[Top] [All Lists]

Re: [TowerTalk] TOWAIR query - proximity to airport, FCC and FAA registr

To:, "Tower and HF antenna construction topics." <>
Subject: Re: [TowerTalk] TOWAIR query - proximity to airport, FCC and FAA registration
From: "Roger (K8RI)" <>
Reply-to: "Tower and HF antenna construction topics." <>
Date: Sat, 03 Apr 2010 09:05:18 -0400
List-post: <">>

Pete Smith wrote:
> This sure suggests a computational error in the TOWAIR routine - like 
> when you do a model in HFTA and a 1-meter change in antenna height 
> produces a big change in pattern.  I think the first thing I'd do is a 
> manual computation based on a topo map.  Measure the distance from the 
> nearest border of the airport (for a conservative calculation), your 
> site's altitude, and apply the algorithm given in the FCC reg.
Remember too, if you line up with any of the runways the criteria is 
different for runway clear zones.

Years ago "they" built a new subdivision right across the highway from 
the S end of 18/38. The N end of that subdivision was so close the trees 
had about the top half cut out of them to maintain clearance. IOW, much 
as I love airplanes I'd never live there even if they gave me one of 
those 500,000 to 750,000 dollar homes.  One day I was on final for 36 
just as I had been the previous day.  It was quite warm and beautifully 
clear, but something just didn't look right. Then I realized I was 
looking at a TV antenna being installed on top of a rather tall tower 
right in front of me. Those things are terribly hard to see, but seeing 
such a thing at 100 - 120 mph and recognizing it for what it is besides 
overcoming the ingrained knowledge that such a thing just can't be there 
takes time. The guy on the tower could probably count the rivits in the 
bottom of the port (left) wing and whether I'd put the cap on the valve 
stem when I check the tires.  The wing went over his head, but the left 
main went beside him.  I probably missed him and the tower by about 3 to 
5 feet. And of course that big engine was at full power which with a 
2-blade prop would have been deafening. (The prop tips go supersonic and 
max RPM). A 3100# airplane that close could be a bit unnerving as well. 

The next day the tower was gone.  I assume the irate home owner called 
about one very scared TV antenna installer (It didn't do my nerves any 
good either) and found what he could be liable for if he pursued a 
complaint. It also gave him a preview of the noise he was going to have 
to endure living there.  Departing aircraft are only a couple hundred 
feet up when they go over the subdivision on a hot day. Of course he 
tried to get the airport closed and the city found to do that they'd 
have to pay back not only any grants for purchasing airport land, but 
for the entire airport at current market value. That brought the push to 
close to a quick halt. 

Normal grants have a 20 year life with no pro rating. Land Grants are 
forever, but become all inclusive and at current market value.


Roger (K8RI)
> 73, Pete N4ZR
> The World Contest Station Database, updated daily at
> The Reverse Beacon Network at, blog at 
> On 4/2/2010 6:26 PM, Dick Dievendorff wrote:
>> At 6 meters of tower height, I don't need to register.  At 7 meters of tower
>> I'm suddenly 22 meters too high for the distance from Whidbey NAS.
> _______________________________________________
> _______________________________________________
> TowerTalk mailing list

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>