Canopy Collisions

Easiest Way?
Jump Alone
(OK, NOT Practical)

Because Skydivers Like To
Jump In Groups
Historically, The Two Greatest Risks Of A
Canopy Collision:
Deployment
Landing Pattern

Deployment Separation
Planning starts on the ground
BEFORE the jump

Two Considerations
Regarding Collisions up high
1. Separation Between Groups
2. Separation Between Jumpers
IN each group

Group Separation
1. Type of jump
2. Size of group
3. Ground speed of aircraft

Group Separation
Exit Order
Slow fallers (belly) largest to smallest
Fast fallers (freeflyers) largest to smallest
Students-solo gear first, then tandems
High deployments
Angle Fliers, Tracking Groups, Wingsuits

Minimum Distance?
1. Canopy speed = 30 mph
(44 feet per second)
2. Three seconds required to see and
respond to an approaching canopy
3. Two canopies on a head-on collision
Will cover 300 feet in three seconds

150 feet
150 feet
3 Seconds
300 feet
Minimum Separation
2 jumpers

To obtain 300’ separation between jumpers in a 4-way, need to track 212 ft from the center so the individuals’ columns of air don’t overlap.
3 seconds after opening there could be canopies anywhere in an area 724 ft in diameter. Each group needs its own column of air.
The corresponding area for an 8-way is more than 1,000 ft. across.
724ft

Break-off and Deployment
Issues
Lack of separation from other jumpers
(Poor tracking skills)
(Low break-off altitude with less tracking time)
Jumpers unable to control the parachute
after deployment
(Line twist)
(spinning canopy due to one brake release)
Followed By

8-way group
4-way group
900 feet bare minimum
Distance Between Groups
This does not account for higher break-off, longer tracks, sliding groups
More distance is actually required

Distance Between Groups
For jump runs flown into the wind,
Ground speed of the aircraft is a large factor
Crosswind Jump Runs-Winds have less
influence on group separation
The stronger the upper winds, the slower
the aircraft ground speed will be
Wait longer between groups with strong
upper winds
(Direction of ground winds will also play a large role in separation requirements)

Separation Chart In Aircraft
Inserting a separation chart near the door of the aircraft can help
provide guidance to jumpers for the necessary amount of time required
between groups.

No deployment collision
Now what?

Orderly Flow
Closest canopies pose the most
immediate threat of a collision
Identify the nearest traffic to determine
what needs to happen next
Make adjustments that will help promote
an orderly flow of canopies towards
the landing area

Wing-loading plays a significant factor
In maintaining separation
If you catch up to another canopy
During your descent, allow for
Plenty of room while passing
Be aware of blind spots
(above and behind)
Try to remain near the same area
with your group

Landing Area
Wind Direction
Traffic Flow

Traffic Pattern
Wind Direction
No wind? Pick a direction
for landing and stick with it!

Split Landing Area

Landing Pattern Issues
High-Performance approaches must
be separated from standard landings
Separate landing areas or;
By time, using separate passes for
H-P landings
Fly a predictable landing pattern
Defined Downwind-Base-Final
Straight-in final approach
Without S-Turns