http://bura.brunel.ac.uk/handle/2438/833 2013-05-23T13:16:19Z 2013-05-23T13:16:19Z Bromfield, MA Gratton, GB http://bura.brunel.ac.uk/handle/2438/3255 2012-01-13T12:39:25Z 2009-01-01T00:00:00Z

Title: Factors affecting loss of control in general aviation aircraft Authors: Bromfield, MA; Gratton, GB Abstract: A quarter of all fatal General Aviation accidents in the UK during the period 1980 to 2006 involved Loss of Control (LoC) in Visual Meteorological Conditions (VMC). LoC – which effectively the stall/spin event, has consistently appeared in accident statistics over this period, but at very different rates for different aircraft types. This raises two important questions - why do these LoC events happen and why is there a difference between aircraft types?. The biggest discrepancy affects the Cessna 150 and Cessna 152, two aircraft similar in appearance and highly popular in the pilot training environment. The Cessna 150 falls approximately on the average for stall/spin related fatal accidents in the UK GA fleet, whereas the Cessna 152 exhibits an extremely low accident rate. Brunel Flight Safety Laboratory, in conjunction with the UK General Aviation Safety Council, undertook to try and understand why. The key design differences affecting performance and handling qualities were thoroughly researched using available published material and informal interviews with type-experienced students, pilots and flying instructors. A comprehensive flight test programme was then commenced using examples of both aircraft types to gather additional research data in order to assess and compare the apparent performance and handling qualities (both qualitatively and quantitatively). The flight tests were performed at different CG conditions relevant to the key design differences, concentrating upon apparent longitudinal (static and dynamic) stability and control characteristics, stalling and low-speed handling characteristics, and cockpit ergonomics / pilot workload. This test was using normal flying club aircraft, but in most cases with a 2-man (TP+FTE) crew with data recorded both manually and using a low-cost, portable Appareo GAU1000A Flight Data Recorder (FDR). The paper covers both the conduct of these tests – flight testing within a university environment, preparation, pre and post-test analysis, construction of Cooper-Harper tasks and the use of low-cost automated flight data recording. It will also however discuss the team’s initial conclusions and ongoing research into both design and pilot training causes behind GA LoC incidents.

2009-01-01T00:00:00Z Farsimadan, E Mokhtarzadeh-Dehghan, M R http://bura.brunel.ac.uk/handle/2438/2313 2009-12-22T15:55:16Z 2008-01-01T00:00:00Z

Title: A large eddy simulation of an airfoil turbulent wake subjected to streamwise curvature Authors: Farsimadan, E; Mokhtarzadeh-Dehghan, M R Abstract: This paper presents large eddy simulations (LES) of the curved wake of an airfoil. The wake was generated by placing a NACA0012 airfoil in a uniform stream of air, which is then subjected to an abrupt 90° curvature created by a duct bend. The trailing edge of the airfoil is one chord length upstream of the bend entry. The duct cross-section measures 457 mm × 457 mm, and the bend has radius to height ratio of 1.17. The flow Reynolds number (1.02 × 105) is based on a mainstream velocity of 10 m/s and airfoil chord length 0.15 m. The sub-grid scale models employed are the classical Smagorinsky, its dynamic variant and the dynamic kinetic energy transport. The performance of LES in depicting the experimental flow is assessed and compared with results predicted by the Reynolds stress model (RSM). The results show the advantages of LES over Reynolds-averaged Navier-Stokes methods in predicting convex wall separation in strongly curved ducts on relatively coarse grids. Results from LES on a considerably finer near-wall-resolved grid lead to much improved comparison with the experimental data in the near wake, bettering predictions by RSM and LES on the coarse grid. Copyright © 2008 John Wiley & Sons, Ltd.

2008-01-01T00:00:00Z Gratton, GB Porteous, TC http://bura.brunel.ac.uk/handle/2438/1239 2012-01-23T12:22:40Z 2007-01-01T00:00:00Z

Title: Protecting the flight test programme Authors: Gratton, GB; Porteous, TC Abstract: Considerable effort is put into the safety risk assessment of any flight test programme - and rightly so, since failures to apply best practice in this area may cause significant expense, and in extremis loss of life. However, it must also be remembered that the flight test programme itself is an essential component in the development of the aircraft or system, and that even if safety is never compromised, the failure of a test programme to deliver the required results on time and budget can cause failure of the entire aircraft programme. This paper considers the areas in which planning and conduct of a flight test programme should be protected. In particular it considers the conduct of flight test personnel in ways which go beyond only safety training, the important of documenting all flight test planning and conduct and the continuous justification of flight test conclusions, planning project manning to ensure that the loss (for whatever reason) of key personnel or equipment does not cause complete failure of the flight test programme, how to recover from significant programme disruptions, and most importantly whilst protecting or recovering the flight test programme – how to ensure that safety is not compromised in the process.

2007-01-01T00:00:00Z Gratton, GB http://bura.brunel.ac.uk/handle/2438/1234 2012-01-23T12:24:05Z 2001-01-01T00:00:00Z

Title: The weightshift controlled microlight aeroplane Authors: Gratton, GB Abstract: Microlight aircraft are increasingly becoming the most popular segment of private aviation. In the United Kingdom the majority (about 2500 of a total fleet of 3500) of these aircraft are of the weightshift class, also known as flexwings or trikes. This paper introduces the main issues involved in the design and operation of this class of aeroplane.

2001-01-01T00:00:00Z