Monday, November 1, 2010

Anatomy of a MiG-21 Drag Parachute

One of the things our MiG-21 was decidedly lacking was a drag parachute. Even with the new extension, lengthening the Lancaster Airport runway to 6,500 feet, stopping the MiG-21 without rapidly going through brakes and tires is going to take a little extra work.

We looked around for parachute sources and, out of curiosity, checked with the importer that brings in things for the Nanchang CJ-6A. Since the Chinese make a MiG-21 copy, the J-7, it stood to reason that drag parachutes might be available at a reasonable price. To everyone's surprise, he discovered that J-7 parts are even more plentiful than are CJ-6A parts. Eventually a box with a military looking bag and some funny nylon umbrellas showed up:


Upon opening the bag, we discovered that there were plenty of goodies in it... but this was starting to look a lot less simple than anticipated.


Fortunately, the bag came with instructions... in Chinese.


But a couple of diagrams go a long way in any language.


Step by step instructions were included for assembling the 14 individual pieces of the MiG-21 drag parachute.


The system consists of a container bag into which a hook mechanism on a plate fills the base end.


A 5 meter multi-part braided line then connects to the plate. The lines are covered with a protective canvas sleeve. One of the reasons that drag parachutes are hard to find in Eastern Europe is that the braided line makes an excellent tow rope for pulling cars.


This line then connects to the base of the parachute itself. At each connection point, a canvas sleeve with drawstrings protects the parachute components from chafing on the runway. We were pleased that a completely new parachute set like the one we'd acquired came with several extra protective sleeves.


Last, but not least, a drag chute drogue chute connects to the top of the parachute to assist in deployment. The inner sleeve of the drogue houses a spring that leaps out into the world and pulls the main chute behind it. It's interesting to see the ratio of various spares... the kit came with three drogues; the drogue must take a lot of abuse.


The instruction manual references a machine that assists in packing the chute into the housing bag:


We haven't acquired one of these machines but we're told that it's possible to manually pack the parachute into the housing bag with a little effort.

The parachute is deployed manually by the pilot upon landing with a push of a button in the cockpit. The housing in the tail opens and pneumatic pressure opens the clamshell in the tail to let the drogue chute leap out into the world. After slowing to a speed where the parachute is no longer effective, a second button releases the chute to be picked up by ground crew.

A final picture shows the parachute tied into the bag with a holding pin that keeps it all together until it's been placed in the aircraft and "armed".

2 comments:

  1. The abuse that the drogues took were probably caused by the "packing machine(?)" :-)

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  2. i hate to be a wet blanket it doesn't look the one we have for our MiG-21MF all though you guys did score some of the parts are used on more than one type.

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