"lfk f; \"A Lt. - Airborne Systems

Inflation Phase Actuators. Pym/mechanical devices
are tt$p.d to ::ontrol the forces developed during parachute
inflation and to modulate the rate of inflation.
Canopy Spreader Gun. The need for a recovery
parachute that opens quickly at very low speeds and
altitudes (zero-zero conditions has been met in a C-
personnel version with a pyrotechnic device
mul-i- radial barreled gLl'1. The gun is j:ositioned at
:he mouth o the canopy by 1: ret2jnin curd extend.
;ng from the canooy apex to the skirt.
Fi;:ure 3.
sholf/s the spreading gun assemblv with rctaining cord
at the top and arming lanyarc arrmgement below.
Each of its tou rtpen projecti les propels adjacent psi rs
of sLlspension lines radially omward W'1en the gun is
fi md.
Reefing Cutters. Reefing ling cCitters are available
in a variety of sizes and delay times. A cLltawDV view
of a typical cutter assembly is sri own in Figure 3. "1.
Tlie small cylindrical device ha3 a transverse hole at
une end througl- which the reefingine passes. At the
opposi te end is a lanyard operated sear and firi n pin.
When the firing pin impact3 t'le primEr. the delay
powder train is initiated by ll- e flash , and the delay
mix burrs lengthwise until it reacres the propellant
charge behind the knife. The explosive pressure de"
veloped then drives t'le nife and reefing line into the
anvil, comp letel y cJttin 9 the line. F gu re 3. 12 5h ows
details of a COlTliOn small cLitter (750-lb nvlon cord
capacity) 811d its mounting bl"acket whic1 n' ay be
hand-stitched to the canopy. The cu lter then mounts
INith a small locking ring when the gr:Jove of the
cutter and t1e slot of tr.e mount ng bracket are aligned.
rhe safety pin must be removed dJring the para-
Sear
Safety
Pin
Time Delav Mix
FigurC1 3. 11 Reefing Line Cutter
121
Figure 3. 10 Canopy Spreader Gun
chute pack n9 process. Line cut:ers are usually available
'n rllOrJi2ed aluminum, but may be ::btCiined in
stainless steel wi tr. tre pyrotechnic elements herneticailv
sealod. Steal bodics are recommended if dense
pressure packing of the parachute is anticipated. Largm
sizes r.e iNailable (2500-lli nylon cord ciipacity)
similar to the small unit, ane others (9000. lb nylon
cord capacity; with 2- irches ITHxe length and 3/11inch
body diameter are representative. Tine delays
to 30 seuJlds ard 1: to erance of 1: 1 0 perce' lt i!t
standard temperatLlre Eire 'easonable, bLlt over a wide
tempe'atu' e range, the accuracy lTay vary as much
:t25 percent.
Knife