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Air Force Lowering Device

Descender

Webbing Kit (Two–Piece)

Webbing Kit (Snap Version)

Webbing Kit (Zipper Version A)

Webbing Kit (Zipper Version B)

Descender Webbing Kit (Two–Piece)
Descender Webbing Kit (Two–Piece)
 
Webbing Kit (Snap Version) Webbing Kit (Zipper Version A) Webbing Kit (Zipper Version B)
Webbing Kit (Snap Version) Webbing Kit (Zipper Version A) Webbing Kit (Zipper Version B)

Overview


Technical Details

I have five of these, as follows:

  1. [Webbing Kit (Snap Version)] One from Para-Gear in 1984. It came with the webbing kit with the snap closures.
  2. [Descender] A second descender (without the webbing kit) from Check Six Aviation in 2000.
  3. [Webbing Kit (Zipper Version B)] A third descender from Michael Bing in 2009. It came with the webbing kit with the zipper closures.
  4. [Webbing Kit (Zipper Version A)] A fourth descender from Paul Cherubino in 2013. It came with a different styls webbing kit with the zipper closures.
  5. [Webbing Kit (two Piece)] A fifth descender from Omaha Army Navy in 2019. This kit had two pouches for storing the webbing.

1. Descender
(#581)

Front View Rear View Side View
Front View Rear View Side View

The descender frame is a small cadmium-plated steel stamping with two rectangular holes at one end and a bend forming a hook at the other. The upper rectangular hole contains a captured brake bar. The brake bar is oval, measuring about 9.5 mm. high and 13 mm. thick. Slots in each allow it to end ride on the frame. Thin (1/8-in) guide rods are fixed to the back of the device at the top and bottom of the wide portion of the frame. A spring-loaded catch is riveted to the bottom of the frame. This catch closes the hook. The back of the descender is stamped 66D1704.

The standing line webbing comes down through the upper guide, and through the lower hole in the frame. From there it passes back through the bottom of the upper hole, around the brake bar, and back through the lower hole, then out through the bottom guide.

2. Webbing kit (Snap Version)
(#483)

Webbing kit (snap version)

This is a unique kit designed to help parachutists extricate themselves from trees. It consists of descender and webbing packed into an olive-drab case measuring 35 cm by 35 cm by about 3 cm. The outside of the case is marked as follows:

PERSONNEL LOWERING DEVICE
TYPE PCU-10P FOR BACK PARACHUTE
USAF PART NO. 66F1701
ORDER NO. F33657-67-C-0846
M. STEINTHAL & CO. INC., N.Y.C.
U.S. PROPERTY
DATE OF MFR. JUNE 1 1967
FSN 1670-897-6730

The case is sewn on one side and secured with snaps on the remaining three sides. A snap on each corner presumably allows one to attach the device to one’s remaining equipment.

The case contains about 140 feet (45 m) of 3/4-in (19 mm.) tubular webbing folded 140 times. The folded bundle is secured by two elastic straps sewn to the case in multiple places, forming eight elastic loops per side. The webbing ends are stuffed into these loops. The webbing is white except for the final 25 feet (8 m) or so, which is yellow. (These lengths are approximate because I've only unfolded enough webbing to test the device. Putting the webbing back neatly is tedious.) The lower end of the webbing is doubled back on itself and sewn so that the descender cannot pass the end. The upper end of the webbing is sewn to a 35 mm. by 6.5 mm. cadmium-plated steel ring. This ring has a 2 feet (60 cm) of additional webbing sewn to it. The second piece terminates in a snap hook that can be clipped to the ring. The auxiliary webbing is marked "M. STEINTHAL & CO. INC. DATE MFD .JUNE 1967" on one side and "TCTO 14D1-2-628 C/W" on the other. The snap hook is stamped "66C1705" and "Fc 72"

3. Webbing kit (Zipper Version A)
(#1394)

Front

This kit consists of descender and webbing packed into an olive-drab case measuring 35 cm by 35 cm by about 3 cm. The outside of the case is marked as follows:

PERSONNEL LOWERING DEVICE
PARACHUTE
USAF PART NO. 69F246
ORDER NO. F41608-89-D-1804
AERIAL 70133
U.S. PROPERTY
DATE OF MFR. 5/91

The case is secured with a zipper that ascends the upper two thirds of one side, crosses the top, and descends three quarters of the other side. It has two 7 by 28 mm. flaps that presumably were for sewing the case to something else. One of the flaps is marked as follows:

98750/69J247-10/70133
DATE OF MFR. 5/91

The case contains about 140 feet (45 m) of 3/4-in (19 mm.) tubular webbing folded 162 times. The folded bundle is secured by two elastic straps sewn to the case in multiple places, forming eight elastic loops per side. The webbing ends are stuffed into these loops. The webbing is olive drab. The lower end of the webbing is doubled back on itself and sewn so that the descender cannot pass the end. The upper end of the webbing is sewn to a 35 mm. by 6.5 mm. cadmium-plated steel ring. This ring has a 2 feet (60 cm) of additional webbing sewn to it. The second piece terminates in a snap hook that can be clipped to the ring. The snap hook is stamped "66C1705" and "90 DJ."

4. Webbing kit (Zipper Version B)
(#1239)

Front

This kit consists of descender and webbing packed into an olive-drab case measuring 35 cm by 35 cm by about 3 cm. The outside of the case is marked as follows:

PERSONNEL LOWERING DEVICE
PARACHUTE, CK, TYPE PCU-10P
USAF PART NO. 8140561-10
ORDER NO. SPO460-96-D-0425/0003
SERIAL 70133
U.S. PROPERTY
DATE OF MFR. 6/98

The case is secured with a zipper that encircles all four sides. A snap on each corner presumably allows one to attach the device to one’s remaining equipment.

The case contains about 140 feet (45 m) of 3/4-in (19 mm.) tubular webbing folded 144 times. The folded bundle is secured by two elastic straps sewn to the case in multiple places, forming eight elastic loops per side. The webbing ends are stuffed into these loops. The webbing is olive drab except for the final 25 feet (8 m) or so, which alternates dark green and O.D. green with 100 to 150 mm. of each color. The lower end of the webbing is doubled back on itself and sewn so that the descender cannot pass the end. The upper end of the webbing is sewn to a 35 mm. by 6.5 mm. cadmium-plated steel ring. This ring has a 2 feet (60 cm) of additional webbing sewn to it. The second piece terminates in a snap hook that can be clipped to the ring. The auxiliary webbing is marked "66 DI703" on one side. The snap hook is stamped "66C1705" and "96 DJ."

5. Webbing kit (Two–Piece)
(#2541)

Front

This kit consists of descender and webbing packed into two olive-drab pouches measuring 35 cm by 12 cm by about 5 cm. each. The rear of each pouch has a small prism-shaped extension with foam inside. One is printed with "LH," the other "RH," and both have "11-1-1865" which is obviously not the date of manufacture.

Each pouch is closed at the top with velcro sewn to a flap. There is a zipper at the top of each pouch to secure the pouch to something else.

98750/69J247-10/70133
DATE OF MFR. 5/91

The pouches contain about 165 feet (50 m.) of 3/4-in (19 mm.) tubular webbing, half in each pouch folded 35 times. The folded bundle is secured by elastic straps sewn to the pouch in multiple places. The webbing ends are stuffed into these loops. Unlike the flat pouches, returning the webbing to these pouches after deployment would be nearly impossible without special tools, and so I have avoided all temptation to pull the webbing out of the pouches.

Comments

I expected this device to be a disaster because the webbing pulls the brake bar tight against the frame, but when I tested it I found that the friction was nearly perfect for my tastes. Naturally, this device was intended for one-time emergency use, not daily sport rappelling. The idea of rappelling on webbing bothers me because tubular webbing lacks the abrasion resistance that good ropes have. I've heard that some canyoners prefer to use webbing instead of 9 mm. rope because of the weight savings. Perhaps their rock is more rounded and more abrasion resistant than what I am used to, if not, I question the safety of this practice.

Hale Laughlin offered to share his experience with this device:

Hi,

I ran across your site while doing some research for climbing; interesting site with interesting info about some unique equipment. I thought I would offer some information concerning the ’Air Force Descender’ that you show. I have used the device for training purposes many times over the past 19 years and you are right on most of your specs. It does work well but there are some precautions that one must be aware of when employing this unique piece of military gear.

It was originally designed for use during Vietnam conflict where it was somewhat common for aircrew to get hung-up in tall jungle canopy after bailout. The braking device is very efficient, and requires very little effort to stop the descent. It operates opposite of most descenders in that you move the brake hand up and to the front of the face to stop the descent, lowering the brake hand to the 6 o’clock position allows the tape to feed through. Rate of descent should be 2-3 feet per second, not to exceed 10 feet per second.

Here is the main precaution; the brake heats up incredibly FAST. Experimenting with it several times, under contolled conditions of course, I have smelled, heard and seen the tape sizzling after stopping subsequent to a rapid 15-20 feet descent. I have no doubt that a sudden brake after a 25-30 foot rapid descent, would likely burn the tape in two, so slow and steady is the only method with this device.

The other precaution is that the tape must feed into the brake smoothly so that it doesn't get twisted and entangled in the brake device. Once this occurs, one must try to do a one armed pull-up, while maintaining a ’brake ready’ position, in order to undo the jam. Again, slow and steady is the method that works best to prevent this. The device suits its designed intent well; lightweight, one-time use tool for aircrew to descend from a parachute hung-up in the trees. Thanks for the info on your site, hope this info is useful.

Cheers,
G. Hale Laughlin

Warning:
Pay attention to Hale’s warning about overheating this device.

As for this device, I can see the military applications. As a pilot, I wonder why anyone would jump out of a perfectly good airplane for sport - being Pilot-In-Command is too much fun.

 

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