Download or read book Reefing of Parachutes written by Theodore W. Knacke and published by . This book was released on 1981 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents data on the forces in reefing lines. The force data were obtained from wind tunnel tests, from aerial free-flight tests and through the analysis of known reefing line failures. It was found that forces in reefing lines vary with the type of parachute used, with the reefing ratio, with the length of the suspension lines and with single or multiple stage reefing. The report discusses the difference in the reefing line forces of first stage drogue chutes, ordnance type retardation parachutes and large final descent main parachutes. Recommendations are made for stressing the reefing lines for various types of application.

Download or read book HIGH ALTITUDE PERFORMANCE OF A 64 FOOT DIAMETER RING SAIL PARACHUTE written by Max C. Kurbjun and published by . This book was released on 1959 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High altitude Flight Test of a Reefed 12 2 meter diameter Disk gap band Parachute with Deployment at a Mach Number of 2 58 written by John S. Preisser and published by . This book was released on 1971 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reefed B.2-meter nominal-diameter (40-ft) disk-gap-band parachute was flight tested as part of the NASA Supersonic High Altitude Parachute Experiment (SHAPE) program. A three-stage rocket was used to drive an instrumented test payload to an altitude of 43.6 km (143 000 ft) and a Mach number of 2.58 where the parachute was deployed by means of a mortar. After a time delay of about 8.5 seconds, the parachute was disreefed at a Mach number of 0.99. The report contains an analysis of parachute inflation, drag, and stability for both the reefed and unreefed parts of the test. In addition, detailed descriptions of the test parachute, the reefing system, and the parachute packing procedurea are included.

Download or read book Reefing of Parachutes written by Theodore W. Knacke and published by . This book was released on 1976 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Apparatus for Simultaneously Disreefing a Centrally Reefed Clustered Parachute System written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a central line attached between the payload and the cutter is stretched upon deployment of the cluster. A pyrotechnic or electronic time delay may be included in the cutter to delay the actual simultaneous cutting of all lines until the clustered parachutes attain a measure of stability prior to being disreefed. A second set of reefing lines and second tether lines may be provided for each parachute, to enable a two-stage, separately timed, step-by-step disreefing.

Download or read book Reefing of Parachutes written by Theodore W. Knacke and published by . This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamics of the Opening of Reefed Parachutes written by Ishwar Chandra Bhateley and published by . This book was released on 1961 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind Tunnel Measurements of Dynamic Reefing Line Tension in Ribbon Parachutes written by D. F. Wolf and published by . This book was released on 1979 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the results of a series of wind tunnel tests conducted to measure the tension in ribbon parachute reefing lines. Three-foot diameter ribbon parachute models with porosities ranging from 10 to 25 percent were tested in the Vought Systems Low Speed Wind Tunnel. Simultaneous measurement of parachute axial force and reefing line tension allowed the reefing line tension to be expressed either as a percent of axial force or as a dimensionless tension coefficient. Maximum reefing line tensions for the 15, 20 and 25 percent porosity chutes ranged from 4 to 5 percent of axial force. Tensions for the 10 percent porosity chute were considerably higher. The 10 percent porosity chute also showed a significant dynamic effect in tension, with maximum values considerably higher than steady values.

Download or read book A Parachute Reefing System to Promote Faster Canopy Inflation written by John W. Watkins and published by . This book was released on 1995 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the development of a reefing system used to speed up inflation of a round parachute canopy. This reefing system, called Mid-Canopy Reefing (MCR), was developed in response to a need to reduce the minimum jump altitude of a developmental low-altitude troop parachute. This reefing system temporarily reduces the size of the parachute canopy, causing it to inflate more rapidly than the same canopy without reefing. Use of this system made it possible to cut the inflation time of the troop parachute in half, and there was a significant reduction in the minimum jump altitude.

Download or read book Radial Reefing Method for Accelerated and Controlled Parachute Opening written by Calvin K. Lee and published by . This book was released on 1994 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Future Army airdrop systems will require aerial insertion of cargo and personnel from low altitudes to minimize ground-fire hazards. A radial reefing method was developed as a potential candidate to meet this requirement. The radial reefing method involves selecting equally spaced radials of a parachute canopy and reefing these radials near the skirt; concurrently, the canopy fabric adjacent to the reefed radials is puckered. Reefing the canopy this way creates large fabric pockets near the skirt during initial canopy inflation, resulting in accelerated and controlled parachute opening. This was confirmed by full-scale air drop testing using single Army personnel and cargo parachutes. In addition to demonstrating promises for single-canopy low-altitude airdrop applications, the radial reefing method also shows potential to improve clustered parachute opening by minimizing canopy enfolding and slumping.

Download or read book Parachute Recovery Systems written by Theo W. Knacke and published by . This book was released on 1992 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this manual is to provide recovery system engineers in government and industry with tools to evaluate, analyze, select, and design parachute recovery systems. These systems range from simple, one-parachute assemblies to multiple-parachute systems, and may include equipment for impact attenuation, flotation, location, retrieval, and disposition. All system aspects are discussed, including the need for parachute recovery, the selection of the most suitable recovery system concept, concept analysis, parachute performance, force and stress analysis, material selection, parachute assembly and component design, and manufacturing. Experienced recovery system engineers will find this publication useful as a technical reference book; recent college graduates will find it useful as a textbook for learning about parachutes and parachute recovery systems; and technicians with extensive practical experience will find it useful as an engineering textbook that includes a chapter on parachute- related aerodynamics. In this manual, emphasis is placed on aiding government employees in evaluating and supervising the design and application of parachute systems. The parachute recovery system uses aerodynamic drag to decelerate people and equipment moving in air from a higher velocity to a lower velocity and to a safe landing. This lower velocity is known as rate of descent, landing velocity, or impact velocity, and is determined by the following requirements: (1) landing personnel uninjured and ready for action, (2) landing equipment and air vehicles undamaged and ready for use or refurbishment, and (3) impacting ordnance at a preselected angle and velocity.

Download or read book NASA Technical Note written by and published by . This book was released on 1975 with total page 958 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Testing of a New Reefing System to Reduce Parachute Opening Shock Characteristics During Seat Ejection written by and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the initial testing of a new parachute slider reefing system to control the opening dynamics of the military C-9 parachute. It has been theorized that if one could control the opening of the parachute canopy used during emergency ejections, the parachute opening forces on the crewmember could he significantly reduced. The report addressed the reefing system modification and summarizes the initial testing results of the new slider reefing system to control the parachute opening dynamics.

Download or read book Spiral Reefed Variable Drag Parachute written by Stanley C. Hulteen and published by . This book was released on 1972 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The invention relates to a parachute having reefing lines formed about the body or canopy of the parachute in a spiral configuration in such a manner as to control the opening shock and rate of descent of such parachute. The spiral reefing of the parachute effectively increases or decreases the canopy area thereby controlling the aerodynamic drag of the parachute. (Author).

Download or read book Reefing Line Length Calculation for Ribbon Type Rarachutes written by R. P. Della-Vedowa and published by . This book was released on 1952 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is presented for calculating reefing line lengths for the highly reefed stages of ribbon type parachutes. The effects of aeroelasticity on parachute porosity, and length of the reefing line are included.

Download or read book Gemini Spacecraft Parachute Landing System written by John Vincze and published by . This book was released on 1966 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Drag and Stability Characteristics of a Variety of Reefed and Unreefed Parachute Configurations at Mach 1 80 with an Empirical Correlation for Supersonic Mach Numbers written by Lana M. Couch and published by . This book was released on 1975 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted at Mach 1.80 in the Langley 4-foot supersonic pressure tunnel to determine the effects of variation in reefing ratio and geometric porosity on the drag and stability characteristics of four basic canopy types deployed in the wake of a cone-cylinder forebody. The basic designs included cross, hemisflo, disk-gap-band, and extended-skirt canopies; however, modular cross and standard flat canopies and a ballute were also investigated. An empirical correlation was determined which provides a fair estimation of the drag coefficients in transonic and supersonic flow for parachutes of specific geometric porosity and reefing ratio.