# red and white patterns on apparent aviation hazards? **URL:** \ **Category:** Factual Questions\ **Created:** [July 12, 2011, 8:40pm UTC](https://boards.straightdope.com/t/red-and-white-patterns-on-apparent-aviation-hazards/588792 "2011-07-12T20:40:45Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 12, 2011, 8:40pm UTC](https://boards.straightdope.com/t/red-and-white-patterns-on-apparent-aviation-hazards/588792/1 "2011-07-12T20:40:45Z")
It seems many objects (fences, buildings, antennas, etc.) in the vicinity of an airport are painted in a red and white checkerboard pattern. Notably, the pattern is not of the same scale on different objects: a fence or shed will have red/white squares a couple of feet across, and larger objects tend to have larger squares. So…why the red-and-white pattern, and why differing length scales? ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [July 12, 2011, 9:34pm UTC](https://boards.straightdope.com/t/red-and-white-patterns-on-apparent-aviation-hazards/588792/2 "2011-07-12T21:34:53Z")
My WAG is that larger objects are a bigger danger, and need to be seen from farther away. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [July 12, 2011, 9:45pm UTC](https://boards.straightdope.com/t/red-and-white-patterns-on-apparent-aviation-hazards/588792/3 "2011-07-12T21:45:22Z")
The simple answer is that red-and-white paint is required by the regulations for a structure greater than 300 feet high. I’m guessing that different sizes are because different structures lend themselves to different sizes. Sorry, I couldn’t turn up a cite. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [July 13, 2011, 1:47am UTC](https://boards.straightdope.com/t/red-and-white-patterns-on-apparent-aviation-hazards/588792/4 "2011-07-13T01:47:26Z")
> [@Johnny\_L.A](#): > > The simple answer is that red-and-white paint is required by the regulations for a structure greater than 300 feet high. I’m guessing that different sizes are because different structures lend themselves to different sizes. > > Sorry, I couldn’t turn up a cite. Radio towers with 24 hour high or medium intensity strobe lights are not required to have the red and white paint scheme. > [@](#): > > 1. OMISSION OR ALTERNATIVES TO MARKING > There are two alternatives to marking. Either alternative requires FAA review and concurrence. > a. High Intensity Flashing White Lighting Systems. The high intensity lighting systems are more effective than aviation orange and white paint > and therefore can be recommended instead of marking. This is particularly true under certain ambient light conditions involving the position of the > sun relative to the direction of flight. When high intensity lighting systems are operated during daytime and twilight, other methods of marking may > be omitted. When operated 24 hours a day, other methods of marking and lighting may be omitted. > b. Medium Intensity Flashing White Lighting Systems. When medium intensity lighting systems are operated during daytime and twilight on structures 500 feet (153m) AGL or less, other methods of marking may be omitted. When operated > 24 hours a day on structures 500 feet (153m) AGL or less, other methods of marking and lighting may be omitted. From Advisory Circular [AC 70/7460-1K](http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/b993dcdfc37fcdc486257251005c4e21/$FILE/AC70_7460_1K.pdf) Link also talks about the different sizes and styles of marking. ---
**Author:** ![constanze](https://avatars.discourse-cdn.com/v4/letter/c/f9ae1b/32.png) [@constanze](https://boards.straightdope.com/u/constanze)\ **Post date:** [July 13, 2011, 10:00am UTC](https://boards.straightdope.com/t/red-and-white-patterns-on-apparent-aviation-hazards/588792/5 "2011-07-13T10:00:12Z")
If you really want to know “Why is it prescribed that way?”, then white is the best colour to be seen at night, as it reflects most (even yellow swallows some amount; and reflectors are a relativly recent invention and also more expensive for big things like sheds compared to two buckets of paint) and red is the best colour to be seen in a fog or snow storm, where white just disappears. So combining those two colours makes sure your shed or whatever can be seen under all weather. Regulating it to checkers just means that it’s easier for pilots to recognize than having to deal with different patterns.