by Tommy H. Thomason

Monday, August 21, 2017

F-4 Phantom ACLS Radar Reflector

ACLS is the initialism for Automatic Carrier Landing System. For more, see http://thanlont.blogspot.com/2011/07/look-no-hands.html

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

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.

You'll note that the fin also appears to have a cambered airfoil, creating lift to the right as in the application of left rudder. My guess is that this isn't as effective at low speeds during a high-power wave-off as the angling of the fin to the left (right rudder) but is important in a dive (the AD was designed as a dive bomber) when the fin angle created too much "right rudder" at that low angle of attack, reduced throttle setting condition at fairly high speed.

This is my picture of the fin of the AD Skyraider at the National Naval Aviation Museum that shows the airfoil and 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 http://skyraider.org/) 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 https://www.amazon.com/1-Skyraider-Walk-Around-No/dp/0897474295) 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 http://www.britmodeller.com/forums/index.php?/topic/234949143-vought-f7u-cutlass/

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 http://www.supersabre.com/200GallonTank.htm).

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 http://tailspintopics.blogspot.com/2015/08/its-not-that-easy-to-get-it-right.html


Friday, July 21, 2017

F-111B Monograph: Buyer Beware

Steve Ginter was my first and still favorite publisher. See http://www.ginterbooks.com/

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, http://www.ginterbooks.com/NAVAL/NF81.htm 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 tommythomason@sbcglobal.net.


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: http://tailspintopics.blogspot.com/2015/04/the-f3ds-of-flying-nightmares-in-korea.html

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

http://tailspintopics.blogspot.com/2009/12/f3d-skyknight.html

http://tailspintopics.blogspot.com/2016/06/sword-172nd-f3d-2-skyknight-sw-72094.html

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 http://www.vought.org/rest/F6U_Book.pdf. 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.

 For another of my posts on the F6U that includes links to others, see http://tailspintopics.blogspot.com/2013/03/vought-f6u-pirate.html


Tuesday, May 30, 2017

Skale Wings 1/72 AD Skyraider Folded Wings

Skale Wings is a new plastic model kit company located in Ukraine. Their first product was the AD-5W Skyraider, which I reviewed here: http://tailspintopics.blogspot.com/2016/09/skale-wings-172-douglas-ad-5w-skyraider.html

Their latest product is a 1/72 folded AD wing conversion. Folded wings are a notable feature on almost all carrier-based airplanes but the detail of the exposed joint can be daunting, not to mention the lack of support for the folded wing when rendered in scale. In fact, the wings on the aircraft are usually supported by externally installed struts after the airplanes are parked.

Since I'm not sure that I have the final instruction sheet (I made recommended changes and suggestions) or photo-etch, this is a work in progress.

This is a test-shot build from Skale Wings:


Note the amount of photo-etch in the fold joint.

As a follow-on to their AD-5W kit, the parts include a pair of canopies, one representing the original "blue room" version and the other, the one with the cabin hatches bulged as they should be for the AD-5W and AD-5Q.
The plastic is pretty thick but parts are provided to slide the pilot's side back and open the rear hatches if desired.

Note that the pilot's canopy could be slid back independently of the one over the right seat and that the aft end of the canopy structure comes more to a point rather than being rounded.

The plastic sprues and photo etch:
One nit is that the wing spar is not fully represented on the the wheel wells.
Note that separate parts are provided to represent the sway braces on the outboard wing pylons (the inboard pylons were included with the AD-5W kit).

The forward-facing main landing gear doors have a cutout for the AD-5 catapult hooks that were mounted on the main landing gear legs but they aren't quite accurate. The bulge should be narrower. See the link above for a comparison of the single-seat and AD-5 doors.

It should be noted that this conversion kit can also be used with the Hasegawa Skyraider single-seat kits to add folding wings, since it provides the details for both types of wheel wells. However, to accurately represent any of the AD-5 versions, the lower center wing part needs to be modified to eliminate the oil cooler air outlet and the catapult hooks.
On the other hand, for a single-seat AD-4 (most of them anyway) or -6/7, you'll have to add the armor plate or cut up the Hasegawa wing for its armor-plated center section.

The folded wings will also be sturdier if you add support struts (which are not provided in the kit). This was a red, telescoping piece of ground-support equipment that was placed in holes in the fuselage and outboard wing panel.
 The location of the hole in the wing:
The hole in the fuselage was in different locations in the single-seat and multi-seat Skyraiders:
The AD-5  strut was therefore in place at a steeper angle.

The strut could be telescoped for compactness and was sometimes carried along on a cross-country trip for use when secure wing folding was desired where this particular piece of support equipment might not be available.

Note that since the wing was mounted at a small angle of incidence on the fuselage and the aft hinge was lower than the forward one, the wing tilted slightly back as it folded.

Monday, May 1, 2017

The Complete F-111B Repaired

It's just come to my attention that some of the illustrations in my earliest F-111B post, http://tailspintopics.blogspot.com/2009/10/grumman-f-111b.html, were not accessible by clicking on them. That would enable you to view them in a larger size and save them if you wish, which is what I intended. Those are all fixed now. Let me know if this occurs on any other post so I can fix them. Also, please let me know if you come across "broken" links. Those are inevitable but I'd like to delete them or find a substitute if I can.

Thursday, April 27, 2017

Kitty Hawk 1/32 T-28C

Glen Coleman has announced that Kitty Hawk's T-28C follow-on to its well-received T-28B/D kit will be available in June.

Not my scale so I don't have personal experience with its predecessor, but this is an illustrated build review of it that includes high praise: http://forum.largescaleplanes.com/index.php?showtopic=60982&page=1

Glen provided photos of a model built from the kit:
As you can see, typical of Kitty Hawk, internal details, positionable control surfaces and canopy, and external stores are provided. (Never mind that the front canopy is on backwards; these display models are usually built from test shots without benefit of the instructions.)

One problem with T-28 kits is that some represent the early T-28A canopy, which bulged upward more than the later T-28A and subsequent canopies.
The fuselage in the foreground is the early version. The one in the background and this one on a T-28C are the later one.

For a good reference, get this early Steve Ginter monograph that featured the T-28:
It can be ordered here: http://www.ginterbooks.com/NAVAL/NF5.htm. It doesn't include a three-view of the T-28C, so here is one suitable for checking dimensions:
Also a guide to the differences between the B and the C:
Note the difference in propeller diameter.

Several marking options are provided:
Note that the one marked as VF-84 is a warbird for which I'm pretty sure that there wasn't an example in Navy service. Similarly, my guess is that the tail code TN represents a warbird owner's initials. (Both of these have an N number on the fuselage, another clue.) I'm not sure that there was a C in the air drone controller scheme (the BuNo provided for that one was assigned to a T-28B). If you're a stickler for accuracy, you should keep that in mind as well as the fact that some of the walkaround photo collections on the interweb have warbird subjects.

One thing that caught my eye was the tailhook installation. I suggest that it look more like this:
Note the separation between the bottom of the fuselage and the rudder. The front of the hook point should be shaped more like a horse's hoof:


Wednesday, April 12, 2017

Things Under Wings: Air-Start Pod

From the August 1956 issue of Popular Mechanics:
 Also see http://thanlont.blogspot.com/2012/01/portable-air-start-cart.html

Ground support equipment will add interest to the display of an airplane model, particularly when it is little known and as beautifully rendered in resin and photo-etched parts as this 1/72 kit, #7019,  produced by F4Models.

 As built (decals not included) and photographed by Alexander Suvorov of F4Models:

The kit includes a resin air hose and instructions on how to permanently bend it to the configuration desired for display.

For more information on this kit and ground support equipment kits available from F4Models, click here: http://f4models.blogspot.com/

Note that these kits must be ordered from Hannants, MisterKit, or Martola.

Monday, April 10, 2017

The Last Propeller-Pulled Corsairs: F4U-5/AU-1/F4U-7

This is a work in progress, updated on 13 April. As usual, comments, corrections, and additions are welcome.

Also, for additional information, see the books recommended in this post: http://tailspintopics.blogspot.com/2011/06/brief-f4u-corsair-oriented-history-of.html

As a hedge against the failure of its transition to carrier-based jets or delays in their availability, the U.S. Navy contracted with Vought for yet another variant of the Corsair, the F4U-5. (For modeler's notes on the F4U-4, see http://tailspintopics.blogspot.com/2014/03/f4u-4-modelers-notes.html.)


The major change was the engine, the Pratt & Whitney R-2800-32W with dual side-mounted, automatically controlled auxiliary stage superchargers. It developed 2,300 horsepower at sea level for takeoff. The combat rating with water injection (from a 28-gallon tank) was 2,700 horsepower at sea level.
The following illustrations are is an overlay of the F4U-5 SAC drawing on the F4U-4 SAC drawing. The installation of the -32W resulted in the most notable changes. First, because of the added length of the auxiliary superchargers and the horsepower increased it was located about 10 inches farther forward and mounted at a nose-down angle of 2.75 degrees. The upper side of the cowling was refaired to take advantage of the downward tilt of the thrust line and therefore provide the same over-the-nose visibility.

Second, the F4U-4's chin inlet was deleted in favor of two cheek inlets at four and eight o'clock (not depicted on this front view) that provided air to the auxiliary air superchargers aft of the engine. The ducts between the inlet and the supercharger required a widening of the lower side of the cowling so it had an pear-shape and flatter bottom when viewed from the front.

 The basic shape of the fuselage from the firewall aft was unchanged.
 Forward of the firewall, the cowling was wider, with a slight but perceptible outward kink in the fuselage at the side of the firewall.


The configuration of the cowl flaps and exhaust collector was also different due to the presence of the ducts between the cheek inlets and the auxiliary air superchargers. The exhaust indentation on the side of the fuselage was located higher than on the F4U-4 (note that there were variations in the exhaust stack configuration). The cowl flaps no longer extended down the entire side of the fuselage. Instead they ended about half way down and the bottom cowl flaps were reinstated that had been eliminated on the F4U-4. There were fewer turning vanes in the wing root inlet.

The propeller was slightly different, primarily thinner (not narrower) tips.

The arresting hook was no longer hydraulically raised and lowered. It simply dropped when released. After landing, a hook man had to manually raise it to a park position for taxi, which was somewhat lower than its latched-up position. When the pilot raised the landing gear after the next takeoff, it was raised to a latched-up position by the retracting tail wheel.

Other changes were the replacement of the fabric on the outboard wing panel with sheet metal and the addition of an avionics compartment access door on the right side of the fuselage aft of the pilot's seat.
A 2,000-lb capacity center-line pylon was added between the two center wing section pylons. The armament was basically the same as the F4U-4B: four 20 mm cannon and eight rocket pylons (Mark 9 Mod 3). Spring tabs were provided on the elevator and rudder controls for lower stick and rudder forces. The catapult hooks were relocated slightly forward and the arresting hook shank was beefed up for the higher gross weight.

Pilot access to the cockpit was improved over the -4's by adding a telescoping step below the folding step in the side of the fuselage (it is extended in the photo above). These were actuated by a cable connected to the tail wheel but could also be closed and opened by deck personnel. The seat was a bucket type with folding arm rests. The center console was eliminated below the instrument panel to allow the pilot to stretch his legs on long flight. The manual hydraulic pump was deleted in favor of an electrically driven auxiliary hydraulic pump. There were some detail changes from the -4, e.g. the arresting-hook and wing-fold controls were moved to the right side of the cockpit. The top of the canopy was raised similar to the late production -4s, with a fairing added to the top of the turtle deck aft of the cockpit. The gun sight was one of the first lead-computing designs, the Mark 6 Mod 0 gunfire control system (with a Mark 8 gun sight) that also incorporated rocket aiming capability.

The F4U-5 was produced in three flavors: basic -5 fighter; -5N night fighter with an autopilot, Mk 20 illuminated sight, and a radar pod on the right wing; and -5P photo-reconnaissance with camera ports on both sides and the belly as well as a small fairing on the fin leading edge for the relocated compass transmitter.

In addition to the radar pod, the F4U-5N external features were a glare shield over the upper engine exhaust stacks, which were all fitted with flame suppressors as well; flash suppressors on the cannon barrels; and additional antennas. A gun-camera light/flash guard was sometimes added.

This F4U-5N has also been equipped with the wing and empennage deicing boots.


The F4U-5P camera ports were fitted with sliding covers:

A hatch was also added to the turtle deck (with a foldable ladder that was stowed in the top of the compartment) for access to the cameras:

The AU-1 was a Corsair tailored for Marine Corps close-air support, provided to them as a placeholder in lieu of AD Skyraiders. (Also see http://thanlont.blogspot.com/2009/03/f4u-corsair.html.)
Originally designated the F4U-6, it was a minimal modification of the F4U-5 optimized for low-altitude performance, incorporating increased protection from flak and small arms fire, and providing more stores options. Since it did not need high-altitude capability, the big auxiliary stage superchargers were removed with the installation of a R-2800-83WA with single-stage supercharging. A new cowl ring without cheek inlets was installed but the pear-shaped cowling remained since the F4U-5 tooling was used. The oil coolers were turned 90 degrees and moved inboard.
Armor was added to the underside of the fuselage and the cockpit.

Because the oil coolers had been moved into the fuselage, there were only turning vanes in the air inlet in the wing leading edge and no oil cooler vent flap behind the inlet under the wing. For some reason, possibly to reduce the glare from the exhaust stacks at night that had been a shortcoming of the -5, the exhaust indentation on the side of the fuselage was located lower than the F4U-5's (this was possible because the ducting between the -5's chin inlets and superchargers had been removed). The cowl flap configuration remained the same.

Five multi-purpose pylons were provided on each outboard wing panel in place of the four rocket pylons of the -4/5.
The wing center-section pylons were subsequently increased to carry 2,000 lb stores.

Finally, the French need some new fighters for their aircraft carriers that were too small to operate jets. Since the Corsair was the best candidate, the AU-1 configuration then in production was adapted for the mission and designated the F4U-7. Note that the armament on the outboard wing panel is identical to the AU's.
Note that the tail hook is in the "park" position. See the French AU-1 picture below for the "latch" position. 

The major difference was the need for a high-altitude capability, which was provided by installing a two-stage supercharged R-2800 engine, reportedly from surplus F4U-4 inventory. However, the fuselage was the same as the AU-1's with the exception that a new cowl ring was incorporated that had a chin inlet to supply air to an F4U-7-unique oil-cooler installation. Note the beginning of the cowling bulge at the firewall that was common to the F4U-5/AU-1/F4U-7.
 Photo via Jim Sullivan

 Like the AU-1 wing root inlet, the F4U-7's only contained turning vanes (and no oil cooler vent flap) but in a different configuration because of the different utilization of the air. This is my current guess at its configuration.

Since it was built using F4U-5/AU-1 tooling, and this is an important distinction, the lower forward fuselage remained pear-shaped up to and including the aft side of the cowl ring.

There is understandably some confusion about the detailed differences between the AU-1 and F4U-7 configuration. For one thing, the French were provided with some Marine AU-1s straight from Korea. As a result, there are blue French-marked Corsairs that are not F4U-7s but AU-1s, the main difference being the lack of a chin inlet.
 AU-1 129391 14 Flotille Cuers NAB 17 March 1964 via Jim Sullivan

Another is that the Corsair marked as a USMC VMA-212 AU-1, including BuNo, at the USS Alabama Battleship Memorial Park in Mobile, Alabama was actually a former French F4U-7;  the -7 cowl was subsequently replaced with an AU-1's, which still left miscellaneous antennas as configuration anomalies. It is now on display at the San Diego Air & Space Museum, again as an AU-1.

And the French F4U-7 war bird featured in a walk-around photo collection here: http://www.arcair.com/awa01/601-700/awa689-Corsair-Salaun/00.shtm is reportedly a converted F4U-5N. Its authentic cowl (note the bulge and chin inlet) reportedly came from the F4U-7 that was on display at Mobile, Alabama.

More later...