A» MANUAL *0-1 



Ground 

Observers’ 

Guide 


DEPARTMENT OF THE AIR FORCE 



Foreword 




Contents 


THE ROLE YOU PLAY 

THE AIR DEFENSE SYSTEM 

THE ORGANIZATIONAL SET-UP 

ADMINISTRATION 
OF THE OBSERVATION POST 


AIRCRAFT IDENTIFICATION 

* Single-Motored Aircraft 

* Bi-Motorad Aircraft 

* Multi-Motored Aircraft 

* Single-Jet Aircraft 

* Multi-Jet Aircraft 


OPERATIONAL INSTRUCTIONS 




V 


the role you play 






the air defense system 











. . . . administration of the observation post 

































. . . aircraft identification 


Recognizing airplanes is just like recognizing jet. Each class has been further divided into groups acc 

Then you barely know a person, especially if you to appearance; thus, within the bi-motored class, i 

infrequently, you have to look very closely to motored bombers have been grouped together, ai 

him. Often you can't do it even then- However. bi-motored transports have been grouped together. 








quite possible that after considerable practice, you can 
become quire proficient at it. 

you may use the following overall differentiation as a first 
guide. The sound of single-motored airplanes is normally 
steady in frequency (pitch) and relatively steady in intensity. 
The sound of bi- motored airplanes is usually steady in 
frequency but varying in intensity. In addition, there is a 
son of beat note (throbbing) effect This beat note, if your 
ears are sharply attuned for it. may alto help you distinguish 
between a bi-mototed airplane and two single-motored 
airplanes flying together In multi-motot airplanes, this 
beat note becomes a son of steady drone of tela lively high 
intensity. Our only tin-motored airplane the B-36 — has 



^distinguish once you become familiar with it The numbet of propulsion units on the airplane. By i 

rnd is readily recognizable if you ate familiar with many propulsion units the 












RECOGNITION FEATURES