Timothy J. Etherington

Terminal area operations with enhanced and synthetic vision: experience in the Boeing Technology Demonstrator

Several emerging technologies were recently demonstrated in a Boeing 737-900 as part of Boeings Technology Demonstrator program. Among these technologies were two enhanced vision systems and a synthetic vision system, including synthetic displays to support surface operations. This project gained operational experience with enhanced and synthetic vision systems operating in a context that included Required Navigation Performance (RNP) terminal area operations, Global Navigation Satellite System (GNSS) approach and landing, and Integrated Area Navigation (IAN). The technologies were demonstrated to a broad mix of constituents involved in research, regulation, and acquisition in the transport category environment. This paper describes the systems demonstrated, the context in which they were used, and perceived benefits of integrating them in an operational environment. Lessons learned in the implementation of these technologies throughout the program are described and subjective data from participants are summarized.

Quantifying pilot contribution to flight safety for normal and non-normal airline operations

Accident statistics cite the flight crew as a causal factor in over 60% of accidents involving transport category airplanes. Yet, a well-trained and well-qualified pilot is acknowledged as the critical center point of aircraft systems safety and an integral safety component of the entire commercial aviation system. No data currently exists that quantifies the contribution of the flight crew in this role. Neither does data exist for how often the flight crew handles non-normal procedures or system failures on a daily basis in the National Airspace System. A pilot-in-the-loop high fidelity motion simulation study was conducted by the NASA Langley Research Center in partnership with the Federal Aviation Administration (FAA) to evaluate the pilots contribution to flight safety during normal flight and in response to aircraft system failures. Eighteen crews flew various normal and non-normal procedures over a two-day period and their actions were recorded in response to failures. To quantify the humans contribution, crew complement was used as the experiment independent variable in a between-subjects design. Pilot actions and performance when one of the flight crew was impaired were also recorded for comparison against the nominal two-crew operations. This paper details a portion of the results of this study.

Quantifying Pilot Contribution to Flight Safety During Hydraulic Systems Failure

Accident statistics cite the flight crew as a causal factor in over 60% of large transport aircraft fatal accidents. Yet, a well-trained and well-qualified pilot is acknowledged as the critical center point of aircraft systems safety and an integral safety component of the entire commercial aviation system. The latter statement, while generally accepted, cannot be verified because little or no quantitative data exists on how and how many accidents/incidents are averted by crew actions. A joint NASA/FAA high-fidelity motion-base human-in-the-loop test was conducted using a Level D certified Boeing 737-800 simulator to evaluate the pilot’s contribution to safety-of-flight during routine air carrier flight operations and in response to aircraft system failures. To quantify the human’s contribution, crew complement (two-crew, reduced crew, single pilot) was used as the independent variable in a between-subjects design. This paper details the crew’s actions, including decision-making, and responses while dealing with a hydraulic systems leak.

Quantifying pilot contribution to flight safety during dual generator failure

Accident statistics cite flight crew error in over 60% of accidents involving transport category aircraft. Yet, a well-trained and well-qualified pilot is acknowledged as the critical center point of aircraft systems safety and an integral safety component of the entire commercial aviation system. No data currently exists that quantifies the contribution of the flight crew in this role. Neither does data exist for how often the flight crew handles non-normal procedures or system failures on a daily basis in the National Airspace System. A pilot-in-the-loop high fidelity motion simulation study was conducted by the NASA Langley Research Center in partnership with the Federal Aviation Administration (FAA) to evaluate the pilots contribution to flight safety during normal flight and in response to aircraft system failures. Eighteen crews flew various normal and non-normal procedures over a two-day period and their actions were recorded in response to failures. To quantify the humans contribution, crew complement was used as the experiment independent variable in a between-subjects design. Pilot actions and performance when one of the flight crew was unavailable were also recorded for comparison against the nominal two-crew operations. This paper details diversion decisions, perceived safety of flight, workload, time to complete pertinent checklists, and approach and landing results while dealing with a complete loss of electrical generators. Loss of electrical power requires pilots to complete the flight without automation support of autopilots, flight directors, or auto throttles. For reduced crew complements, the additional workload and perceived safety of flight was considered unacceptable.

Enhanced Flight Vision Systems operational feasibility study using radar and infrared sensors

Approach and landing operations during periods of reduced visibility have plagued aircraft pilots since the beginning of aviation. Although techniques are currently available to mitigate some of the visibility conditions, these operations are still ultimately limited by the pilots ability to “see” required visual landing references (e.g., markings and/or lights of threshold and touchdown zone) and require significant and costly ground infrastructure. Certified Enhanced Flight Vision Systems (EFVS) have shown promise to lift the obscuration veil. They allow the pilot to operate with enhanced vision, in lieu of natural vision, in the visual segment to enable equivalent visual operations (EVO). An aviation standards document was developed with industry and government consensus for using an EFVS for approach, landing, and rollout to a safe taxi speed in visibilities as low as 300 feet runway visual range (RVR). These new standards establish performance, integrity, availability, and safety requirements to operate in this regime without reliance on a pilots or flight crews natural vision by use of a fail-operational EFVS. A pilot-in-the-loop high-fidelity motion simulation study was conducted at NASA Langley Research Center to evaluate the operational feasibility, pilot workload, and pilot acceptability of conducting straight-in instrument approaches with published vertical guidance to landing, touchdown, and rollout to a safe taxi speed in visibility as low as 300 feet RVR by use of vision system technologies on a head-up display (HUD) without need or reliance on natural vision. Twelve crews flew various landing and departure scenarios in 1800, 1000, 700, and 300 RVR. This paper details the non-normal results of the study including objective and subjective measures of performance and acceptability. The study validated the operational feasibility of approach and departure operations and success was independent of visibility conditions. Failures were handled within the lateral confines of the runway for all conditions tested. The fail-operational concept with pilot in the loop needs further study.

Eliminating visibility problems from low visibility operations

Weather and in particular visual limitations have plagued aviation ever since the Wright Brothers quit flying circles around Huffman Field and tried to go cross-country. Lindbergh famously said “aviation would never amount to much until we learned to free ourselves from the mists.” The paper describes technology that uses enhanced vision to overcome the normal visual limitations. Vision systems, called Enhanced Flight Vision Systems, provide a potential solution to a lack of visual references. The paper describes the global certification basis for Enhanced Flight Vision Systems and how those systems can be used to eliminate visibility problems from low visibility operations. It describes a history of enhanced vision sensors and their usefulness for aircraft operations. The paper details the regulatory history behind Enhanced Flight Vision Systems and the novel way in which the regulatory basis was used to certify these systems. Harmonization of EASA, FAA, RTCA and Eurocae standards will be discussed. The future of Enhanced Flight Vision Systems for use in business jet, cargo and airline operations will be described in detail.