Wave forecasts will soon be prepared using the computer programs de- 

 veloped for wave hindcasting. The observed winds and sea level pressures 

 prior to and at a given surface weather map tinae will be used to generate a 

 description of the present state of the sea. These results will be saved for 

 climatological purposes. Forecasts of the winds for the next thirty hours at 

 six hour intervals will then be used to prepare the wave forecast valid thirty 

 hours from the last available surface map. It is not expected that the fore- 

 casts will be as accurate as the hindcasts, because errors in predicting the 

 wind fields will cause errors in the wave forecasts. However, the verifi- 

 cation statistics just cited were for areas where the sea state varies rapidly 

 due to sequences of rapidly developing and moving cyclones, and for a large 

 area of the Atlantic the swell emanating from cyclones that have already de - 

 veloped and died down will be properly forecasted. 



At each of 519 points on the Atlantic, 180 numbers will describe the 

 directional spectrum of the waves. From this data on significant wave 

 height, wave direction, swell height, and swell direction can be extracted. 



Were it possible to provide a particular ship with 180 numbers describ- 

 ing the directional spectra, a prediction of the motions and capabilities of 

 that ship could be made. Other applications are ship routing and eventually 

 mine warfare problems. 



THE CARRIER LANDING PROBLEM 



The design of an engineering system for maximal effectiveness at mini- 

 mum cost requires knowledge of the class and relative frequency of tasks to 

 be performed by the system as determined in part by the environment in 

 which the system is to be used. This is especially true for weapon systems. 

 A crucial aspect in the design of aircraft to be operated from carriers con- 

 cerns the loads which will be incurred on landing. 



Over the years the Navy has made continuing studies on the contact 

 conditions between the landing gear and the deck so as to evolve proper 

 design criteria for the aircraft structure. In the expected conversion of the 

 landing procedure to an automatic one involving the landing control central 

 AN/SPN-10 , the possibility is large that this conversion of operating pro- 

 cedures will create a substantial change in the distribution of the loads en- 

 vironment of the entire airframe. Therefore, it appears to be the case that 

 a new series of studies will have to be made over a considerable period of 

 time in order to determine this new loads distribution with any sort of 

 accuracy. If the changes in the distribution due to this new doctrine are 

 large, the landing system will either be inadequate to its task or be over- 

 designed thus reducing performance. The question then arises as to 

 whether it is possible by some means to obtain this landing loads distribu- 

 tion other than by the lengthy empirical approach. 



An alternate attack to this problem would be to make an analytic model 

 of the entire carrier landing operation. It is then only necessary to verify 



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