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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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    <item>
      <title>Design of Fully Automatic Drone Parachute System with Temperature Compensation Mechanism for Civilian and Military Applications</title>
      <link>https://trid.trb.org/View/1592770</link>
      <description><![CDATA[Application of Unmanned Aerial Vehicles (a.k.a. drones) is becoming more popular and their safety is becoming a serious concern. Due to high cost of top-end drones and requirements for secure landing, development of reliable drone recovery systems is a hot topic now. In this paper, the authors describe the development of a parachute system with fall detection based on accelerometer-gyroscope MPU – 6050 and fall detection algorithm based on the Kalman filter to reduce acceleration errors while drone is flying. The authors developed the compensation algorithm for temperature-related accelerometer errors. The parachute system tests were performed from a small height on a soft surface. Later, the system was tested under real-world conditions. The system functioned effectively, resulting in parachute activation times of less than 0.5s. The authors also discuss the civilian and military applications of the developed recovery system in harsh (high temperature) environment.]]></description>
      <pubDate>Thu, 25 Apr 2019 11:19:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1592770</guid>
    </item>
    <item>
      <title>Study of minimal effective reefing ratio based on an empirical formula and fluid-structure-interaction method</title>
      <link>https://trid.trb.org/View/1576683</link>
      <description><![CDATA[The reefing ratio for the first stage of a parachute limits the reefing ratio for the subsequent stages, so its minimal effective value is very important. In this paper, an empirical formula is derived to calculate the minimal effective reefing ratio. The empirical parameters are obtained by the arbitrary Lagrangian–Eulerian/fluid–structure interaction (ALE/FSI) method. By using the FSI method, the typical flow and structure fields of effective and ineffective reefed parachutes are revealed. The numerical results including drag characteristics and final shape are very consistent with wind tunnel tests. The curves of the empirical parameters with reefing ratios are obtained. The minimal effective reefing ratio obtained by the empirical formula is consistent with that of the numerical results, which shows that the empirical formula has high accuracy.]]></description>
      <pubDate>Wed, 27 Feb 2019 09:40:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1576683</guid>
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    <item>
      <title>Design of Controllable Unmanned Rescue Parachute Wing</title>
      <link>https://trid.trb.org/View/1576156</link>
      <description><![CDATA[The paper explores the design issues of controllable rescue parachute wing for UAS (Unmanned Aircraft System). The main part of the paper designs a prototype of an aerodynamically defined rescue parachute wing. On top of that, the XFLR5 and fwDesign software are used to design the canopy and its characteristics. The results are mainly available through a summary table containing basic parameters of the prototype, graphs exploring the aerodynamic characteristics and other exhibits of copious amounts of images illustrating dimensions, shape, structure, and the layout of individual construction parts.]]></description>
      <pubDate>Tue, 08 Jan 2019 19:00:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1576156</guid>
    </item>
    <item>
      <title>Parasailing: Elevating safety standards</title>
      <link>https://trid.trb.org/View/1539701</link>
      <description><![CDATA[Over the last decade, a series of parasailing marine casualties involving operations in questionable weather conditions and parasailing rigging exposed an urgent need for a more robust safety regime for this industry. Unfortunately, the Coast Guard still does not have regulatory authority over parasailing rigging on these vessels. This situation prompted the Coast Guard and industry stakeholders to develop voluntary safety standards using the American Society of Testing Materials (ASTM) International’s standards consensus process. The successful collaboration ultimately resulted in promulgation of a comprehensive standard in September 2014, providing guidelines and procedures for the operation, maintenance, and inspection of parasail vessels, equipment, and associated activities, including crew training and flying passengers aloft. The industry has since seen a remarkable reduction in the number of serious injuries and deaths associated with parasailing-related activities. In addition, one state (Florida) and one city (Gulf Shores, Alabama) have passed parasailing legislation, paving the way for other states and municipalities to follow.]]></description>
      <pubDate>Thu, 20 Sep 2018 16:37:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1539701</guid>
    </item>
    <item>
      <title>Report on the Effects of Parachutes on Risk Mitigation to Third Party Property and Individuals</title>
      <link>https://trid.trb.org/View/1532175</link>
      <description><![CDATA[This report is a response to an Office of Commercial Space Transportation (OCST) request that a "quick-turnaround" study be conducted on the subject topic. The research was conducted under the auspices of an existing contractor instruction on Additional Data Sources and included a review of the 17 References listed at the end of this report. The issue was a study of the public's exposure to risk caused by an object or payload landing upon its arrival from an orbital or suborbital flight trajectory. An investigation was conducted looking for research that may have been done or information that may have been gathered that is able to qualitatively or quantitatively discuss the magnitude of risk, or differential (delta) due to the presence of a parachute, to people or property on the ground in comparison to the risks of an object descending in free fall; essentially ballistically. The basic question the study seeks to answer is this. "Why is it safe to release an object on a parachute while it is unsafe to release it without a parachute?" The study did not reveal any existent research that included a side-by-side comparison of objects; one with an aerodynamic decelerator (parachute for this study) and one in ballistic free fall. However, the research conducted and the references and sources contacted do allow for certain comparisons and observations to be made.]]></description>
      <pubDate>Tue, 04 Sep 2018 23:02:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1532175</guid>
    </item>
    <item>
      <title>Drone ballistic recovery system coming</title>
      <link>https://trid.trb.org/View/1501221</link>
      <description><![CDATA[]]></description>
      <pubDate>Mon, 05 Feb 2018 15:48:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1501221</guid>
    </item>
    <item>
      <title>Cirrus Airframe Parachute System and Odds of a Fatal Accident in Cirrus Aircraft Crashes</title>
      <link>https://trid.trb.org/View/1469341</link>
      <description><![CDATA[General aviation (GA) accidents have continued to demonstrate high fatality rates. Recently, ballistic parachute recovery systems (BPRS) have been introduced as a safety feature in some GA aircraft. This study evaluates the effectiveness and associated factors of the Cirrus Airframe Parachute System (CAPS) at reducing the odds of a fatal accident in Cirrus aircraft crashes. Publicly available Cirrus aircraft crash reports were obtained from the National Transportation Safety Board (NTSB) database for the period of January 1, 2001-December 31, 2016. Accident metrics were evaluated through univariate and multivariate analyses regarding odds of a fatal accident and use of the parachute system. Included in the study were 268 accidents. For CAPS nondeployed accidents, 82 of 211 (38.9%) were fatal as compared to 8 of 57 (14.0%) for CAPS deployed accidents. After controlling for all other factors, the adjusted odds ratio for a fatal accident when CAPS was not deployed was 13.1. The substantial increased odds of a fatal accident when CAPS was not deployed demonstrated the effectiveness of CAPS at providing protection of occupants during an accident. Injuries were shifted from fatal to serious or minor with the use of CAPS and postcrash fires were significantly reduced. These results suggest that BPRS could play a significant role in the next major advance in improving GA accident survival.]]></description>
      <pubDate>Wed, 19 Jul 2017 15:44:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1469341</guid>
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    <item>
      <title>FAA UAS Center of Excellence Task A4: UAS Ground Collision Severity Evaluation</title>
      <link>https://trid.trb.org/View/1465525</link>
      <description><![CDATA[This evaluation documents the Unmanned Aerial System (UAS) platform characteristics related to the severity of UAS ground collision based upon the literature search of over 300 publications from the automotive industry, consumer battery market, toy standards, and other fields. The literature search included the evaluation of various criteria developed for human blunt force trauma injuries, penetration injuries and laceration injuries. These injury types represent the most significant threats to the non-participating public and crews operating Micro UAS (mUAS) and Small UAS (sUAS) platforms. The kinetic energy for the worst case terminal velocity or maximum cruise airspeed, energy density, and rotor diameter are the most significant UAS characteristics contributing to blunt force trauma penetration and laceration injuries, respectively. Two impact kinetic energy methodologies are presented to provide a risk and scenario based approach to determining kinetic energy thresholds for safe UAS operations. Parachute mitigations and the application of area weighted kinetic energy methodology for two scenarios are presented to outline thresholds for a broader range of vehicle weights to conduct flight over people than is currently possible with the unmitigated vehicle designs currently available. An initial investigation of energy transfer based on crash testing and dynamic modeling was conducted along with finite element analysis for human head and torso impacts. The crash test results and subsequent analysis strongly suggest that Range Commander’s Council (RCC)-based thresholds are overly conservative because they do not accurately represent the collision dynamics of elastically-deformable sUAS with larger contact areas in comparison to the metallic debris analysis methods for high speed missiles on the national test ranges. Lithium Polymer batteries dominate the mUAS and sUAS market as the principle energy source for these platforms. While many of the manufacturers state they test their batteries in accordance with Lithium Ion battery testing methods for consumer electronics, the batteries are rarely marked to show compliance with these standards and many of the test methods are not consistent with the forces and energy levels associated with ground collision impact energy. More research is required to address the fire hazard and impact hazard presented by the broad spectrum of batteries and battery chemistries used in mUAS and sUAS platforms. Twenty-three knowledge gaps were identified during the execution of the literature search and are recommended for future research efforts.]]></description>
      <pubDate>Wed, 17 May 2017 17:05:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/1465525</guid>
    </item>
    <item>
      <title>Parachute company sees niche in UAVs</title>
      <link>https://trid.trb.org/View/1449533</link>
      <description><![CDATA[]]></description>
      <pubDate>Thu, 02 Feb 2017 14:31:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1449533</guid>
    </item>
    <item>
      <title>Pilot and Passenger Injuries Associated with Powered Parachutes</title>
      <link>https://trid.trb.org/View/1427975</link>
      <description><![CDATA[Powered parachutes are becoming a popular form of sport flying. No previous study has reviewed injuries in this sport. The purpose of this study was to describe the injuries associated with powered parachute flying, the flight factors involved in an incident, and the impact an incident has on current sport involvement. National Transportation Safety Board incident reports involving powered parachutes between 2004 and 2015 were reviewed. Internet searches were performed to contact involved pilots to find further information. There were 71 incidents reported involving 117 people. Of these, 10 incidents involved 14 fatalities (12.0%). Of the 14 fatalities, 11 (78.5%) occurred in midflight. Pilot error was the most common finding for an incident and accounted for 53/71 incidents (74.6%). The main error was misjudging the distance required for takeoff and landing. This accounted for 37/71 incidents (52.1%). Orthopedic extremity injuries were the most common severe injuries reported. Surgical intervention was needed in 43.8% of injuries and 48.0% of those involved fractures. The median return to work was 14 d (range 0–180 d). Only 4/53 (7.5%) of the pilots contacted continued to fly powered parachutes. Powered parachute participants are at risk for unique injuries compared to other forms of flight. A powered parachute injury can have a significant impact on future pilot involvement in the sport. This study provides evidence for design changes in the aircraft and helps direct pilot training. This information can improve the safety and well-being of participants so they can continue to fly powered parachutes.]]></description>
      <pubDate>Tue, 29 Nov 2016 17:05:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1427975</guid>
    </item>
    <item>
      <title>Fluid-Structure Interaction Analysis of Parachute Finite Mass Inflation</title>
      <link>https://trid.trb.org/View/1408301</link>
      <description><![CDATA[Parachute inflation is coupled with sophisticated fluid-structure interaction (FSI) and flight mechanic behaviors in a finite mass situation. During opening, the canopy often experiences the largest deformation and loading. To predict the opening phase of a parachute, a computational FSI model for the inflation of a parachute, with slots on its canopy fabric, is developed using the arbitrary Lagrangian-Euler coupling penalty method. In a finite mass situation, the fluid around the parachute typically has an unsteady flow; therefore, a more complex opening phase and FSI dynamics of a parachute are investigated. Navier-Stokes (N-S) equations for uncompressible flow are solved using an explicit central difference method. The three-dimensional visualization of canopy deformation as well as the evolution of dropping velocity and overload is obtained and compared with the experimental results. This technique could be further applied in the airdrop test of a parachute for true prediction of the inflation characteristics.]]></description>
      <pubDate>Thu, 26 May 2016 14:50:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/1408301</guid>
    </item>
    <item>
      <title>BRS : saving lives one pull at a time : the data is in : whole airplane recovery systems are helping pilots stay alive, despite the naysayers</title>
      <link>https://trid.trb.org/View/1348222</link>
      <description><![CDATA[]]></description>
      <pubDate>Wed, 01 Apr 2015 10:07:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1348222</guid>
    </item>
    <item>
      <title>Development of Criteria for Parachute Landing Areas on Airports</title>
      <link>https://trid.trb.org/View/1313497</link>
      <description><![CDATA[Airport sponsors who accept federal funding are obligated to make the aircraft facility available to all aeronautical activities,  including parachuting and skydiving. Due to the lack of guidance concerning parachute landing areas (PLA) for airports that are  able to accommodate nontraditional aeronautical activities (such as skydiving), research was conducted to determine the  recommended size and location of PLAs on airports and provide guidance material. To do this, transition data were collected from airports currently supporting parachute operations, and international and military  standards were examined. Site visits were conducted and subject matter experts were consulted. It was determined that the experience of the parachutist and type of parachute used should be considered in developing the size of  the PLA. It was also determined that the edge of the PLA should be located no closer than 40 feet from a hazard. In addition, the  report includes recommendations for operational procedures and practices.]]></description>
      <pubDate>Thu, 24 Jul 2014 15:18:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1313497</guid>
    </item>
    <item>
      <title>A numerical study of parachute inflation based on a mixed method</title>
      <link>https://trid.trb.org/View/1238525</link>
      <description><![CDATA[The C9 parachute was the research object in this work and was studied by using a fluid-structure interaction method and computational fluid dynamics (CFD) method. An arbitrary Lagrangian-Eulerian method, a kind of fluid-structure interaction method, was used to simulate the inflation process. The dynamic relationship between canopy shape and flow field was obtained. The canopy shape in a stable phase was exported and was transformed into the porous media domain. Then the flow around the canopy shape was simulated by the CFD method we used based on the k-ε turbulence model. The experiments verified the accuracy of structural change and the feasibility of the porous media model. The arbitrary Lagrangian-Eulerian method not only can obtain the dynamic results of structure and flow field but also can provide a more accurate bluff body for further CFD analysis. The CFD method based on porous media and the turbulence model can obtain more detailed and accurate flow field results, which can be used as a complement to fluid-structure interaction analysis. This mixed method can improve the accuracy of analysis and be useful for other permeable fabric research.]]></description>
      <pubDate>Tue, 05 Feb 2013 09:13:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1238525</guid>
    </item>
    <item>
      <title>Parachute-Payload System Flight Dynamics and Trajectory Simulation</title>
      <link>https://trid.trb.org/View/1146660</link>
      <description><![CDATA[The work traces a general procedure for the design of a flight simulation tool still representative of the major flight physics of a parachute-payload system along decelerated trajectories. An example of limited complexity simulation models for a payload decelerated by one or more parachutes is given, including details and implementation features usually omitted as the focus of the research in this field is typically on the investigation of mission design issues, rather than addressing general implementation guidelines for the development of a reconfigurable simulation tool. The dynamics of the system are modeled through a simple multibody model that represents the expected behavior of an entry vehicle during the terminal deceleration phase. The simulators are designed according to a comprehensive vision that enforces the simplification of the coupling mechanism between the payload and the parachute, with an adequate level of physical insight still available. The results presented for a realistic case study define the sensitivity of the simulation outputs to the functional complexity of the mathematical model. Far from being an absolute address for the software designer, this paper tries to contribute to the area of interest with some technical considerations and clarifications.]]></description>
      <pubDate>Mon, 30 Jul 2012 09:50:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1146660</guid>
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