NO. 3 LANGLEY MEMOIR ON MECHANICAL FLIGHT 7!) 



repairs to the extremely light frame of No. G (formerly New No. 4) it was 

 thought to be iii suitable condition for flight and was accordingly boxed prepara- 

 tory to sending it to Quantico. 



The year, therefore, closed with No. G apparently in condition for test, but 

 it was decided not to take it to Quantico until No. 5, which was still undergoing 

 repairs, could also be got ready. 



1896 



A few days after the beginning of the new year, while the repairs on No. 5 

 were being completed, it was decided that the frame of No. G which had been 

 boxed ready to be carried into the field for trial, was so weak that before putting 

 it to an actual test in flight it would be best to make some tests on the strength 

 of its frame. While testing the frame for torsional strength, it broke under the 

 moderate test of a weight of 500 grammes placed at the tips of the wings, the 

 angle of deflection just prior to its breaking being 35°, while the frame of Old 

 No. 4 in March, 1895, had shown a deflection of only 10.5° under a similar test. 

 This breaking of the frame showed very plainly that the worst fears in regard 

 to it had been realized and that by some means or other the frame must be 

 strengthened. This was finally accomplished by making the midrod continuous 

 through the smoke-stack as had already been done in No. 5, and at the same 

 time an additional improvement was made in the means of attaching the Penaud 

 tail, whereby it was lowered in order to give it a greater clearance in passing 

 under the launching car in actual test. Later the boilers proved defective and 

 new ones were substituted, but except for some minute details no further changes 

 were made in Aerodrome No. 6 prior to its test in May. 



On May 6, No. 6 was unsuccessfully tried at Quantico just prior to the very 

 successful test of No. 5. In this test no serious damage was done to the frame, 

 but before going to Europe in the summer, Mr. Langley ordered that both aero- 

 dromes be completely overhauled and put in condition for further experiments 

 in the fall. In this remodelling practically no changes were introduced in the 

 frame of either No. 5 or No. 6, but the engines of No. 6 were refitted and a new 

 boiler was substituted, which, with slight improvements in the burner, resulted 

 in a somewhat increased power in the engines. 



A complete description, giving all essential details of both Aerodromes Nos. 

 5 and 6, will be found in Chapter X. 



