Design and Development of the Structural Integrity of a Jet Executive, D.H. 125

The paper deals first with the pedigree of the D.H. 125 and then with the background decisions affecting the design and design aims, such as probable flight plans and utilization. The choice of materials and the construction formulae to achieve these aims are then discussed.

The philosophy of thorough analysis backed by comprehensive testing is propounded and the view taken that the right place for trouble to be discovered is on specimens in the laboratory and not on aircraft in service. There is discussion of the difficult task of how and when to test to maximum advantage, bearing in mind the desire to demonstrate the three departments of static loading, repeated loading, and fail safety.

The highlights of experience in this field are then described as they have affected the development of the structural integrity of the D.H. 125 and a rundown on some test programs of major components used to illustrate the achievements.