( 1) To obtain total shearing force between stations 30 and, 40:  (2) To obtain total shearing force between stations 80 to 90:  (3) To obtain total bending moment at station 130:  44. Conclusion.-While static means of sustentation and control  are available  to  lighter than air aircraft, the intelligent pilot should  constantly bear in rriind the effects of aerodynamic forces on his air› ship.  He must understand the relation of velocity to resistance, power  requirements, and fuel consumption.  He must be cognizant  of  the  characteristics of his propellers and be able to make utmost use of  variable pitch should his propellers be•capable of adjustment in that  regard.  He should comprehend the theory of airship stability and  be alert to augment that stability by use of his controls.  It  is essen-•  tial that he at all times appreciate effect of dynamic forces on his flight  path in regard to both direction and altitude, and be able to assist his  static control by dynamic means whenever necessary.  F inally, he  • must be aware of the stresses to which his airship is being subjected  and, knowing maximum performance for which his aircraft was de› signed, so vary the velocity as to preclude possibility of exces.S  structural stresses.  [A. G. 062.11 (9- 11-40) .]  BY ORDER OF THE SECRETARY OF wAR:  Pounds•  Shear due  to  aerodynamic forces from table V  =  3, 004  Shear due to static loading from table IV  =-1, 596  Total shearing force  =  1, 408  Shear due to static loading  Shear due to aerodynamic forces  Total shearing force  Pounds  - 4 624  ’  2,175  6,799  Meter pounds  Bending moment due to static loading from table IV  = - 80, 470  Bending moment due to aerodynamic forces from table V  =  241, 930  Total bending moment  = •  161, 460  AIR CORPS  TM 1-320  43-44  OFFICIAL:  E.  S. ADAMS,  Major General,  The Adjutant General.  G. C. MARSHALL,  Ohief of Staff.  DISTRIBOTION :  D 1 ( 3) ; B 1 ( 2) ; IR 1 ( 5) -; IBn 1 ( 10).  66  II.!.  GOVERNMENT PRINTING OFFICE: 1$41  For sale by the Superintendent of Documents,. W.ashington, D. C. • • - ... - Price, 15 cents 