Lance Sherry

Aiding Vertical Guidance Understanding

Abstract A study was conducted to evaluate training and displays for the vertical guidance system of a modern glass cockpit airliner. The experiment consisted of a complete flight performed in a fixed-base simulator with airline pilots. Three groups were used to evaluate a new flight mode annunciator display and vertical navigation training. Results showed improved pilot performance with training and significant improvements with the training and the Guidance-Flight Mode Annunciator. Using actual behavior of the avionics to design pilot training and FMA is feasible and yields better pilot performance.

Designing User-Interfaces for the Cockpit: Five Common Design Errors and How to Avoid Them

The efficiency and robustness of pilot-automation interaction is a function of the volume of memorized action sequences required to use the automation to perform mission tasks. This paper describes a model of pilot cognition for the evaluation of the cognitive usability of cockpit automation. Five common cockpit automation design errors are discussed with examples.

A structured approach to requirements specification for software-based systems using operational procedures

This paper describes a specification notation and specification methodology that use the operational procedure construct to formulate a complete description of a system. The specification that is generated captures the operation of the system, manages the evolution of the operation of the system, and facilitates the rapid formulation and adaptation of implementation models for software-based systems.<<ETX>>

Evaluation of a Formal Methodology for Developing Aircraft Vertical Flight Guidance Training Material

Aircraft automation, particularly the automation surrounding vertical navigation, has been cited as an area of training difficulty and a source of confusion during operation. A number of incidents have been attributed to a lack of crew understanding of what the automation is doing. This paper describes the translation of information from a formal methodology used in design of an automated vertical guidance system to a training package, and an experiment that tested the new training. This study is part of a larger project to improve the recognition and understanding of the “objectives and behaviors” of automated systems through a formal methodology. The formal method, referred to as the operational procedures methodology, integrates the design of the system with the design of the training and display information requirements for that system (Sherry, 1995). The study utilized a training package designed to teach the vertical guidance portion of the Flight Mode Annunciator (FMA), as seen in normal operations of the Boeing MD-11. The results of the study showed that this type of training can be successfully delivered via a computer based training device. Additionally, a study in a full cockpit simulator showed that the training, coupled with the new display, provided significantly less errors on a simulated flight, although the training alone did not provide significantly better performance.

Estimating the Benefits of Human Factors Engineering in NextGen Development: Towards a Formal Definition of Pilot Proficiency

The concepts-of-operation proposed for the Next Generation Air Transportation System (NextGen) implicitly require a significant improvement over existing standards for flightdeck human-computer interaction. Whereas in today’s airspace operations there is no routing penalty for delayed response to a required ATC maneuver, flights in high density NextGen airspace that are unable to respond to off-nominal situations in a timely manner, will lose their slot and be shifted to a downgraded level of airspace resulting in flight delays and/or increased route distance. Current design and certification processes for avionics, aircraft, and pilots prove the reliability of the “deterministic” automated functions in a comprehensive manner. The design and certification requirements for ensuring and testing the reliability of the inherently “non-deterministic” operator interaction with the automation are not rigorous and are the source of operational inefficiencies and reduced safety margins. Unless the design and certification process are radically modified and refocused, pilots will find themselves with the same types of issues that researchers documented with the introduction of the “glass cockpit” in the 1980s and 1990’s. This paper provides a quantifiable definition of Human Computer Interaction performance and explicit measures of individual and crew proficiency. A method for estimating revenue-service cost savings generated by improved proficiency is described along with an example of the cost savings benefits accrued by a hypothetical large U.S. domestic carrier experiencing improved proficiency in response to FMS error messages (

Application of CASE tools in the development of commercial avionics software

45M per year). A discussion of the implications and limitations of the definition of proficiency and the cost savings model is provided.

Bridging the gap between Human — Automation Interface Analysis and Flight Deck Design Guidance

CASE tools increase productivity in the development of software-based systems by performing analysis that cannot be done by humans, and by automating repetitive tasks. The potential of these tools has not been realized due to limited use by small pockets of engineers. The paper describes the results of a survey that explores the perceptions of the engineers that use CASE tools for the development of certified software for commercial air transport avionics. All the engineers cited improvements in software duality, but were split down the middle on the contribution of CASE tools to reduction in project cycle-time. Ease-of-use of the tool the most critical factor in the individual engineers choice to use a CASE tool. Differences between the format and style of documents and code generated by the CASE tool and the corporate format and style standards is the biggest hurdle to integrating CASE tools into corporate development processes.

Display of altitude and path capture trajectories

Next generation aviation operations will place a much greater dependence on automation usage, and therefore additional emphasis needs to be placed on the evaluation of human automation interaction in the design and evaluation of these systems. Additionally, new airworthiness regulations and regulatory certification processes are beginning to focus on the design and verification testing of the pilot-automation interaction. Current human computer interaction analyses (computational human performance models and task analysis methods) are not effectively usable within the constrained timeline of real world design and certification processes. Fundamental and theoretical work is needed to develop methods and tools that will provide designers and regulators with the means of testing and providing useful feedback about the efficacy of these interactions.