Parachute Type Research Articles

Retrospective study of Parajump injuries in Indian Armed Forces

Introduction: A number of studies on military and civil parachuting injuries have been published in the past. Most of the studies place the incidence of parachuting injuries to vary between 0.22% and 0.89%. The profile of injuries sustained during jumps by Indian paratroopers from Paratrooper Training School (PTS), Agra, between 2013 and 2019 was analyzed. Material and Methods: A retrospective analysis of Indian military parachuting injuries was done to assess injury patterns from the records of static line and combat free fall jumps, available at the PTS. The data pertaining to 270 injuries sustained from 256 jumps were analyzed in terms of number of jumps by each paratrooper, type of course/ mission, age, time of the of jump (day/ night), type of parachute used, wind speed at the time of drop, terrain on which the paratrooper landed, the location / part of body injured, the diagnosis, and finally the possible modality of injury using descriptive statistics. Results: The incidence of injuries ascertained from the records varied from 0.054% to 0.10% with a mean incidence of 0.083% from 306,986 jumps recorded over 7 years. Most injuries were related to refresher jumps and static line jumps. There were three fatalities recorded in this period, all due to failure of main and standby parachutes. Most of the injuries were sustained at the time of landing (218, 86.17%). Lower limb injuries accounted for maximum injuries (109, 40.37%), followed by truncal injuries 95 (35.19%) and upper limb injuries 33 (12.22%). Conclusion: The study brings out an interesting aspect of significantly less military parachuting injuries seen in the present study vis-à-vis reported in literature. A high degree of physical fitness and rigorous training are probably responsible for this low incidence. Increasing the duration of refresher training and physical conditioning may further reduce the occurrence of injuries. A cost-efficacy analysis of the same may be done before effecting changes in the training programme.

Experimental Characterization of Drag Coefficient of an UAV Recovery Parachute

Parachute recovery systems are proved to be an efficient method to recovery and rescue unmanned aerial vehicles (UAV) as it follows most requirements of reliability and airworthiness in flights. Parachutes are key components of the recovery systems and the drag coefficient of parachutes plays a crucial role in evaluating parachute’s performance. The purpose of the research is to determine and compare the impact of some factors on aerodynamic drag force during the inflation of a parachute. The canopy’s shape (flat circular type and extended skirt 10% flat type), of the length of suspension lines (be in proportion to nominal diameter from 0.6 to 1.5) are considered. Measurement of the drag force of the parachute models is carried out in an open return wind tunnel. Experimental results show that flat circular canopy has a higher drag coefficient than extended skirt 10% flat model in the range of low speed from 3 to 6 m/s. However, when wind speed is greater than 6 m/s, the drag coefficients of both two parachute types are nearly 0.85. In terms of the suspension line, the longer length would significantly raise the coefficient of drag force.

Research of the Photo-Optical Method Application for Measuring Selected Data on the Movement of a Parachute for Type M-282

Testing in the field of parachute technology provides space for the application of new and innovative methods of measuring operating and functional parameters. The main aim of the paper is to present the results of research for the verification of the photo-optical method of measuring the vertical speed of the M-282 parachutes, and for its use in testing, collecting, and investigating motion data in parachuting. As part of this measuring technology, twelve jumps were performed. It was verified that the experiment was completed for the M-282 parachute according to the regulation of SAE AS 8015B “Minimum Performance Standard Parachute Assemblies and Components”. An analysis of the influencing factors and quantification of their influence on the uncertainty of the measurement results was also performed. The results of the measurement achieved by using the photo-optical method were compared with the measurement with the electronic variometer FLYTEC 4030. The vertical speed of the M-282 parachute (4.655 m·s−1) defined by the photo-optical method is significantly similar to the vertical speed of the M-282 parachute (4.662 m·s−1) defined by FLYTEC 4030. We can state that the process of identifying the vertical speed of the parachute by the photo-optical method was correct. This is a suitable method of evaluating motion data in the operation of M-282 type parachutes. In the following research for generalization of the methodology, we assume the performance of more than 60 experimental jumps using different types of parachutes, digital sensors (cameras), and a photo-optical method to examine motion data and formulate recommendations for testing, investigative applications, individualized training programs, and aspects of parachuting injury prevention.

УСТАНОВЛЕНИЕ ОГРАНИЧЕНИЙ ПО МАКСИМАЛЬНЫМ СКОРОСТЯМ ДЕСАНТИРОВАНИЯ С УЧЁТОМ ДЕГРАДАЦИИ ПРОЧНОСТНЫХ ХАРАКТЕРИСТИК МАТЕРИАЛОВ КУПОЛА ПАРАШЮТА. СООБЩЕНИЕ 1. ЗАВИСИМОСТЬ ПРОЧНОСТИ ПАРАШЮТОВ ОТ ДЕГРАДАЦИИ ПРОЧНОСТНЫХ ХАРАКТЕРИСТИК КОНСТРУКЦИОННЫХ МАТЕРИАЛОВ

It is introduced the concept of the degradation coefficients of the parachute canopy power structure materials strength characteristics. These coefficients are defined as the ratio of destructive loads after long-term operation or storage to the original, taken at the design stage. It is noted revealed the dependence of safety factors on degradation factors. It was determined the condition of safety factors equality after the long-term operation and during the design stage. It was shown that the ratio of maximum permissible loads is equal to the degradation coefficient. It was defined as the method for calculating the load on the parachute during deployment. It was applied to the simplified approach proposed by N. A. Lobanov. The following statement was determined according to this approach: a dynamic coefficient equal to two, a method for determining the dangerous section of the dome when assessing the fabric strength, the dependence of the speed at the moment of full filling of the parachute canopy from the generalized empirical coefficient. Characteristics of the standard atmosphere, depending on the height of throwing the aircraft are given by approximating functions. The movement of the body until the parachute opens is given in the form of differential equations with known initial conditions. The equation allows you to find the falling speed at the initial moment of the parachute opening, depending on the delay time. It is given the speed of steady free fall without the introduction of a parachute into the work and with a stabilizing parachute, the landing speed with the main parachute. The dependences of the maximum permissible loads on the dome at the opening moment on the strength degradation factors for the fabric of the dome, lines, and free ends of the suspension system are established. It was proposed the correlations for the maximum allowable speed at the time of the beginning of the parachute opening on the requirements of strength. This speed determines the maximum allowed landing speed for a particular type of parachute after long-term operation or storage.

Harness/container assembly for sport parachutes – A new concept

The paper presents a new design concept of the harness/container assembly for sport parachutes. It can be used with reserve parachutes and main parachutes of different volumes. So the assembly will be multifunctional. The container is the subassembly that keeps the main and reserve parachute canopies in a folded condition, together with the suspensions lines, the deployment device and the pilot chute in the reserve and main compartments. The harness, or suspension system, ensures the link between the parachute jumper and the canopies and supports the weight of the parachute jumper. Currently, container parachute manufacturers produce containers whose compartments have a well-defined volume and dedicated to a particular type of parachute with the same volume in folded state. The new concept consists in the design and development of a harness/container assembly with variable volume compartments. Thus it is possible to have a multifunctional container usable with canopies of different volume in a folded state.

A novel algorithm for conceptual design and optimisation of an affordable gliding airdrop platform using TCOMOGA

ABSTRACTUnlike conventional ballistic parachutes, gliding parachutes have been extensively used as guided precision aerial delivery system (GPADS) platforms in recent years. The reasoning may be found in gliding and manoeuvering capabilities, which make this kind of ram-air parachutes superior for precision aerial delivery application. In contrast, wing-shaped configuration along with more design variables create a cumbersome design procedure for this type of parachute. Especially, when an affordable configuration is demanded, the design procedure will be a more important problem. In this respect, an innovative integrated design framework is proposed in which significant design aspects are considered so that the gliding parachute configuration can be optimiseoptimised through a bi-objective optimisation problem to find optimum cost for achievable gliding ranges. To do so, the configuration is defined with minimum required parameters and design space is constrained by performance and stability as significant design requirements to guarantee the feasibility of the solutions in practice. The objective functions are defined in terms of gliding characteristics and amount of materials for fabrication which are representative for maximum reachable stand-off distance and unit cost, respectively. As an effective numerical optimisation method, a niched multi-objective genetic algorithm (MOGA) is used to generate a pareto-optimal set for a specific payload mass whereas constraints are handled through a tournament selection process. Based on results, the provided pareto front can aid the designers in decision-making and trade-off between demanded objectives for a payload weight. The underlying design problem is solved using an all-at-once (AAO) approach and the design loop converges to favourable results in a reasonable time. Finally, as a comparative study, an optimiseoptimised affordable cargo parachute is proposed for the GPADS application in which the material cost is reduced by at least 25% with respect to an available low-cost gliding parachute with the same glide ratio.

Psychophysiological response in parachute jumps, the effect of experience and type of jump

We aimed to analyse the effect of experience and type of parachute jump on the psychophysiological responses of jumpers. We analysed blood oxygen saturation, heart rate, blood glucose, lactate and creatinkinase, leg strength, isometric hand strength, cortical arousal, specific fine motor skills, self-confidence and cognition, and somatic and state anxiety, before and after four different parachute jumps: a sport parachute jump, a manual tactical parachute jump, tandem pilots, and tandem passengers. Independently of the parachute jump, the psychophysiological responses of experienced paratroopers were not affected by the jumps, except for an increase in anaerobic metabolism. Novice parachute jumpers presented a higher psychophysiological stress response than the experienced jumpers, together with a large anticipatory anxiety response before the jump; however, this decreased after the jump, although the high physiological activation was maintained. This information could be used by civil and military paratroopers' instructors to improve their training programmes.

S1910204 超音速パラシュートの非定常連動特性に関する実験的研究

Supersonic parachute are investigated in supersonic wind tunnel. A new type of device for the model support is employed to reduce the aerodynamic interference to the parachute model and compared with typical strut support. There are three types of parachutes which differences are canopy fabric types and trailing distance x/d: Case A is made from nylon fabric and x/d=10; Case B is made from nylon fabric and x/d=5; and Case C is made from elastic polyester fabric and x/d=10. In this research, the elastic polyester has high flexibility than nylon and Case A is treated as the reference case. As a result, the motion of Case C parachute with high flexibility has 35% lower peak frequency and 17% lower amplitude of oscillation than reference case A. Case A has 42% lower peak frequency than pendulum oscillation model because of the external force caused by pressure of outside canopy increasing due to shock/shock interaction between oblique shock wave and bow shock from canopy edge. Comparing Case A (wire support) with strut support, double pendulum oscillation occurs in Case A because constraint condition is unclear at parachute connecting part.

Simulation of Motion Trajectory of Parachute Inflation Process

Motion trajectory is the fundamental basis for the design and research of parachute. The fall state, the minimum safe altitude and airborne site are closely associated with the motion trajectory. Particularly due to rapid changes in these parameters such as canopy shape, velocity, dynamic load of the parachute, it is very difficult to determine the motion trajectory of parachute inflation process. Currently, the trajectory is mainly obtained by airdrop tests or wind tunnel tests. The tests are very expensive. Based on the force analysis and mathematical model of a certain type of parachute, we used the computer system to study the motion trajectory of parachute.

Cytogenetic Analysis of Otiorhynchus bisulcatus (Fabricius, 1781) and O.(Zadrehus) atroapterus (De Geer, 1775) (Coleoptera, Curculionidae, Entiminae) using C Bands, NORs, and DAPI/CMA3 Staining

The structure of the karyotypes of two Otiorhynchus species belonging to separate subgenera, viz. Otiorhynchus s.str. bisulcatus and O. (Zadrehus) atroapterus, is compared and described for the first time. Both species have the same chromosome number (2n = 22), sex chromosome system of an achiasmate parachute type (Xy(p)), symmetric karyotype with the prevalence of metacentrics, similar meiotic behaviour, localization of NORs and positive DAPI signals. The main differences involve the morphology of autosomes and the X chromosome in the C-banding pattern and DAPI/CMA3 signals as well as in the presence of additional B chromosomes.

터보프롭 항공기의 스핀/실속 회복장치 설계

본 논문은 KC-100 소형민항기의 스핀시험을 위해 장착될 스핀회복장치의 설계 및 지상활주 전개 시험에 대해 기술하였다. 스핀회복장치에 대한 상세 설계 단계에서 공력, 구조, 안정성, 조종성 등에 대한 해석적 결과를 토대로 낙하산 단위면적당 라이저 길이, 낙하산 다공성, 낙하산 펼침 시간, 및 전개방법 등의 설계 변수를 결정했다. 본 시스템의 검증을 위해 항공기에 스핀회복장치를 장착한 상태에서 기능점검 후 KC-100 고속활주 중 스핀슈트 전개를 수행했다. This paper deals with Spin/Stall Recovery Parachute System from design to ground taxiing stage which would be deployed on the high speed taxi of turbo-prop airplane. In detail design phase, design parameters- riser length, parachute type, size, porosity, parachute canopy filling time, and deployment method- were considered based on the analytical disciplines such as aerodynamics, structures, and stability & control. Before the installation of Spin/Stall Recovery System of turbo-prop airplane, all control functions of this system were validated by the SBTB(System Breakout Test Box) in the laboratory. SBTB was used to confirm if it can detect faults, and simulate the firing of pyrotechnic devices that control the deployment and jettison of it. Once confirmed normal operation, deployment of parachute on the high speed taxiing were performed.

Double orifice mitral valve with normal function: an echocardiography and MRI study of a rare finding

Double orifice mitral valve (DOMV) is a rare congenital lesion often associated with other abnormalities such as bicuspid aortic valve or aortic coarctation. Also abnormalities of the subvalvular apparatus such as malformation of chordae tendineae (abnormal attachment, parachute type, etc.) and papillary muscles are found frequently. The atrio-ventricular connection consists of two anatomically distinct orifices separated …

Cytotaxonomy and karyology of the tribe Otiorhynchini (Coleoptera: Curculionidae)

A cytogenetic study of bisexual species belonging to the genera Cirrorhynchus, Dodecastichus and Otiorhynchus is presented in order to confirm their taxonomic position. The karyotype characterization was accomplished by an analysis of mitotic and meiotic chromosomes after differential staining, namely by C-banding, silver impregnation, DAPI and CMA3. A review of the cytogenetic data for the tribe Otiorhynchini contributed to knowledge of chromosomal evolution in this group. An investigation of five of the species studied showed some similarities such as a sex chromosome system of "parachute type" (Xyp), the presence of 10 autosomal bivalents (2n = 22) and heterochromatin localized around centromeres. These observations are similar to those already described for Otiorhynchini species, and confirm the karyological conservatism of this weevil group. In contrast, another species Cirrorhynchus kelecsenyi has an additional four autosomal bivalents (n% = 14 + Xyp, 2n = 30), which differs considerably from the chromosomal homogeneity of the other genera. Karyotypic evolution in this species was achieved most probably by increasing the number of chromosomes by centric fissions, resulting in variation in the number of acrocentric chromosomes. DAPI-positive and CMA3-negative reactions of heterochromatic DNA in all the species studied suggest that it has an AT-rich composition. Impregnating chromosomes with silver nitrate reveals NORs on one pair of autosomes, and probably argentophilic material in the interspace between the X and y sex chromosomes. The karyological findings support the taxonomical revision of Otiorhynchini based on morphological characters.

Karyotype differentiation patterns in species of the subfamily Scarabaeinae (Scarabaeidae, Coleoptera)

The aim of this study was to describe the karyotype of species belonging to the subfamily Scarabaeinae (Coleoptera, Scarabaeidae) and to compile the conventional cytogenetic data available in the literature for this group. The karyotypes of ten species belonging to the tribes Canthonini, Coprini, Onthophagini and Phanaeini were analyzed by conventional staining. Eight of these species were described for the first time ( Canthon aff carbonarius, Canthon chalybaeus, Coprophanaeus dardanus, Deltochilum aff amazonicum, Dichotomius geminatus, Oxysternon silenus, Phanaeus chalcomelas and Malagoniella aff astyanax) and two were redescribed ( Diabroctis mimas and Digitonthophagus gazella) since their karyotypes differed from those previously published in the literature. Four species studied showed a diploid number of 2n = 20 and a parachute type sex determining system and the karyotype was 2n = 20,Xy in two species and 2n = 18,Xy p, 2n = 19,X0, 2n = 12,XY and 2n = 14,neoXY in one each. The chromosome morphology of the different species varied, with the observation of metacentric, submetacentric, subacrocentric and acrocentric chromosomes. The X chromosome was predominantly meta or submetacentric in the species analyzed, whereas the y chromosome presented two arms or was punctiform. In conclusion, the subfamily Scarabaeinae comprises 120 species analyzed cytogenetically, and are observed the occurrence of five chromosome rearrangements (autosome–autosome and X-autosome fusions, pericentric inversions, fissions and loss of the y chromosome) that are related to the chromosome variability and evolution in the group.

Decisive Roll of Filling Time on Classification ofParachute Types

In a low altitude recovery, a parachute has to reduce the recovery mass velocity to a predefined velocity before its ground impact within a vertical distance as low as possible. The article classifies various parachutes based on the parachute opening shock and distance necessary to satisfy the steady descent condition in an unreefed situation using numerical solutions of experimental and theoretical relations linked with the parachute opening and flight dynamics. Results show that the parachute filling time is the main parameter to differentiate all parachutes from each other. Based on the parachute filling time, slotted parachutes velocity history coverage locates between ribbon and ringsail parachutes, whereas solid textile parachutes span a range between extended skirt 14.3% and guide surface parachutes. In each group, a decrease in the parachute filling time as a result of the change in the parachute type causes an increase in the parachute opening shock as well as a decrease in the parachute steady distance.

Momentum-Impulse Balance and Parachute Inflation: Fixed Point Drops

A S documented in [1], the momentum–impulse theorem (or “MI theorem”) is a very useful tool for analyzing parachute inflation, given that the duration of the net drag force generated during the inflation process is a well-documented empirical input. In particular, the MI theorem can be used to extend a well-known technique for estimating the maximum drag Fmax to any type of parachute and reefing designs, and to any type of drop conditions. This Note aims at building on the insight gained in [1], by applying the theorem to drops of hemispherical-type canopies from fixed points rather than from aircraft. Such fixed points would not only include cranes and ceilings, but also (slow-moving) lighter-than-air aircraft and even (slow-moving) personnel parachutes. This analysis shall reveal several inflation facts that were previously unknown to the parachute engineering field. The extended Fmax estimator technique is based on the following formula, which uses the a priori knowledge of the opening-shock factor Ck [1–5]

Momentum-Impulse Balance and Parachute Inflation: Clusters

I N a previous publication [1] the momentum-impulse theorem (or MI theorem) was used for estimating the maximum parachute drag forceFmax generated during inflation. This paper showed how to calculate Fmax for any type of parachute, reefing, and drop conditions. The author [2] continued the discussion, this time by applying the theorem to amore specific application, namely to that of hemispherical parachutes dropped from fixed points such as cranes, buildings, or from very slow-moving aircraft. This engineering note continues using the impulse and momentum concepts, this time for the analysis of clusters of hemispherical parachutes dropped from slowor fast aircraft (parachute clusters are built by connecting at least two parachutes side-by-side [3]). As with [1,2], the goal here is to sharpen our understanding of the inflation process in general and of cluster inflation in particular, using new analytical approximations derived from the MI theorem. In some cases, these approximations confirm key knowledge that so far has been acquired only empirically. In other cases, the results suggest altogether new or extended conclusions. The estimator used herein is based on the following formula, which expresses the maximum drag Fmax in terms of the a priori knowledge of the opening-shock factor Ck [1,3–5]:

Experimental Investigation of Three Rotating Parachutes

INCE they were first invented, parachutes have been widely used to lower men and goods to the ground safely, and to decelerate aircraft, race cars, etc. Although new types of parachutes were designed, this mission remained the same for years. During the last decades, new tasks began to be given to parachutes. These tasks are related to controlling the trajectories of their payloads and following complex flight patterns to carry out defined flight requirements. Today, rotating parachutes are a means of introducing dynamic maneuvers to their payloads to follow a predefined flight path and/or traces on the ground. In the design of a rotating parachute-payload system, the appropriate parachute system can be found by studying the aerodynamic properties of rotating parachutes in wind tunnels. While different types of parachutes are designed and studied in a windtunnel[1],thesameparachutecanalsobetestedbychangingits geometrical parameters such as suspension line length and staggering distance [2–6]. Inthisexperimentalstudy,threerotatingparachutesweretestedin a wind tunnel. Each canopy had the same surface area but had a different shape. The affects of the canopy geometry and the physical parameters (suspension line length and staggering distance) on the tangential force coefficient and the spin rate were studied [7]. Because the same size cross canopies and the same canopy fabric materialwereused,thespinrateandtheforcecoefficientresultswere compared with the corresponding results of the experimental studies found in the literature. During the tests, the oscillations of the configurations constructed from their symmetry axes were also observed, and different dynamic behaviors were classified.

Karyotypic characterization of representatives from Melolonthinae (Coleoptera: Scarabaeidae): karyotypic analysis, banding and fluorescent in situ hybridization (FISH).

Meiotic chromosomes of Phyllophaga (Phytalus) vestita, Phyllophaga (Phyllophaga) aff capillata and Lyogenys fuscus (Melolonthinae) were analyzed by conventional staining, C-banding, fluorochromes, silver nitrate and FISH. The three species had a diploid number of 2n=20 and a sex mechanism of the (Xyp; XYp) parachute type. P. (Phytalus) vestita,P. (Phyllophaga) aff capillata and Lyogenys fuscus showed pericentromeric constitutive heterochromatin (CH) in all autosomal bivalents and on X chromosomes. Staining with CMA3 and DAPI fluorochromes showed that the CH of P. (Phytalus) vestita is not specifically rich in AT and GC-base pairs, whereas in P. (Phyllophaga) aff capillata the sex bivalent and one autosomal pair were found to be enriched in GC base pairs with CMA3, and in Lyogenys fuscus CH was positive for DAPI. Silver nitrate staining revealed nucleolar remnants in all three species. However, FISH obtained a precise identification of nucleolar organizing regions with an rDNA 18S and 25S probe. A signal of hybridization was seen in each species, being detected in the X chromosome of P. (Phytalus) vestita and Lyogenys fuscus, and in a small autosomal bivalent of P. (Phyllophaga) aff capillata.

Parachuting: a sport of chance and expense

This paper seeks to determine the cost to the NHS associated with treating parachute-related injuries. More specifically, it compares the training received by civilians to that received by military personnel together with the types of parachutes used or the type of jump. It also reviews the information given to civilian jumpers prior to their first jump. Fifty-three jumpers suffered injuries in the period under review. Of these, 32 cases with 41 injuries were transferred to Accident and Emergency Department for treatment. Injuries involved most of the musculoskeletal system. Twenty-six ( n=32) patients were admitted for treatment, with an average length of hospital stay of 6.8 days. Post-discharge, the length of time lost from work was 42.8 days. The cost to the NHS was calculated at £4026.50 per patient treated. This did not include time lost from work, subsequent follow up or any other secondary procedures. Civilian parachute jumpers were trained for 6.5 h compared to 31.5 h for military personnel. Twenty-seven patients used rectangular rather than circular parachutes. Thirty of the 41 injuries occurred during static line jumps, with 7 occurring during tandem jumps and only 5 during free-fall jumps. Twenty-three of the 32 jumpers sustained the injury during their first jump. First-time civilian jumpers were given a minimum of information regarding risks and injuries prior to their jump and were inadequately insured against potential injuries. The cost of caring for these patients is substantial when compared to the money that is raised for charity during some of the jumps. Private insurance, with the NHS legally able to claim expenses would help to offset these medical costs. It is also possible that by increasing civilian training, there may be a reduction in the number of injuries sustained by first-time civilian jumpers from 1.1 to 1.2% (11% in charity jumps) to the military figures of 0.22–0.89%.