To: BlenderPilot
In military design programs the constructors of the aircraft will have a product assurance department consisting of Reliability, Maintainability, Systems Safety and Human Factors Engineers. Two of the documents that drive the design for Human Factors are MIL-STD 1472 and MIL-HDBK 759A. 1472 is titled Human Engineering Design Criteria for Military Systems, Equipment and Facilities. 759A is titled Human Factors Engineering Design for Army Material.
Both of these documents address the design and layout of control panels and the switches and control devices applicable to those panels but not specifically those used in aircraft or helicopters. This would include the desired direction of switch movement in order to standardize the operation and control of differing equipments. Because of these documents you will find a high degree of commonality between different systems employed by the military. It is not to say that the designers will adhere to the documents to the letter but in most cases the systems will be inspected by representatives of the military service that will employ the systems and if they feel that the design is “Non-Standard” they will recommend a change. If in certain cases the manufacturer has limited experience in the design of the required system (Hughes had no experience when they won the Apache contract) so they hired a former Army combat pilot experienced in the Cobra and he finalized the design of the cockpit.
When some companies design an aircraft or helicopter to spec, that is, to penetrate the market there are no outside guidelines to adhere to. On a military contract RMS&HF are a part of the contract and the customer is billed for their design input. On a commercial development the participation of these groups is limited and what the customer gets is what the company designs which may or may not adhere to the two controlling documents described above.
