Fact-checked by Grok 2 weeks ago

Parachute landing fall

The parachute landing fall (PLF) is a fundamental technique used by parachutists to safely absorb the impact of landing during a parachute descent by distributing the force across five sequential points of contact on the body: the balls of the feet, calves, thighs, buttocks, and pull-up muscle on the side of the back.^[1] Executed with feet and knees locked together and slightly bent, the jumper maintains a tight body position—chin tucked to chest, elbows drawn in, and head facing the horizon—before initiating a controlled roll upon ground contact to prevent injury from concentrated force on the lower extremities.^[2] This method, which adjusts for wind drift through side, front, or rear variations, ensures rapid recovery and mobility after landing in both military and civilian contexts.^[3] Developed for military paratroopers to mitigate risks during static-line and free-fall jumps, the PLF is a core safety protocol emphasized in official training manuals, where it addresses normal descents as well as emergencies like entanglements, tree or wire contacts, shallow water landings, and off-field terrain.^[1] In sport skydiving, it is integrated into canopy control procedures, requiring jumpers to flare properly at 10-15 feet above ground before committing to the fall, particularly in scenarios such as canopy collisions or low-turn recoveries.^[4] The technique's purpose is to spread impact over fleshy body areas, reducing sprains, fractures, and other injuries that commonly result from improper execution, which accounts for the majority of jump-related harm.^[2] Training for the PLF occurs within 24 hours of jumps through sustained airborne programs, utilizing mock doors, two-foot platforms, and swing landing trainers to simulate impacts and ensure proficiency in all directional rolls under jumpmaster supervision.^[1] Jumpers must demonstrate at least one satisfactory PLF in each of four directions (left side, right side, front, rear) before qualifying, with equipment like body armor and helmets adjusted to avoid obstructing contact points.^[3] Standing landings are strictly prohibited, as the PLF enables quick canopy release and assembly, enhancing operational effectiveness in tactical environments or competitive skydiving events.^[4]

Overview

Definition and Purpose

The parachute landing fall (PLF) is a standardized safety technique employed by parachutists to execute a controlled roll upon ground contact, thereby distributing impact forces across multiple body parts including the balls of the feet, calves, thighs, hips, and shoulders.^[5] This method originated from U.S. military parachuting protocols during the early development of airborne operations in the early 1940s, where it was formalized to enable safe descents under combat conditions.^[6] The primary purpose of the PLF is to minimize the risk of injury during landings from typical vertical descent speeds of 15 to 20 feet per second (4.6 to 6.1 m/s), achieved by converting the parachutist's linear momentum into rotational energy and avoiding concentrated forces on the lower extremities or torso.^[7] This technique was specifically developed to counteract the high rates of lower extremity fractures and sprains observed in early 20th-century parachuting, when rigid upright landings from balloon jumps and rudimentary aircraft drops frequently resulted in severe injuries due to unmitigated impact forces.^[8] In contemporary applications, the PLF remains essential across various parachuting contexts, including military static-line deployments, sport skydiving, and tactical operations, evolving from its origins in balloon-era descents to support modern ram-air parachute systems that maintain similar landing velocities.^[9]

Historical Development

The parachute landing fall (PLF) technique originated in the early 20th century amid the nascent development of military parachuting during World War I, when parachutes were primarily employed for emergency escapes from observation balloons and early fixed-wing aircraft. Initial landing methods were rudimentary, often relying on attempts to absorb impact by standing upright or using basic rolling motions to mitigate injury upon ground contact, as parachutes of the era provided limited control and descent rates around 20 feet per second. These early practices were informed by trial-and-error experiences in military aviation units, where high injury rates from hard landings prompted informal adaptations borrowed from existing physical training disciplines.^[10]^[11] A key milestone occurred in the early 1940s during World War II, when the PLF was formalized as standard doctrine by the U.S. Army's Airborne Command to address injury risks in mass paratrooper jumps, reducing lower extremity fractures and sprains by distributing impact forces across the body. This technique was rapidly implemented worldwide among Allied forces, including European militaries, lowering overall landing injury rates from approximately 21-24 per 1,000 jumps to 6 per 1,000 jumps through mandatory training. The U.S. Army's Parachute Test Platoon, established in 1940, played a pivotal role in refining and validating the PLF amid the expansion of airborne operations.^[12]^[6]^[11] Following World War II, the PLF was adopted by civilian skydiving organizations as sport parachutists transitioned from surplus military equipment. Refinements in the 1970s and 1980s addressed wind drift and higher forward speeds associated with emerging ram-air canopies in recreational jumping, emphasizing variations for off-heading or bumpy landings. By the 1990s, the technique was integrated into NATO and international military manuals as a core element of static-line parachuting protocols. In the 2020s, updates driven by injury report analyses have focused on adapting the PLF for tandem operations and high-performance landings under modern canopies, aiming to further minimize risks in diverse conditions.^[13]^[12]

Biomechanics

Impact Absorption

The impact of a parachute landing involves dissipating the kinetic energy (KE) acquired during descent, calculated as KE = \frac{1}{2} m v^2, where m is the parachutist's mass, typically 80-100 kg including gear, and v is the descent velocity, ranging from 4.6 to 6.9 m/s for standard military parachutes like the T-10B.^[14]^[15] Without proper technique, this energy dissipates over a short contact time in a rigid upright landing, resulting in extreme peak forces. The parachute landing fall (PLF) extends this absorption period to approximately 0.1-0.13 seconds by distributing the impact sequentially across multiple body segments, thereby reducing peak ground reaction forces (GRF) from 10-18 times body weight in suboptimal landings to 4-7 times body weight in an optimal PLF.^[14]^[16] Energy absorption in the PLF begins with initial contact at the balls of the feet, oriented at a 45-degree angle to the direction of travel to initiate body rotation, followed by sequential transfer to the calf, thigh, hip, and finally the shoulder via the latissimus dorsi muscle.^[14] This progression allows eccentric muscle contractions and joint flexion to convert linear kinetic energy into deformation and heat, increasing the time over which deceleration occurs and lowering the rate of force application. Rotational dynamics play a critical role, as the roll transforms vertical momentum into angular momentum, with the body functioning as a lever arm; friction between clothing, ground, and body surfaces further dissipates rotational energy without significant rebound, as evidenced by measured joint torques up to 12,000 Nm during the maneuver.^[14]^[16] An optimal PLF can reduce average deceleration from up to 17 g (observed in peak accelerations during high-velocity impacts) to 4-7 g, based on military drop test analyses that correlate extended absorption phases with lower injury risk.^[15] In varied environments, such as water landings where buoyancy aids initial deceleration or soft surfaces providing compressive absorption, the core principle of redirecting energy vectors through rotation and sequential contact remains consistent, though peak forces may decrease further due to environmental compliance.^[14]

Injury Prevention

Without proper technique, parachute landings pose significant risks to the lower extremities and spine, with ankle sprains and fractures accounting for 37% to 80% of injuries in military paratroopers. Knee ligament tears and compression fractures of the thoracolumbar spine also frequently occur due to axial loading, representing up to 17% of cases in static-line jumps. In less experienced or untrained landings, such as those during basic training, injury rates can reach 19.7 per 1,000 jumps, far exceeding the 1.5 to 3.8 per 1,000 observed in more seasoned operations. The parachute landing fall (PLF) mitigates these risks by distributing impact forces across multiple body points rather than concentrating them on vulnerable joints like the ankle (talocrural), thereby reducing the likelihood of ligament damage and excessive joint loading. This technique preserves structural integrity in the lower extremities and minimizes secondary risks, such as concussions from uncontrolled head movement during impact. U.S. military data indicate that adherence to PLF has historically reduced overall injury rates by approximately 85%, from 120 injuries per 1,000 trainees pre-PLF to 18 per 1,000 post-implementation, with non-compliance contributing to 71% to 87% of incidents in modern jumps. Anatomically, the PLF engages robust muscle groups including the quadriceps and glutes during thigh and hip contact, alongside bony prominences like the calf and hip, to dissipate energy and limit soft tissue trauma. This sequential absorption protects delicate structures in the knee and ankle while leveraging the latissimus dorsi in the final roll phase. Gender differences influence outcomes, with females experiencing higher injury risks—particularly lower extremity fractures—often linked to improper PLF execution rather than environmental hazards, potentially exacerbated by lower average muscle mass; emphasis on technique training addresses this disparity. Repeated PLFs, while protective acutely, contribute to long-term cumulative wear on the hips, shoulders, and lower back through overuse mechanisms, leading to chronic strains and reduced operational readiness. Preventive measures include specialized gear such as parachute ankle braces, which cut ankle injury rates by about 50%.^[17] Recent analyses highlight environmental factors, with high winds exceeding 10-15 knots increasing the risk of lower extremity injuries through disrupted landing control, underscoring the need for wind-aware protocols.^[18] As of 2024, parachuting remains a leading cause of severe injuries in military special operations forces.^[19]

Technique

Preparation and Approach

The preparation and approach phase of the parachute landing fall (PLF) begins under canopy during the final descent, typically initiating at altitudes between 1,000 and 300 feet above ground level (AGL), where skydivers establish a stable position to ensure controlled energy management leading into touchdown.^[20] In this aerial preparation, for steerable ram-air canopies used in sport skydiving, the jumper maintains a neutral body position with feet and knees together and knees slightly bent, arms positioned for steering via toggles or risers, and head up to monitor the horizon and canopy.^[20] This configuration, oriented facing the wind direction, promotes canopy stability and prevents excessive drift, with separation of at least 50 feet from other jumpers to avoid collisions. For military static-line jumps using non-steerable canopies like the T-11 or MC-6, preparation includes a post-deployment count to 6,000 (fixed-wing) or 8,000 (rotary-wing) for the T-11, or 4,000 for the MC-6, to confirm opening, followed by a 360-degree canopy check to remove twists via a bicycling leg motion if needed.^[21] The flare technique is executed 2-3 seconds before anticipated touchdown, typically at one body height above ground during the final approach leg starting at 300 feet AGL, to decelerate vertical descent speed from approximately 1,200 feet per minute to near zero while reducing forward airspeed from a full-glide rate of about 20 miles per hour to 10-15 miles per hour through progressive toggle or riser deployment.^[20] This involves initially pulling toggles to half brakes at twice the height of the jumper above ground for a controlled glide, then a full flare with hands driven forcefully to the chest just prior to contact, achieving an optimal 45-degree angle of the feet to the ground for initial impact distribution.^[20] In military contexts with non-steerable canopies like the T-11, the equivalent adjustment is a two-riser slip into the wind at around 200 feet AGL to align descent without toggles.^[21] Environmental assessment is integral throughout the approach, with jumpers scanning for obstacles such as power lines, trees, or buildings every 500 feet below 500 feet AGL, prioritizing clear areas and planning alternate landing patterns if off-target by 2,000 feet.^[20] Adjustments for wind involve facing into gusts of 5-10 miles per hour (not exceeding 13 knots surface wind for static-line operations) by turning or slipping the canopy at 100-250 feet AGL, maintaining a predictable rectangular pattern: downwind leg at 1,000 feet, base leg at 600 feet, and final into the wind.^[20] In tandem jumps, the instructor signals readiness with a verbal cue such as "feet and knees," prompting the student to assume the PLF stance.^[9] Body alignment emphasizes relaxation to avoid tensing, with muscles loosened in the legs and torso; the chin is tucked to the chest, with eyes on the horizon until ground contact. Elbows are kept tight to the sides, hands positioned on risers or toggles at eye level, and the lower body prepared for a 45-degree rotation toward the landing direction. In military static-line jumps, preparation incorporates a structured countdown following the "STAND BY" command, during which jumpers perform final equipment checks to verify harness symmetry, static line routing, and securement of gear like rucksacks or weapons via the jumpmaster personnel inspection (JMPI). This ensures even weight distribution and prevents twists, with jumpers maintaining feet together, knees locked rearward, and body bent slightly forward from the exit through descent.^[1]

Execution Steps

The parachute landing fall (PLF) commences upon ground contact, with the parachutist striking the balls of the feet first while keeping the knees slightly flexed to absorb the initial shock through the ankles and legs. The feet and knees remain together, and the body's forward momentum from drift carries it diagonally across the landing surface.^[22]^[21] As contact is made, the parachutist simultaneously lowers the chin to the chest, tenses the neck muscles, and begins the roll progression by pivoting over the outside of the lead foot. The body then rolls continuously across the calf, thigh, hip, and buttocks of the weighted leg, transitioning to the opposite shoulder blade or pull-up muscle (the side of the back), distributing the impact across five points of contact in a near-straight line. This sequence ensures even weight distribution across the body, preventing excessive load on any single area. The entire roll occurs in a fluid, rapid motion upon touchdown.^[22]^[21] During the roll, the elbows remain tucked tight to the sides to protect the torso, with arms bent at the elbows and hands positioned near the shoulders, palms facing down in an open position to slap the ground and cushion the final phase. The head is turned away from the direction of fall, maintaining eye contact with the horizon until contact before tucking to avoid whiplash or direct impact.^[22]^[21] The PLF concludes with the parachutist ending in a prone position on the back or side, facing the direction of travel, ready to immediately activate one canopy release assembly using the hand-to-shoulder or hand-assist method to disconnect the harness and prevent further drag from the canopy. Adaptations to the technique account for surface conditions, such as a slightly slower roll on soft grass compared to firmer sand, while maintaining the core sequence. In standard military practice, a left-side roll is preferred for right-handed steering to align with typical drift, though right-side variations are used based on wind direction, equipment, or personal preference.^[22]^[21]

Training and Practice

Instructional Methods

Instructional methods for the parachute landing fall (PLF) emphasize progressive skill-building through structured ground-based drills, simulator sessions, in-air practice, and adherence to certification standards. These approaches ensure trainees develop the reflex to absorb impact across the five points of contact—balls of the feet, calf, thigh, buttocks, and pull-up muscle—while minimizing injury risk during landings.^[22] Ground-based drills form the foundation of PLF training, beginning with judo-style rolls on padded surfaces such as mats or 12-inch-deep sawdust pits to simulate controlled falls and teach body positioning. Trainees start in a kneeling or seated position, practicing forward, side, and rear rolls to distribute impact force, then progress to standing drops from a two-foot-high platform under instructor supervision. Feedback is provided through immediate verbal critiques from instructors, focusing on corrections for errors like feet apart or incomplete rolls, with visual aids such as demonstrations ensuring proper form.^[22]^[2] Simulator training builds on ground drills by replicating descent and landing dynamics, often using drop towers or mock-door setups for 20-30 repetitions per session to achieve proficiency before live jumps. In military contexts, such as with the 82nd Airborne Division, trainees practice exits from mock aircraft doors during sustained airborne training, integrating PLF execution upon simulated touchdown. Vertical wind tunnels, approved by the United States Parachute Association (USPA), support body position awareness but are primarily for freefall; emerging virtual reality systems like PARASIM provide immersive parachute control and landing simulations with realistic physics.^[2]^[23]^[24]^[25] In-air integration occurs during supervised jumps, where tandem instructors guide students with verbal cues such as "flare" to initiate canopy deceleration, followed by PLF execution upon touchdown. Post-jump debriefs incorporate video analysis to review timing and technique, allowing trainees to refine responses to variables like wind or terrain.^[20] USPA certification standards for the Accelerated Freefall (AFF) program require demonstration of safe landings, including PLF execution, under supervision in Level 1, with two instructors monitoring freefall and landing until proficiency is shown. International standards from the Fédération Aéronautique Internationale (FAI) incorporate variations such as water landing practice, emphasizing PLF adaptation to surfaces like shallow water alongside standard grass drop zones.^[20]^[26]^[27]

Common Errors and Corrections

One of the most frequent errors in executing the parachute landing fall (PLF) is the stiff-legged landing, where the knees remain straight upon impact, concentrating force on the lower extremities and leading to sprains or fractures in the ankles, feet, and legs, which are among the most common acute injuries in military parachuting.^[18] This improper technique arises from anticipation or rigid posture and accounts for a significant portion of lower limb injuries during basic airborne training.^[21] To correct this, trainees emphasize a slight knee bend of less than 45 degrees in the landing attitude during drills on two-foot platforms or swing landing trainers, building muscle memory through repeated practice to ensure progressive absorption across the five points of contact: balls of the feet, calves, thighs, buttocks, and latissimus dorsi.^[16]^[22] Improper roll direction, such as facing backward or sideways relative to the drift, often results from poor body alignment or wind misjudgment, causing torso twists or uneven impact distribution that heightens the risk of spinal or soft tissue injuries.^[18] This error fails to utilize the full body roll, leading to concentrated shock on fewer contact points. Corrections involve practicing directional PLFs in all four orientations (left, right, front, rear) using lateral drift apparatuses to simulate wind conditions, with jumpmasters providing cues for a 10-degree forward lean into the wind to maintain orientation.^[21]^[22] Arm extension during contact, where hands or elbows flare out instead of staying tucked, frequently causes wrist fractures or shoulder dislocations by exposing joints to direct force, contributing to upper body injuries such as wrist fractures or shoulder dislocations among trainees.^[28] This defensive reaction stems from hesitation or leaning forward. Targeted corrections include tuck drills on padded platforms, reinforcing an elbow-in position with arms close to the sides and forearms rotated for protection, often using mock door training to habituate the motion.^[21]^[22] Tensing the entire body on contact amplifies force transmission through rigid muscles, exacerbating injury risk by resisting the natural roll and increasing peak ground reaction forces on joints.^[18] While moderate tension in the neck and legs aids control, overall rigidity from anticipation undermines absorption. Corrections incorporate relaxation breathing exercises prior to the flare—such as deep inhalations to maintain a soft-but-springy posture—combined with progressive drop heights in tower training to foster fluid execution.^[29]^[22] As of 2024, USPA reports indicate landing-related incidents, often involving poor technique, accounted for 48.1% of non-fatal skydiving incidents.^[13] Military training reports from 2020-2024 indicate that a significant portion of training accidents occur in high-risk airborne operations, with fatigue contributing to lapses in technique like improper body positioning. Studies on load carriage suggest fatigue-specific training, such as repeated PLF drills under simulated loads, can improve endurance and reduce injury risk.^[30]^[31]

References

[1]
https://www.marines.mil/Portals/1/MCWP%203-15.7.pdf
[2]
[PDF] *TC 3-21.220 (TC 3-21.220/MCWP 3-15.7/ AFMAN 11-420/NAVSEA ...
Oct 24, 2018 · ... Parachute ... Landing Fall Devices ................................................................................ 4-1. Mock Door Training ...
[3]
None
### Summary of Parachute Landing Fall (PLF) from T-11 Pre-Jump Study Guide
[4]
Chapter 4 - United States Parachute Association
Recommended techniques include pulling in the less-inflated canopy, hand over hand, to contain it, or pumping the brakes or rear risers of both parachutes to ...
[5]
Glossary - United States Parachute Association
PARACHUTE LANDING FALL (PLF) A method developed by the U.S. military to minimize the chance of injury from a hard landing under parachute. The jumper ...
[6]
[PDF] Lower Extremity Assistance for Parachutist (LEAP) Program - DTIC
The landing technique taught to parachutists in the Army is the parachute landing fall. The idea behind the PLF is to reduce impact forces and injuries by ...
[7]
[PDF] AN ANALYSIS OF THE U.S. ARMY'S T-11 ADVANCED TACTICAL ...
Dec 12, 2016 · Parachute Landing Fall (PLF). A ... attainable ROD, changing it to 18 feet per second (Threshold) and 16 feet per second. (Objective).
[8]
United States Military Parachute Injuries. Part 1 - PubMed
This article traces the early history of military airborne operations and examines studies that have provided overall incidences of parachute-related injuries ...
[9]
Category A (Arch) - United States Parachute Association
Parachute Landing Fall (PLF). Performing a PLF can help you reduce the risk of injury during landing by distributing the impact across five points of your body.
[10]
U.S. Military History: Parachutes in the Armed Forces
Aug 10, 2020 · The history of parachute use in the military dates back to World War I when they were used as a means of escape from various aircraft and observation balloons.
[11]
The jump that changed US warfare history | Article - Army.mil
Aug 15, 2025 · Paratroopers today learn their craft in the Basic Airborne Course at Fort Benning, Georgia, where Soldiers leapt into history 85 years ago. On ...
[12]
[PDF] Military Paratrooper Injuries: Current Evidence and Data Gaps - DTIC
The findings of this review reflect studies conducted long after worldwide implementation of the parachute landing fall (PLF) in the 1940s (Bricknell 1999 ...
[13]
Risk Factors for Injuries During Military Static-Line Airborne Operations
Proper landing procedures consist of executing a parachute landing fall (PLF). Since the early 1940s, the United States and many European paratroopers have ...Missing: origin | Show results with:origin
[14]
Skydiving Then and Now—50 Years of Change
Jul 1, 2019 · By 1969, after 50 years of freefall parachuting, skydiving had come into its own. Now, 50 years after that, the changes have been equally pronounced.Missing: 1950s | Show results with:1950s
[15]
The 2024 Non-Fatal Incident Summary Part One: Landing Incidents
Jun 8, 2025 · These usually involve a jumper initiating a high-performance turn at an altitude too low for the parachute to return to straight-and-level ...Missing: 2020s | Show results with:2020s
[16]
Parachute landing fall characteristics at three realistic vertical ...
Results: Most biomechanical variables characterizing PLF technique were significantly affected by descent velocity. For example, at the fast velocity, the ...
[17]
Kinetics Study in Parachute Landing Fall Technique by Comparing ...
This paper discusses the torque data during Parachute Landing Fall (PLF) activity on the sagittal plane by applying Kane's method.
[18]
[PDF] USPA SKYDIVER'S INFORMA TION MANUAL
The manual provides basic skydiving standards and recommendations for safe skydiving, and describes USPA programs. Compliance with Basic Safety Requirements is ...Missing: 1950s | Show results with:1950s
[19]
None
Below is a merged summary of the Parachute Landing Fall (PLF) from MCWP 3-15.7, consolidating all provided segments into a single, comprehensive response. To retain all details efficiently, I’ve organized key information into a table format where appropriate, followed by a narrative summary that integrates additional context and details not suited for tabular representation. The response avoids exceeding any token limits by focusing on clarity and conciseness while preserving all critical information.
[20]
None
Below is a merged summary of the Parachute Landing Fall (PLF) execution steps from TC 3-21.220, consolidating all information from the provided segments into a comprehensive response. To retain maximum detail and ensure clarity, I will use a table in CSV format for key execution steps, followed by additional details in narrative form. This approach allows for a dense representation of the data while maintaining readability.
[21]
[PDF] Safe Falling Techniques (ukemi) during the Eight-Week Judo-Based ...
• Side-falls & side-rolls from standing on soft landing or Judo mat. • Standing backward break-falls onto the Judo mat. • Side-rolls & roll diagonally forward ...
[22]
Building Mock Doors [Image 15 of 27] - DVIDS
Mar 2, 2021 · 82nd Airborne Division ... The mock doors allow Paratroopers to practice exiting an aircraft during Sustained Airborne Training.
[23]
United States Parachute Association > Experienced Skydivers > SIM ...
Any USPA member conducting a tandem jump must have successfully completed a tandem instructor course conducted by the manufacturer of the tandem parachute ...Missing: 1950s PLF<|control11|><|separator|>
[24]
PARASIM: VR Parachute Simulator & Training Systems
PARASIM is a VR parachute simulator for safe, cost-effective training, recreating real jumps with VR, physics, and realistic controls. It's used by military ...Missing: apps PLF feedback
[25]
https://parasim.com/
[26]
[PDF] FAI Sporting Code Section 5 – Skydiving Class G
(1) PARACHUTE JUMP: A parachute jump is a skydive by a person from an aircraft, an aeroplane or a spacecraft with the intention of using a parachute for the ...Missing: PLF water urban
[27]
Water Training for Skydiving
Jul 7, 2021 · An online course for the ground portion of water training for skydivers taught by professional skydiver, S&TA, USPA Instructor, and National Director, Melissa ...
[28]
None
### Summary of Parachute Injuries (https://ph.health.mil/PHC%20Resource%20Library/cphe-ip-parachute-injuries-factsheet.pdf)
[29]
https://wnyskydiving.com/blog/execute-perfect-parachute-landing-fall/
[30]
How to Execute a Perfect Parachute Landing Fall - WNY Skydiving
Mar 2, 2018 · What is a Parachute Landing Fall (PLF) in skydiving, when to use it, and what's the perfect technique? Learn from the pros at WNY Skydiving.Missing: guide | Show results with:guide
[31]
GAO-25-108104, MILITARY READINESS
Mar 12, 2025 · [10] About 40 percent of the total reported training accidents occurred in two high-risk training areas, parachute training, and combat dive ...
[32]
The Effects of Load Carriage and Muscle Fatigue on Lower ...
Aug 10, 2025 · Load carriage and muscular fatigue are major stressors during military basic training. To examine effects of load carriage and muscular ...