Search Results

To review specifications of a next-generation supersonic commercial transport (SCT), conceptual design is performed. The study covers the cruise speed between Mach 2.0 and 2.4, and the range between 4,000 nmi and 6,000 nmi with the number of seats fixed to 300. Engines for Mach 2.0, 2.2 and 2.4 are conceptually designed and the data are applied to Japan Aircraft Development Corporation (JADC)'s SCT sizing and performance prediction tool (“CAD”). The maximum take off weights (MTOW) are surveyed to find the best combination of cruise speed and range.

Gulfstream has developed its new G-V aircraft as the next generation in the Gulfstream product line. This all-new aircraft will have a range of 6,500 miles, allowing it to fly from New York to Tokyo nonstop. The aircraft has an overall wingspan of 93.47 feet, almost sixteen feet greater than its predecessor, the G-IV-SP, and is more than eight feet longer. The airplane was essentially built by computer using a concurrent engineering approach. An important part of the concurrent engineering technology was the modal testing which was conducted prior to first flight. This testing was necessary to confirm analysis predictions of the dynamic behavior of the aircraft assembly. As much of the aircraft assembly was being conducted “just-in-time,” the rapid acquisition and confirmation of test data were essential.

The growth of international markets as well as business partnerships between U.S. and Asian-based firms has lead to an increased interest in an economically viable business jet capable of supersonic cruise and trans-Pacific range with one stop over (or non-stop trans-Atlantic range)1. Such an aircraft would reduce the travel time to these regions by as much as 50% by increasing cruise Mach number from roughly 0.85 to 2.0. In response to this interest, the 1996 AIAA / United Technologies / Pratt & Whitney Individual Undergraduate Design Competition has issued a Request for Proposal for the conceptual design of a supersonic cruise business jet. The design of this aircraft considered both performance and economic issues in the conceptual design phase. Through the use of Response Surface Methodology (RSM) and Design of Experiments (DoE) techniques, the aerodynamics of this vehicle were modeled and incorporated into an aircraft sizing code, FLOPS.

Extreme rain and hail conditions have caused engine rundowns during commercial airplane flights. In some cases, rain and hail conditions have caused all of the engines on the airplane to rundown simultaneously. This paper presents an analysis that quantifies the rain and hail threat in terms of the probability of encountering a storm of a given intensity for a given period of time. This analysis was used to establish recommended rain and hail concentration levels for design and certification of turbine engines.

Curves are derived that show probability versus rain water content and hail water content. These curves apply at the “worst case” single point. The rain curve indicates rain water contents of 15.3, 18.9, and 22.4 g m-3 at probability levels of 10-7, 10-8, and 10-9, respectively. The hail curve indicates hail water contents of 8.5, 12.5, and 16.5 g m-3 at probability levels of 10-7, 10-8, and 10-9, respectively. The rain and hail water content values listed above apply at 19,700 feet above mean sea level (rain), 15,000 feet above mean sea level (hail). Complete atmospheric vertical profiles for rain and hail are shown.

Albert S. Menasco, SAE member and distinguished aircraft engine designer active in the 1920s and 1930s, produced a series of inverted, inline, four- and six-cylinder, air-cooled engines that achieved great success in many U.S. air races before World War (WW) II. Menasco's engines found substantial use in such light airframes as the famous Ryan monoplane ST, but his company was not commercially successful until it shifted to manufacturing landing gear in the 1940s. Menasco's historical legacy in aircraft engines is a fine testimonial to U.S. engineering accomplishment. This paper chronicles the engineering development of Menasco's relatively light aircraft engines and their air racing success in the hands of “golden age” pilots. Menasco furnished special superchargers, cams, pistons, and other parts to achieve extra speed with available racing fuels.

The aircraft design goals utilized over a forty year period to produce a family of successful Business Aircraft are presented. The results, in terms of the primary long range business travel mission, are provided. The inherent capabilities as a high altitude, long endurance, military reconnaissance or surveillance mission aircraft platform are detailed. The seemingly unrelated Business Aircraft design goals that produce the excellent military mission performance are discussed. Noted are several applications of the aircraft family in the special mission role. Examples of two current production models, selected for special mission applications are presented. The capabilities of the two models and the application of advanced applied aerodynamic technologies are illustrated for several special mission roles through out the world.

The Aerostructures Corporation has realized significant reductions in the number of work hours required to create surfaced, 3D wireframe CAD models of aerospace structures and tooling through the use of knowledge based engineering (KBE) and generative design models. Generative models are electronic representations of the design process that contain all of the information needed to design, analyze, and manufacture a product in a single integrated solution. This paper documents the development and use of generative models on: composite aircraft ribs, bond tooling for composites, and age forming tools. Reductions in the number of design work hours, allow time for optimizations, with the result being more efficient, manufacturable designs.

Development of a light structure with composite materials is one of the key technologies to realize an economic HSCT(High Speed Civil Transport). FHI(Fuji Heavy Industries) has continued to investigate heat resistance polymer (thermoplastic polyimide) matrix composite materials and their application to aircraft structures since 1987 jointly with MTC (Mitsui Toatsu Chemicals), Inc[1, 2 and 3]. FHI has started Ti Honeycomb Sandwich Panel Development and Fiber/Metal Laminate Development for high temperature aircraft structures. The status of above studies FHI has ever investigated and the concerns for future studies are summarized herein.

Numerical simulations indicate that blast loading on aircraft structural joints can impart loading rates in excess of 10 Mlb/sec (ten million pounds per second, Reference 1). Experimental evidence, on the other hand, suggests that mechanical joint failure loads are highly loading rate dependent; for example, the failure load for a dynamically loaded tension joint can double from its static value. This paper discusses the progress and to-date findings of research on the assessment of strength failure of aircraft structural joints subjected to loading rates expected from an internal explosive detonation, and several associated experimental procedures to generate such dynamic loading. This work is conducted at MDC and at the University of Dayton Research Institute (UDRI) in support of the FAA Aircraft Hardening Program.

A method of estimating the load-bearing fuselage weight and wing weight of transport aircraft based on fundamental structural principles has been developed. This method of weight estimation represents a compromise between the rapid assessment of component weight using empirical methods based on actual weights of existing aircraft, and detailed, but time-consuming, analysis using the finite element method. The method was applied to eight existing subsonic transports for validation and correlation. Integration of the resulting computer program, PDCYL, has been made into the weights-calculating module of the AirCraft SYNThesis (ACSYNT) computer program. ACSYNT has traditionally used only empirical weight estimation methods; PDCYL adds to ACSYNT a rapid, accurate means of assessing the fuselage and wing weights of unconventional aircraft.

USAF Wright Laboratory, in conjunction with the Joint Technical Coordinating Group on Aircraft Survivability, Naval Air Warfare Center, Army Research Laboratory, and USAF Phillips Laboratory, tested the electromagnetic vulnerability of a complete digital flight control system. These tests, spanning three years, generated a wealth of data and numerous lessons learned. This paper examines some of those lessons learned, and how they can reduce vulnerability of future vehicle management systems. While this is focused toward flight control systems, the principles can be applied to any electronic system of interest.

Advanced lightweight ceramic/composite armor systems have been investigated for the defeat of ball and armor piercing projectiles. Several material systems have been identified that will provide weight reductions of approximately 33% - 45%. The materials investigated for this effort include Boron Carbide (B4C) and Silicon Carbide (SiC) ceramics combined with high strength fiber reinforced plastic backing materials such as Kevlar 29, KM2, Spectra 900, 1000 and SpectraShield. An extensive database is also being complied for other less expensive alternative armor materials against an array of small arms threats. The materials and systems developed are applicable for combat vehicles, aircraft, executive vehicles and personnel protection.

The social and economic impacts resulting from SST operation were examined and a quantitative analysis was performed to determine the stimulation potential to the Japanese and world economy around 2020 when the aircraft will operate. The indirect boosting in output of three industrial sectors of manufacturing, trade business and tourism related industry was estimated to be roughly 1 - 1.5% of the country's and world's GDP.

This paper discusses a simplified method for analyzing the response of aircraft fuselage structures subjected to internal blast loading. By assuming that the loaded section of the fuselage acts like an expanding membrane, a single-degree-of-freedom (SDOF) model which tracks the radial displacement of the membrane can be used to characterize structural response. Results obtained using the model are evaluated against data obtained from tests conducted on retired aircraft. Comparisons with the test data indicate the method provides reasonable estimates of structural strain- and motion-time histories, as well as combinations of charge size and standoff distance associated with the onset of failure.

Operation Heli-STAR (Helicopter Short-Haul Transportation and Aviation Research) was established and operated in Atlanta, Georgia, during the period of the 1996 Centennial Olympic Games. Heli-STAR had three major thrusts: 1) the establishment and operation of a helicopter-based cargo transportation system. 2) the management of low-altitude air traffic in the airspace near the Olympic venues, and 3) the collection and analysis of research and development data associated with items 1 and 2. Heli-STAR was a cooperative industry government program that included cargo shippers in the Atlanta area, the helicopter industry, aviation electronics manufacturers, the Federal Aviation Administration (FAA), the National Aeronautics and Space Administration (NASA), and support contractors.

Over the last several years, the Federal Aviation Administration (FAA) and the rotorcraft industry have maintained a dialogue regarding minimum airspace requirements at visual flight rule (VFR) heliports. The industry is anxious to locate heliports in strategic downtown city-center areas and wants to size heliport airspace to fit these constrained geometries. The FAA, on the other hand, is concerned that the minimum recommended airspace for VFR heliports or vertiports must be sufficient to ensure safety of operations. Prior FAA studies and testing on this issue have been concerned with a very limited number of obstacles in the vicinity of a specific heliport. No consideration has been given to the psychological effect of a large number of obstacles, or an obstacle-rich environment (ORE), in the vicinity of a heliport or vertiport on pilot performance. This research project is designed to explore and investigate what part obstacles play in pilot performance and perception.

The next oil crisis will create a new round of interest in alternative energy, renewable sources. The economics of military and commercial sailing will again be hotly debated by naval architects and marine engineers. The difference this time will be the abundance of data from the large world fleet of unmanned air vehicles (UAV), which just might be the key to wind assisted freighters. Our pioneering efforts with recreational kite sailing and buggies have provided part of the database needed to apply UAV technology to the task of wind assist for global transport. This paper will tie the UAV and kitesailing technology to military and commercial needs. For example, the Boeing Condor (Fig 1), with her jumbo jet span and 40,000 lb lift capability, could generate 10,000 lbs of thrust from the trade winds, tethered to a ship at sea.

The desire of achieving faster cruise speed for rotorcraft vehicles has been around since the inception of the helicopter. Many unconventional concepts have been considered and researched such as the advanced tilt rotor with canards, the tilt-wing, the folding tiltrotor, the coaxial propfan/folding tiltrotor, the variable diameter tiltrotor, and the stopped rotor/wing concept, in order to fulfill this goal. The most notable program which addressed the technology challenges of accomplishing a high speed civil transport mission is the High Speed Rotorcraft Concept (HSRC) program. Among the long list of potential configurations to fulfill the HSRC intended mission, the stopped rotor/wing is the least investigated due to the fact that the existing rotorcraft synthesis codes cannot handle this type of vehicle. In order to develop such a tool, a designer must understand the physics behind this unique concept.

This is a progress report for the concept design for a roadable helicopter; i. e., a helicopter that can fold up its blades and drive off like a car. The study is funded by NASA's Langley Research Center, and is the result of a survey of the American helicopter industry two years ago to determine if there was any interest by those companies to study this concept which has the added features of a fully automatic stability / control / navigation system for complete hands-off flight, could be built at a rate of at least 500,000 units per year, and would sell for a price equivalent to a then-year luxury automobile. The unanimous response was that this would be a fantastically attractive engineering project, could undoubtedly be made to work, but reaching the suggested production rate and cost would be a substantial challenge. McDonnell Douglas Helicopter Systems (MDHS) agreed to look into the matter, and this paper describes where we were about three months into the study.