Notes on Kite Aerial Photography: Background

Notes on KAP Safety continued


This page continues my project to assemble notes and suggestions on the relatively sobering but important topic of   kite aerial photography  safety.  Give this section, and the page that precedes it, a quick read to see if it prompts useful precautionary thoughts. I will be refining these pages over time, your suggestions are very welcome.


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Issues of interference and courtesy with remote control radios

Advanced KAP rigs often apply radio control equipment adapted from the Radio Control (RC) Model Aircraft world. The principal risk here is that our actions might jeopardize nearby RC flyers.  As an occasional RC sailplane pilot I can readily attest that RC modelers are sensitive about their frequencies and take a dim view of anyone who uses them improperly.  This is with good cause, it is not unthinkable that model flyers will have invested hundreds of hours and thousands of dollars in the aircraft they fly.  So even though you buy the radio think of the radio frequencies as belonging to the modelers.  Protect their interests, and yours, by being purposeful about where and how you use the radio.

Guidelines for radio use are also confused by the fact that frequency assignments can vary from country to country.  If you take your KAP gear on international expeditions then a little pre-trip research is in order.

Addendum: In 1999, I received a communication from Steve Kaluf, Technical Director of the Academy of Model Aeronautics (AMA), expressing concern that kite aerial photographers might be using frequencies assigned to model aircraft. The full text of Steve's letter(s) can be found in the KAP Discussion Pages. Now that this concern has been raised, the most prudent course in the USA would be to use the 27Mhz channels per AMA's recommendations. Note that these frequencies would be shared as well.

Addendum: In 2000, I received a note from Patrick Clow saying:

I came across your web site when I was doing a little research on radio controlled photography.  You have a section that talks about using model airplane frequencies  and the trials/courtesies involved.  I'd like to suggest some equipment that my company manufactures that I think is a perfect solution for aerial photography -- the PocketWizard radio slave.  Bottom line - entry level systems around $300  have an 800 foot range, more advanced systems (1600 feet range) are around $500.  They will NOT interfere with radio controlled model airplanes, nor will they be affected by them.  They are on their own frequencies, approved by the FCC, just for this purpose.  Receiver and Transmitter weigh the same -- 4 to 5 oz with 2 AA batteries (runs for 200-250 hours on a set).  We are experts at triggering cameras remotely and have cables for just about every motor drive imaginable.
 

Here is contact information for Patrick:


Patrick Clow, Manager, Tech Support

LPA Design
1350 Shelburne Road
Suite 265
South Burlington, VT  05403
(800) 695-2696
(802) 864-8572
(802) 658-6125 FAX

notes2.gif (2646 bytes) Always conduct a receiver check before turning on your transmitter - Two transmitters must not be operated at the same time within range of each other.  To do so corrupts the signal reaching the radio receiver(s).  If the receiver is in a flying aircraft the corrupted signal will cause loss of control over the model. Without positive control models will crash within seconds. You can check to see if a transmitter is operating on your frequency in your area by powering the receiver up first.  Watch your rig after doing this to see if it is responding to someone else's control inputs. If it is moving unexpectedly then do not turn on your transmitter as someone could be using your frequency within range.

Become familiar with the location of RC flying fields in your area - Motorized model airplanes are often but not always operated out of fields maintain by RC Model Clubs. A visit to the local hobby shop will usually yield a guide to the RC flying fields in your area.  These fields, and sites with a mile and a half of them, should be off limits for KAPing.

Take care even in remote places - RC aircraft are also operated away from organized sites.  The new, quiet electric motor aircraft are often flown in parks and the countryside.  Model sailplanes can be flown almost anywhere there is a hill or open field.  In essence you should never assume that an area is free of RC enthusiasts. Conduct that radio check!

There are serious economic and safety consequences to carelessness with your radio.  It is clearly incumbent on us to take every action possible to safeguard the mainstream users of these radio frequencies.


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Roadway-related hazards

In the United States it seems that roadways are virtually everywhere. These highways, arterials, streets, and lanes contain massive, accelerated vehicles and serve as right-of-way corridors for the distribution of electricity, telephone, and other services. They are not particularly friendly places to fly a kite nor are they particularly safe.

A fine general rule is "do not overfly roadways." Still, the sheer preponderance of roadways often leads us to fly in their proximity.  This is not something you would want to do in the early stages of your kite flying career. If you do fly near roads, think ahead to reduce risk.


notes2.gif (2646 bytes) Do not provide an "attractive nuisance" - Many people have suggested that I photograph the Golden Gate Bridge, an undeniably photogenic object. I have not done this for fear that my KAP rig will distract drivers on this accident prone stretch of Highway 101. There is a legal doctrine in the United States that assigns fault to a property owner that provides an "attractive nuisance" (e.g., swimming pool) that draws children to loss or injury.  I suspect that our practice of hanging unusual objects from kites could be an "attractive nuisance" of sorts. 

So the issue is whether or not you think your kite and/or rig will be visible in a way that will distract motorists and cause them to wreck into each other or handy inanimate objects. As you gauge the scene remember those times when curious passerby became mesmerized with "whatever that is hanging from your kiteline." I suggest we play it safe my not flying adjacent to high speed roadways.

Aggressively survey your flying location for power lines - Power lines, particularly those operating at high voltage, represent a hazard to kites and kitefliers.  If you take a tour of the electric utility WWW sites you will find a consistent mention of kites and model planes in their safety sections.  For instance:

Fly kites, model planes & balloons safely. Only fly your kite, model plane or balloons in wide-open spaces like a field or beach. Never fly them around power lines. Never use metal, foil or wire in your kite or kite string.  If your kite gets caught in a powerline, leave it there. (Ask Mom or Dad to tell the power company)

One wonders what we should do if neither Mom nor Dad is available.  In any event the warning reflects the circumstance that many overhead power lines are not insulated. This means that they will conduct an electric charge to anything that touches them. When this occurs, the electric current from the wire will travel down any convenient path (conductor) to the ground. For instance, a kite string, particularly a moist one, can become a conductor of the electrical current in the line. The water in a human body makes it a good conductor. If someone comes in contact with an object that is carrying a current, the current can flow through the person and injure or kill him/her. People who work with power lines have special training and wear special protective gloves to prevent the current from traveling through their bodies. Kite fliers do not.

Avoid "clothes-lining" cars, bicyclists, and pedestrians - When the wind is blowing hard I often clip my kiteline off to a stationary object and walk the kite down.  During the process the kiteline is stretched tautly in a horizontal line between the anchor and myself as I walk toward the kite.  One day, after photographing the Golden Gate Park windmill, I was using this technique to retrieve the kite in 20+ mph winds. At the very edge of my peripheral vision I picked up a bicyclist intent on passing behind me and approaching with some speed.  I immediately let the kiteline go as a bicyclist closed unknowingly on the horizontal kiteline (which is admittedly difficult to see.)  I was lucky to have seen him coming out of the corner of my eye. I now ask an assistant or passerby to watch the line while I walk it down and warn those approaching the hazard.


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Trees as a hazard to your kite and KAP rig

It is a basic law of nature that trees and kites do not mix.  Tales of tree-related kite loss abound and take on an apocryphal character. Peanuts cartoon character Charlie Brown's kites have been meeting their demise in the "kite-eating tree" for almost a half-century now. (Charlie's kites have also succumbed to a sewer, burned, exploded, and been impaled on Violet's toy tree and Lucy's arm.)

I will stop short of saying that trees are inherently evil though that is one possible interpretation of the facts.  A more charitable view would have it that they cannot avoid the kites that we guide to their branches.  It is up to us to protect their honor.


notes2.gif (2646 bytes) Be very wary of trees - Seriously, it is a tremendous annoyance to snag a kite In a tree.  Tree branches seem almost designed to capture the lines of our kite bridles and Picavet suspensions.   Thus give them ample clearance and pay close attention when flying in their vicinity.

Think hard before climbing after a kite - I will admit to climbing a tall tree to retrieve one of my Suttons a year or so ago.  After all I used to climb trees for fun  when I was a kid in Georgia.  On the other hand that was forty years and about 120 pounds ago. I retrieved the kite but wondered afterwards if the risk was worth it.

You might be interested in Simon Harbord's tree anecdote.


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Water as a hazard to your kite and KAP rig

I am fascinated by aerial images of shorelines, water, boats -- indeed anything nautical.  In consequence, I have spent many hours flying over water.  The principal hazard here is exposure of your equipment to a dunking.

I should note that this entire safety section was inspired by James Aber's comments on safety at his fine Great Plains Kite Aerial Photography Site. Professor Aber pretty much sums the water issue up by advising that you:

"Be cautious about flying a KAP rig over a lake (or other water body). A crash into water can lead to disaster, as the camera acts like a sinker to drag kite and all to the lake floor, where hidden snags may ensnare equipment permanently. If the equipment can be recovered quickly, the kite will most likely survive, and the camera may function (partially) after thorough drying, but color film almost certainly will be ruined--as the author knows firsthand."

There is nothing like the voice of experience.


notes2.gif (2646 bytes) Practice flying the kite without the camera - One of my practices is to fly the kite without camera for 10 or so minutes to see if the winds are consistent.  I often extend this period if I will be flying over water - because the stakes associated with  failure are higher.

Prepare ahead - As I understand it, the protocol for a dunked camera is to keep it submerged in fresh water until you can get it to a repair shop.  I've also heard that this works better for older, mechanical cameras than it does for contemporary electronic ones.  You might ask someone who really knows, its not a bad idea to know where the repair shop is anyway.

On flying from boats - My limited experience flying the camera from boats suggests that it is important to communicate with the boat pilot or at least have assurance that the course will hold steady. I once had a kite up when the "skipper" decided to make a 180 degree turn.  Upwind became downwind and the kite settled toward the water - not good. Boats are also different in that you and the kite are moving through linear space.  Think ahead about bridges, overhead lines, etc.

 



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