Early US Navy Monoplanes

Modeling Subjects Aircraft
1

Nice article by Paul Boyer on the XF4U-1 in this month’s FSM. It reminded me of three details to remember when doing a model of the early (yellow upper wing surface) US Navy monoplanes:

  1. The cockpit interiors were almost always painted an aluminum color except for black instrument and control panels and “boxes”.

  2. There were no shoulder harnesses. These weren’t introduced until after Pearl Harbor.

  3. They almost all had a downward vision window in the bottom of the fuselage with no obstruction between it and the pilot’s eyes - hence no floor board in the F4U for example until the -4, long after the window was deleted. I think the SB2C was an exception to this requirement.

2

Hey Tailspin

Oops - never mind. I re-read your original post and my comment doesn’t apply.
That “upper” wing threw me.

Regards from a NavAvn fan
Dick

3

I love those colorful pre-war schemes!

4

Re your edit - thanks, I got it.

Dick

5

Dick,

When I edited it after seeing your first response (added the word “surface” in the parenthetical statement) and realized how poorly worded it was originally, I really should have noted what the change was and why - for completeness, I later added the “XF4U-1” to the first sentance.

I also took a closer look at XSB2C photos to see if there was a downward vision window in front of the bomb bay. There doesn’t appear to be, but I noted that the pilot seemed to be sitting farther forward of the wing than most of the other early Navy monoplanes so maybe they got a pass on the requirement for that reason. Or it had been dropped by then and the XF4U was the last that it was imposed on.

I had originally thought that the window was a requirement because the pilot set more over the wing of a monoplane than in biplanes. However, in reviewing the pilot position in some Navy biplanes, there are several examples where the pilot is positioned over the bottom wing, although the wing chord is usually less. It may just have been a bright idea. Not having a cockpit floor can be a real pain if you drop something, however.

6

Maybe the weight distribution of additional crew in bombers (BT, SBD, SB2U, TBD) allowed the pilot to be forward of the wing. Also, weren’t the planes with windows all fighters? (F4U, F4F, F2A) They would need the extra visibility in combat.

Dick

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I’m not absolutely certain about the SB2U - the cockpit doesn’t have a floorboard and there is a dark panel on the bottom of the fuselage just behind the cowl flaps in some pictures, but there definitely isn’t a window in most of the few pictures of the belly. The SBD and TBD both had the window - I’m not certain about the BT at the moment but the cockpit floor configuration suggests that it did. The original SBA configuration did not have a window and the Navy’s initial evaluation of it did not mention the lack of or need for it, but some photos of the last iteration appear to have a pair of small windows on the belly behind the cowl flaps.

8

There’s either a lack of interest in or a lack of knowledge about this downward vision window situation but not on my part, particularly because I’ve come to realize that I definitely overstated the likelihood that it was in “almost all” of the early Navy monoplanes. Of the four monoplanes contracted for in 1934, only the TBD clearly has one, a bombardier’s window (located behind doors beneath the pilot’s feet) as did its biplane competitor, the TBG. The other three, the BT (forerunner of the SBD), the SBA and the SB2U, possibly had the windows at some point.

The two fighters contracted for in 1936 definitely had windows - the F2A had a really big one and the F4F had two small ones straddling the fuel cell (pilots smoked in the cockpit too). The one-off NF-1 (a Seversky designation standing for Naval Fighter #1) was provided gratis to the Navy for flight evaluation in 1937 but I’ve never seen a picture of its belly so I don’t know if it was compliant in this regard.

Two of the three fighters contracted for in 1938 had windows and the third may have had. The XF4U and early production F4Us definitely had the window as did the Bell XFL-1. After closely studying XF5F photos, it looks like there might be a window where the fuselage fairing begins on the underside of the wing. It’s not depicted on any drawings, and the cockpit photos don’t quite cover the area, but there are indications of one.

Finally the SBD, which was in development throughout during this period, definitely has the window.

The new aircraft contracted in 1939 for development, the SB2A and the SB2C, clearly don’t have it nor do any subsequent aircraft.

So it would appear that sometime in 1935 or 1936, the Navy decided that it wanted downward vision windows in its monoplane fighter and dive bomber designs and after 1938 they didn’t, although the aircraft that had them continued to be produced that way for at least a while.

As implemented, except maybe for the F2A, it provided very little extra visibility for fighter pilots since on all the other aircraft they weren’t more than smallish portholes. I could see some value for a dive bomber pilot being able to spot a ship when it was between his feet but it apparently wasn’t valued enough to continue the practice. TheTBD and TBG windows were for a specific requirement - it was to be used by a bombardier for horizontal bombing. In the TBD he crawled down under the pilot from his middle seat position and used a bomb sight located in the window; in the TBG, the bombardier was located in the most forward cockpit ahead of the upper wing and the F4F-like landing gear and had a bomb aiming position with window in the lower fuselage. Did I mention it was ugly?

As Dick suggested, one possible explanation is that the fighter pilots liked the downward visibility that they had in the F3F with the cockpit located just aft of the lower wing. The manufacturers, except for Brewster with the F2A, apparently paid only lip service to the requirement as they sometimes do and it disappeared after further consideration.

9

Doh - the fighters in the 1938 competition that resulted in the F4U, FL, and F5F were to be armed with little bitty bombs in the wings as an anti-aircraft weapon. Obviously you needed a downward vision window to see when to drop them.

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I think this may show a window on an SB2U: