by Tommy H. Thomason

Thursday, August 12, 2021

North American FJ-2/3 Cockpit and Landing Gear Color

For some reason, North American was allowed to deliver FJ-2 and -3 Furies with a decidedly nonstandard green cockpit color. This is a picture of the cockpit of an FJ-2 in a museum that appears to be authentic.

Bill Nourse via Jeff Wasal

For background, see

I haven't come across a specific specification for the color but in response to a question, have done some more research into how long North American continued to deliver FJ-2/3s with this cockpit color. Some have speculated that the changeover to a Dark Gull Gray interior occurred when FJ-3s began to be delivered in the gray/white scheme (note that the requirement for a DGG cockpit predated the one for a Light Gull Gray/White exterior by almost a year. However, color photos of FJ-3Ms clearly show that at least before overhaul and for the ejection seat headrest, the green persisted although I don't know for long in production.

Note that the FJ-3M to the left of the one pictured immediately above, same squadron, appears to have a Gull Gray ejection seat headrest.

This could mean that it had been through overhaul or that the seat had been replaced with a spare that was gray.
However, there's no question that FJ-3s at least eventually had DGG headrests although the cushion stayed green on at least some examples.

The other anomaly recently called to my attention was "black" landing gear on some FJ-3s. The usual color was "aluminum" paint with the interior of all the landing gear doors painted red, not just the edges, although there are white examples much later on.

In the following example, it appears that the coating was extended to the inside of the gear doors and the wheel wells but this may not have always been the case. 

I first made note of it in a screen shot of an F9F-5 Panther in the movie Bridges at Toko-ri.

It was a tar-like application similar to automobile undercoating. When "unpainted" F7U-3 Cutlasses experienced unacceptable corrosion susceptibility and were repainted in the grey/white scheme, the protection was extended in some squadrons to spraying a coat of parel-keytone on the landing gear struts, wheels, inside of the landing gear doors, and wheel wells.

It proved to be a terrible idea. It not only hid the development of existing corrosion on the landing gear structure, it precluded the readability of identification on wire and tubes in the wheel well.


Sunday, August 8, 2021

LF Models Piasecki HRP-1

 15 September 2021 update: Paul Boyer built the LF Models HRP-1 as one of the three operated by the U.S. Coast Guard, the original customer for it (the silver cylinders around the landing gear wheels are pop-open floats for emergency landings on the water).

His summary of the build:

Some build difficulties -  Lack of positive parts locators, weak instructions with respect to assembly process, poor fit of interior parts, no flanges on cabin or door windows (replaced with clear packaging tape slightly larger than the window and applied on the outside of the fuselage along with the addition of decals)

Very fragile rotors (THT note: delicate parts at 1/72nd scale)

Good decals

An illustrated history of the Coast Guard's use of the HRP-1 is available HERE

 The Coast Guard decals are in LFM-PE7250; the USMC decals are in LFM-PE7251

Although only 20 HRP-1s were produced by Piasecki, it represents a major milestone in the early history of helicopters and an amazing achievement for a young man and his small band of helicopter enthusiasts, rivaling and paralleling that of James McDonnell's fledgling company successfully creating a twin-engine carrier-based jet fighter, the FD/FH Phantom. In the unlikely event that anyone is interested, I wrote a paper on the Piasecki and the HRP for a Vertical Flight Symposium that is available for the asking.

I never imagined that an injection-molded kit would ever be produced of the Rescuer. As a result, a few years ago I bought Unicraft's resin HRP kit, even though I was aware from experience that it would be a challenging build at best and likely of marginal accuracy. I was therefore not disappointed when I opened the box, which I have done at least once a year without doing more than considering whether it was worth the effort to build it at all, much less correct its shape and size errors.

I was therefore very surprised to learn that LF Models in the Czech Republic was to release one in early 2021 and disappointed that its projected availability came and went with no update. Nevertheless, it came to pass and was well worth the wait. It is not only injection molded with a good representation of detail including the steel-tube framework in the forward fuselage and the internally mounted engine, it includes injection molded (not vacuum formed) clear parts, canopy masks, decals, photo-etched parts, and a printed representation of the instrument panel dials. It exceeded my expectations by much more than the Unicraft kit failed them.

The HRP was a huge helicopter for the time, dramatically so relative to the little two-seat Sikorskys. I regret to report that the kit is slightly huger than 1/72 but only by a 1/4" or 18 actual inches, which is only about 3 percent not to mention a bit difficult to rectify. I'm certainly going to live with it. Note that I have not built it yet so this is a preliminary review after a close look at the contents of the box.

The instruction sheet is pictorial. This early inboard profile (ignore the rotor-hub fairing depiction) may be of help in understanding and orienting the drive system:

The pilot and copilot seats in the forward fuselage were actually offset slightly to the left side for access from the cabin:

 Note that the pilot had an instrument panel with nine instruments on it as provided in the kit but there was also an upper instrument panel visible in the picture above as a narrow black rectangle above eye level.

The copilot only had a four-instrument panel in front of him.

The vents on the bottom of the engine compartment are well represented but not the big air intake (it was an air-cooled engine) on the top of the fuselage:

I'm not sure about the shape of the blade tips: the kit's are squared off but I'm sure that some, if not all, were rounded:

Note that the rotor diameter should be 6 13/16 inches (41 feet) when assembling it and the rotors did not in fact overlap. That was a later refinement of the tandem rotor concept.

Note that statically, the rotor blade themselves are relatively stiff but angle down from the hub attach point.

In the unlikely event that you see a picture of the attachment of the main landing gear to the bottom of the fuselage that is different from the kit's, that was an early configuration:

A couple of challenges for those wanting to add a degree or two of difficulty:

1. Folded (necessary for stowage aboard ship):

2. Lightened for ASW research with a dipping sonar:

Friday, August 6, 2021

Things Under Wings: North American FJ-4 Inflight Refueling System


Angelo Romano Collection

For an introduction to inflight refueling, see and

For tactical delivery of a nuclear bomb, jets were superior to the AD Skyraider in terms of survivability during both ingress and egress, as well as cruise speed but were notably inferior in range.  Inflight refueling was adopted by the Navy to increase the mission radius of its carrier-based jets, first with big AJ Savages providing en route fuel to F2H-2 Banshees and then with the "buddy" concept, in which the jet carrying the bomb was refueled by one carrying a store equipped with the hose and drogue system. The "tanker" would top up the "bomber" and then turn back with enough fuel to return to the carrier while the bomber pressed on to the target. This is an example of the increase in range provided (the A2U was an attack variant of the Vought F7U-3 Cutlass).

During the Malvina/Falkland Islands war in 1982, the British used an extreme example of this concept to deny the use of the runway in the Falkland Islands to Argentine fighters and take out air defense radars there with a Vulcan bomber taking off from and returning to a base on Ascension Island, 3,400 nautical miles away. See

Douglas developed the D-704 refueling tank for this purpose for its A4D Skyhawk. This is a illustration of the very similar store that the Navy subsequently bought from Sargeant-Fletcher:

The Navy, as was its practice at the time, contracted with North American for a modification of its FJ-4 Fury as a backup to the Douglas Skyhawk program. However, since it did not have the ground clearance necessary to carry the Douglas store, North American designed a "symmetrical" two-tank configuration that did, one tank containing the reel, hose, and drogue along with fuel and the other full of fuel. The hose reel was relocated to the midsection of the tank and the drogue streamed out of the bottom of its aft end.

 The bespoke FJ-4 tank didn't have much ground clearance either.

Sam Morgan provided a valuable insight into the configuration of the tanks when he noted that the black stripes used to position the handling cradle were in different locations:

Another view of the tanks:

I created this drawing of the reel tank from illustrations in the maintenance manual for the system provided by Jerry Wells and photos provided by Angelo Romano. The side-view outline is based on a partially dimensioned manual drawing that was clearly approximate in detail; for the rest I relied on photo interpretation. The status light configuration is notional since I don't have a high resolution image of the aft end of the tank; there were three lights, yellow/amber, green, and red. A hose "floodlight" for night refueling is also mentioned in the manual but I have no other information as to its location or configuration.

Note the side-ward bulge in the midsection where the hose reel was located to provide clearance with the bottom of it. There also appear to be two different diameter propeller shrouds: the larger one accommodates the blades of the D-704 pod; my guess is that the smaller propeller proved inadequate for the power required. Or it may have been a desire to standardize the pump.

The left-hand tank was identical in size and also in shape with the exception of the midsection.

The FJ-4B had an unusually large number of different stores pylons (as well as external fuel tanks). The one used for the IFR tanks:

Two triangular flat plates provided lateral stiffness to the pylon (the picture was taken of two pylons upside down on the ground; the small pylon is marked with Xs and the picture has been inverted).