98 REPORT OF THE No. 3 



Comparative Overhaul Periods Averaged for Engine Types: 



The records for the past eight years pertaining to the Liberty engines show 

 that the average period between overhauls for each year made an appreciable 

 increase, as the experience of the personnel with this type of engine increased. 

 The average overhaul period for the eight years stands at 95 hours between 

 overhauls. Since 1932 is the last season that Liberties will be operated, the 

 average life of the engines owned by the Service stands at 815 hours. 



The large static radials which are now replacing the Liberty engines, have 

 come on the strength too recently to be able to estimate what the average length 

 of life will be. The experience to date regarding overhauls, however, may be 

 briefly listed as follows: 



Hornet 500- 25 H.P.— 285 hours per overhaul 



Wasp 400- 25 H.P.— 255 " « 



Wright 300 H.P.— 270 B « 



The records for the small in-line air colled engines are complete, and may be 

 rather closer since the various types of this particular power style have been on 

 the strength since 1927. 



The Gipsy II are the most recent to come on the strength, and so far have 

 shown a decided improvement over all types. The comparison in this power 

 class is as follows: 



Cirrus II 65- 85 H.P. — 205 hours per overhaul 



Gipsy 1 85-100 H.P.— 325 " " 



Gipsy II 100-115 H.P.— 330 " " 



This would indicate that a steady improvement in durability and reliability 

 may be expected from year to year, as new engines are brought on the strength 

 of the Service. Such factors have a strong influence in giving a downward 

 trend to the cost of operating and maintaining up-to-date equipment, in com- 

 parison to older types. 



Conclusion 

 Survey of the Year's Operations: 



The operations for the year 1932, looked at as a whole, show significant 

 improvements in nearly every department of the work of the Air Service. 



Alterations in the structure of the equipment in order to adapt it to the 

 specialised needs of the Service were held to an absolute minimum. Major 

 repairs to both flying and ground equipment were negligible, while forced landings 

 on account of mechanical failure reduced to the vanishing point. 



The records for both mechanical and service efficiency reached almost 

 100 per cent, in both cases, and the uncontrollable factors such as very bad 

 weather curtailing necessary flying, were not abnormal. 



Maintenance figures were reduced this year, due to the increased proficiency 

 of the personnel, and the general increase in experience throughout the staff. 

 Another helpful factor in this regard is found in the fact that machines, both 

 individually and by types have been better fitted to the needs of the Service. 



