Notes on Kite Aerial Photography: Background
|
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:
LPA Design
1350 Shelburne Road
Suite 265
South Burlington, VT 05403
(800) 695-2696
(802) 864-8572
(802) 658-6125 FAX
|
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. |
|
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. |
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:
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. |
|
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. |
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. |
|
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:
There is nothing like the voice of experience. |
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. |
[ Home Page | Background | Equipment | Gallery | Maps | Discussion | Others | Search | What's New ]
Comments to author: crisp@socrates.berkeley.edu . All content,
graphics and
images contained throughout are Copyright (C) 1995 - 2005 by Charles C. Benton
and are protected by United States and International copyright laws.
No text, graphic or image may be used whole or in part, individually,
or as part of a derivative work without express written permission.
All rights reserved. Revised: 25 June, 2010
URL:
http://www.ced.berkeley.edu/~cris/kap/background/safety.html