Boeing (Canada)

Compressible flow fields over flush static pressure ports (SPPs) with sharp and rounded rims, which are used on airplanes and wind-tunnel models are studied for a range of diameters and speeds. Both steady RANS computations with the use of different eddy-viscosity models and turbulence-resolving simulations in the framework of the Improved Delayed Detached-Eddy Simulation (IDDES) approach are performed for an SPP in the flat plate boundary layer. The primary objective is to evaluate the capabilities of the two approaches for predicting the difference between the pressure deep in the SPP tube and the ambient pressure in the boundary layer, including a limited comparison with experiment. It is shown that although both approaches return results that agree qualitatively with the available experimental data, the RANS models’ predictions disagree appreciably among themselves and with the IDDES predictions, the latter being close to the experiment for both sharp and rounded port rims.

Abstract On 16 July 1999, a Boeing 737-800 on final approach for landing sustained a major lightning strike. Damage to the fuselage structure primarily was in the form of melting or partial melting of widely-separated rivets and adjacent Alclad 2024-T3 fuselage skin. The damage was confined to a 0.25-in. (6.4-mm) radii around the affected rivets. The repair process involved removal of the locally-affected material and addition of a skin doubler to restore the aircraft structure to the originally designed condition. Damage features are described briefly.

Abstract An AISI 4340 Ni-Cr-Mo alloy steel draw-in bolt and the collet from a vertical-spindle milling machine broke during routine cutting of blind recesses after relatively long service life. Based on fracture surface features, it was suspected that the draw-in bolt was the first to fracture, followed by failure of the collet, which shattered one of its arms when it struck the work table. Scanning electron microscopy showed the presence of hairline crack indications along grain facets on the fracture surface of the bolt. This, coupled with stepwise cracking in the material, generally raised suspicion of hydrogen embrittlement. It appeared that fracture in service progressed transgranularly to produce delayed failure under dynamic loading. The pickling process used to remove heat scale was suspected to be the source of hydrogen on the surface of the bolt. The manufacturer was requested to change its cleaning practice from pickling to grit blasting.

Purpose: The aim of this article is to analyze the evolution of fuel consumption efficiency of the domestic flights in Brazil along the period 2000-2015 in order understand the overall efficiency of the aeronautical infrastructure in this country.Design/methodology: This article proposes a method for high level assessments of the aeronautical infrastructure efficiency (either on ground or airspace) in a fast and easy to grasp manner, using the key performance indicator of useful distance per flight hour. The method estimates the average flight time spent by the national carriers to accomplish the average stage lengths in each year of the period 2000-2015 and compare these results with the flight time baseline included in the flight planning data of the aircrafts composing the Brazilian commercial aircraft fleet.Findings: This approach leads to huge differences between the referred results and the fuel consumption shown by flight operations manuals and were attributed to the inefficiencies existing in the acknowledged overloaded aeronautical infrastructure (either in the air or on ground) in Brazil. With that it is concluded that there is a potential reduction opportunity of almost 30% in aircraft fuel consumption in domestic flights in Brazil, which has been until the moment almost unconsidered. Thus, government policy-makers and all stakeholders will be able to quantify the impacts and recommend investments in infrastructure in a well-founded way. Furthermore, the return on investments of public funds, which are especially scarce in the developing countries, will be assessed in a simple manner. Under this scope investments and research on Air Traffic Management (ATM) new technologies and flow management techniques are strongly suggested in order to improve airspace operational efficiency.Originality/value: A new and innovative method for high level assessment of the aeronautical infrastructure efficiency.

abstractExploring the complex lives of incarcerated African women is a powerful site for deepening our knowledge and responsibility as a transforming country. Empirical research by South African researchers on circumstances that lead African women to imprisonment, and the conditions they experience in prison, is sadly lacking. We take a narrative inquiry stance to explore what can be learned about life in a South African prison from an ex-inmate, Bakke. Drawing on the conceptual frame of dilemmatic spaces and Foucault's theory of ethics, we analyse two vignettes: Bakke's pathway to prison, and her decision to turn her life around during incarceration. The analysis opens our eyes to a deeper understanding of the dynamic, complex everyday lives of young African women growing up in rural settings, and who turn to crime.

<div class="section abstract"><div class="htmlview paragraph">A new portable floor drilling machine, the 767AFDE, has been designed with a focus on increased reach and speed, ease-of-use, and minimal weight. A 13-foot wide drilling span allows consolidation of 767 section 45 floor drilling into a single swath. A custom CNC interface simplifies machine operations and troubleshooting. Four servo-driven, air-cooled spindles allow high rate drilling through titanium and aluminum. An aluminum space frame optimized for high stiffness/weight ratio allows high speed operation while minimizing aircraft floor deflection. Bridge track tooling interfaces between the machine and the aircraft grid. A vacuum system, offline calibration plate, and transportation dolly complete the cell.</div></div>

Direct numerical simulations (DNSs) are used to analyze a flat-plate turbulent boundary layer with separation and reattachment. In the present DNSs, the strong blowing and suction are imposed at the upper boundary for producing a large turbulent separation bubble, thus dealing with massive separation. Particular attention is given to Reynolds number dependence in the bubble, streamline curvature effects and similarity to a mixing layer.

Shot peening involves bombarding the surface of a metal part with small spherical media called shot. It creates a uniform layer of compressive residual stress at surfaces and considerably increases the part life. This study is devoted to an evaluation of the edge (corner) effects in the shot peening process. Geometry variations in metal parts such as edges or corners cause variance in the residual stress profile induced by shot peening. This paper presents the finite-element modeling and scheme that we use to simulate the shot peening process by both single impact and multiple impacts for part geometries with different edge radii. The results achieved show that, after the same shot peening process, a part with a relatively larger edge radius results in a satisfactory residual stress profile which could equal or exceed that expected for a part with a smaller edge radius. The results may enable the automated edge preprocess step for shot peening with an easily machined large radius to reduce cost and improv...

A new benchmark wing model for optimization algorithm comparisons that may include flutter and divergence, aeroelastic tailoring, buckling and post buckling, vibration and natural frequency analyses is proposed. The idea behind this wing model is that the laminate design of the wing root joint is used for the entire wing structural box (upper and lower skin panels, ribs, and front and rear spars). The structure is purposely over designed to provide a starting point for subsequent structural optimization. The wing model will be made freely available to researchers.

<div class="htmlview paragraph">Boeing's wholly owned subsidiary in Australia, Hawker de Havilland produces all ailerons for the Boeing 737 family of aircraft. Increasing production rates required to meet market demand drove the requirements for a new updated approach to assembly of these parts. Using lean principals, a pulsed flow line approach was developed. A component of this new line is the integration of a flexible robotic drilling/trimming system. The new robotic system is required to meet aggressive tack time targets with high levels of reliability.</div> <div class="htmlview paragraph">The selected system was built on a Kuka KR360-2 conventional articulated arm robot. A significant challenge of this project was the requirement for the process head to work efficiently on an aileron in an existing jig. As a result a new side-mounted drill and trim end effector was developed. Automated tool changers for both cutters and pressure foot assemblies eliminated the requirement for in- process manual intervention. The robot was also configured to allow safe operation in two opposing work zones. This permitted the robot to continue working while parts are loaded and unloaded from an adjacent cell, improving the overall cell efficiency.</div>