A3D (A-3) Flap to Pylon Fairing

I was having trouble visualizing the A3D wing flap to pylon interface from available pictures so I stopped off at the excellent New England Air Museum at Bradley Field north of Hartford, Connecticut and took a close look at their A3D.

In summary, the aft part of the pylon fairing is attached to the flap and pivots with it when the flap is lowered.

What I indicate to be a rub area might just be dirt and there may not actually be a pivot point between the fairing on the flap and the pylon although it seems likely that there is since there is an access panel there...

This is a Bill Spidle picture of the extended flap, showing how the top and bottom of the forward edge of the fairing on the flap have moved with respect to each other (top going aft and bottom going forward).

Note that the forward edge of the flap itself has moved aft, creating a slot between it and the flap cove.

The inboard side of the fairing is quite different.

In another Spidle photograph, the flat area at the top of the interface is apparent.

And the view from the bottom shows that the split line between the pylon and the flap fairing is perpendicular to the flap hinge line. (This picture is actually the left side flopped but the fairings are mirror imaged.)

Why such a convoluted arrangement? My guess is that it had something to do with the aeroelastic problem that Douglas had with the relatively thin, high aspect ratio wing. If you can get a good look at the pylon, you'll see that it is cambered at its aft end so as to generate lift outboard and below the wing for some important reason, since lift results in drag. (The purpose might be to stiffen the pylon/engine nacelle combination by loading it to one side; it is therefore less likely to "wobble" in roll or yaw.) The pylon is also fairly wide at the aft end of the wing torque box, probably to provide adequate torsional stiffness to the wing. A fairing on the pylon aft of the wing torque box is therefore desirable to reduce drag. If you want as much flap as possible (i.e. not have an inboard section and an outboard section with a gap in between for the pylon fairing), then the fairing has to be attached to the flap and if it's attached to the flap, when it pivots it moves perpendicular to the flap hinge line, not in parallel with the pylon, which means it can't retract within the pylon. And so you wind up with something as convoluted as my hypothesis...

I don't know if the Trumpeter kit reflects this area accurately or not.

Grumman WF-2/E-1B Redux

I covered the Grumman WF-2 Tracer configuration fairly well here: http://tailspintopics.blogspot.com/2010/11/trader-and-tracer.html

One question was whether the 1/72 Mach 2 E-1B fuselage length was correct. Jackman on ARC (Aircraft Resource Center) has begun a thread (here) on building this kit and in the process, determined that the overall length at least is correct. I'll watch his progress with some interest. Hopefully he won't burn out like I did with the Falcon conversion. See http://tailhooktopics.blogspot.com/2013/08/half-baked-172nd-grumman-wf-2e-1b.html

Things Under Wings - Douglas Low-Drag External Tanks

I've provided illustrations of the various Douglas low-drag external tanks here: http://tailspintopics.blogspot.com/2011/07/douglas-low-drag-external-fuel-tanks.html

and a survey of 1/72 scale tanks in various kits here:
http://tailspintopics.blogspot.com/2012/07/douglas-low-drag-external-fuel-tanks.html

Freightdog (http://www.freightdogmodels.co.uk/) is now producing 1/72 150-gallon and 300-gallon (finned and bobtailed) Douglas external tanks as well as the D-704 refueling pod. Colin sent me samples and they look really good, both size and finish. Note the separate and finely molded turbine on the D-704:

(Note that the jettison pipe is on the bottom of the tank.)

Pablo Ziegle called my attention to another 1/72 option for 300-gallon tanks from Attack Squadron in Poland.

 

See: http://attacksquadron.blogspot.com.ar/2013/05/usn-douglas-300-gal-fuel-tank.html

Hannants is listing them (http://www.hannants.co.uk/product/ASQ72014). Each set includes three tanks and the fin options for each. Pablo is awaiting a set so he wasn't able to comment on the accuracy or quality.

Early SH-3 Configuration by Jodie Peeler

Jodie Peeler provided the following information on the configuration of the early SH-3s; note that the Fleet Introduction Program for the SH-3, then designated HSS-2, was accomplished in late summer of 1961 and deliveries to fleet squadrons began to be accomplished immediately thereafter:

While rounding up some references for the Mercury recovery helicopters, I found this picture that's of particular interest to your Tailhook Topics Draft post, http://tailhooktopics.blogspot.com/2013/02/us-navy-asw-sh-3-sea-king-variations.html, about the Sea King.

It is a screen capture from a film taken aboard USS Intrepid on 24 May 1962; it is HS-3's HSS-2 BuNo 148964 landing aboard Intrepid with astronaut Scott Carpenter inside.

Four interesting things about this HSS-2:

-- Both air data probes over starboard side of cockpit;
-- No rotor cap;
-- No flotation bags on the sponsons; and
-- Take a look behind the transmission hump - there's no little doghouse back there.

In a quick look at my hard drive, here's what I've found, if reviewing the pictures of Gemini recovery helicopters (which were all members of fleet ASW squadrons) can be considered a decent cross-section:

-- By early 1965 some SH-3s had received the doghouse. The Gemini 3 recovery helo (BuNo 148984) had it in March 1965. The Gemini 4 recovery helo (BuNo 148999) didn't have it in June 1965. By the Gemini 5 recovery (August 1965, with BuNo 149005) it shows up and remains consistent. It appears those built without it got the mod whenever they could.

-- The air data probes consistently appear separated by early 1965

-- Flotation bags had come in by early 1965

-- Main rotor caps really don't show up a lot until about the end of 1965*

By December 1965/early 1966 the "standard" SH-3A/early SH-3D configuration has become the norm, with doghouse, separated probes, rotor caps and flotation bags.

The VH-3A/HSS-2Zs were delivered with the rotor caps, but without the doghouse. By June 1963 they had been fitted with the doghouse. Not sure when the air data probe configuration changed; probably sometime in 1964 or early 1965. I don't believe VH-3s have ever carried flotation bags, at least not while on white-top duty.

* In case you want to build your model in this early configuration, here is a photo of the uncapped rotor hub from the 16 January 1961 issue of Aviation Week, page 52.

Good luck with that...
 

Well, That Was Special

On 10 July 2013, the Northrop Grumman X-47B made the first unmanned, autonomous, arrested landing on an aircraft carrier at sea.

 U.S. Navy photo MC3 Kevin J. Steinberg

I think I've included enough qualifiers as did the Navy press release (although for some reason it didn't mention Northrop Grumman). They are necessary because this wasn't the first or even second autonomous carrier landing. See http://thanlont.blogspot.com/2011/07/look-no-hands.html. Nevertheless it was the first without an on-board pilot to take over in the event of a malfunction, a significant step in demonstrating the maturity of the technology required to operate an unmanned airplane from an aircraft carrier. 

The at-sea landing was preceded by a very careful buildup program that included shore-based launches and arrested landings. The first at-sea event was a deck handling evaluation aboard Harry S. Truman in December 2012.

This was followed by the first catapult launch at sea from George H.W. Bush in May 2013, erroneously claimed to be the first catapult launch of an unmanned airplane at sea (see http://thanlont.blogspot.com/2013/05/the-first-launch-of-unmanned-aircraft.html)

The final build up event was a series of at-sea touch and goes with the hook up in late May 2013.

At that point, the Navy had enough confidence that nothing untoward would happen during the first at-sea landing to invite the Secretary of the Navy, Ray Mabus, and the Chief of Naval Operations, Adm Johathan Greenert, to stand on the LSO platform.

Note that the flight deck is lined with C-2 CODs, another expression of faith in the X-47B's computers to keep it inside the foul lines.

The event was not really marred by the X-47B taking its own waveoff on its third landing attempt and being directed to fly back to NASA's Wallops Flight Facility for a shore-based final recovery. That proved that self-check features in the on-board computers were functioning as intended to keep the X-47B from continuing an approach with a possible fault in a critical system.

The two X-47Bs will soon be retired to museums at Patuxent River, Maryland and Pensacola, Florida. Time will tell whether the bright future of operational Unmanned Combat Air Systems lies ahead or will go unrealized...

Planet 1/72 XF10F

The Westinghouse J40's only victim was the ambitious Grumman XF10F Jaguar (the other programs using the J40 managed to transition to other engines in its place*) with a variable sweep wing**:

I had published a few notes on the Planet 1/72 kit on my draft Tailhook Topics website:
http://tailhooktopics.blogspot.com/2012/06/xf10f-pictures.html

Navy Bird over on Britmodeler perservered where I hadn't and did the kit justice. His build series:
http://tailhooktopics.blogspot.com/2012/06/xf10f-pictures.html

This is a picture of Navy Bird's finished model:

For more finished pictures of, and notes on, his excellent model are here:
http://www.britmodeller.com/forums/index.php?/topic/234942572-172-grumman-xf10f-1-jaguar/

*For more on the Westinghouse engine saga, see http://thanlont.blogspot.com/2011/03/from-hero-to-zero.html

** For more on the XF10F program, see http://thanlont.blogspot.com/2009/07/variable-incidence-wing.html and http://thanlont.blogspot.com/2009/01/it-seemed-like-good-idea-at-time.html or better yet, buy my book on U.S. Navy jet fighter development: http://www.amazon.com/U-S-Naval-Air-Superiority-Delevelopment/dp/1580071104

AD Armor-All

The question comes up from time to time about the presence and effectivity of the exernal "armor" on the AD (A-1) Skyraider. This is evident as clearly scabbed-on plates on the forward fuselage sides and belly.

The additional shrapnel protection actually dates back to early 1952 and was retrofitted to AD-3 and AD-4 Skyraiders as described in this May 1953 Naval Aviation News article.

(If you click on the image and then double-click—for a Mac—or right click to "view" it, it gets bigger.)

This was the kit, as shown on the AD-6 Standard Aircraft Characteristics chart:

 

 It should be noted that this kit was in addition to the basic protection provided:

One way to tell if an AD has the deflector plate kit added is the step on the side of the fuselage. If it's a kick-in door, it hasn't been; if it's external, like a little ledge, then it has been.

An AD-4 that does not have the  kit:

An AD-6 with the kit:

Crop from a Pete Bulban photograph

One AD configuration for the nuclear-strike mission was to 1) remove the deflector plate kit, the AERO pylons on the outboard wing panels, at least two of the 20mm cannon, and anything else not mission-critical that added weight and/or drag and 2) cover any holes with speed tape.

The AD-5 armor kit was slightly different because of the relocation of some engine accessories. See https://tailhooktopics.blogspot.com/2017/08/douglas-ad-5-armor.html