by Tommy H. Thomason

Saturday, December 2, 2017

Grumman F9F-2 vs. F9F-5 Wing Root Comparison

On my 2009 post comparing the F9F-2 with the -5 (, "davedd" commented that there was a difference between the interface of the fuselage break and the inboard trailing edge of the flap. I hadn't noticed that before, but he is correct.
The F9F-2 example is a crop from the Luc Colin walkaround photo collection in Prime Portal HERE. The F9F-5 example is a crop from the Howard Mason walkaround photo collection in Prime Portal HERE.

The reason is that the -5 had a thinner outboard wing (10%) than the -2's (12%) in order to delay the drag rise at transonic speed, an aerodynamic benefit demonstrated in flight test of Air Force and Navy research airplanes in the late 1940s.
Note that the thickness ratio can be reduced by either decreasing the thickness of the wing or increasing its chord.

Since it was desirable to retain the depth of the wing at the wing fold, the location of the wing-folding hardware and the main landing gear, and still reduce the thickness ratio there, the wing and fairing chords were increased on both sides of the wing fold. The change to the leading edge is obvious but it turns out the trailing edge was moved aft as well.
 Hence the difference in the interface between the fuselage break (which remained at the same fuselage station) and the inboard trailing edge of the flap.

Note that the end of the wing-to-fuselage fairing was relocated aft as well to decrease its thickness ratio as well (on the F9F-8 Cougar, it was moved all the way aft to the end of the fuselage).

Sunday, October 22, 2017

Sword 1/72 North American FJ-2/3 Furies

12 November 2021: A review of the FJ-2 rerelease:

26 October 2017: Added sketch of nose correction, inlet comparison, and nose landing gear comparison, normal and pressurized.

25 October 2017: Added a discussion (more than you probably want to know) of the nose landing gear here:

24 October 2017: Added discussion of the shape of the upper nose.

At last, injection-molded kits of the North American FJ-2 and -3 Furies have been released, thanks to Sword Models (! It's inexplicable to me why it has taken this long. The swept-wing Fury, like the iconic F-86 Sabre it was based on, is not only beautiful jet but it was dressed in the some of most colorful of 1950s and 1960s markings. Sword has released three high-quality and detailed kits:

FJ-2 SW 72107
FJ-3 SW 72108
FJ-3M SW 72109

The FJ-2 kit has a different fuselage and wing than the -3 and -3M. The FJ-2 had a slightly smaller engine intake, a slightly less deep forward fuselage, and a slightly different air inlet on the after aft side of the fuselage. These differences are correctly represented in the kit rather than making do with the almost identical FJ-3's fuselage. The FJ-2's wing was similar in planform to the F-86E and early Fs with aerodynamically actuated slats. Again, instead of making do with a common wing, the FJ-3 and -3M kits have the notably different, later, so-called "hard wing" with the cambered 6-3 leading-edge extension (and teeny barricade snaggers, although the most outboard one wasn't included). For more on these differences, click here:

The FJ-2 was assigned to the Marine Corps and shore-based since it had retained the F-86's J47 engine but was burdened with an increase of about 1,000 lbs in empty weight for carrier-basing capability. It was also one of the airplanes assigned to the Navy's experimental bare-metal exterior project. These are the decals provided with the kit:

As far as I know, all the FJ-3s with the cambered leading edge 6-3 wing were painted gray and white (blue ones would have had the same slatted wing as the FJ-2). These are the markings in the FJ-3 kit:
These are the markings in the FJ-3M kit (the only difference in the plastic from the FJ-3 kit is the addition of Sidewinder missiles and the associated pylons):
 Both the -3 and -3M, but not the FJ-2, come with the inflight refueling probe and optional rudders and horizontal stabilizers that have the external ribbing on the trailing edge. (The rudder was an early change; my understanding is that few if any FJ-3s had the ribbed stabilizer when they were assigned to deployable squadrons.)

If you're thinking that not coming from a Japanese model kit manufacture means these must be short-run, relatively crude moldings with 1/4-inch sprues,  you will be very pleasantly surprised. The control surface and panel lines are engraved and petite. All the many detail parts such as the pitot look as close to scale as can probably be done in 1/72. The canopy is injection molded in two parts and clear. The ejection seat consists of two pieces, seat and headrest, with very fine face-curtain handles and knee guards (however, it is missing a cushion, backpack parachute, and straps). I haven't checked the fit except for fuselage halves and the wings but so far, so good except that the trailing edge of the wings will require some work to be reasonably thin enough.

I regret to report that the kits are not quite perfect in size and shape. The most notable (but not to the eye) is that the fuselage of both the -2 and -3s is about 3/16 inch (5 mm in 1/72; 13 inches full scale) too long due to a misunderstanding about a length measurement. Since the error is pretty much spread along the fuselage, it would be a lot of work to correct and in any event, really isn't noticeable.

What is slightly off and noticeable, at least to my eye, is the nose. It doesn't appear to curve downward enough, the lower intake lip seems to protrude slightly forward, and the inlet is too far forward relative to the cannon ports (which some don't think angle downward enough):
This is another assessment of the upper nose shape based on a pretty good NAA FJ-3 drawing compared to a Craig Kaston photo of a museum's FJ-3 (it looks like the top of the nose curves down a bit too much in the drawing) and the Sword FJ-3 forward fuselage. You'll have to ignore interior detail not matching up due to distortion and the slight stretch in the Sword fuselage.

There appears to be, however, enough plastic in the inlet to cut it back and reshape it if you desire, which also solves the problem of the cannon ports appearing to be too far aft of the inlet lip. Here's one possibility for the -3:
Note that the cannon ports are supposed to be angled downward at 6.5 degrees. The -2 inlet was a little less deep, which the Sword kit represents.
Note that the top of the inlet curves down from the outer edge of the lip notably more than the sides curve in or the bottom curves up.

However, some or most modelers will doubtless be happy with the shape of the Sword nose as is. Neither the downward curve on the top of the nose or change in the curve of the side of the inlet lip  is  as prominent in this picture on an early FJ-2 being evaluated at NAS Patuxent River because the shape of the inlet lip varies with the viewing angle to some extent.

There are some other nits that have been discovered so far. For one thing, the FJ-2 fuselage (but not the -3s) has some "bumps" or bulges that should be removed.

Some wish that Sword had produced the FJ-2 wing with separate slats, since being aerodynamically actuated, they were almost always extended when the Fury was parked or even taxiing. Note that although this was also the static configuration of the F-86's slatted wing, very few kits of the Sabre have this feature either.

The nose landing-gear assembly illustration (seven pieces!) in the instructions appear to suggest that the nose-wheel yoke should be placed on the bottom of the strut. It really goes on the bottom of the small canted cylinder at the front of the bottom of the strut. The yoke itself may be too long but I've haven't confirmed that yet. The top of nose gear door should go into the well a short way, not be mounted outside of it. Also see

Also the nose landing gear was presssurized for catapult launch to for a greater nose-up attitude.
However, the strut might also also be extended at other times for other reasons...

The windscreen interface with the fuselage appears to need trimming either the forward end of the windscreen or the fuselage where it touches.

There are several threads running in Britmodeller that discuss the kits, with particularly informative and detailed posts by Sabrejet. There are links to a couple of them in my FJ-2/3 post for which  a link is provided above. Searching the Britmodeller website ( will uncover more.

More later...

Monday, September 25, 2017

Douglas A3D-2P/RA-3B/ERA-3B Skywarrior

27 October 2017: Added configuration comments by Joe Hawkins

Douglas built less than 300 A3D Skywarriors but its family tree had many branches. For a summary, click HERE

Phil Clayton is building the Trumpeter ERA-3B kit with the Steel Beach update set and asked for clarification on the location of some of the details. That led me down the usual rabbit hole of research in the process of resolving some issues that I uncovered in the process of answering his questions.

I hadn't spent much time on the ERA-3B (not to be confused with the EKA-3B, which was a derivative of the bomber) because it was restricted from carrier operations and fulfilled a vital but peripheral Navy mission, training the crews of Navy ships and aircraft to operate in a hostile electronic-warfare environment.

All eight ERA-3Bs were originally delivered as A3D-2Ps, a photo-reconnaissance "Version" of the A3D-2 bomber. Like the other Versions, the interior had been permanently rearranged to provide a cabin aft of the cockpit.
In the case of the A3D-2P, the cabin was divided into two compartments, one for cameras and the other for photo-flash cartridges and bombs, separated by a bulkhead.

Another distinctive feature was the addition of a periscope sighting system providing a downward view through windows on the underside of the radome.

The view ports dominated the instrument panel (also see

The long narrow fairing on the lower side of the fuselage housed the doors that could cover the camera ports as did similar ones on the belly.

When the RA-3Bs began to be supplanted by the supersonic RA-5Cs for reconnaissance, four were repurposed in the early 1970s to be ERA-3B electronic-warfare aggressors, BuNos 144827, 144832, 146446, and 146447. Note that the last two were delivered with the Cambered Leading Edge (CLE) wing, readily identified by the addition of a leading edge slat between the wing and the fuselage.
The major external modifications were the addition of a "canoe" on the belly like the EA-3B's; four ram-air turbines, two on each side of the fuselage, for additional electrical power; a extended aft fuselage for chaff dispensing; flare/chaff dispensers on the lower sides of the aft fuselage; and several antennas.

Side-facing crew seats were added for two equipment operators in the cabin.

 From the illustration above, it appears that the bulkhead that separated the camera compartment and the truncated bomb bay was removed. However, per Joe Hawkins: "The bulkhead was never removed from the photo compartment and the flash bomb bay. The flash bomb bay is still there. It was full of equipment for the ALR-40 and ALR-75.

The starboard flash bomb-bay doors were secured. The door actuators were unpinned from the doors and door locks were installed if I remember correctly.

The port doors could be actuated externally by either a selector valve when hydraulic pressure was applied or a small hand pump. They were (now) access "panels" for the removal and installation of the ALT-40 and ALR-75 systems equipment."

An escape hatch (19 above) was added above the aft compartment.
In the early 1980s, four more RA-3Bs were converted to the ERA-3B configuration, BuNos 142668. 144838, 144841, and 144846. However, these appear to have been delivered with a smaller canoe, a different aft fuselage extension, different antennas mounted on the sides of the fuselage in four locations, and a different antenna under the nose.
Rick Morgan Photo

Of the original four ERA-3Bs, at least BuNo 146446 and 7 were converted to this configuration.

An excellent walkaround of a moldering 146447 by Bill Spidle can be found HERE. Note that its RAT hubs and propellers have been replaced by conical fairings. It was not unusual to see one or even two RAT pods on operational ERA-3Bs with a fairing instead of the RAT.

The Trumpeter A-3 series continues to disappoint. A detailed build article of the ERA-3B kit (the early configuration) by Philip Cavender is provided HERE

Note that it's missing two of the four RATs and numerous antennas. Not apparent from this angle, but the radome leaves a lot to be desired as well. The kit's cabin is also taken directly from the EA-3B kit, so it has four seats instead of two, but since nothing can be seen of it, that's a moot point.

However, Steel Beach has come to the rescue with an accessory kit for the later configuration (small canoe, etc.) reviewed by Haagen Klaus HERE

The Steel Beach ECM pods appear to have the ALQ-99"s outwardly bulged lower sides rather than the flat-sided ALQ-76 pods that were carried by the ERA-3B according to Rick Morgan. Another stores option is the ALQ-167 "Bullwinkle" pod, an example of which is in the Revell F-14D kit.

The Trumpeter engine nacelles are inaccurate but might be acceptable to most given all of the other inaccuracies. However, an excellent replacement set is available from HYPERSONIC

The Trumpeter canopy is equally off-putting. Hypersonic has a replacement in work but availability is TBD.

More later after comments are provided by my subject-matter experts...

Sunday, September 3, 2017

Things Under Wings - Before Douglas High-Speed External Tanks

 I've updated my post on the 150 and 300-gallon tanks in use before the introduction of the Douglas high-speed tanks thanks to research by David Collier. See

Monday, August 21, 2017

F-4 Phantom ACLS Radar Reflector

ACLS is the initialism for Automatic Carrier Landing System. For more, see

Up until now, I'd never seen a good picture of the radar reflector as incorporated on the F-4 Phantom although I'm sure there must be one or more in the F-4 books that I don't have. This was the best I could come up with. There was a door under the nose and a corner reflector extended from the compartment it was housed in.

Thanks to Angelo Romano, we now have one:
It took me a few minutes to figure out how it folded up even with this illustration in hand, which depicts the reflector from behind:
If you look closely at Angelo's picture above, there is a line on the panel on the left (on the right side of the F-4) that shows where it folds in half. It is then sandwiched between the upper panel and the one on the right to form a very compact package that can be stored in the space available.

Tuesday, August 15, 2017

Relying on Museum Pieces for Accuracy Part 3

6 December 2022: Oops - I relied on an inaccurate Douglas drawing that showed the vertical fin with  cambered airfoil that was lifting to the right, whereas the fin itself is angled to the left, therefore lifting to the left. After reviewing Douglas manufacturing drawings with my AD subject-matter expert, Ed Barthelmes, it is clear that the vertical fin has a symmetric airfoil, with a slight amount of asymmetry at the top of the fuselage as it fairs back toward the airplane's center line. I've deleted the error from this post along with the fanciful theory as to why vertical fin was cambered and lifting in the opposite direction to the fin's offset...

Restored airplanes, either static or warbirds, can lead a kit manufacturer and/or modeler astray from an accuracy standpoint. Missing parts, ersatz replacement parts, flat oleo struts, one-off test program modifications, etc. have all resulted in kits and built models with errors. Sometimes, however, what's there is ignored or disbelieved. A case in point is the Douglas AD (A-1) Skyraider vertical stabilizer.

In addition to thrust, the propeller on a single-engine airplane creates other forces that must be taken into account. Consider the following for a propeller turning clockwise from the pilot's point of view. When the propeller is inclined nose up to the relative airflow, the down-going blade produces more thrust on that side than the other, resulting in a turning moment to the left (this effect is known as P-factor). The turning propeller also creates torque, causing the airplane to roll to the left; opposing this requires right stick, which increases lift on the left wing and therefore potentially drag and a turn to the left (some aileron-control designs compensate for this). When the airplane is on its takeoff roll, the torque also puts more pressure and therefore more drag on the tire on the left side of the airplane, causing a turn to the left. The swirl from the propeller, equivalent to downwash from a wing, impinges on the vertical fin, pushing it to the right and therefore the nose to the left.

In other words, a lot of right rudder (which results in a turn to the right) can be required to oppose these forces that cause a left turn. They change with the throttle setting and, in the case of P-factor, angle of attack. More powerful engines and bigger, heavier propellers result in higher forces. The flight-control forces to counteract them decreases with airspeed. As a result, the designer of a powerful single-engine, propeller-pulled airplane sometimes provides a built-in assist like a vertical fin with the leading edge angled left, providing a right rudder effect.

The Douglas AD (A-1) Skyraider incorporates such a feature, with the fin angled left at three degrees.

Although in the drawing above (from the Standard Aircraft Characteristics Chart prepared by the manufacturer) the fin also appears to have a cambered airfoil, in actuality the fin has a symmetric airfoil.

This is my picture of the fin of the AD Skyraider at the National Naval Aviation Museum that shows the angle to the left relative to the dorsal fin that can be seen forward of the red anti-collision beacon.

Byron (SpadGuy) Hukee (see provided this picture of a Skyraider's rudder.
If you look closely, you'll see a kink in the trailing edge of the rudder just above the location of the horizontal stabilizer. You'll also note a difference in the fairing of the fuselage into the fin between the left and right sides of the airplane.

An even more striking example was provided by Ed Barthelmes (see of the AD-5's vertical fin leading edge. Its air inlet and dorsal fin provide an excellent perspective of the fin's offset to the left side of the fuselage.

The old Airfix 1/72 kit of the AD Skyraider incorporated this feature. Some modelers have erroneously gone to the trouble of removing it...

Saturday, August 12, 2017

Relying on Museum Examples for Detail Accuracy: Part 2

Today's example is the gorgeous "F7U-3M" at the National Naval Aviation Museum at Pensacola.
This picture is from the walkaround section of Britmodeller curated by Julien and in this case credited to Bootneck Mike. For more, see

I hadn't noticed it until F7U expert Al Casby of Project Cutlass pointed it out to me, but the external tanks are almost certainly bogus. External tanks are not often seen on the F7U-3 (even though it was short on endurance) but if present, they would have been either the standard Douglas-design AERO 150-gallon tanks, the very similar Fletcher 150-gallon tank, or the bespoke belly-mounted tank. These tanks have no fins and their afterbody has a distinctive upward sweep.
 Don Hinton Photo Cropped

 I suspect that they are either the 200-gallon tank that was carried by F-86s.
Or even more likely, given the flange on the left side of the NNAM tank, the one for the F-100s (see

Note that this F7U was delivered to the Pensacola museum with these tanks installed so they weren't a goof by the workshop at the National Naval Aviation Museum.

These are what the F7U-3 tanks should look like:
Note that the pod under the belly was also a fuel tank that could be jettisoned. (A very similar pod could be carried in its place that contained 2.75-inch folding fin rockets.)

For other detail issues with this airplane from an accuracy standpoint, see

Friday, July 21, 2017

F-111B Monograph: Buyer Beware

Steve Ginter was my first and still favorite publisher. See

I prefer to write about the also-ran, unappreciated, much-maligned aircraft that were not flown by operational squadrons. Few publishers would consider even a paperback monograph on one of those little-known (in most cases for pretty good reasons) programs. Steve has been willing to front the printing of a monograph on whatever esoteric loser I am interested in writing about, which has sometimes been a loser from his standpoint as well. (You would do us both a favor if you'd order my excellent—don't just take my word for it; see the review on Amazon—monograph on the XFL-1 Airabonita, from him. He has plenty.)

He did finally sell all of my F-111B monographs that he printed, mainly because that was almost 20 years ago. You'll see that he doesn't include it on his website.

However, it is for sale on Amazon. Unfortunately, some of what is being sold is not one of the originals but a "print-on-demand" version. I haven't seen one but I've been told that that at least some are not very good reproductions, indifferently reproduced on low-quality paper. There is now a review on Amazon to that effect. A known purveyor of them has graciously agreed to stop at my request, but I'm not sure that was the only supplier and of course there are the extant copies.

What to do? I have no control over what's out there and legal action would be a waste of time and money. I can only suggest that you ensure that what you're buying is an original, unless of course you don't need good quality pictures.

For a limited time, you can also buy the monograph directly from me, which will include a multi-page errata document that corrects and augments information in it. For a quote, email me at

Friday, June 23, 2017

F3D (F-10) Skyknight Post Synopsis

Unfortunately, the "Whale" doesn't get the respect it deserves. Portly and underpowered from the beginning, it eventually received one of the most derogatory nicknames of all time, "Drut". However, it may well have been the longest-serving combat airplane used by the US military during the Vietnam War (depending on how you keep score, the C-47 might have that title).

I've recently updated one of my posts on the F3D for the variations in the overhead hatch configuration:

Two of my other posts on the F3D may also be of interest:

Friday, June 9, 2017

Relying on Museum Examples for Detail Accuracy

You really shouldn't. Today's extreme example of why not is the Vought F6U on display at the National Naval Aviation Museum at Pensacola.

It was created from an incomplete F6U hulk by retired Vought employees at the Vought Aircraft Heritage Foundation. For an illustrated description of the process, see One entire wing and many other parts had to be created from scratch. As a result, there were some liberties taken.

This is what a production F6U should look like:

Note the difference in the canopy and the shape of the tip tank (the reproduction has simple conical additions to the front and back of a cylinder). Another major error is the location of the bullet fairing on the empennage. It should be directly aft of the stabilizer. Unfortunately, repair of this F6U was begun at the New England Air Museum and this was their contribution.
The actual fairing was not round and it incorporated a taillight. The F6U reproduction also has a brace between the fuselage and the fairing as well as a longitudinal stiffener on the tail cone that weren't on the airplane when it was delivered or in service.

Vought retirees had to provide the landing gear from scratch so the struts are approximations, available wheels were used, and the outboard main landing gear doors were reduced from two to just one.

At some point between delivery of this F6U to Pensacola in February 2011 and November 2015, a modified canopy was installed to replace the single curvature one. It has more of a bulge but is still not accurate as the bulge is not quite as prominent as it should be and there is more sheet metal on its aft end than it should have. The bogus tip tanks were also removed.

For another of my posts on the F6U that includes links to others, see