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This report details the results from the sensitivity study portion of the Combat Traction II, Phase 2 (Extended) Program and also contains the calculations resulting from prediction equation formulation for the B-52, KC-135 and F-111 airplanes., See also Volume 1, ADA039966 and Rept. no. ASD-TR-77-7, ADA039968.

A sensitivity analysis of airplane braking distance was conducted on a hardware-analog brake control simulator for the USAF B-52, KC-135 and F-111 airplanes. Using dimensional analysis a braking distance prediction equation was developed for each airplane. The results of this study were combined/compared with the braking prediction equations developed, for five other airplanes, Boeing 727, 737 and 747 and USAF C-141 and F-4, under a similar previously contracted effort. The resulting braking prediction subsystem (BPSS) model (equations) are shown to be compatible and valid. The BPSS has been integrated with a ground Friction Prediction Subsystem (FPSS) and a specification criteria is developed for this Total Braking Prediction System (TBPS). A test program is also outlined to verify the effectiveness and reliability of the TBPS., See also Volume 2, ADA039967 and Rept. no. ASD-TR-77-7, ADA039968.

An analytical tire model was developed that correlates with existing tire test data to within + or - 5%. The model consists of a prediction equation expressing the relationships between seven dimensionless groups (pi terms) needed to define the aircraft tire-runway interface friction. A tire test program was recommended to validate the said model. A specification criteria has been established for the interface Friction Prediction Subsystem and various ground vehicles in use to date were evaluated. None of the vehicles meets the specification criteria., See also AD-A039 966 and AD-A039 967.

Taxi performance in terms of airplane CG acceleration for the KC-135, T-43A, and YC-14 type main gear are calculated with a digital simulation. Simple landing gear oleo modifications, such as bypass orifices and dual stage air chambers, are proposed and evaluated and reduce CG (RMS) acceleration by as much as 47%. Improved taxi performance also results in reduced gear loads when bomb crater repair patches are encountered with the KC-135 and YC-14 type gear. Fatigue damage due to taxi on austere fields decreases by 6% or more. However, fatigue damage due to taxi on prepared fields is not affected by the proposed oleo modification. (Author)

The development of a breadboard pneumatic-fluidic antiskid system is described. This includes a computer concept simulation, development of the wheel-speed sensor, the antiskid circuit, and modification of an existing antiskid valve. Performance evaluation of the fluidic antiskid system on an analog-hardware brake control simulator and the dynamometer demonstrated stopping efficiencies above 80%. Evaluation of the system on the simulator is supported by a brake dynamics test for the establishment of a suitable brake torque model., See also report dated Oct 74, AD-A008 536.

This report details the results from the Sensitivity Study portion of the Combat Traction 2, Phase 2 Program and also contains the calculations resulting from prediction equation formulation. The objectives, results, and recommendations of this effort are contained in ASD Technical Report ASD-TR-74- 41, Volume I., See also Volume 1, AD-A008 206.

The basic components and operation of airplane antiskid systems are described. Test and performance criteria are established on a system as well as component level to support the development of a new brake control system. These criteria are established for the analog-hardware simulator, the dynamometer, and full airplane tests.

A sensitivity analysis of airplane braking distance was conducted on a hardware-analog brake control simulator for the Boeing 727-200, 737 Advanced, and 747-200, the Lockheed C-141A, and the McDonnell F-4E aircraft. Parameters affecting braking distance by at least 2% were identified. With the application of dimensional analysis, these parameters were arranged in dimensionless groups, and a braking distance prediction equation was developed for each airplane. A new methodology for predicting airplane braking distance is recommended, based on a dimensional equation, a suitable ground friction prediction system, and accurate weather data., See also Volume 2, AD-A008 207.

Improvements of an existing pneumatic-fluidic antiskid system leading to operating efficiencies above 85% and installation concepts for a full system test on the T-43A aircraft are described. A fluidic locked wheel and touchdown protection circuit is proposed. Initial design of the integrated fluidic circuit and the modification of the antiskid valve in accordance with a detailed system specification are shown., See also report dated Oct 74, AD-A009 170.

During periods of inadequate human respiration, artificial ventilation can satisfactorily assume the function of the patient's breathing mechanisms in most situations. Such ventilation can be administered by mouth to mouth techniques, manual methods, or automatic devices. The purpose of this report is to discuss the physiological parameters governing the design of automatic respirators and to review the design of those currently in use. (Author)

A system of dynamic armor for tanks (Dash-Dot) is under investigation. A successful system will sense the presence of an anti-tank round, compute it trajectory, and defeat it by automatically firing defending charges that will destroy the attacking rounds before impact. A sensing system of three optical screens, employing filtered IR sources and photo-conductive detectors (PbS cells) has been devised. Preliminary evaluations of the physical and geometrical detection parameters are discussed. In tests of an experimental screen system, an accuracy of about 3% has been achieved in determining the unknown altitude and velocity of 75 mm shells at velocities up to 2500 fps. Preliminary calculations on the complete geometry of the system are presented as an appendix.