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A seaplane, distinctively designed for water takeoffs and landings, differs significantly from conventional ships and airplanes in terms of hydrodynamic performance. Accurately assessing the hydrodynamic characteristics of a taxiing fuselage using traditional ship methods, particularly at high speeds, presents considerable challenges. Consequently, this study delves into an extensive investigation to explore the variables influencing numerical simulations, aiming for a comprehensive comprehension of the fuselage's hydrodynamic behavior during taxiing. The research begins by conducting numerical computations to analyze the fuselage's taxiing state across varying speed coefficients, comparing these against experimental data. Results indicate a critical threshold within a speed coefficient range of 3.5–4.5. Numerical outputs closely align with experimental observations below this range, while a noticeable deviation occurs beyond it. Concurrently, with increased speed, the fuselage wake elongates longitudinally and contracts laterally. A subsequent detailed investigation focuses on the condition where the speed coefficient equals 4, examining diverse numerical parameters. The findings emphasize the efficacy of the Realizable k−ε turbulence model during the high-speed taxiing phase of seaplanes. Additionally, it is evident that the scale of the surface mesh directly influences the computed surface liquid phase volume fractions upon model stabilization, subsequently impacting the model's orientation. Larger surface meshes can lead to significant numerical discrepancies. • The resistance of a taxiing fuselage has a close relationship to trim. • The pressure distribution obtained by Realizable k- ε turbulence is more accurate. • As The taxiing speed increases, the hydrodynamic wake gradually becomes elongated. • The surface mesh of the body and the CFL number is meaningful for the accuracy. [ABSTRACT FROM AUTHOR]

An introduction is presented in which editor discusses various articles within the issue on topics including history of the Canadian Vickers Vedette Flying Boat; careers of Paul Davoud and bush pilot Punch Dickins, and history of the Keng Wah Aviation School for Chinese pilots.

Seaplanes are planes that can take off and land from the surface of water. Due to their ability to take off and land from the surface of water, seaplanes need a pair of pontoons in the form of a catamaran hull at the bottom of seaplanes so that the seaplanes can float above the surface of water. Research on the catamaran hull model was conducted to examine the effect of istiophorus platypterus design distance between hulls (clearance) variation on the total resistance of the catamaran hull model through experimental method and computational fluid dynamics (CFD) simulation method. There are three values of clearance (S/L) used in this research: 0.15, 0.2, and 0.25. The most optimal clearance configuration can be determined using a configuration which has the lowest total resistance. The results of experiments and simulations show that the distance between hull variations has a considerable effect on the total resistance of the catamaran hull model. The catamaran hull, which has the optimal clearance configuration, will cause the resulting wave interference and resistance to be small. The model was towed with Froude numbers ranging from 0.35 to 0.65. The results showed that hull separation made a difference in the total resistance coefficient on the same experiment configurations. The configurations with S/L 0.25 showed the least total resistance coefficient, whereas the configurations with the S/L 0.15 showed the highest total resistance coefficient. The simulations were conducted with the model with Froude numbers ranging from 0.35 to 0.65 using 700,000 cells in meshing and an error rate of 7.6% in convergence.

Tropical cyclones (TCs) are among the most intense and feared storms in the world. What physical processes lead to cyclogenesis remains the most mysterious aspect of TC physics. Here, we study spontaneous TC genesis in rotating radiative–convective equilibrium using cloud-resolving simulations over an f plane with constant sea surface temperature. Previous studies proposed that spontaneous TC genesis requires either radiative or surface-flux feedbacks. To test this hypothesis, we perform mechanism-denial experiments, in which we switch off both feedback processes in numerical simulations. We find that TCs can self-emerge even without radiative and surface-flux feedbacks. Although these feedbacks accelerate the genesis and impact the size of the TCs, TCs in the experiments without them can reach similar intensities as those in the control experiment. We show that TC genesis is associated with an increase in the available potential energy (APE) and that convective heating dominates the APE production. Our result suggests that spontaneous TC genesis may result from a cooperative interaction between convection and circulation and that radiative and surface-flux feedbacks accelerate the process. Furthermore, we find that increasing the planetary rotation favors spontaneous TC genesis. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to present a novel retractable main landing gear for a light amphibious airplane, while the design, synthesis and analysis are given in details for constructing the main landing gear. Design/methodology/approach: The constraint three-position synthesis has given the correct path of all linkages that suitably fit the landing gear into the compartment. The additional lock-link is introduced into the design to ensure the securement of the mechanism while landing. Having the telescopic gas-oil shock strut as a core element to absorb the impact load, it enhances the ability and efficiency to withstand higher impact than others type of light amphibious airplane. Findings: By kinematics bifurcation analysis, the optimized value of the unlock spring stiffness at 90 N/m can be found to tremendously reduce the extended-retracted linear actuator force from 500 N to 150 N at the beginning of the retraction sequence. This could limit the size and weight of the landing gear actuator of the light amphibious airplane. Practical implications: The drop test of the landing gear to comply with the ASTM f-2245 (Standard Specification for Design and Performance of a Light Sport Airplane) reveals that the novel landing gear can withstand the impact load at the drop height determined by the standard. The maximum impact loading 4.8 G occurs at the drop height of 300 mm, and there is no sign of any detrimental or failure of the landing gear or the structure of the light amphibious airplane. The impact settling time response reaches the 2% of steady-state value in approximately 1.2 s that ensure the safety and stability of the amphibious airplane if it subjects to an accidentally hard landing. Originality/value: This paper presents unique applications of a retractable main landing gear of a light amphibious airplane. The proposed landing gear functions properly and complies with the drop test standard, ensuring the safety and reliability of the airplane and exploiting the airworthiness certification process. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Each year in Canada, there are a number of pilots and passengers who die in seaplane water accidents. A study examining the human factors and fatality rates associated with these accidents was conducted. METHODS: Seaplane water accident investigations by the Transportation Safety Board of Canada (TS B) between 1995 and 2019 were reviewed. RESULTS: There were 487 accidents involving 1144 occupants (487 pilots, 657 passengers). There were less than 15 s warning in 86% of cases. There were 60 pilots and 88 passengers who died--a survival rate of 87%. Drowning, trapped within the cabin was the principal cause of death (54%). Loss of control on landing, wheels down landings, and other landing problems (49%) were the principal causes of the accidents and 77% of the fatalities occurred in this group. These arose because the pilot(s) misjudged wind, waves, and glassy water. Over 50% of seaplanes inverted and 10% floated briefly then sank, resulting in the highest percentage of fatalities. Wearing the seat harness incorrectly, injury, in-rushing water, and inability to locate and operate exit mechanisms (including rescuers' inability to open the exits external to the fuselage) all contributed to the fatalities. Life jackets would have been of benefit in several cases. Of the accidents, 57% were private flights. CONCLUSIONS: Passengers require a thorough preflight briefing, life jackets should be worn by all pilots and passengers, and private and commercial pilots should receive Underwater Egress Training. [ABSTRACT FROM AUTHOR]

The design of successful water-based aircraft requires a close collaboration between the aeronautical engineers and naval architects, who perform high-speed towing tests, stability calculations, or computational fluid dynamics in support of the design. This article presents the fundamental design considerations of waterborne aircraft, which are outside of the typical educational scope of most naval architects, but which they are sometimes asked to address. These include 1) the hydrostatic and hydrodynamic problems associated with seaplane design, 2) early-stage methods for sizing the hull, 3) prediction techniques using archival data, and 4) hydrodynamic model testing procedures. Although a new design will often require substantial iteration to achieve the desired outcome, the information in this article will assist in developing a reasonable starting point for the design spiral and provides sufficient details for a hydrodynamic model testing facility to perform a successful series of model tests on the design. Althoughmuch of the work in this field dates fromthe 1940s, it is important to review this material in light of the current practices being used at hydrodynamic research facilities today. A detailed description of the model testing apparatus and procedure, used in a recent study at the U.S. Naval Academy, is presented to demonstrate the current applicability of these methods and some pitfalls that can be expected in testing. [ABSTRACT FROM AUTHOR]

Featured Application: This paper provided a numerical approach to predict the resistance and attitude of a seaplane taking off in calm water. The investigations on take-off performance of the seaplane would provide some guidance in the integrated design of aerodynamics and hydrodynamics of the seaplanes. Nowadays, with the escalating tensions in maritime dispute and the development of marine economy, there has been renewed interest in seaplanes for their special capacity of taking off and landing on water. Prediction of take-off performance, involving aerodynamic analysis and hydrodynamic analysis, is a main challenge in seaplane design, while the prediction methods have been little improved since the 1960s. This paper aims to investigate the attitude and resistance characteristics of a seaplane at different speeds during the take-off by numerically modeling the air-water flow field using RANS equations with VOF method. The trim and heave motion of seaplane in response to aerodynamic forces, hydrodynamic forces, hydrostatic forces, and propeller thrust was realized by solving rigid body dynamics equations and adopting dynamic overset mesh technique. The variations in heave, trim angle, and resistance characteristics during the takeoff were investigated, and their inherent relationships with the aerodynamic, hydrodynamic, and hydrostatic performance were revealed. Particular investigation on the hydrodynamic resistance indicates that the stagnation line located at the convex bow would contribute a considerable increase of pressure resistance at the first hump, and the trim angel of a seaplane should be operated in an optimum trim range, typical between 4–6 deg, to minimize the hydrodynamic resistance at the second hump. Additionally, the dynamic motion convergence study proves that the utilization of damping terms was an effective way to accelerate the convergence of the dynamic motion ending with a quasi-static state. [ABSTRACT FROM AUTHOR]

On the basis of data from reanalysis and objective analysis for the second half of the 20th century, it is confirmed that the reemergence of anomalies of the characteristics of the upper mixed layer (UML) during the next year after their occurrence is possible in most of the North Atlantic (NA). Exceptions are regions near the western boundary currents and south of 15° N. The extracted signal is very pronounced in the leading empirical orthogonal functions (EOFs) of the UML temperature and mixed-layer depth, with contributions to the total variance of 17.9 and 23.9%, respectively, thus indicating the importance of this process in generating the anomalies of the upper ocean characteristics. The leading EOFs of the UML temperature and mixed-layer depth for 1959–2011, after the removal of third-order polynomials and the annual cycle, have a well-known tripole structure associated with the North Atlantic Oscillation. The EOF analysis in the time–depth plane for the Sargasso Sea and the northeastern NA demonstrates the process of reemergence of temperature anomalies at the ocean surface. The temperature anomalies formed throughout the UML in the period of its greatest winter deepening in February–March persist at depths of 50–200 m for the Sargasso Sea and 50–300 m for the northeastern NA throughout the year. These deep anomalies emerge at the surface in December, the period of the beginning of winter mixing. Subsurface temperature anomalies for 15 months (January–March of the next year) extend deep to the ocean, where they finally dissipate. [ABSTRACT FROM AUTHOR]

The year 2020 marked the 95th anniversary of Francesco De Pinedo and Ernesto Campanelli's record-breaking flight of 55,000 km, from Italy to Australia, Japan and back, in a seaplane named Gennariello. Their achievement was lauded worldwide, especially in Australia, where the press reported on it intensively. This paper reconstructs the story of the flight by analysing the Australian press accounts and De Pinedo's diary, to understand how the Australian public perceived the event. It investigates the aviators' arrival in Perth, Adelaide and Melbourne, where their popularity was greatest and where the local Italian communities enthusiastically welcomed them. The analysis shows that the flight engendered increased public interest and paid dividends in terms of image for the commercial companies involved, while fascism exploited it to display its progress in aviation. The paper concludes by exploring the legacy of the endeavour in modern Italy and Australia, emphasising the differences between the countries. [ABSTRACT FROM AUTHOR]

AS YOU MAY RECALL FROM THE PREVIOUS INSTALMENT OF AIRCRAFT MAINTENANCE ENGINEER (AME) BILL WALTON’S “NORTHERN ENGINEER” CHRONICLE IN VOLUME 57 NUMBER 1, HE HAD JUST ARRIVED IN HAY RIVER ON HIS WAY TOYELLOWKNIFE, NWT, WHERE HE WOULD BE STARTING A NEW JOB WITH MCAVOY AIR SERVICE. After finding his new employer, Chuck McAvoy, “staggering out of the hotel,” they drove down to the Northern Transportation dock where Chuck’s Cessna 180 floatplane was tied up. Bill picks up the story: We loaded all my gear on board and left my car there to be brought over to Yellowknife later by barge. We took off from the river and headed out across Great Slave Lake, which to my surprise, is so big I couldn't see the shore on the other side. It was like flying across the ocean. My education was just beginning. Chuck coming out of the bar had obviously been drinking but flew anyway. Out over the lake he asked me if I'd like a beer, which I said okay, so he reached behind and pulled out a couple of bottles of beer, popped the tops off and we drank beer at 2,000 feet (600 m) over the lake. When we finished drinking, he opened the side window and tossed the empties out. [ABSTRACT FROM AUTHOR]

THIS EVENT OCCURRED IN MARCH 1974 IN SIOUX LOOKOUT, ONTARIO, AT THE SEVERN ENTERPRISES LTD BASE OWNED BY ORVILLE J. WIEBEN. WIEBEN ALSO OWNED SUPERIOR AIRWAYS AND THE LAKEHEAD FLYING SCHOOL WHICH WERE HEADQUARTERED IN THUNDER BAY. At the time, he put together a plan to have spar mods installed on his fleet of Beech 18 aircraft, and wanted the work completed on all the aircraft in time for the beginning of float season in mid-May. The initial recipients would be CF-WYR, CF-YDV, CF-YQB, and CF-ZQR, which all operated on floats in the summer. One other Beech 18, CFZQH that operated on wheels, would receive the mod later, while the fleet’s remaining two,CF-PRZ and CF-VCE, would not since they were to be retired. [ABSTRACT FROM AUTHOR]

Focuses on the sale of defective flying boats known as K-Boats by Curtiss Aeroplane Co. of the U.S. to the Russian Navy in the summer of 1914. Brief description of the aircraft; Details on the dispute between the two countries over the contract in 1916; Outcome of the investigation into the cause of the defect; Impact of the defective aircraft on Russia's aerial operations in the Great War.