This thesis is concerned with the development of a new measurement device for the realistic assessment of braking capability of landing airplanes for winter runways. Landing represents one of the most safety-critical phases of aircraft operation. Aircraft runway excursion incidents occur due to the unpredictability of the runway pavement condition. This is especially true during winter time when the runway is often covered by deformable contaminants. Several accidents are discussed that list the deteriorated condition of the runway pavement and the inability to accurately report this condition as the main causes for the excursions. The accuracy of the approaches currently adopted by the airport authorities around the world to monitor the condition of the runway pavement are evaluated. The conventional and current practice of runway condition monitoring is focused on identifying the maximum tire-pavement frictional drag mu value and often neglects the characteristics of actual aircraft brake control system as well as the comprehensive effects coming from various factors such as deformable contaminants on the winter runway. The braking availability tester discussed here is designed to take a different approach for the realistic assessment of braking availability of landing aircrafts. The main idea of this device is to mimic the braking operation of actual aircrafts as closely as possible by incorporating the same brake mechanism and the brake control system used in existing aircrafts. The architecture of the device from the ground-up including the suite of sensors, the structure of the wheel, important actuators, and the real-time brake control system are discussed in detail. More importantly, the operational principles of the braking availability tester (BAT) are outlined which help one understand how the system works together. A new method to quantify the braking availability on the runway using the BAT is explained. The testing and data collection strategy for implementing this technique is also outlined. Additionally, the results from preliminary tests are presented to verify the functionality of the BAT. The results are used to verify that the BAT operates with the brake control system of an aircraft. Finally, experimental data sets from dry and contaminated pavement testing are presented to show the effect of different weather conditions on the operation of the BAT.

This thesis is concerned with the development of a new measurement device for the realistic assessment of braking capability of landing airplanes for winter runways. Landing represents one of the most safety-critical phases of aircraft operation. Aircraft runway excursion incidents occur due to the unpredictability of the runway pavement condition. This is especially true during winter time when the runway is often covered by deformable contaminants. Several accidents are discussed that list the deteriorated condition of the runway pavement and the inability to accurately report this condition as the main causes for the excursions. The accuracy of the approaches currently adopted by the airport authorities around the world to monitor the condition of the runway pavement are evaluated. The conventional and current practice of runway condition monitoring is focused on identifying the maximum tire-pavement frictional drag mu value and often neglects the characteristics of actual aircraft brake control system as well as the comprehensive effects coming from various factors such as deformable contaminants on the winter runway. The braking availability tester discussed here is designed to take a different approach for the realistic assessment of braking availability of landing aircrafts. The main idea of this device is to mimic the braking operation of actual aircrafts as closely as possible by incorporating the same brake mechanism and the brake control system used in existing aircrafts. The architecture of the device from the ground-up including the suite of sensors, the structure of the wheel, important actuators, and the real-time brake control system are discussed in detail. More importantly, the operational principles of the braking availability tester (BAT) are outlined which help one understand how the system works together. A new method to quantify the braking availability on the runway using the BAT is explained. The testing and data collection strategy for implementing this technique is also outlined. Additionally, the results from preliminary tests are presented to verify the functionality of the BAT. The results are used to verify that the BAT operates with the brake control system of an aircraft. Finally, experimental data sets from dry and contaminated pavement testing are presented to show the effect of different weather conditions on the operation of the BAT.

The research described herein is composed of four major areas of practice. It examines the overall performance of runways and provides tools designed to improve current runway operations and management with particular emphasis on contaminated surfaces. Presented in this thesis is an overview of how to design airport pavements in order to achieve optimal friction by specifically focusing on material selection and construction techniques for rigid and flexible pavements. Rubber buildup and the impact rubber accumulation has on decreasing runway friction, particularly in a range of climatic conditions, is discussed. Four commonly used rubber removal techniques are presented and evaluated. Through this research, an analytical hierarchy process (AHP) decision making protocol was developed for incorporation into airport pavement management systems (APMS). Runway surface condition reporting practices used at the Region of Waterloo International Airport are evaluated and recommendations for improving current practices are identified. Runway surface condition reporting can be improved by removing subjectivity, reporting conditions to pilots in real time, standardizing terminology and measurement techniques, and including runway pictures or sketches to identify contaminant locations where possible. Reports should be incorporated and stored in the APMS. Aircraft braking systems and their effects on landing distances under contaminated conditions are discussed. This thesis presents a proposed solution for monitoring and measuring contaminated runway surfaces and identifying the risks associated with aircraft landing through using the Braking Availability Tester (BAT). Also proposed in this thesis is a testing framework for validating the Braking Availability Tester. The proposed BAT measures interaction between aircraft antiskid braking systems and runway contaminants to determine landing distances more accurately. Finally, this thesis includes a discussion explaining how pavement design, contaminant removal, results from friction tests, and results from the BAT can be incorporated into airport pavement management systems. APMS data can be analyzed to economically optimize and prioritize scheduling of pavement maintenance, preservation and rehabilitation treatments to maintain a high level of service, thereby contributing to runway safety and optimization.

The research described herein is composed of four major areas of practice. It examines the overall performance of runways and provides tools designed to improve current runway operations and management with particular emphasis on contaminated surfaces. Presented in this thesis is an overview of how to design airport pavements in order to achieve optimal friction by specifically focusing on material selection and construction techniques for rigid and flexible pavements. Rubber buildup and the impact rubber accumulation has on decreasing runway friction, particularly in a range of climatic conditions, is discussed. Four commonly used rubber removal techniques are presented and evaluated. Through this research, an analytical hierarchy process (AHP) decision making protocol was developed for incorporation into airport pavement management systems (APMS). Runway surface condition reporting practices used at the Region of Waterloo International Airport are evaluated and recommendations for improving current practices are identified. Runway surface condition reporting can be improved by removing subjectivity, reporting conditions to pilots in real time, standardizing terminology and measurement techniques, and including runway pictures or sketches to identify contaminant locations where possible. Reports should be incorporated and stored in the APMS. Aircraft braking systems and their effects on landing distances under contaminated conditions are discussed. This thesis presents a proposed solution for monitoring and measuring contaminated runway surfaces and identifying the risks associated with aircraft landing through using the Braking Availability Tester (BAT). Also proposed in this thesis is a testing framework for validating the Braking Availability Tester. The proposed BAT measures interaction between aircraft antiskid braking systems and runway contaminants to determine landing distances more accurately. Finally, this thesis includes a discussion explaining how pavement design, contaminant removal, results from friction tests, and results from the BAT can be incorporated into airport pavement management systems. APMS data can be analyzed to economically optimize and prioritize scheduling of pavement maintenance, preservation and rehabilitation treatments to maintain a high level of service, thereby contributing to runway safety and optimization.