F-111B Conversion Part Two: Landing Gear

 A work in progress

The nose gear of the F-111B was very different but so was the main landing gear to a degree. As it happened, with two exceptions, the landing gear of the first three F-111Bs (BuNos 151970/71/72) was essentially identical to the landing gear on production F-111As, making the landing gear in the Hasegawa/Hobby 2000 kits usable as-is for them The two exceptions were that the nose gear on BuNo 151972  was damaged in the first of its two emergency landings and replaced with an F-111B nose-tow gear (at some point prior to its retirement, an F-111A nose landing gear was reinstalled) and the different aft main landing gear door on all seven F-111Bs.

BuNo 151972 with a nose-tow nose landing gear:

The aft main landing gear door was originally identical on the prototype F-111As and Bs. During extension and retraction it was articulated on two pairs of links so that on extension it swung down and back, remaining parallel to the bottom of the fuselage.

One pair of links was attached to pivot points on the main landing gear trunnion to which all its other parts were attached, one on either side of it, just below its pivot point on the back of the wheel well. The other pair were attached on the door just outboard of the first pair and to pivot points on each side of the wheel well. When the landing gear was extended or retracted, the door was driven by the first pair of links and remained parallel to the bottom of the fuselage when extended and retracted by the second pair of links (idlers).

Note that the trunnion on the 172 Hasegawa/Hobby 2000 kits is an open frame that should be covered with a thin piece of plastic.

A montage to illustrate the shape of the links and the location of the door: 

Apparently the rigging of the original aft main landing gear door was both finicky and subject to going out of adjustment, requiring a gear swing to remediate. As a result, early in F-111A production/operation, the door was simply mounted on the back side of the trunnion. This required that about six inches be removed from the back end of the door to clear the bottom of the fuselage when the landing gear was extended, so when it was retracted, there was a six inch wide opening on the bottom of the fuselage aft of the door.

This is the arrangement on all the F-111 kits except for the Revell, which has a simplified version of its original articulation. All seven of the F-111Bs flew with the original door, although in production it seems likely that it would have been mounted on the trunnion as well. While no aftermarket F-111B main landing gear tires are available, the F-111 kit tires can be narrowed and reduced in diameter accordingly.

All of the F-111Bs after the first three were delivered with the Navy landing gear. The F-111B main landing gear was the same as the F-111A’s and subsequent shore-based F-111s with the exception of the tires and the aft main landing gear door. At some point, to minimize a tipback problem in service, at least BuNo 152715 was modified to move the main landing gear wheels eight inches aft.

The Navy nose landing gear was completely different, however, except for the tire size. It was redesigned to add the nose-landing-gear tow and hold back for catapult launch as well as the Automatic Carrier Landing System radar corner-reflector. Both the strut and its actuation reflect the requirement that the nose landing gear react both the hold back and launch loads. Although no aftermarket F-111B nose landing gear is available, scratch building one is relatively easy.  Except for the wheels, the USAF nose gear isn't much use in that regard, though.

 Note that its shock strut angles forward (this is 151970 with the USAF nose gear) and ends well above the tire; the red markings on the nose wheel door were there to verify that the gear was fully extended:

 The Navy nose gear had a somewhat longer (the shock strut extended down to the axle) and beefier shock strut; the retraction actuator was also much beefier and attached above the shock strut piston:

 The Navy nose gear strut was mounted vertically:

 Ready to launch (the trail bar would hold the airplane back at full thrust and then release at the fitting to the strut when the catapult fired, remaining on the ship for reuse):

 The radar reflector was attached to the scissors so when the strut was extended in flight, it was raised to be vertical and above the right tire. Note the amber approach light, indicating to the LSO that the pilot is at the proper angle of attack.

 

F-111B Conversion Part One

A matrix of the seven different F-111Bs by Bureau Number is provided HERE along with a illustrations of the features and/or links that describe them.

There have been a few 1/72 and 1/48 conversions released to convert an USAF F-111 kit to the F-111B configuration. Most were only partial representations and there were only a couple of decal sheets available. Nevertheless, Bill Gillman (Navy Bird) was able to make do with them: Click HERE and HERE

 HERE is another 1/72 build by DrPlastic in 2012 using the Pete's Hangar conversion set (not recommended even if you could find one).

All of these conversion options have been eclipsed by the recent CAT 4 release of mostly 3D printed parts and a comprehensive decal sheet and instructions for any of the first three F-111Bs, which diverge the least from the production USAF F-111s. Click HERE for a description of the sets and a source.

These are the 3D-printed ejection seats provided in the CAT 4 1/72 conversion set R72016 that provides the majority of changes for the first three F-111Bs. The protective cover in front of the upper and lower ejection handles has been removed on the left seat.

 
There are various F-111 kits that provide a basis for that but their quality and build-ability varies significantly. I’m only familiar first hand with the 1/72 alternatives; however, Googling “1/48th F-111 kits” will result in the many detailed reviews that will provide a basis for selection.

Four 1/72 kits were originally issued, reissued as variants, and also distributed by other kit manufacturers:  

- Hasegawa/Hobby 2000: Unless your standards for accuracy and build-ability are low, these are the only acceptable starting point (also, the CAT 4 conversion sets are designed for them).

- Esci/Ertl/AMT/Gunze/Italeri: Disappointing in accuracy and fit but buildable (full disclosure, Paul Boyer binned his attempt at it)

- Revell/Monogram: The first release provided parts for both the development F-111A and F-111B airplanes. It was quite accurate in shape for those aircraft except for, ironically, the F-111B nose. The landing gear was retractable but necessarily simplistic as was the interior of the separable crew module. Later releases deleted the F-111B option.

- Airfix/MPC/Heller: Minimal detail (e.g. cockpit, no wheel wells), and the crew module is a separate, ill-fitting assembly

Note that one significant difference in kits is the wing span but CAT 4 has created a conversion (R72025) for the low-aspect-ratio wing that was present on the F-111A/D/E/F to the higher aspect-ratio F-111B wing (the F-111C/G and FB-111A had the same wing span as the F-111B).

 Other options are DIY and using the wing extensions from the original Revell F-111A/B kit.

 Do It Yourself (degree of difficulty reduced if you glue the flaps and slats up and scribe the ones on the extension):

 Revell Kit Wing Tip Extensions:

 However, the CAT4 modification includes the extension of the trailing edge flaps and leading edge slats, which would be difficult to accurately represent deployed otherwise.

Another consideration is the two different lengths of the engine shroud aft of the afterburner. Both of these were present at one time or another on all of the first five F-111Bs and the ones in the Hasegawa kit are all long and configured with “feathers” that resemble those on variable-area afterburner nozzles, unlike the smooth exterior of the shrouds on the F-111Bs (my guess is that the feather configuration was added to reduce the stress from heat expansion). CAT4 provides a shroud length option or the kit shroud feathers can be filled and smoothed to the F-111B configuration.

All of the F-111 kits will have the USAF landing gear. As it happens, the first three F-111Bs flew with them but the remainder were delivered with the very different Navy nose landing gear and main landing gear wheels. Also, except for the Revell, the F-111 kits do not have the original retractable aft main landing gear door flown on the first seven F-111Bs.

The engine inlets also varied among the kits with some overlap of those on the first seven F-111Bs (General Dynamics was responsible for inlet development; Grumman was roughly one inlet modification behind in production). As noted on the Conversion Set Application matrix, which specific F-111B you model will determine which Hasegawa/Hobby 2000 kit to buy.

The F-111B cockpits were notably different. The first three F-111Bs had ejection seats. All had flight controls only on the left hand side. The F-111Bs delivered to Hughes for Phoenix system installation (151971/2 and 152715) had the right side instrument panel provided in the CAT 4 set R72016 but the remainder had a flight-test-only substitute with few instruments and switches.

To be continued in Part 2

An F-111B Configuration Update

 6 April 2026: I should have prefaced this post as being a preliminary draft, i.e. corrections and additions to come.

The Configuration Difference matrix has been updated 

CAT4 is in the process of releasing decals and conversion sets for the F-111B. As a result, I'm reviewing and updating previous F-111B posts providing modeler-oriented configuration details of the seven that were built and flown. This was the original post from 2009 that summarized them:

 https://tailspintopics.blogspot.com/2009/10/grumman-f-111b.html

A comparison summary by BuNo:

For the difference in the inflight refueling installation for the short vs. long nose, see https://tailspintopics.blogspot.com/2012/01/f-111b-inflight-refueling-probe.html

For the landing gear and inlet differences, scroll down here: https://tailspintopics.blogspot.com/2009/10/grumman-f-111b.html

For more on note 2) above, https://tailspintopics.blogspot.com/2011/09/f-111b-aft-main-landing-gear-door.html. Also, the F-111B aft main landing gear door extends a bit farther aft than production USAF F-111s because it was attached to the landing gear and therefore had to be trimmed to clear the bottom of the fuselage when the landing gear was extended.

For more on changes to the main landing gear for production, see https://tailspintopics.blogspot.com/2017/02/the-f-111b-production-main-landing-gear.html 

The first three F-111Bs had ejection seats. See https://tailspintopics.blogspot.com/2016/07/f-111ab-ejection-seats.html

 The rotating glove was added to the fuselage adjacent to the leading edge of the wing to increase lift for takeoff and landing, offsetting the increase in gross weight. The leading edge slat was also extended inboard.

 The auxiliary flap was a late addition to further increase the lift on takeoff and landing. See https://tailspintopics.blogspot.com/2014/09/f-111-auxiliary-flaps.html

The original venting of some of the boundary layer air kept out of the inlet was on the side of the fuselage under the wing. Ducts were subsequently added to increase the suction.

 

The venting was subsequently moved to the top of fuselage.

 

 

 A comparison of the "A" and "B" boat tails (in this instance, A and B represent boat-tail configurations, not the F-111A vs the F-111B).

Not included in the comparison above are the two different engine exhaust shrouds that were present on the F-111 prototypes. These shrouds were mounted on the engine behind the afterburner, probably to provide sonic and thermal protection to the adjacent aircraft structure. Free-floating "blow-in" doors were located forward of the shrouds. My understanding is that these were either open or closed in flight depending on the difference in external and internal (engine bay) pressure. The shrouds were originally just slightly tapered metal cylinders. In production, at least the aft portion of the shrouds consisted of linked longitudinal panels resembling an afterburner nozzle but were not controlled and had only limited movement, probably to relieve stress from thermal expansion of the shroud; the nomenclature changed from "shroud" to "feathers". The blow-in doors were also then fixed in the open position.

There were two different shroud lengths. The original ones were longer and the shorter ones possibly introduced as a weight reduction change that was short-lived.

 Note that 151970 originally flew with long (green arrow) shrouds but was photographed at Edwards AFB with short ones (red arrow). 151973 was also flown with both short and long shrouds.

  

Douglas F3D Skyknight 20 mm Cannon Installation

 12 November 2025: Corrected cannon case/link ejection location

Thanks to Smellybeard (obviously a nom de plume), I know more about this subject than I did a few days ago. It began when he asked for confirmation that two of the F3D's four 20 mm cannons were located in the nose wheel well, a detail that hadn't occurred to me but obviously necessary from the front view.

Thanks to his research and the files of my F3D subject-matter expert, Paul Bless, I have reappeared out of this particular rabbit hole with information new to me if not to you.

 

First, text from the Erection and Maintenance Manual:

And an illustration:

The inner cannon is located lower and farther aft than the outer cannon ( the inner and outer cannons are staggered by the width of the ammunition feeds and fire into blast tubes). The location of the inner cannon and blast tubes isn't obvious from any pictures of the nose wheel well I've seen because they have been removed; see links provided by Smellybeard: http://nabe3saviation.web.fc2.com/images3/twaf3-10.jpg and https://media.net-maquettes.com/2024/08/Douglas-TF-10B-Skyknight-72.webp . In the latter one, he notes that there is a mount on each side of the well that corresponds with detail B in the illustration above. He also wonders if the landing light was original equipment because of its potential interference with the left hand cannon.

However, an opening in the aft end of the nose landing gear door is usually still present: this was where the cartridge cases and clips were dumped overboard (the corresponding ones for the outboard cannons were located farther forward and outboard of the nose gear compartment).

From Paul Bless Photo

The nose gear bay opening is not as wide as it appears from the front based on the location of the nose landing gear doors because they are mounted on goose-neck hinges.

 But the opening is also much longer than it needs to be, apparently to provide for access to the ammunition feed to the cannons.

 

 

In an F3D nose wheel well I looked up into, roughly the aft half of the opening was closed off by a panel, but at the moment I don't know if that was original or something added when the Skyknight was prepared for display.

 

Sikorsky HH-3A Sea King for Combat Rescue

 This is a work in progress...

 With the advent of the Korea War in mid-1950, enemy-opposed rescue of pilots who had been shot down had become a mission for which the U.S.Navy was unprepared. The obvious solution was the use of the Sikorsky HO3S helicopter that had only recently become the standard plane guard for carrier takeoff and landings, supplementing the destroyers that had been utilized for that role. It had a rescue hoist and could carry three passengers, although from a practical rescue mission standpoint, the crew was limited to a pilot and a hoist operator and only one passenger, the rescuee. For a combat rescue, the pilot was armed with a revolver and the hoist operator, a carbine. There was minimal protection from small arms and none from heavier weapons. This is a screen grab from one of the most accurate aviation movies ever produced, The Bridges at Toko-Ri (also see https://thanlont.blogspot.com/2008/11/most-accurate-aviation-movie-ever.html):

As upon occasion in real life, the movie did not end well for the downed pilot and the helicopter crew.

After the armistice in July 1953, the priority for maintaining a combat-rescue capability rapidly lowered to be indistinguishable from zero, with no chance of rescue in August 1964 for the first Navy carrier-based pilot to survive being shot down over North Vietnam. He was quickly captured and remained a prisoner of war for more than eight years.

The solution was again to assign the mission to the existing carrier plane-guard helicopters, the Kaman UH-2A/B Seasprite* and the Sikorsky SH-3A Sea King. The former was assigned to air groups on the attack carriers and the latter, ASW carriers that had ASW Sea Kings assigned for detection and destruction of enemy submarines. At first the addition of armor and armament to them was not significantly improved over that implemented for the HO3S but it was constantly upgraded as quickly as possible. In addition, both contractors began to design significant modifications to improve both passive and active protection from enemy fire.

Early in the war, only offshore rescue attempts were attempted but on 20 September 1965, the crew of an HC-1 UH-2  flying from the cruiser Galveston—to minimize the distance to be flown—and escorted by two VA-25 Skyraiders was able to rescue a pilot unable to get past the coast and over the water before ejecting. In August 1965, Hornet had deployed to WestPac with five of its 18 HS-2 SH-3As stripped of ASW systems, minimally armed and armored by later standards, and with subdued markings to provide more range and payload capability than the smaller H-2's.

Kaman received a contract for 12 HH-2Cs, which added a second engine for better hover and payload performance, armed not only with M-60 door guns but a remotely controlled turret under the nose that contained a 5.56 mm six-barrel "microgun", and with some armor protection.

However, only six were delivered, the turret was deleted early on for various reasons, and the second engine further reduced range and endurance. While it was used for combat rescues beginning in 1970, the Sikorsky H-3, nicknamed the Big Mother in view of the size difference, was more capable with a bigger cabin and eventually replaced it.

 Twelve HH-3As were delivered beginning in 1970 although not operationally employed until 1971. The prototype was a heavily armed and armored Sikorsky modification of an early (No. 14) SH-3A, BuNo 148036:

Uprated T-58-GE-8F engines were installed to somewhat compensate for the greater weight. A window was added in the aft fuselage for the aiming of the remotely controlled miniguns. It was located one frame forward of a similar window in the RH-3A minesweeper variant (see https://tailspintopics.blogspot.com/2022/12/sikorsky-rh-3a-seaking-minesweeper.html):

Note that some SH-3As modified for combat rescue and painted/marked accordingly are misidentified as HH-3As since they lack that aft cabin window, not to mention the additional armor:

 The HH-3A engine and transmission armor:

 The remotely controlled turret was not used operationally because of weight among other shortcomings:

 It was replaced by a cabin-door mounted minigun and an M60 machine gun located in the forward entry door.

Note that the forward entry door has been modified to provide a larger opening. A second M60 was reportedly employed from a left-side window but I have not seen a depiction of that option.

The HH-3A was also intended to carry two 175-gallon external tanks for additional range.

 In addition to the prototype, BuNo 148036, 11 SH-3As were modified from Sikorsky-furnished kits by the NARF at NAS Quonset Point, RI: 149682, 149896, 149903, 149912, 149916, 149922, 149933, 151531, 151552, 151533, and 151556. All 12 were initially assigned to HC-7, tail code VH. It is a credit to the modifications, training, tactics, and mission planning that none were lost in combat rescue missions. Most of the 10 remaining were transferred to HC-9, a Reserve squadron dedicated to maintaining combat-rescue capability, when HC-7 was deactivated in June 1975**. 151531 had crashed in California while on a training exercise and 149896 was stricken in May 1973, an innocent bystander parked on a carrier, when an A-3 Skywarrior landed too far to starboard on 8 January 1973, hitting it with a wingtip.

HC-9, tail code NW, was capable of deploying around the globe within 15-days of notification. In 1986, a two-aircraft detachment was deployed in support of Operation Prairie Fire in the Gulf of Sidra, Libya.  Three Carrier Strike Groups in the Mediterranean Sea needed CSAR support due to possible overland operations while enforcing freedom of navigation.  The detachment was based on Coronado (AGF-11), the command ship of the U.S. Sixth Fleet.   

When HC-9 was disestablished on 31 July 1990, replaced by Helicopter Combat Support (HCS) squadrons assigned the much more capable Sikorsky HH-60S Sea Hawks, that was still not the end of HH-3A air frame utilization (helicopters are the aeronautical equivalent of George Washington's proverbial ax). One, 151556, is on display at the American Helicopter Museum in West Chester, PA. The other eight survivors** were eventually purchased for civil applications (one even became an S-61T). In most if not all cases, the extra rear windows were no longer present on the fuselage. This is the former 149916, in civil service for fire fighting and heavy-lift construction:

One remaining mystery is the purpose for the four "lunch boxes" (my nickname for them) scabbed onto the HH-3A fuselage—two on each side and one each fore and aft, with no apparent opening— following Vietnam, possibly following transfer to HC-9. They are faceted, with the side not being a rectangle: the side of the aft box is angled slightly forward; the forward box is a mirror image of it with the side angled slightly aft. My guess is that they are associated with a warning system, either radar or gunfire detection.

 *For a complete history of the H-2 Seasprite, buy this book: https://thanlont.blogspot.com/2025/06/hu2k-seasprite-book-wayne-mutza.html 

 ** At least one HH-3A, BuNo 149912, was transferred to HC-1 and subsequently stricken in October 1976.

Navy F4H (F-4) Phantom 370-gallon External Tanks

4 February 2026: An update of Hypersonic Models 1/72 tanks

There were at least three different suppliers of the F-4 370-gallon external tanks that were slightly but clearly different externally. See http://tailspintopics.blogspot.com/2013/06/things-under-wings-f4h-f-4-phantom.html

Few F-4 kits provide the original McAir tank, which did not have a constant diameter at any point from either end to the middle and did have flanges on both sides of the tank. Jeffrey Kubiak of Hypersonic Models originally provided a 1/72 option for this several years ago when he lived in the UK:

These were 1/72 scale,  accurate in size, and include the handed pylons to which the tanks were attached. The resin in my example, provided by Hypersonic, was flawless.

However, Jeffrey has since moved to Japan and been updating his product line. For his replacement of this aftermarket item, now 3D printed, click HERE

 His resin-cast 1/48th tanks are still available: Click HERE

This is the current Hypersonics website: https://hypersonicmodels.com/