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Post by parajag on Mar 29, 2017 11:24:55 GMT -8
As a WWII reenactor, you may be interested in learning to jump with a round parachute, and jumping with RCPT-USA at one of our events. We jump at air shows as part of WWII demonstrations, or in Europe on historical drop zones at the anniversary events in Normandy and Holland. We also conduct training events throughout the year to maintain parachutist and Jumpmaster proficiency and currency. The purpose of this thread is to provide information concerning the parachutes used by RCPT-USA for round parachute WWII demonstration and sport jumping.* (*The information provided here does not apply to the modified parachutes used by the WWII Airborne Demonstration Team.) You may ask, if I attend one of these events do I have to jump with a WWII parachute? Do I need to use a special parachute to make a static line parachute jump from a C-47? The answer to both questions is emphatically “no.” The parachutes we use are standard US military parachutes. We do not modify any of our parachutes for WWII-style jumping. (While the FAA regulations might permit you to attach a WWII era T-5 or T-7 canopy to a modern harness and jump it, that is something I would strongly discourage.) The RCPT-USA Airborne Standing Operating Procedures (ASOP) prohibit any modifications to a parachute, unless in accordance with military, FAA, or manufacturer’s instructions. The round parachutes listed here are maneuverable. Steering is accomplished with a set of toggles. Pulling the left toggle down turns the canopy to the left. Pulling the right toggle down turns the canopy to the right. Maneuvering the canopy allows you to select a better landing spot and avoid obstacles. You will also face the canopy into the wind when landing to reduce landing speed. Other troop parachutes, such as those used in WWII, the T-10 (used by the US military from the early 1950s until recently) and the current T-11 Advanced Tactical Parachute System (ATPS), are non-steerable. We do not use non-steerable parachutes for demonstration jumps.  |
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Post by parajag on Mar 29, 2017 11:25:55 GMT -8
MC1-1B/C/D  The MC-1 series is the round parachute most often used by WWII demonstration jumpers, although it is quickly being replaced by the SF-10A, below. The main parachute is a 35-ft nominal diameter canopy. A “T-U” modification to the canopy provides forward drive and maneuverability. Pulling on the toggles closes the modifications, making the parachute turn. The MC-1 series parachute is worn on the T-10 series harness assembly. The T-10 series harness is the legacy parachute harness that was used with the T-10 parachute (the legacy model non-steerable round parachute). The MC-1 series is likewise a legacy model parachute, but is still in service with some USAF units. The MC-1 series parachutes have been replaced by the MC-6 (below).  T-10 harness.  T-10 pack tray. The canopy has 30 gores and suspension lines. The average rate of descent for the MC1-1C at sea level is 18 fps. The canopy will make a 360 degree turn in 8 seconds. It has a maximum suspended weight capacity of 360 lbs. The canopy is available in 4 variants: MC1-1B, MC1-1C, MC1-1D and MC1-1E. The MC1-1B “Bravo” is constructed of the same ripstop nylon parachute cloth as a T-10. The “Bravo” has a much faster rate of descent and should only be used by someone with a low body weight. The MC1-1C “Charlie” is constructed of low porosity material. The MC1-1D incorporates the Universal Static Line and Universal Static Line snap hook (below). All models have an anti-inversion net. The anti-inversion net is sewn 18 inches down on each suspension line and is made of 3 3/4-inch square mesh, knotless, braided nylon. The anti-inversion net reduces the chance of an inversion malfunction (Mae West).  |
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Post by parajag on Mar 29, 2017 11:26:47 GMT -8
MC-6/SF-10A  The SF-10A canopy is currently in use with the US Army as part of the MC-6 parachute system. It has a 32-foot nominal diameter canopy, with 28 gores and 28 suspension lines. The parachute was first used by US Forest Service smoke jumpers who needed a parachute that could make accurate landings and performed better at high altitudes. It was selected as an off the shelf replacement for the MC-1, and designated the SF (“Special Forces”) 10. The difference between the SF-10A and the MC-1 is that instead of the “T-U” modifications, the SF-10A has “extended gores” located on gores 4-5, 6-7, 21-22 and 23-24. Pulling the toggles closes the gores on that side, redirecting the air flow, and making the parachute turn. The SF-10A is also capable of reverse flight, if the toggles are pulled all the way down. The SF-10A is used on the T-10 series harness, and is compatible with the T-10R, MIRPS or MIRPS-SLCP reserve parachutes. It is also used on the T-11 harness, with the T-11 Reserve as part of the MC-6 parachute system. It also features an anti-inversion net sewn to the bottom of the lower lateral band. Innovatively, the suspension lines are attached with a girth hitch to loops on the anti-inversion net, which allows them to be easily replaced without sewing. If you buy a “demilitarized” SF-10A canopy with the lines cut, replacing the lines is a very easy job for a rigger. The SF-10A parachute has demonstrated many superior performance characteristics over and above the MC1-1C. As part of the MC-6 Parachute System the SF-10A has for the most part replaced all the MC-1 steerable troop parachutes in the U.S. military. There are still a few USAF units which use the MC1-1D. The SF-10A is fast becoming the parachute most favored by round parachute and WWII demonstration jumpers. I started jumping with the SF-10A in 2014, and have used it ever since. The SF-10A has a higher turn-rate and greater forward velocity. The canopy is constructed of low permeability nylon parachute cloth, like the MC1-1C. It has a rate of descent of between 14.5 to 18.5 feet per second, depending the jumper’s weight, which is slower than the MC1-C. The canopy has a forward speed of 10 knots and can complete a 360-degre turn in 5 seconds. The slower rate of descent, greater forward drive, and faster turn, allow you to get to a better landing spot in the event of a bad drop. Six opening vents located on the front canopy gores prevent the front of the canopy from collapsing, improving the forward drive and maintaining the rigidity of the canopy. It doesn’t dump air out of the T-U modifications like the MC-1 and it has a much gentler landing. I can’t say enough good things about the SF-10A and prefer it over any other round canopy. I also have an MC-6 parachute, with a T-11 harness and reserve. The T-11 harness has some improvements over the T-10 harness. It has two more points of adjustment, which are main lift web adjusters that allow sizing of the harness to someone who is very large (and to allow the harness to be worn over body armor if necessary). The reserve “D” rings sit higher on the body, and allow the force of the reserve parachute opening to be distributed along the long axis of the body, rather than at the waist like the T-10R. The T-11 Reserve has several improvements, including a better performing canopy and risers, which allow you to slip or control the reserve canopy. The pack tray of the MC-6 (and T-11 main) closes with a curved pin rather than a pack closing tie. There are only a few MC-6 parachutes on the civilian market. A T-11 qualified Jumpmaster must do the pre-jump equipment inspection (JMPI). I use the MC-6 for training jumps, but not air shows.   MC-6 parachute, with T-11 Reserve.  Main curved pin.  |
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Post by parajag on Mar 29, 2017 11:27:43 GMT -8
OTHER MAIN PARACHUTE COMPONENTS The common components to the MC-1, SF-10A and MC-6 parachutes are the deployment bag and static line. The RCPT-USA ASOP requires the Universal Static Line and Universal Static Line Snap Hook. The Universal Static Line Snap Hook has a dual spring opening gate. The legacy model snap hook is the one that looks like a WWII snap hook with the sliding sleeve and button. A 5-foot extension is required when jumping from a C-47 to prevent the parachute from fouling on the tail wheel. In the military, the 5-foot extension is used when jumping from the C-17. The Universal Static Line attaches to both the Universal Static Line Snap Hook and deployment bag with a girth hitch. The legacy model static line requires a different type of extension that has a metal ring and cotton duck cloth cover that is more difficult to attach and must be taped over. Thus, the Universal Static Line Extension is much easier to take on and off the static line. The static line for the MC-6 which has a main curved pin instead of a pack opening loop is called the Universal Static Line Modified. Deployment bag and Universal Static Line.  The parachute suspension lines are stowed across the deployment bag in a set of static line stow loops. The last two line stows are routed through two locking stows that close the mouth of the bag. A cotton suspension line protective cover prevents nylon to nylon contact between the suspension lines and the pack tray. The cover is secured by two break cord ties to the connector links and connector link tie loops. Line stows on deployment bag.  |
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Post by parajag on Mar 29, 2017 11:29:25 GMT -8
SEQUENCE OF OPERATION OF ALL PARACHUTES The parachute deployment sequence is the same for both the MC-1 series and SF-10A main parachutes: 1. The parachutist falls to the end of the static line. His body weight breaks the pack closing tie, and the deployment bag is pulled from the pack tray. 2. Two connector link ties break, and the suspension lines are pulled from the deployment bag. 3. Two suspension line locking stow loops disengage, and the canopy is pulled from the deployment bag to its full length. 4. The break cord tie securing the apex of the canopy to the static line buffer loop breaks, and the parachute begins to inflate, retarding the parachutist’s rate of descent. The deployment sequence of the MC-6 parachute is as follows: 1. The parachutist falls to the end of the static line. The jumper’s body weight snatches the curved pin from the pack-closing loop, and the deployment bag is pulled from the pack tray. 2. Two connector link ties break, and the suspension lines are pulled from the deployment bag. 3. Two locking stows disengage, and the canopy is pulled from the deployment bag to its full length. 4. The break cord tie securing the apex of the canopy to the static line ending loop breaks, and the parachute begins to inflate, retarding the parachutist’s rate of descent. All the US military static line parachutes use the above “direct bag” method of static line parachute deployment. The direct bag is a more positive method of static-line deployment because it reduces the chance of the jumper interfering with the main canopy deployment. These parachutes are intended to be used at low altitude. Our training jumps are at 1,250-1,500 feet. At an air show or demo jump in Europe, we may jump at 1,000 feet. In wartime, the minimum jump altitude for these parachutes would be 475 feet. It is therefore important that the deployment system be reliable. Video of the MC-1/SF-10A deployment sequence. www.youtube.com/watch?v=ccWAELRahpc&t=66s |
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Post by parajag on Mar 29, 2017 11:30:30 GMT -8
RESERVE PARACHUTES MIRPS-SLCP The Modified Improved Reserve Parachute System - Soft Loop Center Pull (MIRPS-SLCP), is the second major improvement to the former T-10 reserve parachute. The MIRPS-SLCP is chest mounted, manually operated, and loaf-shaped when packed.  The T-10 Reserve with the side-pull ripcord grip was the previous model reserve parachute, which looked like the T-5 reserve parachute used in WWII. The T-10 Reserve had some obvious limitations. In order to activate the T-10R during a partial malfunction you had to open the container, grasp as much canopy as possible and throw it away from your body or in the direction of the spin in order to get it outside the line cone of the malfunctioning main parachute. Not an ideal situation. The first MIRPS (side pull model) added a pilot chute, which assists in deployment of the reserve parachute canopy by serving as an air anchor. It is a 5-foot, flat, circular parachute with a bridle line and is constructed from zero porosity nylon parachute cloth and marquisette netting on the bottom half. It has no suspension lines and is shaped like a ball when inflated. The pilot chute is attached to a 13-foot bridle line with a 5 oz deployment weight that assures positive launch of the pilot chute. The pilot chute is launched from the container with a deployment assistance device, a 30-inch long helical spring encased in marquisette netting and fitted with an end cap at each end. All you have to do to activate the MIRPS is pull up and out on the rip cord grip and drop it; the “pull drop method.”  MIRPS pilot chute. The MIRPS-SLCP added red soft loops that prevented the metal cones on the previous MIRPS from locking, and moved the rip cord grip to the center to enhance rip cord grip protection and allow the rip cord grip to be pulled with either hand. The T-10R, MIRPS, and MIRPS-SLCP all use a 24-foot, flat, circular parachute. Depending on the jumper’s total weight, its rate of descent varies from 15 to 22 feet per second. T-11R  The T-11 Reserve features many improvements over the MIRPS-SLCP. As far as I know, I’m the only sport jumper using one right now, but there may be more as they become more frequent on the secondary market. The T-11R attaches to two D-rings, which are positioned higher on the harness in order to allow the jumper to maintain a vertical orientation and proper landing attitude. It has a lower profile to allow the jumper to look down when making a landing. Like the MIRPS-SLCP, it has a center pull handle and can be operated with either hand. The nylon rip cord handle reduces the possibility of snagging, as can happen with a wire handle, to prevent accidental activation. The T-11R has a 29 foot aeroconical canopy. The design shape resists malfunctions, such as a line over and, if this event happens, tends to release the line. The canopy has four apex-assist pockets in the crown that aid in the inflation process. The T-11R also has a pilot chute called the reserve extractor, which is a 6-foot diameter, circular parachute with twelve suspension lines that attach to a nylon vent bridle assembly. The T-11R has a covered spring similar to the deployment assistance device called an ejector spring, which is 19 inches long and packed within the canopy folds. It positively launches the assist pockets laterally into the airflow when the reserve is activated. |
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Post by parajag on Mar 29, 2017 11:31:21 GMT -8
BA-22 The BA-22 is not used for intentional jumpming. It is an emergency bailout back type parachute worn by the Safety or a static (non-jumping) Jumpmaster. The BA-22 can be manually activated with a ripcord and can also be equipped with an oxygen bottle and 14,000 foot automatic release (which mine does not have). The BA-22 has a C-9, 28-foot flat circular canopy with a four-line release for steering and maneuverability and has a rate of descent of 18-20 fps. It weighs 35 lbs.  The BA-22 allows the Safety to move up and down the cargo compartment of the aircraft to check on the jumpers and correct any equipment issues (as opposed to wearing a harness).  The replacement for the BA-22 is the Advanced Emergency Bailout Parachute (AEBP). The AEBP has an advanced parachute system and is much lighter. It is vacuum sealed and has a 5-year repack cycle, which means unfortunately we cannot use it for civilian parachute operations because the FAA requires that all parachutes be packed within 180 days. |
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