This report presents the results of Project MAX QAP, a method of predicting pilot induced oscillations (PIO) caused by actuator rate limiting. The overall test objective was to correlate, if possible, Pilot-induced Oscillation Tendency Ratings with a new preflight calculation called the Gap Criterion. The Air Force Institute of Technology, Engineering Department (AFIT/ENY) requested this testing. The USAF Test Pilot School (TPS), Class 03A, conducted 8 flight test totaling 10.8 hours at Edwards AFB, California, from 16 to 22 October 2003.
This thesis evaluates the OCM in predicting handling qualities and PIO pilot ratings during the approach and landing task. Using two existing PIO databases, analytical prediction schemes were developed using the OCM. The prediction schemes used were flight path error and crossover frequency. The prediction schemes were applied to 12 different aircraft/flight control system landing configurations. The 12 configurations were flight tested using a USAF/Calspan variable stability NT-33A. The OCM was able to predict pilot handling qualities ratings (PHQR) accurately (within one pilot rating) 80% of the time. PIO ratings were accurately predicted 96% of the time. Due to a PIO rating problem in the original databases, the PIO prediction schemes were modified using flight test data. Additional flight test configurations should be flown to verify the revised flight path error and crossover frequency prediction schemes. Because of the subjective nature of PHQRs and PIO ratings, the flight test results varied between pilots. The correlation between multiengine pilots was better than with the fighter pilot. The crossover frequency prediction scheme was the most accurate predictor of pilot ratings, while the flight path error prediction scheme was slightly more accurate for PIO ratings. Both predictors agreed with classical control theory, showing correlation between flight path error, crossover frequency, and pilot/PIO ratings. The flight path error and crossover frequency rating prediction methods should be used as a tool in flight control system design. Variable stability aircraft; Flying qualities. (edc).
The Lockheed Blackbirds hold a unique place in the development of aeronautics. In their day, the A-12, YF-12, M-21, D-21, and SR-71 variants outperformed all other jet airplanes in terms of altitude and speed. Now retired, they remain the only production aircraft capable of sustained Mach 3 cruise and operational altitudes above 80,000 feet.This is the first book to address the technical aspects of these incredible aircraft. The author describes the design evolution of the Blackbird, from the Archangel to the Senior Crown (the Air Force's SR-71.) He describes in detail the construction and materials challenges faced by Lockheed, as well as the Blackbird's performance characteristics and capabilities.A NASA historian, the author describes NASA's role in using the aircraft as a flying laboratory to collect data on materials, structures, loads, heating, aerodynamics, and performance for high-speed aircraft. The reader will benefit from the technical and programmatic lessons learned.This volume was produced in cooperation with the National Aeronautics and Space Administration.
Downscaled physical models, also referred to as subscale models, have played an essential role in the investigation of the complex physics of flight until the recent disruption of numerical simulation. Despite the fact that improvements in computational methods are slowly pushing experimental techniques towards a secondary role as verification or calibration tools, real-world testing of physical prototypes still provides an unmatched confidence. Physical models are very effective at revealing issues that are sometimes not correctly identified in the virtual domain, and hence can be a valuable complement to other design tools. But traditional wind-tunnel testing cannot always meet all of the requirements of modern aeronautical research and development. It is nowadays too expensive to use these scarce facilities to explore different design iterations during the initial stages of aircraft development, or to experiment with new and immature technologies. Testing of free-flight subscale models, referred to as Subscale Flight Testing (SFT), could offer an affordable and low-risk alternative for complementing conventional techniques with both qualitative and quantitative information. The miniaturisation of mechatronic systems, the advances in rapid-prototyping techniques and power storage, as well as new manufacturing methods, currently enable the development of sophisticated test objects at scales that were impractical some decades ago. Moreover, the recent boom in the commercial drone industry has driven a quick development of specialised electronics and sensors, which offer nowadays surprising capabilities at competitive prices. These recent technological disruptions have significantly altered the cost-benefit function of SFT and it is necessary to re-evaluate its potential in the contemporary aircraft development context. This thesis aims to increase the comprehension and knowledge of the SFT method in order to define a practical framework for its use in aircraft design; focusing on low-cost, short-time solutions that don’t require more than a small organization and few resources. This objective is approached from a theoretical point of view by means of an analysis of the physical and practical limitations of the scaling laws; and from an empirical point of view by means of field experiments aimed at identifying practical needs for equipment, methods, and tools. A low-cost data acquisition system is developed and tested; a novel method for semi-automated flight testing in small airspaces is proposed; a set of tools for analysis and visualisation of flight data is presented; and it is also demonstrated that it is possible to explore and demonstrate new technology using SFT with a very limited amount of economic and human resources. All these, together with a theoretical review and contextualisation, contribute to increasing the comprehension and knowledge of the SFT method in general, and its potential applications in aircraft conceptual design in particular.
This book is an attempt to present under one cover the current state of knowledge concerning the potential lightning effects on aircraft and that means that are available to designers and operators to protect against these effects. The impetus for writing this book springs from two sources- the increased use of nonmetallic materials in the structure of aircraft and the constant trend toward using electronic equipment to handle flight-critical control and navigation function.
"Much has been written about the famous conflicts and battlegrounds of the East during the American Revolution. Perhaps less familiar, but equally important and exciting, was the war on the western frontier, where Ohio Valley settlers fought for the land they had claimed -- and for their very lives. George Rogers Clark stepped forward to organize the local militias into a united front that would defend the western frontier from Indian attacks. Clark was one of the few people who saw the importance of the West in the war effort as a whole, and he persuaded Virginia's government to lend support to his efforts. As a result Clark was able to cross the Ohio, saving that part of the frontier from further raids. Lowell Harrison captures the excitement of this vital part of American history while giving a complete view of George Rogers Clark's significant achievements. Lowell H. Harrison, is a professor emeritus of history at Western Kentucky University and is the author or co-author of numerous books, including Lincoln of Kentucky, A New History of Kentucky, and Kentucky's Governors."
The Manual of Tests and Criteria contains criteria, test methods and procedures to be used for classification of dangerous goods according to the provisions of Parts 2 and 3 of the United Nations Recommendations on the Transport of Dangerous Goods, Model Regulations, as well as of chemicals presenting physical hazards according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). As a consequence, it supplements also national or international regulations which are derived from the United Nations Recommendations on the Transport of Dangerous Goods or the GHS. At its ninth session (7 December 2018), the Committee adopted a set of amendments to the sixth revised edition of the Manual as amended by Amendment 1. This seventh revised edition takes account of these amendments. In addition, noting that the work to facilitate the use of the Manual in the context of the GHS had been completed, the Committee considered that the reference to the "Recommendations on the Transport of Dangerous Goods" in the title of the Manual was no longer appropriate, and decided that from now on, the Manual should be entitled "Manual of Tests and Criteria".
