-build aircraft had a different outboard shape, being straight instead of curved, and a small leading-edge extension was added along the side of the nacelle.
Early RA-5C inlet:
Late RA-5C inlet and leading edge extension:
There were, of course, detail changes over time to the ECM antennas, tail cone, etc. It also appears that some of the conversions from A-5As (and a couple of early build RA-5Cs) were to the later build inlet configuration with the leading-edge extension like BuNo 146702 shown here. Note that the RA-5C vertical fin tip slopes downward from front to back due to the addition of an IFF antenna.
Trumpeter has produced both 1/72nd and 1/48th kits of the RA-5C. It is reportedly a mix of features of the early and late configurations, but the major knock on the kit is the shape of the forward fuselage and vertical fin. For comparison, here are Rockwell drawings. (The first one shows the tip of the vertical fin as being roughly straight across, which is incorrect for almost all, if not all, of the RA-5Cs.)
As usual, Steve Ginter offers one of the best monographs on the subject, North American A-5A/RA-5C Vigilante Naval Fighters Number 64. It is also generally available from Sprue Brothers, along with lots of other Vigilante kits and stuff.
To be continued...
I am researching the dimensions and stenciling of the RA-5 speed brake, which I understand these were not speed brakes per se, but spoilers on the upper surface of both wings that could be raised simultaneously to create drag. In various drawings I can see several upper wing horizontal control surfaces but am not sure which one is the spoiler/speed brake (I know this aircraft had a complicated flight control system). Any information you could provide would be helpful.
ReplyDeleteThere were two sets of spoiler, slot, and deflector on each wing (and no ailerons). The deflector was hinged on its aft side so it directed air into the slot; the spoiler was hinged on its forward side to open the slot for the deflected air to escape. One set raised that wing. The other set lowered it. The inboard set took up more of the span than the outboard set, presumably to equalize the rolling moment. If you look closely at the comparison pictures of the A3J and RA-5C above, you'll see two different roll-control configurations, one to roll left and one to roll right. I've added an illustration of the spoiler/slot/deflector.
ReplyDeleteSpeed brake actuation opened all four sets of roll controls simultaneously. Roll control was then accomplished by partially closing the opposing sets, reducing speed brake effectiveness.
Thank you very much for your prompt and complete answer and I appreciate the illustration you added - I've always wondered how that flight control arrangement worked. I don't know how to attach a file in this blog but the overhead views I've found of the A-5 show what appear to be 3 (maybe 4) control surfaces forward of the trailing edge flaps and inboard of the wingfold. I'm trying to find the measurements of these surfaces and what any stenciling was, such as "NO STEP" and if any would have been marked "SPEED BRAKE". I've looked at various plastic modeling sites but they either show no stenciling or the images are not high enough resolution to make out the words. Any images or URLs are appreciated.
ReplyDeleteTrying to contact aircrew (Harry Hawken?) or others from NAS Albany 1972. I'm former Air Force pilot who joined up with distressed Vigilante that had complete hydraulic failure. Finally they lost control and ejected as we approached the airfield. Their canopy & seats nearly hit me on the way out.
ReplyDeleteTy Harris tyowah@gmail.com