A Usability Study for Electronic Flight Bag (EFB) Flight Planning Applications on Tablet Devices for Ab-initio Pilots

The proliferation of mobile technology has prompted the use of tablet devices in the cockpit and during ground operations in general aviation. Due to the increase in affordable and reliable hardware (i.e. iPads etc.), the development of pilot-specific software has led to the creation of a commercial-of-the-shelf (COTS), electronic flight bag (EFB) market. EFBs have many advantages, such as reducing the space requirements for flight documents, enabling faster searching and indexing of files, providing useful tools for flight planning, and providing automatic updates. The increase in availability of mobile technology and flight applications has allowed general aviation enthusiast and ab-initio pilots to utilize EFBs. This paper examines the usability of three of the most popular commercial EFB software programs: Foreflight mobile, Garmin Pilot, FltPlan Go. The usability study was developed for the ab-initio demographic (time), which primarily constitutes pilots who have completed their cross country training. The study assessed 30 ab-initio collegiate flight students on a series of tasks during each flight application. The usability of the applications was based on task success, time to complete the task, efficiency of the application, and learnability. The students also completed a pre survey, the NASA Task Load Index (TLX), System Usability Survey (SUS), and post survey, respectively. An Analysis of Variance (ANOVA) was conducted to compare the scores of the three applications. The results of the study show that Foreflight had the best scores across all metrics

Uncertainty Analysis of Reaction Rates in a Finite Rate Gas-Surface Model

A finite–rate–catalytic wall boundary condition incorporated into hypersonic flow simulations is investigated. Benchmark simulations of hypersonic flow over a cylinder are presented using the finite–rate–catalytic model parameterized with a test air–silica chemical model comprising the gas–surface reaction mechanisms and their associated rates. It is demonstrated that backwards recombination rates should not be arbitrarily set but must be consistent with the gas–phase thermodynamics, otherwise a drift from the equilibrium state may occur. The heat flux predicted by the finite rate model lies between non–catalytic and super–catalytic limits depending on the surface temperature. It is found that even for a constant surface temperature, the oxygen recombination efficiencies determined by the model are not only a function of temperature, but also a function of the surface coverage, where recombination efficiencies are seen to rise as coverage decreases. Monte Carlo uncertainty analysis is performed to correlate the influence of individual mechanisms to the stagnation point heat flux and the expected progression of dominant mechanisms is found as the surface temperature is raised. Additionally, it is found that increased surface reactivity increases the chemical heat flux while also altering the boundary layer in a manner that decreases the conductive heat flux. Finally, efforts to use computational chemistry to reduce the uncertainty in individual rates of dominant oxidation mechanisms for oxygen–carbon interactions will be summarized

Computational Chemistry Modelling of the Oxidation of Highly Oriented Pyrolitic Graphite (HOPG)

Under high heat flux, carbon based Thermal Protection Systems (TPS) are observed to rapidly ablate and an accurate characterization is essential to their design. Dissociated oxygen atoms (from the gas phase) striking the surface of TPS could lead to several possibilites. The O atom could adsorb on the surface, recombine with another O atom to form O2 and oxidize the surface to produce CO or CO2 resulting in recession of the surface (ablation). The goal is to predict finite rate models for these reactions which could be incorporated into CFD and DSMC solvers. Our efforts are to predict the rates through large scale Molecular Dynamics (MD) simulations using the ReaxFF potential which enables accurate simulation of large chemically reacting systems of molecules. In this work, we simulate the collision of hyperthermal (5eV) O atoms on Highly Oriented Pyrolitic Graphite (HOPG) at 525K. The simulations are compared to molecular beam experiments performed by Minton and co-workers

Progress and Future Prospects for Particle-Based Simulation of Hypersonic Flow

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106455/1/AIAA2013-2613.pd