AD-3 versus AD-4 Skyraider

 Sword has just released a very nice 1/72 AD-3/4 Skyraider kit. This is the illustrated Hyperscale review: 

https://www.hyperscale.com/2025/reviews/kits/sw72151reviewbg_1.htm 

Brett mentions the addition of armor as a result of combat experience (also see discussion and link below) but not that the kit fuselage does not have it. Sword was aware of the option and chose to produce the kit without the armor. For one thing, most if not all of the Skyraiders represented by the decals in the kit did not have the armor. It is a lot easier to add it than to remove it. The most obvious difference is a fixed step on the side of the fuselage (armor) versus a kick-in step. The presence of the 1/2" thick applique plating itself is subtle, not much more than a layer or two of paint in 1/72 scale. 

Of note is that the -4 was initially very similar to the -3 but there were a few external detail differences. In fact, the only external difference between the last AD-3 built and the first AD-4 appears to be the windscreen, both of which are in the kit :

However, over time, changes were made to the -4 in production, which were retrofitted to delivered AD-4s and some AD-3s. For example, the addition of "armor" (it was really only effective against shrapnel and glancing bullets). See https://tailspintopics.blogspot.com/2013/07/ad-armor-all.html 

This is a work in progress on the AD-4 configurations: https://tailspintopics.blogspot.com/2022/04/douglas-ad-4-skyraider-variants.html

 I advised Sword that these configurations were representative of late AD-3 and AD-4 production :

 AD-3

- no armor

- two cannon

- early rudder (no bottom notch)

- no static source boom at the top of the fin

- no nose flaps

AD-4

- armor

- four cannon

- later rudder (bottom notch)

- static source boom at the top of the fin

- exhaust glare shield

- nose flaps

 

However, there would be significant variation from that with individual aircraft, e.g.  Antennas, wing tip lights, exhaust glare shield, etc.

The AD-3 and AD-4 had the same centerline (except for the -4B), and inboard stores pylons. There were three different outboard pylons: small (rocket only); bigger (rocket and small bomb); and biggest: it's likely that the AD-3 could utilize the "bigger" one; for sure the biggest one that was standard on the AD-5/6/7 could be used on the AD-4. See https://tailhooktopics.blogspot.com/2013/12/things-under-wings-aero-pylons.html

 These are my notes on Jay Sherwood's Skyraider Modeling Guide: https:tailspintopics.blogspot.com/2011/10/ad-skyraider-modeling-notes.html

More later...

Target Towing and Drone Control Color Scheme: Engine Gray and Orange Yellow

 The same MIL specification dated 23 February 1955 that implemented the Gull Gray/White paint scheme changed the paint scheme of target towing and drone control aircraft. From Elliott, Volume 3:

The fuselage, cowling, and engine nacelles on multi-engine aircraft were Engine Gray except surfaces extending into the topside of wings. In this case, these surfaces were painted to match the wings. The horizontal stabilizer, elevators and vertical fin were Orange Yellow. The vertical fin fairing was painted to match the fuselage. The Orange Yellow terminated on a line formed by projecting the fin leading edge down to the fuselage. Wing walkways could be either Engine Gray or, in the case where the wing is utilized to enter the aircraft, they could be antiskid black material. The rudder was painted Insignia Red. Insignia Red bands three feet wide encircled the wing panels. On single-engine aircraft, the bands were located one-third the distance from fuselage to wing tip, with the center line parallel to the thrust line. On multi-engine aircraft, the bands were located midway between the national aircraft insignia and the engine nacelle with the center line of the bands parallel to the thrust line. However, in the event there was insufficient space to locate these bands as specified above they could be located adjacent to the outboard nacelles. The national aircraft insignias could overlap the wing bands, but the bands could not overlap the insignia. The national aircraft insignia could not be altered in size or location to accommodate these markings.

 

In August 1959, florescent Red-Orange replaced Insignia Red and the entire vertical fin was to be red.

 Florescent paints weren't very durable, so in May 1965, they were replaced with International Orange.

 

More later...

Ginter Books

 Steve Ginter no longer has his own website but he is still creating and publishing books. You can contact him directly for availability and pricing (nfbooks@sbcglobal.net ) or look for them here: https://daviddoylebooks.com/ginter-books-covers?rq=Ginter

 

F7U-3 Series Model Kits - Part Two

18 October 2004:  Sylvain Deloire informed me of the availability of "3D" decals for the 1/72 Fujimi kit. For details, click HERE

For an introduction and Part One, which was dedicated to the 1/72 Fujimi kits, click here: https://tailspintopics.blogspot.com/2024/10/f7u-3-series-model-kits.html

 Several model kits of the F7U-3 have been produced, beginning shortly after its first flight. Some are long out of production and now sought after collectors and modeling enthusiasts willing to pay many multiples of a kit’s original price. Note that the vacuum-formed kits consist of plastic sheets from which the individual parts have to be cut out and prepared for assembly.

For more detail on these kits and many others, search for "F7U" on Scalemates 

Vacuum formed

Airmodel 1/72 F7U-3/3P Kit Number 156: A very simple kit with no cockpit parts, decals, or landing gear. However, it is an appropriate basis for creating a manufacturer's desktop model.

 

Rare Plane 1/72nd Scale F7U-3: It is more complete than the Airmodel kit with good surface detail (female mold) but slightly inaccurate in shape and does not include decals.

ID Models 1/32 F7U-3 (subsequently reissued by Tigger Models):Vacuum formed on a male mold so the surface detail is all but nonexistent and complex shapes are not rendered accurately. The manufacturer characterizes them as “very basic canvases”, which is accurate.

Injection molded

 
Revell 1/60th Scale F7U-3/3M Cutlass: First released in 1953, there were several different variations released through 2010. It's pretty crude with raised lines for the placement or coloring of markings.

Brett Harper

Hobby Craft 1/48: This kit was first released in 1990 and subsequently released with other decals and/or  photo etched and while metal detail parts. Unfortunately, it has some notable shape and accuracy issues, e.g. the forward fuselage. For example, the radome and lower forward fuselage should not curve upward as much as they do in the kit. The windscreen has too big a step at its front edge and slopes aft at too shallow an angle. The cockpit detail is sparse and inaccurate, particularly the ejection seat. The late, great Phil (Bondo) Brandt also noted that the afterburners were undersized (read his full review and corrections—note that should not be an inflight refueling probe on an F7U-3M—HERE).

 As a result, several aftermarket improvements have been produced.

Lone Star Models produced a very detailed resin cockpit, that is far superior to the one in the kit as well as a resin F7U-3P nose. However, I was unable to determine their availability.

Reskit also produces a 1/48 Sparrow I missiles, RS48-0319.

CAT4 Scale Model Accessories has produced conversion parts for the detail problems other than the canopy:
R48029—Early F7U-3/-3M/-3P wheel hubs and tires
R48030—Later F7U-3/-3M/-3P wheel hubs and tires
R48040—Corrected radome (no inflight refueling probe)
R48041—Corrected radome with inflight refueling probe
R48046—Final production intake
R48047—Final configuration intake (Ubangi lower lip)

Falcon included a vacuum formed F7U-3 canopy in its Set No. 39, U.S. Navy Part 3 but it may not have improved on the shape in the Hobby Craft kit. Squadron subsequently produced one as a separate item, Squadron 9629 but again it is not known whether the shape was corrected; however, it is reportedly clearer and thinner than the kit canopy. Note that Squadron's name has been acquired by a new entity; the canopy is listed in their catalog but as out of stock.

Collect-Aire Models produced the ultimate Hobby Craft correction set.

Its resin parts replaced everything from the engine intakes forward. Also included was an accurate, but very thin vacuum formed canopy. Cast metal parts were provided for the cockpit detail and to replace the landing gear, except for the wheels. The decals allowed for the unique markings of VX-4 F7U-3M, a VA-212 F7U-3M, a VF-124 F7U-3M(129963?), and a VA-? (tailcode T) F7U-3M (129559?). One version of the kit and the Collect-Aire conversion is described in detail here: http://www.olddogsplanes.com/f7u.htm 

Resin

Fisher Model & Pattern 1/32 F7U-3M (#3209): Unfortunately not only out of production but the masters were destroyed in a fire since a complete, detailed, and accurate masterpiece can be created from the contents with no aftermarket corrections required.

Paul Fisher

In addition to exterior detail, the kit features inlet ducts leading to engine compressor faces and full-length afterburners. Brass main landing gear struts provide the strength necessary to support the weight of the resin wings and fuselage. All the control surfaces and the sliding canopy are positionable. There's a review with pictures by Mike Williams HERE.

F7U-3 Series Model Kits - Fujimi 1/72

9 October 2024: I've made detail changes to the text and added illustrations with more to come

10 October 2024: Lots of changes; now I await comments and corrections

11 October 2024: Revised Fujimi -3M Pylon Shape modification

In our F7U-3 book (click HERE), Al Casby and I had intended to include an appendix covering all the F7U-3 series model kits available. We decided to cut it in part because of the size of Al's F7U-3 kit and toy collection ("I’ve got enough material and photos to do an entire monograph on them") but also because of the transient nature of the availability of even the more recent plastic and resin kits. 

However, before we decided not to, Steve Ginter and I had created draft text describing most of the model kits and obtained or created illustrations to accompany it so this post and a subsequent one have the benefit of that.

Fujimi released 1/72 scale injection-molded kits of all three F7U-3 Cutlass variations, the -3 (also released as a Testors kit), -3M, and -3P. These are excellent kits, providing positionable ailavators and leading edge slats and a two piece canopy. With few exceptions, they are accurate straight from the box, there are corrections and aftermarket improvements. Fujimi wasn't helped by inaccuracies in the Vought PR-issued three view drawing or refurbishment of the F7U-3 in the Naval Aviation Museum at Pensacola (click HERE and HERE for details).

This is Paul Boyer's build of the F7U-3M.

 

F7U-3: The kit includes the belly-mounted rocket pack, inboard pylons, and 150-gallon external tanks. It is missing the inflight refueling probe that was added to many (but not all) -3s.

 As shown above, the F7U-3s had the early probe tip that resembled a nipple rather than a ball:

The cockpit is satisfactory but can be improved with Obscureco's F7U-3/3M Detail Set, OBS72030: click HERE.  It's not listed on his website but you can contact Chris at bucholtzc@aol.com.

Eduard produced a sheet of photo-etched parts, RES-IM No PE72009, to detail the cockpit, landing gear, etc.

Brengun and F4Models produced photo-etch boarding ladders, BRL72191 and FM7015 respectively.
 

Neither Fujimi or Obscureco do the instrument panel justice but it would difficult to do so in 1/72 scale. Probably the significant improvement would be the addition forward of the top of the instrument panel of the projector that put the gun-aiming image on the windscreen.

 

The radome shape when viewed from the side is just a little off, hardly noticeable if at all. This is a comparison with a very good Vought drawing. However if you want to tinker with it, the upper side needs to be a little steeper and a bit added to the lower side so it is even less symmetrical.

Note that this is F7U-3M forward fuselage part that has a vent halfway back along the left side of the canopy. Unfortunately the vent is not on the corresponding half of the F7U-3 part (at least in my kit), which is an error for most -3s.

The self-boarding pegs alongside the left side of the fuselage were extended whenever the landing gear was down. They aren't represented in the kit but are easily added.

The fairing at the base of the windscreen may also be enhanced. At the moment, these are the best pictures that I have to illustrate it:

The little mast at the base of the windscreen, located slightly left of the center line so it is behind the left frame of the windscreen, is the Davis barrier activator, aka guard. It should be added.

I haven't taken a close look at the kit to be sure that the radome cross section is correct, but this photo suggests that the radome tip is a symmetrical oval angled slightly forward (see the refueling probe picture above) while its aft end is slightly narrower at the top compared to the bottom in order to provide a little more visibility over the nose for a carrier-landing approach.

F7U-3M: Ironically, the kit includes the inflight refueling probe that could not be used on the -3M because of the larger radar antenna in the nose. The instructions state that it is optional but it was not like it was on the -3s. Fortunately, no hole was added to the radome for it. One excellent change is that the inlets have the lower intake lip modification for more thrust at approach speed. Some -3s also received this modification.

This kit provides the requisite pylons and Sparrow I missiles but these are not accurate in shape or the location of the missiles on the launch rails.

First, the missiles are too short, scaling to 135" rather than 150" in length. The pylons and rails are undersized to match.

Much better Sparrow Is are resin parts produced by RESKIT, RS72-0319. These are accurate in length and have the wave guides that were on each side of the missile. Also included are a decal sheet and tiny photo-etched rocket nozzles. However, if you elect to replace the missiles, the pylons/rails need to be replaced by slightly larger ones. I couldn't find drawings of the pylons or the launch rail but I did have pretty good pictures of the missiles on the pylons and since I did have an accurate drawing of the Sparrow I, this is the result:

Second, the Sparrow I launch rails (highlighted in blue on the color illustration above) on the inboard and outboard pylons are different lengths. They should be the same length. Scaling down my drawings to the length of the results in these red-line changes to the pylons/rails (cream) so the Fujimi missiles (blue) are correctly located with respect to the launcher rail using the slot in the missile and corresponding "peg" on the bottom of the launch rail (cream). However, the yellow/red line denoting the upper side of the pylons may not be accurate with respect to the kit's lower wing surface: The inboard Sparrows should be level and the outboard, nose slightly down as shown above and in the second illustration below. I suspect that the top of the kit's inboard pylon should be left alone for example and the locator pegs for the outboard pylons moved aft as shown in yellow so the leading edge of the pylon is just aft of the aft side of the closed leading edge slat.

 

Since the missiles are only about 3/16" (.47 cm) short, that seems like an easier solution to a more accurate installation than creating new pylon/rails for the resin missiles.

 

One thing I discovered in the process was that the outboard missiles were angled slightly downward relative to the inboard missiles by means of an adapter (which is missing in early pictures of the F7U-3Ms) between the pylon and the launcher rail:

My guess is that this was necessitated by the importance of having the missile, which was initially unguided, in a relatively small window out ahead of the Cutlass after being launched so it would be in the radar beam pointed at the target and then be guided to it. It may be that the relative wind at the outboard pylon was different from that at the inboard pylon so a missile there had to be launched at a different angle.

The Sparrow I launch rails look black but this photo suggests that they are really the dark blue of the prior overall blue color scheme (in another color picture, however, they appear to be black).

 

Because the F7U-3M did not have a radar scope in the cockpit, its instrument panel was not notably different from the -3's, particularly in 1/72 scale.

F7U-3P: The -3P comes with a good representation of the photo nose and also the inboard pylons and 150-gallon external tanks.

 

The engine inlets provided have the cannon muzzle openings deleted entirely and do not have the slight bulge aft of the inlets where the photo-flash bomb ejectors replaced the cannons. The -Ps retained the muzzle shape on the upper inlet lip with the muzzle openings and gun-gas outlets aft of the inlet blanked off.

The instrument panel provided is the same as the ones in the -3 and -3M kits and therefore does not have the prominent periscope viewing screen at the top center of the instrument panel (this is a picture of the mock up):

For a post on the larger scale and 1/72 vacuum-formed kits, click HERE

The Chance Vought F7U-3 Cutlass

 

Now available to order from:

Amazon US: https://www.amazon.com/Vought-F7U-3-Cutlass-Tommy-Thomason/dp/1800352948

Amazon UK: https://www.amazon.co.uk/Vought-F7U-3-Cutlass-Tommy-Thomason/dp/1800352948

Modex Number

 This is a work in progress but I'm pretty sure of the basics...

The number on the side of the nose of U.S. Navy carrier-based airplanes is often referred to as the modex number (I don’t know of a USAF equivalent). In fact, strictly speaking, it is only one element of the modex number and is in fact, more accurately the “Unit Aircraft Numeral” [MIL-I-18464 (Aer)] or more colloquially, side number.

The "NH" on the vertical fin of this F3H-2N in 1960 is the Unit Identifier or tail code (for posts discussing tail codes, click HERE and HERE)  and the number under it is the last four digits of the Bureau Number, also known as a call number. Note that some units that were only assigned a few of a particular type of aircraft typically used the last three digits (occasionally four in the event of a duplication of the first three) of the BuNo for a side number on the nose.

The term modex apparently didn't exist until the early 1960s, perhaps coincidental with the introduction of the Grumman E-2A with an advanced Airborne Early Warning radar system that used the octal number system for computations like civil ATC's Mode 3 use of a four-digit octal code (4096 possible combinations, no 8s or 9s). It therefore resulted in the elimination of side numbers with the digits 8 and 9 (some arguably knowledgeable experts believe that this was also the result of the introduction of an early maintenance reporting system with a similar limitation). At some point thereafter it became fashionable but incorrect to refer to an aircraft’s side number as the modex number even though it was only part of it and even refer to a side number an aircraft in a picture taken before the early 1960s as a modex.

The Modex number was actually a four-digit code used to identify a specific aircraft by means of its Mode 2 Identification Friend or Foe (IFF) capability. According to Jan Jacobs, a former F-4 and F-14 RIO, it was not resettable by the pilot like the Mode 3 code, which was assigned by civil Air Traffic Control for radar aircraft identification. The first number was peculiar to the Air Wing that the squadron was assigned to and the second, third, and fourth digits were the aircraft’s side number. For example, Jan wrote “Air Wing 2's unique code was "7" so the CAG bird from VF-21 would have a 7200 Mode 2 squawk. The skipper's bird would be 7201. The AWG-10 radar in the F-4J had the capability of reading Mode 2 or 3 squawks by using the APX-76 IFF interrogator system. It was very handy in finding your tanker overhead the ship when there were 2 or more tankers on station. The RIO would set in the tanker's (modex) and the aircraft's distance and azimuth would show up as a double-bar on the radar scope.”

Jan goes on to describe why the side numbers never included the digits 8 or 9:  “The 50's/60's-era IFF systems used 8-bit data systems (Base 8). Digits available were 0 through 7 (a total of 8 bits). In this system, 8 and 9 did not exist as 1-digit numbers. Mode 2 used this system so no aircraft that were in a tactical air wing could use 8 or 9 in their (side numbers) because Mode 2 did not support it. You'll see RAG aircraft and other Navy aircraft with 8 and 9 in their side numbers, but they were not in a tactical air wing.”

Presumably the limitation of the first digit to 8 numbers (if 0 is included) was not a problem since there were never more than a few air groups flying in one geographical area.

There is one somewhat cryptic modex statement in the subsequent  Paint Schemes and Exterior Markings document, MIL-STD-2161A dated 1 May 1993: “MODEX numbers applied to aircraft with the tactical paint scheme shall be FED-STD-595, color number 36081…”. There is no definition of “MODEX number” in that Standard Practice document but there might be in subsequent revisions. More relevant and not inconsistent with this statement, assuming that it only applies to the tail code as well as the side number, is this Call Sign Requirements statement in NATOPS General Flight and Operating Instructions dated 23 November 2009 (it may not be current): Call sign selection for cross-country flights shall be made in accordance with DoD FLIPS. It is strongly recommended that squadron modex (NJ213, DB214) be used in flight planning. If the use of tactical/squadron call signs is necessary, call signs shall be the approved JANAP 119 call sign for the unit concerned. Abbreviations or contractions of these call signs in not authorized.

n.b. I had thought that the typical call-sign used in civil-aviation circumstances was the word Navy or Marine as appropriate followed by the last three or four digits of the Bureau Number.

The practice by some to caption a picture taken after the mid 1960s referring to the combination of the tail code letter(s) and side number (in that order) as a modex would be legitimized by this NATOPS statement but an anachronism for one taken earlier.

 I have yet to find an explanation of the origin of the term Modex, other than it may hark back to the post-war "Mark X" IFF system that could identify a specific aircraft as opposed to simply friend or foe. TACAN systems have a Mode X and Y but those denote two different frequency ranges.

Knowledgeable (e.g. not Wikipedia) comments, additions, and corrections welcome.