Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

SJ30-2 High Performance Business Jet Development: A Prototype Based Approach

1999-04-20
1999-01-1593
The SJ30-2 is a high performance, entry level business jet with the design goal of offering performance superior to other aircraft in its class. Critical data were obtained and evaluated early in the development program through flight and structural testing of a prototype aircraft. Prototype testing helped to achieve aggressive design goals and minimized potential design changes for the globally located manufacturing team. This prototype based approach reduced the program schedule risk in the production and certification phase.
Technical Paper

FTIMS/2000™ A Strategic Flight Test Management Solution

1999-04-20
1999-01-1600
For many years manufacturer’s had to devote considerable work to demonstrate that an aircraft met the specific requirements. The indicator of credibility lies primarily in the award of Type Certification, marked by a Certification of Airworthiness. Since flight test engineering accounts for a major portion of aircraft manufacturer’s controllable cost; the implementation of structured methods and advanced operational procedures will yield the most dramatic single cost savings. The FTIMS/2000™ seamlessly links a complex array of strategic flight test business processes into a logical flow and is used as a true management tool. It is one of the only systems of its kind and is recognized by major aerospace corporations worldwide.
Technical Paper

Compliance Criteria for Side Facing Aircraft Seats

1999-04-20
1999-01-1598
A series of side facing seat impact sled tests were conducted using the SID, EuroSID-1 and BioSID side impact Anthropomorphic Test Dummies (ATDs) at the FAA Civil Aeromedical Institute (CAMI). The tests were performed on a side facing sofa fixture with a rigid bulkhead adjacent to the forward end of the seat. The purpose of the research project was to examine the methods utilized by the automobile industry to assess thoracic injuries due to side impact accidents, and to investigate the potential applicability of these methods for side facing seats and sofas in civil aircraft. Tests were conducted with single and double occupants. The test conditions complied with the 16g 44 f/s horizontal impact specified in 14 CFR 25.562. Various side impact injury criteria were evaluated in the tests, including the Thoracic Trauma Index (TTI), Viscous Criteria (VC), rib deflection and pelvis acceleration.
Technical Paper

Application of Shape Memory Alloys for Leading Edge Deicing

1999-04-20
1999-01-1585
Ice accumulation on aircraft wings during flight is a dangerous situation. To deal with this problem, current deicing systems either prevent ice accumulation by heating or break the ice layer once it is formed by dynamic motion of a leading edge device such as a boot. These systems may be deficient due to excessive energy requirements or ineffectiveness. In this project, the feasibility of using shape memory alloy (SMA) composite material for deicing purposes is investigated. SMA such as Nitinol wire has an unusual characteristic where it can be trained to generate a compressive strain upon application of an electric current through the wire. Several different versions of two inch radius semi-circular SMA composite specimen were manufactured and tested at Wichita State University. Ice was successfully shed in static icing tests while each of the subsequent versions reduced the power input requirement.
Technical Paper

Detection of Icing and Related Loss of Control Effectiveness in Regional and Corporate Aircraft

1999-04-20
1999-01-1583
This paper presents a method of detecting aircraft icing by monitoring its effects on aircraft dynamics. This paper shows that uncontrolled icing on control surfaces directly influences control effectiveness. Using data from onboard attitude and navigation sensors via highly computationally efficient algorithms, the control effectiveness is estimated, thereby detecting icing. Using actual flight test data from NASA Lewis Research Center, this paper demonstrates the ability of this method to detect the loss of elevator effectiveness that occurs with uncontrolled horizontal stabilizer icing that could result from a failed deicing boot. The method is generally applicable to loss of control effectiveness due to icing. Icing affects the aerodynamic performance of aircraft by contaminating the aerodynamic surfaces. Without anti-icing equipment icing, if sufficiently severe, can relatively quickly lead to a situation in which controllable flight is impossible.
Technical Paper

Heating Aircraft Reciprocating Engines

1999-04-20
1999-01-1568
Aircraft engines need preheating to be able to start without damage in cold weather. It is possible to do this efficiently by placing a small amount of heat in the proper places. An installed electric system is very convenient and easy to use. A good design will be light weight and energy efficient. Corrosion in engines that operate in cold weather can be reduced or eliminated by the right preheater design and the proper operation of the engine. Some designs of preheater systems aggravate other problems. A certain amount of caution is needed in selecting the system. The unit should be specifically matched to the aircraft and engine.
Technical Paper

Fatigue Analysis of an Aircraft Wing Spar

1999-04-20
1999-01-1561
During full body fatigue testing, an aircraft wing spar initiated a crack from a rivet hole and crack growth data was obtained unique to the test spectrum loading. Fatigue testing of the 7050-T73511 spar material was used to obtain crack growth rate data and variable amplitude fatigue crack growth tests were performed on specimens fabricated from the spar material. Calculated results were in excellent agreement with these experimental results. A layered analysis of the adhesively bonded spar showed that the stress intensity in the lower cap was approximately constant, independent of crack length. When the constant stress intensity is used in a variable amplitude fatigue crack growth analysis, there is good correlation between the predicted and observed crack growth rates.
Technical Paper

Aviation Weather Information Systems Research and Development

1999-04-20
1999-01-1579
President Clinton announced in February 1997 a national goal to reduce the fatal accident rate for aviation by 80% within ten years. Weather continues to be identified as a causal factor in about 30% of all aviation accidents. An Aviation Weather Information Distribution and Presentation project has been established within the National Aeronautics and Space Administration’s Aviation Safety Program to develop technologies that will provide accurate, timely and intuitive information to pilots, dispatchers, and air traffic controllers to enable the detection and avoidance of atmospheric hazards. This project, described herein, addresses the weather information needs of general, corporate, regional, and transport aircraft operators.
Technical Paper

Newton II Aircraft Powerplant Test Cell Mount

1999-04-20
1999-01-1580
The study of piston aircraft engines with the propeller mounted as the load has been restricted due to the equipment needed to measure the combination of instant engine torque and vibrational movements. This work details the development of an engine mount that has a torque sensitivity of less than 0.05 pound-feet for measuring horsepower, vibration forces, and torque. The hydraulic force measurement system used in the project is discussed and evaluated with the limitations encounter. A torque balance system that can be checked with primary weights for absolute accuracy was developed and described as well as the methods for determining instant vibrational forces and rotational stresses.
Technical Paper

Activities of the Federal Aviation Administration’s Aviation Weather Research Program

1999-04-20
1999-01-1578
Weather is a major cause of aircraft accidents and incidents and the single largest contributor to air traffic system delays. Through improvements in the knowledge of current weather conditions and reliable forecasts, the Federal Aviation Administration (FAA) can improve aviation safety, increase system capacity, and enhance flight planning and fuel efficiency. The FAA has established an Aviation Weather Research (AWR) program to address specific requirements for weather support to aviation by providing the capability to generate more accurate and accessible weather observations, warnings, and forecasts and also by increasing the scientific understanding of atmospheric processes that spawn aviation weather hazards. The goal of AWR is to provide meteorological research that leads to the satisfaction of specific aviation weather requirements.
Technical Paper

Strength of Stiffened Panels with Multiple Site Damage

1999-04-20
1999-01-1575
Multiple site damage (MSD) on aging aircraft accumulates from fatigue loading over a period of time. For ductile materials such as 2024-T3 aluminum, MSD may lower the strength below that which is predicted by conventional fracture mechanics. An analytical model referred to as the linkup (or plastic zone touch) model has previously been used to describe this phenomenon. However, the linkup model has been shown to produce inaccurate results for many configurations. This paper describes several modifications of the linkup model developed from empirical analyses. These modified linkup models have been shown to produce accurate results over a wide range of configurations for both unstiffened and stiffened flat 2024-T3 panels with MSD at open holes. These modified models are easy to use and give quick and accurate results over a large range of parameters.
Technical Paper

Beech AT-10 Wichita

2000-05-09
2000-01-1679
This paper describes the design and development of the Beech AT-10 multi-engine pilot transitional trainer. It also covers the use of the AT-10 as a research aircraft.
Technical Paper

Aerodynamics of the Bell P-39 Airacobra and P-63 Kingcobra

2000-05-09
2000-01-1678
This paper provides a retrospective of the aerodynamics of the Bell P-39 Airacobra and the Bell P-63 Kingcobra. Design details and information obtained from several drag reduction investigations conducted on these aircraft are presented. Additionally, results from a modern Computational Fluid Dynamics analysis of these aircraft are shown.
Technical Paper

The Rise and Fall of General Aviation — An Economists View with Focus on Single Engine Aircraft and the Impact of Airline Deregulation

2000-05-09
2000-01-1677
The catastrophic decline of general aviation in the early1980’s – exemplified by the rapid fall in sales of single engine piston powered models – is old news. But as the industry, emboldened by legislative relief in product liability, now embarks on revitalization it is worth revisiting its history to see if there are any lessons for today. To an economist that history (starting post WWII) would include the impact of the evolving national economy on the industry and the contribution of “products” competing for the composite intercity travel and leisure markets in terms of price and changing tastes. Economists prefer statistical evidence to draw conclusions, and that has been gathered for addressing the specific competition with the airline industry as well as the market ceiling for general aviation airplanes. Quantitative, but non-statistical, evaluation of alternative ways of “flying” for recreation was also done. The results are not encouraging.
Technical Paper

A New Approach to the Design of a Diesel Engine for General Aviation Aircraft Propulsion

2000-05-09
2000-01-1686
A diesel engine of unconventional configuration and construction is described with particular reference to general aviation propulsion application. The technical approach is justified and some supporting development experience is described. Some details are presented for a specific engine design to serve an aircraft application that requires 630 shaft horsepower at an altitude of 10,000 feet. This six-cylinder turbocharged engine displacing 9.0 liters was estimated to weigh 755 lb. and develop 980 BHP at sea level with a specific consumption of less than 0.36 lb./BHP-hr.
Technical Paper

Evaluation of an Unconventional Diesel Engine as a General Aviation Powerplant

2000-05-09
2000-01-1685
A novel two stroke cycle diesel engine is evaluated as a general aviation aircraft powerplant. Two certificated spark-ignited gasoline reciprocating engines are also evaluated in the same aircraft. The evaluation of aircraft propulsion performance considered only the effects of altered powerplant parameters on the range of an aircraft having a fixed gross weight and payload cruising at a given lift/drag ratio. Thermodynamic analysis finds the diesel engine can have a sea level power rating exceeding the 10,000 foot cruise power requirement by 55% with nearly equal specific fuel consumption, a low engine speed and a modest cylinder pressure. It uses a single-stage, radial turbocharger without intercooling or auxiliary mechanical scavenging. The diesel engine can significantly increase the range of a particular airplane now powered by a certificated turboprop engine. The candidate gasoline engines could not equal the turboprop-powered aircraft performance.
Technical Paper

NASA / SATS Life Cycle Cost Model

2000-05-09
2000-01-1690
This paper is a derivative of a report submitted to NASA which investigated the affordability of Small Aircraft Transportation System (SATS) aircraft. The initial effort developed a Life Cycle Cost (LCC) / Total Ownership Cost (TOC) model. The model is grounded in practical expertise as well as theories relevant to the affordability of significant and discontinuous technological innovations. Input data were either researched from valid and reputable sources, or where assumptions were needed to be made, were made in the spirit of the NASA vision and using its literature. Thus the perspective maintained throughout this phase of research might be termed “realistically optimistic.” The challenge of making the NASA SATS vision bear fruit is ambitious and imposing, yet NASA has earned a reputation for success in such projects.
Technical Paper

GV Heated Cabin Window - Design, Testing, and Certification

2000-05-09
2000-01-1668
Due to the increased flight envelope of GV aircraft and the industry-wide problems with crazing of structural acrylic transparencies, a re-design of the Gulfstream cabin windows was undertaken for the GV. The primary goals of this effort were to develop a cabin window that remained condensation free in all operating conditions, had improved service life, retained the size and shape of the classic Gulfstream cabin windows, and met all current FAA and JAA certification requirements. Cost and weight, as well as structural interchangeability with earlier Gulfstream aircraft, were also important issues. These goals were met during a significant design and testing effort undertaken both at Gulfstream and with the vendor, PPG Industries Inc. Aircraft Products. The resulting design, currently installed in all GV aircraft, retains the large field of view that is synonymous with all Gulfstream models while incorporating a number of newer technologies and improvements.
Technical Paper

Estimating the Rate of Technology Adoption for Cockpit Weather Information Systems

2000-05-09
2000-01-1662
This paper summarizes the results of a survey to estimate the market penetration rate of cockpit weather information systems in five aviation markets: transport, commuter, general aviation, business, and rotorcraft. It begins by describing the general features that survey respondents identified as necessary characteristics for the market success of cockpit weather systems. Next the paper analyzes the financial benefit of cockpit weather systems for each market segment. Decision reversal tables and Monte Carlo simulation are employed to examine the sensitivity of the financial results to changes in the cost and savings elements. Finally, estimates for adoption rates in the five aviation market segments are presented.
Technical Paper

Dynamic Analysis of Crew Seats and Cockpit Interiors

2000-05-09
2000-01-1674
Improved safety standards are becoming a focus of the aerospace industry. In particular, standards for occupant protection have been changed to include dynamic seat testing and occupant injury assessment. Methods to model these situations are evolving. A method of modeling an occupant on a crew seat during a sled test is presented. This method combines a rigid body occupant model with a finite element model of the crew seat structure. Validation to sled test results obtained with the model is also presented. Modeling dynamic events with MADYMO software has been proven to be efficient and accurate in many aerospace and automotive applications. Using this tool, a model was developed to investigate how modeling can be used efficiently to provide guidance in crashworthy design. Both finite element methods (FEM) and multibody techniques were used to create a detailed model of a typical aircraft crew seat.
X