by Tommy H. Thomason

Monday, December 26, 2016

Kitty Hawk 1/48 F2H-2 Outboard Flap

I've seen some very nice built-up Kitty Hawk 1/48 F2H-2 kits. Unfortunately, in some the modeler attached the outboard flaps according to the kit instructions. In fact, the part identified as the lower half of the flap (A15 and 16) should really be glued on as the upper surface of the wing and the part identified as the upper half (A14 and 18) attached under it, either extended or up. This is the Kitty Hawk build, which shows the outboard flap attached correctly per the instructions but incorrectly with respect to the actual airplane:

This is what the extended outboard flap should look like:
The aft portion of the upper surface of the outboard flap is also part of the upper surface of the wing when the flaps are up.

For more on the Kitty Hawk kit, see http://tailspintopics.blogspot.com/2016/09/kitty-hawk-148-f2h-22p-banshee.html and http://tailspintopics.blogspot.com/2016/12/kitty-hawk-148-f2h-banshee-kit-redux.html

Tuesday, December 13, 2016

Kitty Hawk 1/48 F2H Banshee Kit Redux

20 December 2016: Added a picture by Michael Rieth comparing the kit main landing gear doors to the kit landing gear wells.

Click HERE for my first post on the Kitty Hawk 1/48 Banshee kit.

Michael Rieth subsequently provided me with illustrations of his more detailed assessment of more notable shape errors in the kit in addition to the upper inner wing interface with the fuselage, which is excessively bulged upward, and the shape of the inlet.

Both the upper and lower wing engine fairings are misshaped, the shortened upper likely forced by the high inner wing contour.
A true bottom view of the lower fairing is not available, either as a McDonnell drawing or a photo, but there are good enough photos to establish that the Kitty Hawk interpretation is incorrect.
To check my observation that the inboard pylons were not staggered, Michael overlaid a photo of an F2H-3/4 inner wing (identical in this regard) to confirm that the Kitty Hawk pylons (red outlined squares) are incorrectly staggered and the inner one is slightly too far outboard, although it appears to be correctly positioned longitudinally.

However, what becomes obvious from this overlay is that the inner main landing gear doors are oversized, extending too far forward.
The kit doors also don't match the incorrect kit wells, so building the model gear up and rescribing the outline of the wells involves some additional work.

The Hawk kit, deemed by some to be superior in shape to the Kitty Hawk offering, has its pylons even more out of position and the main landing gear well may be, although that could be due to the kit part being at an angle to the camera in the following comparison.
Bob Norgren

The significant lateral indentation of the bottom of the fuselage of the Hawk kit toward the front of the wing inner section is also incorrect. The Kitty Hawk kit is more accurate in this regard.

Saturday, December 10, 2016

Blackburn Buccaneer

For a little background on the Royal Navy's Blackburn Buccaneer versus its U.S. Navy contemporary, see http://thanlont.blogspot.com/2016/12/horses-for-courses-intruder-vs-buccaneer.html.

CMR (short for Czech Master Resin) Models has released an excellent kit of the Buccaneer S.Mk.1, the original underpowered "Banana" (from its initial proposition as the Blackburn Advanced Naval Aircraft).

For a detailed build article by master modeler, Bill Gilman, see: http://www.britmodeller.com/forums/index.php?/topic/235007140-172-scale-resin-blackburn-buccaneer-smk1/

Finished model photos and comments are HERE

The kit is the result of research provided by Buccaneer subject-matter expert Andy White in the form of drawings, illustrations, and as importantly, involvement in the review of test castings (definitely state of the art) and creation of the assembly instructions. See his website: http://www.blackburn-buccaneer.co.uk/

Friday, November 18, 2016

F9F Armament Installation - A Cautionary Tale

11 January 2017: Added comments by David Collier


A new model kit of an aircraft is invariably found to have at least a few errors if not downright fatal ones. I don't wonder as much about how they could get it wrong as how they could possibly avoid error. The F9F armament installation is an example. This is an excellent picture of it, taken in 1949, showing the four cannon, the feed chute to the inboard ones, the avionics shelf, the black boxes above the cannon, etc.

The ammo boxes were located behind the nose wheel well, easily accessible from within it.

The only problem from a modeling standpoint is that this installation was only applicable to a total of 10 of the very first F9F-2s and -3s. For some reason, the installation was almost immediately changed to one with only two of the ammo boxes located behind the nose wheel well with the other two mounted above the cannon on the equipment shelf.
My guess is that the original location of the ammo boxes was predicated on center of gravity considerations. The change might have had something to do with problems with jamming in the feed chutes that went to either the inboard or outboard cannons. Or weight reduction. And perhaps locating 1950s avionics above cannons was a bad idea.

The F9F-6/7 Cougar used the same armament installation as the Panther. Note that the feed chutes from the aft-mounted ammo boxes are not shown.

David Collier provided a comment from his experience working on the F9F-7, which was identical to the -6 from an armament standpoint, at NAS New York during the summer of 1955:

Re the center of gravity, the two  ammo cans in the nose were fitted with metal weights which were installed when no ammo was loaded. All expended cartridges and links ended up in the lower portion of the nose below the guns. If no metal weights could be found, sandbags were used as weights. I remember cleaning sand out of the area where the cannons and feed mechanisms were installed and the shelf above the cannons where the ammo cans and chutes, batteries and cables were installed. A real mess!

Naturally, you would assume that the F9F-8 Cougar would have the same armament installation as the -6/7. You would be wrong.
According to the flight manual, all four ammo boxes were located above the cannon.

For other differences between -6 and -8 Cougars, see http://tailspintopics.blogspot.com/2010/11/f9f-6-vs-f9f-8-cougars.html

For details on the nose cones of the Panther and Cougar, see http://tailspintopics.blogspot.com/2016/02/grumman-f9f-nose-cone-variations.html 

Tuesday, November 1, 2016

McDonnell XF2H-1 Banshee BuNo 99860

Ron Downey is a retired McAir engineer who has an excellent blog, Aviation Archives, here: http://aviationarchives.blogspot.com/

He frequently posts high-resolution pictures, drawings, and illustrations, most but not all of McAir aircraft. I look at it about once a week and frequently see something that is new to me. In this case, it was a repost of an XF2H-1 drawing that I hadn't taken a close look at the first time: http://aviationarchives.blogspot.com/2015/07/xf2h-1-aerodynamic-three-view.html

There were three XF2H-1 (né XF2D-1) prototypes. This is the first one, BuNo 99858:
 Note the "thick" engine nacelle and the significant dihedral on the horizontal tail.

Several changes were required to solve aerodynamic problems. (see http://tailspintopics.blogspot.com/2009/12/f2h-banshee-modeling-notes.html). This is the second prototype after wing, nacelle, and empennage changes and the addition of the tip tanks similar to the ones that would be incorporated on the production F2H-2:

The production F2H-1 design was also lengthened a foot forward of the engine intakes to increase the amount of internal fuel. As it turns out the XF2H-1 drawing shows that the third prototype, BuNo 99860, incorporated this change. I hadn't noticed that until now because it retained the distinctive short XF2H canopy.
Note that it still has the handholds and steps on the right side of the forward fuselage and does not have an ejection seat.

Friday, October 28, 2016

North American FJ-4/4B Fury Notes

 27 January 2017: In response to a question about the tail bumper;
Unlike most tail bumpers, the FJ-4's was very narrow - basically a blade - and not retractable. There was a fixed guard in front of the bumper, which could pivot to absorb the shock of a tail-low touchdown. There was almost certainly a damper involved, since the bumper is always extended except on museum examples (see second picture) where the damper is missing or inoperative. There was a tie-down hole in the bumper.


23 January 2017: Some notes on and pictures of the 1/72 Emhar kit can be found here:
http://www.britmodeller.com/forums/index.php?/topic/235015791-emhar-fj-4-fury-172/

 October 2016: Updated to revise the horizontal tail discussion and correct other details.

In the process of preparing an information package requested by a kit maker, I revisited a question raised several years ago, the size and shape of the horizontal stabilizer. The problem is a fundamental inconsistency among the drawings and data available to me, which include the excellent North American FJ-4 four-view drawings, the FJ-4/4B Standard Aircraft Characteristics (SAC) charts, two NACA spin tunnel test reports, and a couple of measurements of an actual FJ-4B stabilizer by Jim Robbins. Thanks to FJ-4 maintenance manual data provided by Frank Truchi, a volunteer at the National Naval Aviation Museum, I can confirm that the NAA drawing of the horizontal tail is correct except for the span and the location of the elevator.


Note that the FJ-4 empennage was subjected to development changes.

The original FJ-4 horizontal tail was swept at 35° at the 25% chord. At some point in flight test, the sweep was changed to 35° at the leading edge, probably to reduce the overall length of the airplane, an important consideration from the standpoint of compact parking on aircraft carrier flight and hangar decks. The span was subsequently reduced by 18 inches on each side for production due to structural problems found in flight test.

In the process of reviewing the documentation I have, I discovered a detail that I wasn't aware of before. The major change between the FJ-3 and the FJ-4 was the wing. The new one provided more area to lift more weight, much of which was fuel. The knock on the FJ-3 was that performance suffered when it was carrying external tanks and endurance suffered when it was not. As a result, the FJ-4 was to have the same internal fuel capacity when clean (no external tanks) as the FJ-3 configured with external tanks. The ailerons were also to be moved inboard to avoid weight that would otherwise have been needed to stiffen the wing torsionally, which didn't leave much trailing edge available for flaps. As a result, the FJ-4 had narrow-chord leading edge flaps to further increase camber and a panel hinged to the bottom of the flap to scoop air into the slot between the leading edge of the flap and the aft spar of the wing.

This panel isn't shown on the NAA drawing bottom view.

One tidbit about the FJ-3 versus the FJ-4 that I'd forgotten was the increase in tread. This didn't result from the main landing gear struts being relocated more outboard: the wheels were simply located on the outboard side of the strut rather than the inboard side.

The FJ-4 had excellent handling qualities, eliminated the FJ-2/3's gunnery inaccuracy that resulted from the excessive downward angle of their cannon, and was almost certainly one of the best jet fighters from a performance and maneuverability standpoint that didn't have an afterburner.  Unfortunately, fighters with afterburners had an innate interception and air-to-air combat advantage so the Navy gave all the FJ-4s to the Marine Corps, which was happy to have them until Vought produced more F8U Crusaders than the Navy needed.

However, that wasn't the end of the FJ-4. The Bureau of Aeronautics decided that Douglas' Ed Heinemann wasn't paying proper attention to its concerns about the A4D Skyhawk program so it contracted with North American for an attack variant of the FJ-4.
Note the spoilers added to the upper surface of the wing for increased roll-control power required for the asymmetric loading of the heavy nuclear weapon that was the raison d'etre for the A4D/FJ-4B. Most descriptions of the FJ-4B state that these were located forward of the flaps, which I had presumed to be correct since that is where they would normally be.

It turns out that they were on the upper surface of the flaps as shown in the SAC drawing above. Note the open spoiler on this FJ-4B's damaged flap.
They are also evident in this FJ-4B walkaround photo taken by Fotios Rouch (for the complete set, see http://www.aircraftresourcecenter.com/awa01/401-500/awa463-FJ-4-Rouch/00.shtm).

For an FJ-4B configuration with the left-hand cannon removed, see: http://tailspintopics.blogspot.com/2012/03/modelers-guide-to-sabre-fury.html

For some detail under the canopy see http://tailhooktopics.blogspot.com/2012/12/fj-4-detail-under-canopy.html. Note that the FJ-4B was in service long enough to be retrofitted with the Martin-Baker ejection seat.

For an excellent set of annotated photos with configuration and other information, see this Phil Friddell post: http://tailhooktopics.blogspot.com/2012/12/fj-4-detail-under-canopy.html

For a summary of all the different FJ Furies, see http://tailspintopics.blogspot.com/2009/10/fj-fury.html

And, of course, there's great information and drawings in Steve Ginter's FJ-4/4B monograph, Naval Fighters Number Twenty Five, which is regrettably out of print.

Tuesday, October 18, 2016

Grumman AF-2W Guardian Redux

In a 25 May 2015 post to a Special Hobby 1/48 AF Guardian thread on Britmodeler (HERE), "Homebee" noted that there appeared to be two different radomes for the AF-2W. To my chagrin, I must report that I hadn't notice the difference before I tripped over his unanswered post yesterday.

Here is an early AF-2W in Grumman flight test (it is configured with an ejection seat):

Here is a Navy Reserve AF-2W:

My post on the AF Guardian (HERE) failed to note that. I overlooked the obvious yet again.
The interface of the radome with the fuselage on the early version is smoothly faired between the bomb bay opening and the radome. The later interface (possibly an added sheet-metal fairing) is flat sided and appears to terminate abruptly. Unfortunately, I don't have a good picture of the aft end of the later radome.



I have no idea when or why the change occurred. It appears to have been a production change as evidenced by this picture of BuNo 124783 on the Grumman flight line.

Wednesday, September 21, 2016

Kitty Hawk 1/48 F2H-2/2P Banshee

6 January 2017: Another build is in work, beginning with a fix to the upper nacelle shape. See http://tailspintopics.blogspot.com/2017/01/kitty-hawk-f2h-engine-nacelle-correction.html

13 December 2016: Some more notes on the kit: http://tailspintopics.blogspot.com/2016/12/kitty-hawk-148-f2h-banshee-kit-redux.html

3 November 2016: I just noticed in the ongoing Aeroscale build (see link below) that Kitty Hawk misinterpreted a photo of the ammo bay and added a "block" on the gun-bay aft bulkhead that shouldn't be there:

17 October 2016: I'm periodically adding information and links to build articles as I come across them. These will be identified from now on by being in bold.

Kitty Hawk sent me a kit for review but all I've been able to do so far is compare the big pieces to McAir drawings and dry fit the inboard wing and the fuselage. There's a good summary of what the kit includes here: http://www.cybermodeler.com/hobby/kits/kh/kit_kh_80131.shtml

For a very detailed and helpful build article, see http://modelingmadness.com/scott/korean/us/usn/f2h.htm. (One nit is that the positionable surface on the outboard wing panel is a flap, not an additional speed brake.)

This Cybermodeler build article provides detailed insight into assembly glitches: http://www.cybermodeler.com/hobby/builds/kh/build_kh_80131.shtml

Another illustrated and complete build at Aeroscale: http://aeroscale.kitmaker.net/modules.php?op=modload&name=SquawkBox&file=index&req=viewtopic&topic_id=252094 It is pretty much out of the box with one difference being the correct attachment of the outboard flap.

My first impression was very, very favorable (others building the kit think otherwise, e.g. "The kit is over-engineered and over-complicated with too many gimmicky parts that fit poorly together"). There are many detail features like a complete gun bay for the F2H-2 and a camera bay for the F2H-2P, the seldom-seen speed brakes, and options for extended flaps and folded wings. Assembly and fit are facilitated by the presence of small tabs and posts and corresponding slots/ledges and holes. For example, if you choose to close the gun bay doors, which have a neat representation of the piano hinge at the top edge, there is a lip on the other three sides that sits on a ledge in the opening of the nose to minimize fit problems.
I held back initially on some of my observations about the assembled kit that I saw at the IPMS Nationals this summer and photographs of sprues when they fell into one of three categories: 1) the problem would be fixed before production, 2) distortion due to lens effects, and 3) the builder was working without instructions or familiarity with the subject and therefore had to guess where some parts went. (In the latter category, for example, the assembled F2H-2 had the right-hand ammo cans on the left side of the nose).

Some of the problems noted on modeling websites early on were exaggerated by camera effects. Yes, the model is a little sway backed but not as bad as photos would have it and it can be reduced by some shimming between the aft side of the inboard wing assembly and the lower side of the fuselage. The overall fuselage height and length are to scale: the model is not tubby. The canopy ledge is not too steep; it is as close to the right angle as I can measure. The engine inlet looks a lot better than it does in the picture although it is a bit too deep.

There are some things that could be fixed or not. Few will notice that the nose landing gear yoke is too long or the vertical tail is a little oversized in height and chord. However, there is that excessive upward bulge in the engine nacelle. It is by no means eggplane-like in appearance, but if you think of the Banshee as being sleek as I do, it is distracting. I haven't been able to come up with a reasonably easy fix to minimize it.

Some have speculated as to the usability of the ancient Hawk F2H  center wing section that appears to have a more accurate upper contour. For one discussion and comparison photos, see this thread on Hyperscale: http://www.network54.com/Forum/149674/message/1476637062/1-48+scale+Kittyhawk+vs.+Hawk+inner+upper+wings-

Another comment elsewhere cited the box art as an accurate depiction of the nacelle:
Note that the box art is based on this picture of the XF2H-1 prototype BuNo 199859:
As a result, it depicts the prototype's short forward fuselage, short canopy sliding section, the windscreen with the straight-sided center panel, and the prototype tip tanks. However, the engine nacelle is the same as the production F2H-1 and -2.

The kit does not include the fighter's gunsight, only the -2P view port. The gun sight was a Mk 8 Mod 0 that set in a trough in the glare shield similar to the photo view port's.
This is one of several pictures of this gunsight on the web site, http://www.aircraft-gunsights.com/usn-collection/

 Another omission is some of the detail stuff behind the headrest.

I'm not sure about the size and angle of the armor plate behind the ejection seat. It's present in the illustration above but doesn't seem very prominent in pictures, if there at all.

Note the fixed links on each side of the forward lower edge of the canopy. They have rollers on the bottom that slid back in a trough that angled upward as it went aft so the canopy bow rose to clear the pilot's head.

Nose landing gear improvements/corrections:

The wing flaps need some work to be accurate. The two inboard flaps should not have mostly parallel leading and trailing edges; the trailing edge tapers forward toward the fuselage center line so that the flaps are parallel to the ground when extended. The assembly instructions for the outboard flap are incorrect. The narrow chord section (A15 and 16) should be glued to the upper wing half. The wider chord section (A14 and A18) is the flap; its trailing edge includes a small portion of the upper wing surface.
Although the two inboard flaps (shown in the color inset above) are separate structures, they are actually bolted together to form one surface and are roughly parallel to the ground when extended.


Another view of the wing upper surface included on the outboard flap trailing edge. Note the corresponding "cutout" in the upper wing trailing edge.

The top of the engine "nacelles" are incorrectly bulged upward and the intakes, not raked enough when viewed from the side.
Note also the position of the nose wheel relative to the wheel well on the assembled kit.

The kit has the two most inboard pylons staggered longitudinally. It would appear that they were in fact not staggered. They may also be slightly too close together. Unfortunately, I don't have station data for them.

Only the two inner-most pylons could be loaded with 500-lb bombs and if they were, the adjacent pylons could not be used. All four of the most inboard pylons could be loaded with 250-lb bombs; the pylons on the outboard wing panels could only be loaded with 100-lb bombs. All eight pylons could be loaded with rockets. (The kit includes two 250-lb bombs and four rockets.)
Note that the tip tank is not mounted square to the wing tip but is notably angled downward. (The kit parts provide a lot of latitude with respect to the mounting angle.)

The following illustration (note the correction to the size of the box from the original post) provides the lines-drawing information to check the engine nacelle size and shape if you are so inclined. (FYI, the top of the nacelle is about 1/8" too high; the top of the engine inlet is a bit too high, making the inlet too deep, but the width looks about right.) Note that the cut of the nacelle is slightly outboard of the fuselage and therefore does not include all of the interface of the nacelle with the fuselage going aft:
Compared to this McDonnell lines drawing, the leading edge of the vertical fin is almost 1/8" too far forward and it is about 1/8" too tall. The horizontal stabilizer is positioned about 1/16" too high. The most notable problem to my eye though is that the tip of the horizontal stabilizer is not raked slightly outboard as it should be and the aerodynamic balance (the tip of the elevator that extends forward to the leading edge) is not clearly demarcated relative to the panel lines.

An F2H-modeling post from several years ago: http://tailspintopics.blogspot.com/2009/12/f2h-banshee-modeling-notes.html

Two recommended references:
http://www.ginterbooks.com/NAVAL/NF73.htm


















http://www.milavnarc.com/f2h_banshee_in_detail_scale_part_1_digital_book.html