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Viewing 1 to 30 of 1885
2015-09-15
Technical Paper
2015-01-2401
Michael Schmidt, Philipp Nguyen, Mirko Hornung
Abstract The projected uptick in world passenger traffic challenges the involved stakeholders to optimise the current aviation system and to find new solutions being able to cope with this trend. Since especially large hub airports are congested, operate at their capacity limit and further extensions are difficult to realise. Delays due to late arrival of aircraft or less predictable ground operation processes disrupt the airport operations in a serious way. Various concepts improving the current turnaround processes have been presented thus far, whereby radical aircraft design changes have little chances for realisation in the short term. By maintaining the established overall aircraft configuration, the concepts promote higher probability to become commercially available for aircraft manufactures and operators.
2015-09-15
Journal Article
2015-01-2397
Angelo C. Conner, Luis Rabelo
Abstract In planning, simulation models create microcosms, small universes that operate based on assumed principles. While this can be powerful, the information it can provide is limited by the assumptions made and the designed operation of the model. When performing schedule planning and analysis, modelers are often provided with timelines representing project tasks, their relationships, and estimates related to durations, resource requirements, etc. These timelines can be created with programs such as Microsoft Excel or Microsoft Project. There are several important attributes these timelines have; they represent a nominal flow (meaning they do not represent stochastic processes), and they are not necessarily governed by dates or subjected to a calendar. Attributes such as these become important in project planning since timelines often serve as the basis for creating schedules.
2015-09-15
Journal Article
2015-01-2440
Robert Moehle, Jason Clauss
Abstract Labor costs rank second only to fuel in expenses for commercial air transports. Labor issues are a growing concern in the airline industry, with an impending worldwide pilot shortage. One solution proposed and requested by some of the industry leaders is to allow a single flight crew member to operate the aircraft. Safety concerns represent the dominant barrier to single-pilot Part 121 operations. The FAA and Congress consistently demonstrate a bias toward conservatism in their regulation of airlines and commercial aircraft. Bureaucrats and the general public fall prey to isolated news stories that highlight pilot error and anchor their viewpoint on further regulating a two-person crew. Yet, in an alarming spate of recent airline accidents, the presence of multiple crewmembers did nothing to prevent, and actually may have contributed to, the crash. Technology is not the problem.
2015-08-24
Standard
AMS1424L
This specification covers a deicing/anti-icing material in the form of a fluid.
2015-08-21
WIP Standard
ARP6344
This Aerospace Recommended Practice (ARP) establishes a test procedure and recommended surge pressure limit value for the evaluation of fixed aircraft pressure fuel dispensing systems. Note: This ARP is not applicable to aerial refueling systems or mobile aircraft refueling systems (trucks, hydrant servicing vehicles, etc.). Testing of aerial refueling systems is addressed in ARSAG documents. Testing of mobile refueling systems is addressed in ARP 5918. Note: This ARP does not address requirements that may be specific to the testing of shipboard aircraft refueling systems.
2015-08-13
Standard
ARP5818A
This document is a guideline for the design and operation of Aviation Aircraft Refueling Vehicles and for the materials, components, and systems used thereon. The criteria set forth herein are the minimum recommendations for all types of aircraft refueling vehicles, including tanker vehicles, hydrant service vehicles, towable hydrant carts, fixed refueling cabinets, and any other type of aircraft refueling vehicles used at airports for aircraft refueling operations with nominal operating fuel pressures and flow rates as specified within this document.
2015-08-07
Standard
AS5562
This SAE Aerospace Standard (AS) establishes minimum ice and rain performance criteria for electrically-heated pitot and pitot-static probes intended for use on the following classes of fixed-wing aircraft and rotorcraft. The classes of fixed-wing aircraft are defined by aircraft flight envelopes and are shown in Figure 1. The flight envelopes generally fall into the classes as shown below: Class 1: Cruise altitude ≤ 23 000 feet Class 2: Cruise altitude ≤ 31 000 feet Class 3: Cruise altitude ≤ 42 000 feet Class 4: Cruise altitude > 42 000 feet Class R: Rotorcraft The user of this standard must evaluate the aircraft level installation requirements for the probe against the class definition criteria to ensure adequate coverage for the application. It may be necessary to step up in class or modify the test conditions in order to meet the applicable installation requirements. NOTE: Class 2 is divided into two subgroups identified as either Class 2a or Class 2b.
2015-08-04
WIP Standard
AIR4730A
This document provides information on the preparation and use of video for operational and maintenance training of personnel associated with GSE.
2015-07-17
Standard
AS1284B
The test procedure and related limit value are intended to apply to fixed and mobile ground pressure fuel dispensing sytems and to aerial refueling tankers.
2015-07-13
Standard
ARP1816D
This SAE Aerospace Recommended Practice (ARP) describes three general types of Ground Support Equipment (GSE) battery chargers. The battery charger typically requiring up to 8 hours to recharge a 100% discharged battery, hereafter called “Conventional Charger.” A charger, hereafter called “Opportunity Charger,” which has the ability to charge at a slightly faster rate than a conventional charger. A charger, hereafter called “Fast Charger,” which has the ability to charge at a much faster rate than a conventional charger. Recommendations that apply to all types will refer generically to “charger.”
2015-07-09
WIP Standard
AIR6341
The purpose of this AIR is to compile in one definitive source, commonly accepted calibration, acceptance criteria and procedures for simulation of Supercooled Large Droplet (SLD) conditions within icing wind tunnels. Facilities that meet the criteria for either some or all of the recognized conditions will have known SLD icing simulation capability.
2015-06-22
WIP Standard
AS36100B
This SAE Aerospace Standard (AS) defines the minimum performance requirements and test parameters for air cargo unit load devices requiring approval of airworthiness for installation in an approved aircraft cargo compartment and restraint system that complies with the cargo restraint and occupant protection requirements of Title 14 CFR Part 25, except for the 9.0g forward ultimate inertia force of § 25.561 (b)(3)(ii).
2015-06-15
Technical Paper
2015-01-2078
Alric Rothmayer, Hui Hu
Abstract A strong air/water interaction theory is used to develop a fast simplified model for the trapping of water in a film that flows over sub-grid surface roughness. The sub-grid model is used to compute correction factors that can alter mass transport within the film. The sub-grid model is integrated into a covariant film mass transport model of film flow past three-dimensional surfaces in a form that is suitable for use in aircraft icing codes. Sample calculations are presented to illustrate the application of the model.
2015-06-15
Technical Paper
2015-01-2076
Caroline Laforte, Neal Wesley, Marc Mario Tremblay
Abstract This study presents a new method to evaluate and compare the anti-icing performance, i.e., the ability to delay the reformation of ice, of runways and taxiways deicing/anti-icing fluids (RDF) under icing precipitation, based on the skid resistance values, obtained with the Portable Skid Resistance Tester (PSRT). In summary, the test consists of applying, on a standardized concrete pavement sample, a given quantity of de-icing fluid. Following this application, the concrete sample is submitted to low freezing drizzle intensities, in a cold chamber at −5.0 ± 0.3°C. The skid resistance of concrete is measured at 5 minute intervals, until the concrete becomes completely iced. The anti-icing performance of 5 different fluids, both experimental and commercial, was assessed in comparison with a reference solution of 50% w/w K-formate. The anti-icing performance is analyzed based on two parameters: the duration (Icing Protection Time, IPT) and the effectiveness of this protection.
2015-06-15
Technical Paper
2015-01-2097
Timothy A. Shannon, Stephen T. McClain
Abstract Changes in convection coefficient caused by the changes in surface roughness characteristics along an iced NACA 0012 airfoil were investigated in the 61-cm by 61-cm (24 in. by 24 in.) Baylor Subsonic Wind Tunnel using a 91.4-cm (36-in.) long heated aerodynamic test plate and infrared thermometry. A foam insert was constructed and installed on the wind tunnel ceiling to create flow acceleration along the test plate replicating the scaled flow acceleration the along the leading 17.1% (3.6 in.) of a 53.3-cm (21-in.) NACA 0012 airfoil. Two sets of rough surface panels were constructed for the study, and each surface used the same basic random droplet pattern created using the Lagrangian droplet simulator of Tecson and McClain (2013). For the first surface, the roughness pattern was replicated with the same geometry over the plate following a smooth-to-rough transition location noted in historical literature for the case being replicated.
2015-06-15
Technical Paper
2015-01-2093
Maxime Henno
Abstract Advanced sizing of the thermal wing ice protection system (WIPS) requires an improved and a robust manner to simulate the system operation in unsteady phases and particularly in de-icing operations. A two dimensional numerical tool has been developed to enable the simulation of unsteady anti-icing and de-icing operations. For example, the WIPS may be activated with delay after entering into the icing conditions. In this case, ice starts to accrete on the leading edge before the WIPS heats up the skin. Another example is the ground activation of the WIPS for several seconds to check its functionality: low external cooling may cause high thermal constraints that must be estimated with accuracy to avoid adverse effects on the structure. Thermal de-icing WIPS integrated in composite structures intrinsically have unsteady behaviors; the tool enables the computation of the skin temperature evolution with the time.
2015-06-15
Technical Paper
2015-01-2092
David M. Orchard, Catherine Clark, Myron Oleskiw
Abstract Simulations of supercooled large droplet (SLD) icing environments within the NRC's Altitude Icing Wind Tunnel (AIWT) have been performed in which broad band mass distribution spectra are achieved that include a distinct pattern of liquid water content (LWC) over a range of droplet sizes (i.e., bi-modal distribution). The mass distribution is achieved through modification of the existing spray system of the AIWT to allow two spray profiles with differing LWC and median volumetric diameter (MVD) to be simultaneously injected into the flow. Results of spray profile distributions measured in the test section have demonstrated that freezing drizzle conditions, where MVD is either less than or greater than 40 μm, can be achieved.
2015-06-15
Technical Paper
2015-01-2102
Guilin Lei, Wei Dong, Jianjun Zhu, Mei Zheng
Abstract The numerical simulation of ice melting process on an iced helicopter rotor blade is presented. The ice melting model uses an enthalpy-porosity formulation, and treats the liquid-solid mushy zone as a porous zone with porosity equal to the liquid fraction. The ice shape on the blade section is obtained by the icing code with a dynamic mesh module. Both of the temperature change and the ice-melting process on the rotor blade section surface are analyzed. The phenomenon of ice melting is analyzed through the change of temperature and liquid fraction on the abrasion/ice interface. The liquid fraction change as with time on the abrasion/ice surface is observed, which describes the ice-melting process well. The numerical results show that the ice melting process can be simulated effectively by the melting model. The de-icing process can be monitored by observing the change of the liquid fraction of the area around the abrasion/ice interface.
2015-06-15
Technical Paper
2015-01-2120
Yong Han Yeong, Eric Loth, Jack Sokhey, Alexis Lambourne
Researchers have recently focused on superhydrophobic coatings as an ice-mitigation tool. These surfaces have a high degree of water-repellency and were shown in previous low-speed droplet studies to reduce surface ice adhesion strength. However, there is little research regarding testing in aerospace icing conditions, i.e. high-speed super-cooled droplet impact (> 50 m/s) on a freezing substrate and air temperature. A detailed set of experiments were conducted in an icing wind tunnel to measure the ice adhesion strength of various superhydrophobic coatings by subjecting the surfaces to a super-cooled icing cloud consisting of 20 μm droplets and at a constant LWC of 0.4 g/m3. Test conditions include air speeds of 50 m/s and 70 m/s and in glaze (−5°C) and rime ice regimes (−15°C). The accreted ice was then removed by pressurized nitrogen in a mode 1 (tensile) adhesion test.
2015-06-15
Technical Paper
2015-01-2135
Martin Schulz, Michael Sinapius
Abstract A designer of a new mechanical ice protection system for airplanes needs to know how much and in which way he has to deform the surface to break off the ice. The ice adhesion strength is often used as a design value. Several methods have been published to measure the adhesive strength of ice. This paper analyzes the interface stresses created by those methods and discusses the way the adhesion strength is derived. A finite element method tool is used to provide insight into the stress state for different load cases. The implication of these illustrations is that equations which use only ultimate force and total interfacial area to calculate adhesion strength miss local stress concentrations and crack nucleation. Hence, the derived adhesion strength may not be comparable within different testing methods, because each testing procedure neglects different parameters like specimen size, substrate thickness and stiffness.
2015-06-15
Technical Paper
2015-01-2160
Alidad Amirfazli
Abstract The surfaces that shed drops helps with mitigation of icing. Shedding of drop depends on surface hydrophobicity, which becomes affected when exposed to water and/or UV. The hydrophobicity degradation of six (Spray SHS, Etched Al SHS, Hydrobead, Neverwet, Waterbeader, and WX2100) different super-hydrophobic surfaces (SHS), exposed to water or UV, were studied from the drop shedding perspective. Two methods were adopted for the hydrophobicity analysis. Among them, one is to study the contact angles (CA) and contact angle hysteresis (CAH) change at static state (i.e., no airflow) compared to the untreated surface. The other one is to analyze the change in critical air velocity (Uc) for a given drop exposed to airflow, on water/UV treated surfaces at room temperature (22 °C) and icing conditions (−1 and −7 °C).
2015-06-15
Technical Paper
2015-01-2157
Mengyao Leng, Shinan Chang, Yuanyuan Zhao
Abstract Aircraft icing causes a great threaten to flight safety. With the development of anti-icing or de-icing systems for aircraft, some attention has been paid on coating strategies for an efficient way to prevent water remaining on the surface. By application of hydrophobic or super-hydrophobic coatings, characterized by low surface adhesion, shedding of liquid from the surface can be enhanced. The motivation behind this work is to identify the way that wettability affects the motion of runback water, and establish an empirical formula of critical departure diameter. The surface property is characterized by the equilibrium contact angle and the hysteresis angle. The relationship between the air speed and the droplet shedding diameter is studied, corresponding to different surfaces.
2015-06-15
Technical Paper
2015-01-2159
Philipp Grimmer, Swarupini Ganesan, Michael Haupt, Jakob Barz, Christian Oehr, Thomas Hirth
Abstract As known de-icing methods use a high amount of energy or environmentally harmful chemicals, research has focused lately on passive de-icing by functional surfaces with an improved removal of ice (de-icing) or a reduced formation of it (anti-icing). Inspired by the Lotus plant leaf, a “superhydrophobic” surface can be produced by the combination of a hierarchical micro/nanoscale roughness and a hydrophobic surface coating. By a hot stamping process we have generated differently shaped microstructures (cylinders, ellipses) on polyurethane (PU) films which were afterwards coated by a plasma enhanced chemical vapor deposition (PECVD) process with thin, hydrophobic fluorocarbon films. This combination of methods could be a process for the production of large area functionalized films. PU films are suitable for outdoor use, because they are resistant against erosion and UV radiation. The films can be glued to different geometries and can easily be exchanged if damaged.
2015-06-15
Technical Paper
2015-01-2149
Caroline Laforte, Caroline Blackburn, Jean Perron
Abstract This paper depicts icephobic coating performances of 274 different coatings, including 11 grease-type coatings, which were tested over the past 10 years in various research projects at the Anti-Icing Materials International Laboratory (AMIL). Icephobic performance is evaluated using two comparative test methods. The first method, the ice Centrifuge Adhesion Test (CAT), measures the force required to separate the accreted ice from the coating (e.g. adhesive failure). The test involves simultaneously icing, under supercooled precipitation, the extremity of bare reference and freshly coated aluminum samples. The ice adhesion shear stress is calculated from the ice detachment rotation speed. The results are reported as Adhesion Reduction Factor (ARF), which is the ice adhesion stress on the bare aluminum reference samples divided by the ice adhesion stress on the coated samples.
2015-06-15
Technical Paper
2015-01-2158
Tatsuma Hyugaji, Shigeo Kimura, Haruka Endo, Mitsugu Hasegawa, Hirotaka Sakaue, Katsuaki Morita, Yoichi Yamagishi, Nadine Rehfeld, Benoit Berton, Francesc Diaz, Tarou Tanaka
Coating has been recently considered as having good potential for use in preventing in-cloud icing on the leading edge of the lifting surfaces of an aircraft in cold climates. In terms of wettability, a coat may exhibit hydrophobicity or hydrophilicity depending on its specific properties. The same applies to the ice adhesion strength, which may be either high or low. It is thus necessary to determine which type of anti-icing or de-icing coat would be appropriate for a particular application in order to fully utilize its specific properties. Notwithstanding, a coat is incapable of preventing ice accretion by itself, and a perfect icephobic coat is yet to be developed. Coating is also sometimes applied to the surfaces of electrical heaters and load-applying machines to enable them to function more effectively and use less energy. The coating used for an electric heater, for instance, should be hydrophobic because of the need for rapid removal of molten water from the surface.
2015-06-08
Standard
AIR1558B
This Aerospace Information Report (AIR) discusses damage to aircraft caused by ground equipment contact and suggests methods of protecting against that damage.
2015-04-28
WIP Standard
AIR6892
This SAE Aerospace Information Report (AIR) is applicable to rotorcraft structural health monitoring (SHM) applications, both commercial and military, where end users are seeking guidance on the definition, development, integration, qualification, and certification of SHM technologies to achieve enhanced safety and reduced maintenance burden based on the lessons learned from existing Health and Usage Monitoring Systems (HUMS). While guidance on SHM business case analysis would be useful to the community, such guidance is beyond the scope of this AIR. For the purpose of this document, SHM is defined as “the process of acquiring and analyzing data from on-board sensors to evaluate the health of a structure.” The suite of on-board sensors could include any presently installed aircraft sensors as well as new sensors to be defined in the future. Interrogation of the sensors could be done onboard during flight or using ground support equipment.
2015-04-16
Book
Robert J. Flemming
The effects of inflight atmospheric icing can be devastating to aircraft. Universities and industry have been hard at work to respond to the challenge of maintaining flight safety in all weather conditions. Proposed changes in the regulations for operation in icing conditions are sure to keep this type of research and development at its highest level. This is especially true for the effects of ice crystals in the atmosphere, and for the threat associated with supercooled large drop (SLD) icing. This collection of ten SAE International technical papers brings together vital contributions to the subject. Icing on aircraft surfaces would not be a problem if a material were discovered that prevented the freezing and accretion of supercooled drops. Many options that appeared to have promising icephobic properties have had serious shortfalls in durability.
2015-04-08
WIP Standard
AIR1168/4B
This section presents the basic equations for computing ice protection requirements for nontransparent and transparent surfaces and for fog and frost protection of windshields. Simplified graphical presentations suitable for preliminary design and a description of various types of ice, fog, frost, and rain protection systems are also presented.
2015-04-03
WIP Standard
AS1614D
This SAE Aerospace Standard (AS) specifies the interface requirements for tow bar attachment fittings on the nose gear (when towing operations are performed from the nose gear) of conventional tricycle type landing gears of commercial civil transport aircraft with a maximum ramp weight higher than 50 000 kg (110 000 lb), commonly designated as "main line aircraft". Its purpose is to achieve tow bar attachment fittings interface standardization by aircraft weight category (which determines tow bar forces) in order to ensure that one single type of tow bar with a standard connection can be used for all aircraft types within or near that weight category, so as to assist operators and airport handling companies in reducing the number of different tow bar types used.
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