Jumping Near Clouds
by Tom Buchanan, S&TA

Imagine you are flying your canopy after a routine freefall when a flash appears.   In an instant you recognize a commercial jet thrusting out of a nearby cloud and flying directly at you.  There is nothing you can do but hope the "Big Sky Little Me" theory of collision avoidance, and perhaps fate, will provide a thin margin of protection.  As the jet abruptly banks away you take a deep breath and steer your canopy with an increased sense of awareness, and elevated respect for the "See and Avoid" concept of separation.

Every skydiver should understand that the airspace over The Ranch is always available for public use by other airplanes, and pilots do not need to contact air traffic control for approval to fly overhead.  Transient airplanes can include small planes, as well as large commercial jets.  Jumpers always need to be aware that traffic may fly overhead without warning, and we need to be certain that we can see approaching traffic before we exit, and that the traffic can see our parachutes in time to prevent a collision.

Clouds can add an extra degree of excitement and fun to a jump, but they also increase risk, and make collision avoidance far more challenging.  Airplanes may be hidden by clouds, and jumpers that exited on an earlier pass or load may be below a cloud.   Likewise, if the clouds are lower than opening altitude, we will need to fly our parachutes in and around the clouds, and we may have a tough time seeing other canopies in time to avoid a collision.  Since collision avoidance is a shared responsibility between pilots and jumpers, and since clouds make it so difficult for airspace users to see and avoid each other, the FAA has established a series of regulations that govern how close we may be to a cloud.  These regulations apply to every skydiver, including IAF students and tandem jumpers.  There are two specific regulations that we should be aware of, listed as 105.5 and 105.17.

Specific Regulations

The most often referenced regulation related to skydiving near clouds is 105.17, which says that a skydiver may not jump into or through a cloud.  Further, this regulation tells us that when we are below 10,000 feet we must remain 500 feet below a cloud, 1,000 feet above a cloud, and 2,000 feet horizontally from a cloud.  That means that in order to avoid a cloud, a single jumper needs a horizontal gap between clouds that is at least 4,000 feet wide, or almost a mile from edge to edge.  When a full load is put out on a single pass it is important to remember that jumpers will be spread out over a greater distance, and thus require a larger hole so that every jumper is at least 2,000 feet from the cloud.   In addition to cloud limits, we must also have a minimum of three miles of visibility when below 10,000 feet.

The 105.17 standard above 10,000 feet is a bit more demanding because airplanes fly faster at higher altitudes.  When we are above 10,000 feet, we must remain 1,000 feet below a cloud, 1,000 feet above a cloud, and one mile horizontally from any cloud.   That means that when clouds are above 10,000 feet, a hole must be a minimum of two miles wide for a single jumper, and must be far larger for multiple jumpers on a single pass.  In addition to the cloud limits, we must also have five miles of visibility when above 10,000 feet.

Our runway at The Ranch is about ½ mile long (roughly 2,500 feet), and the Shawangunk Mountain ridge to the northwest is about five miles away.  We can use these known values as a means of measuring cloud clearance and visibility.  If you can see detail in the mountains while on the ground, we have adequate visibility.  If you can fit two runway lengths between clouds (below 10,000 feet), then we probably have a large enough hole for at least one person/group to exit on a single pass.

The other critical regulation is 105.5.  This rule is a catch-all regulation that tells us we may not create a hazard to air traffic or persons or property on the ground.   It may be possible for us to maintain the clearance requirements listed under 105.17, but we may still be in violation of 105.5 if the clouds obstruct enough of the sky to make it difficult to see other traffic, and thus jumping creates a hazard.  Each of us has a duty to remain both legal and safe, and in fact 105.5 places the very concept of "safe" into the regulations without providing a detailed definition.  If jumping near clouds creates a hazard or is unsafe, it may be a violation of this regulation, even if it is not specifically prohibited by 105.17.  This is an important concept to understand.

Describing Cloud Layers

Most of us have heard cloud layers described as "broken" or "scattered" and wondered what those terms really mean.  The FAA has specific definitions of cloud cover based on how much of the sky is obstructed when viewed from the ground.  Observers using this system will look toward the sky and break the space into eight segments.  If there are no clouds it will be considered "clear."  If clouds obstruct 1/8 or 2/8 of the sky, it will be reported as "few clouds."  If the clouds obstruct 3/8 or 4/8 of the sky it will be reported as "scattered."  If the clouds obstruct 5/8-7/8 of the sky it will be called "broken."  If the clouds cover more than 7/8's of the sky it will be called overcast.

When there are multiple layers, the layers will be added together vertically, from the lowest layer to the highest layer.  A scattered layer blocking 3/8 of the sky at 3,000 feet, and a second scattered layer blocking 3/8 of the sky at 6,000 feet, will be reported as scattered at 3,000, and broken at 6,000, because from the ground the two layers combine to obstruct 6/8 (75%) of the sky at and above 6,000 feet.   It is important to realize that when clouds are layered they increase the vertical obstruction, and that increases the risk of jumping above them because pilots and jumpers will have a more difficult time seeing and avoiding each other.

It may seem reasonable to jump above a "broken" layer that obstructs 6/8 of the sky as long as the minimum cloud clearance requirements can be met, but the jump may still create a hazard and be prohibited by 105.5.  Consider that when looking down on jumprun a "broken" layer will always block well over half of the ground from view (5/8-7/8), and it may be impossible to identify airplanes within or below that layer.   Several different scattered layers could have the same obstruction potential, so even if the individual clouds are far enough apart to allow adequate horizontal separation, we may still be in danger of colliding with an airplane if the clouds prevent us from identifying that traffic while on jumprun.

Enforcement of the Regulations

I think most of us agree that safety should be our number one consideration when jumping near clouds.  Obviously nobody wants to be hit by an airplane, and I haven't met a single skydiver who is willing to be responsible for the destruction of a commercial jetliner.  With this in mind we should always endeavor to be safe, and to minimize the risk of collisions.  We should also understand that jumps in violation of 105.17, or those that create a hazard, could attract the attention of the FAA and might bring heavy fines against each jumper, the jump pilot, The Ranch Parachute Club, or the school.   Keep in mind that transient pilots can easily file a complaint if they see us jumping too close to clouds, or if they feel threatened by our activity.  Our students are often videotaped on tandem jumps, and those tapes may find their way to the FAA.  Likewise, neighbors or spectators watching from Sandhill Road may witness or videotape an inadvertent cloud violation and contact the FAA.  Even without video, it is easy for the FAA to confirm reported cloud levels based on measurements taken automatically at nearby airports, coupled with pilot reports and archived satellite photos.

Review

We should all understand that flight safety is a critical shared responsibility.   Not only are we responsible for complying with the restrictions of 105.17, we are also responsible for ensuring we do not create a hazard.  Before jumping, it is a good idea to check the sky and confirm that the jump is legal, and that you are certain that no transient airplanes are being placed at risk.  The threat of a violation notice from the FAA is a serious concern, but more important is the feeling of personal responsibility if a jump you are involved in is too close to clouds or otherwise unsafe, and a passing airplane is damaged or destroyed.  Skydivers sometimes enjoy taking on risky activities, but we should never inflict additional risk on another jumper, or a transient aircraft.  Before making a skydive ask yourself if the jump is legal, and confirm that it is safe for everybody who will be involved, including transient airplanes you can't see, that are flown by pilots you hope never to meet.

Additional Resources

FAA regulations about skydiving are available at:  FAR Part 105 - Parachute Operations .

For additional discussion about FAA regulations related to skydiving see:  Article 13 - FAA Regulations Applied .

For additional discussion about public use airspace see:  Article 8 - Airspace .

For additional discussion about how and where to check for traffic before leaving the jump plane see:  Article 1 - Checking for Traffic .

- Tom Buchanan S&TA