AIRPLANE PERFORMANCES — HAMLIN AND SPENCELEY 443 



craft having conventional wing and tail arrangements, conventional 

 pilot accommodations, and internal fuel only. 



Figures 10-13 show the general arrangements and physical char- 

 acteristics of the airplanes and table 1 lists the weiglit break-downs. 

 Less armament is carried by the two airplanes whose range and dura- 

 tion of combat are obviously restricted. Unit wing weight depends 

 greatly upon thickness, and structure in general is affected by the 

 operational speed ranges, which affect the design air loads. Landing- 

 gear weight is primarily influenced by the gross weight at landing 

 condition. 



Table 1. — Component weights 



A practical limit to the internal fuel capacity appears to be about 

 200 gallons of high-octane gasoline in self -sealing fuel tanks for this 

 size of propeller-driven fighter. Laminar flow wings of 15 percent 

 thickness are employed. A nominal wing loading of the order of 35 

 to 40 pounds per square foot represents a present-day compromise 

 between performance on the one hand, and maneuverability and serv- 

 iceability with respect to tactical airfield considerations on the other. 

 Armament load is 1,100 pounds. 



Because of the disadvantageous fuel-consumption characteristics 

 of the turbojet and also the considerably increased high-speed regime 

 of operation, this type of airplane is forced to higher wing loadings, 

 in this case of 50 pounds per square foot, resulting in a greater differ- 

 ence between take-off and landing wing loadings. Wing thickness 

 of 13 percent compromises internal fuel capacity with low drag char- 

 acteristics. In this case, also, leak-proof fuel tanks for kerosene are 

 a necessity. Fuel here represents about 31 percent of the take-off gross 

 weight compared to 16 percent in the case of the propeller, resulting 

 in landing wing loadings of 35 and 33 pounds per square foot, 

 respectively. The same 1,100-pound provision is allowed for 

 armament. 



