Paracfiuln tquipmnnt Industry ilssnuiatiun - Parachute Industry ...

WINDTUNNEL TESTS
A total of (26) deployment bag extraction tests were conducted on (3) different
harness & containers with square reserves. The tests were conducted in a windtunnel
with the harness & containers mounted on a torso dummy bolted to the windtunnel
floor. All of the deployment bag extractions were f ilmed with a 16 millimeter movie
camera at 200 frames per second. All of the quantitative data was obtained using a
frame by frame motion analyzer.
Deployment bag extractions were lilmed at 60, 12O, 150. and 180 miles per hour.
The (3) rigs tested were Para-Flite, Inc.'s MT-1 with a 1O1,/z lb. reserve, a Para-Flite MT-
1 S with an 81/z lb. reserve, and a Strong Enterprises Eagle System with a 6 lb. reserve.
These rigs were selected because of their heavier reserves being more likely to
produce the bag stripping phenomena that we wanted to observe.
Each rig was run (3) times at 60 mph, (3) times at 12Q mph, and (1)time each at 150
and 180 mph. The following graphs all depict the average of the (3) runs at 120 moh
and the 150 & 18O mph runs. The 60 mph runs were basically not used in this
summary.
The MT-1 on the 150 mph test run broke both 'O' rings. This was the same set of 'O'
rings used on all the previous test runs. The f ollowing test at 180 mph. the 'O' rings
stretched but did not break.
The MI-1S didn't break any'O'rings on any ol the test runs.
On the Eagle System, (1)'O'ring was broken on one of the 120 mph runs and both'O'
rings were broken on the 180 mph run. Additionally, the Eagle System was tested
with (1)'O'ring intentionally not connected, resulting in the only'O'ring being used
breaking at 120 mph.
To summarize the tunnel observations, the reserve canoples were removed f rom the
pack tray e\.'en on those runs where both 'O' rings broke. The nraximum acceleration
point of the deployment bag \Jvas measured to be nearly 4 feet behind the pack tray
The Velcro line pouch on the Para-Flite deplgymgnl bags was observed to be working
well. The fact that there,,vere no O'ring breaks on the MT'1S. even at a relatively
heavy reserve canopy weight (872 lbs or so), occurred for one or both of the f ollowing
reasons: 1) The most likely reason is the pilotchute
-
lt doesn t seem to exhibit the
exoonential increase in drag as the velocity is increased one would e.\pect; 2) The
method of attaching the 'O' ring to the deployment bag may also be a contributing
f aclor.
Figure 1 shows the maximum D-bag velocity measured at the various lunnel speeds.
It is evident that the MT-1S D-baq speed did not increase ven/ much as the iunnel
speed was increased
Fiqure 2 shows the deployment bag distance in feet frorn the container at the tirne it
was experiencing maximum acceleration