By Tommy H. Thomason

Friday, December 14, 2012

Fitting In IV

The maximum folded span on a U.S. Navy carrier-based airplane and how it changed over time is obviously a subject of interest to me. See:,,

To recap briefly, the 1949 XF3H mockup review report mentions a limit of 25' 4" due to the requirement for two airplanes to pass in the hanger. The span of what was to become the A4D was 25' when it was first laid out by R.G Smith. Based on the actual or proposed spans of some early 1950s single-seat jets, the limit was subsequently increased to about 27' 6".
One answer based on this 1948 Douglas proposal illustration is that it depends. Princeton was an early Essex-class carrier. The aircraft shown, an XF4D proposal, has a computed span when folded of 25' 9.5" based on the diagram (it was actually 25' 6"):
 Note that the clearance on the left side is only 18," whereas the other two clearance points are two feet apart, and that the clearance on the right is dependent on the height of the wing and then perhaps on the wheel base of the main landing gear. In other words, the limit for the folded span could vary somewhat based on the specific configuration of the airplane. Also, a subsequent ship alteration may have increased the width of this pinch point or resulted in the narrowest passage being someplace else on the hangar deck (fire-door openings didn't count). Another constraint as previously mentioned was the width of the elevator and the desire to move two aircraft up to the flight deck or down to the hangar deck at the same time.

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