Stand-off Distance From Guyed Towers

jnmeade

jnmeade

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Jim Meade
The new AC 70/7460-1L gives some examples of how far to stay away from a guyed tower. For a 2,000 ft tower, you need to stay away 2,000 feet horizontally. They show why that is necessary to remain at least 500' from an obstacle and do the math on where the guys are. They make a few assumptions along the way. :) Such as the distance of the guy anchors from the base of the tower (they assume they are as far out as the tower is high - you tower guys know that is not at all the case in all instances).

No one is disputing that one needs to avoid guy wires. The AC gives a good discussion of the FAA's thinking if you want to pass it on to your students.

"2.2 Guyed Structures.
The guys of a 2,000-foot (610-m) skeletal tower are anchored between 1,600 feet (488 m) and 2,000 feet (610 m) from the base of the structure. This places a portion of the guys 1,500 feet (458 m) from the tower at a height of between 125 feet (38 m) and 500 feet (153 m) AGL. Title 14 CFR Part 91, Section 119, requires pilots, when operating over other than congested areas, to remain at least 500 feet (153 m) from man-made structures. Therefore, the tower must be cleared by 2,000 feet (610 m) horizontally to avoid all guy wires. Properly maintained marking and lighting are important for increased conspicuity because the guys of a structure are difficult to see until the aircraft is dangerously close."

Question - does this include your unmanned aircraft (drone)?
 
I used to spray one field that had a tower, the rule to stay the height away horizontally is a good one. It's more than you need at the ground, but not by a heck of a lot.
 
This tower here (center of picture)

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Is scary. You can't see it. I came real close to it, almost hit it, didn't see it until I was right on it. It's a miracle I didn't run in to a guy wire.
 

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The guy that trained me for Ag died hitting the wires of an unlit tower around Tampa spraying mosquitos after Hurricaine Frances.
 
We have a lot of those in KS. Some are part of clusters, so if you see one, you know there are others. But usually they seem to be singles, off by themselves. The good thing is that we don't have a lot of elevation changes, so there aren't towers sitting on top of a hill someplace that makes it that much higher than the rest.
 
Matthew said:
We have a lot of those in KS. Some are part of clusters, so if you see one, you know there are others. But usually they seem to be singles, off by themselves. The good thing is that we don't have a lot of elevation changes, so there aren't towers sitting on top of a hill someplace that makes it that much higher than the rest.
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That's the problem with the above tower between Watsonville and SJC. It blends in with the terrain. It's lit, so it's easy to see at night, but in the daytime, even the light is hard to spot.
 
But if you fly close enough and low enough you can get under them. :eek:
 
EdFred said:
But if you fly close enough and low enough you can get under them. :eek:
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I'd work under them for three full loads and a partial before I finished that section of wheat, but I was well aware of where every anchor was.
 
Sac Arrow said:
That's the problem with the above tower between Watsonville and SJC. It blends in with the terrain. It's lit, so it's easy to see at night, but in the daytime, even the light is hard to spot.
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That's why you need to be well below the top of the tower - they are much easier to see against the sky.
 
The Santa Cruz ridge towers are only about 500 ft above the peaks and they are tough to spot but really, you should be aware of them if you're flying in that area. The ones that always gave me the creeps are the ones out by Walnut Grove on the delta. Those suckers are 2100 feet above the surrounding flat terrain. There used to be only one but I think there are four of them now.

Still, not as bad as Florida, Texas and the midwest where towers are everywhere but these days, even with something like a little Garmin 296 you've got increased awareness of them all.
 
Man, around here they are everywhere. Taking off out of N Perry in the morning there is an antenna farm of 4 just South of the departure corridor that are basically invisible until an hour or two after sunrise because the sun is right behind them most of the year. I'm always careful to track the streets straight out to the ICW before turning South.
 
:mad2::mad2::mad2: Yet they were still allowed to rebuild the KFI radio tower close to Fullerton after it was hit *a second time*.

I witnessed the last "hit" out of the corner of my eye was taxiing.

:mad2::mad2::mad::mad::mad::sad::sad::sad:
 
Well flying above the top is your safest bet. Otherwise, what others have said.

There's a 2000 footer east of Denver and 2 or 3 2000 footers south of Houston. I flew by the ones in Houston IFR on my way to Galveston in 3 mile vis at 3000. I knew they were there and was looking for them. I asked ATC about the towers and they said that's the reason they had me at 3000. I finally saw the towers and it was shocking how close they were before I saw them come out of the mist. Even when I knew it was physically impossible (OK... at that altitude) for me to hit them they were intimidating.

The Foreflight hazard advisor is a good thing. It can get busy at certain zooms around cities, but I find it handy.
 
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Capt. Geoffrey Thorpe said:
That's why you need to be well below the top of the tower - they are much easier to see against the sky.
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That's the problem, you can't be down too low because of the terrain, plus if you're on flight following (the tower is near if not within SJC's Class C outer area) you're going to have altitude restrictions traveling across the SJ valley.

Silvaire said:
The Santa Cruz ridge towers are only about 500 ft above the peaks and they are tough to spot but really, you should be aware of them if you're flying in that area. The ones that always gave me the creeps are the ones out by Walnut Grove on the delta. Those suckers are 2100 feet above the surrounding flat terrain. There used to be only one but I think there are four of them now.

Still, not as bad as Florida, Texas and the midwest where towers are everywhere but these days, even with something like a little Garmin 296 you've got increased awareness of them all.
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Those don't worry me too much, they are easy enough to see plus I normally cruise at least at 3,000 feet across the valley.
 
Five NM northeast of Mt. Pleasant, SC,(KLRO) are two 2000 ft guyed towers. They are lighted but not painted in the classic red and white scheme. Coming in from the northwest they are a ***** to see against the almost constant marine layer over the ocean. You are best advised to keep your pattern relatively close to the airport.
 
jnmeade said:
Question - does this include your unmanned aircraft (drone)?
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No, any you'll note that the NPRM for Part 107 (small UAS) does not have a minimum distance requirement from structures, including guyed towers.
 
Sac Arrow said:
This tower here (center of picture)

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Is scary. You can't see it. I came real close to it, almost hit it, didn't see it until I was right on it. It's a miracle I didn't run in to a guy wire.
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That tower is why I'll climb to at least 4500' when RHV to WVI despite the short distance. Daytime, it's may as well be invisible.

At night, it's lit up like a Christmas tree. I can see it easily from the Central Valley. Always makes me feel closer to the Bay Area than I really am.
 
Jeff Oslick said:
:mad2::mad2::mad2: Yet they were still allowed to rebuild the KFI radio tower close to Fullerton after it was hit *a second time*.

I witnessed the last "hit" out of the corner of my eye was taxiing.

:mad2::mad2::mad::mad::mad::sad::sad::sad:
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I flew in and out of FUL a few times while based at TOA. That tower is in a very bad place.
 
Brad Z said:
No, any you'll note that the NPRM for Part 107 (small UAS) does not have a minimum distance requirement from structures, including guyed towers.
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They should have just gave them the same distance requirements as manned aircraft and been done with it.
 
sourdough44 said:
Just keep above all that trash, fly higher than the MEF.
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You must have a really fast airplane if you don't mind climbing into the wind.

I prefer to not get higher than a few hundred AGL if there is any kind of headwind.

Kinda locks you out of scud running as well.
 
I'm a huge non-fan of the new gray towers with white lights. There's a 2000' agl gray tower near where I used to live. On gray, overcast days and near sunup/sundown, it was nearly impossible to see between the spaced-long-apart white flashes.

Why paint an obstacle the same color as the clouds you must spot it against?
 
Hank S said:
I'm a huge non-fan of the new gray towers with white lights. There's a 2000' agl gray tower near where I used to live. On gray, overcast days and near sunup/sundown, it was nearly impossible to see between the spaced-long-apart white flashes.

Why paint an obstacle the same color as the clouds you must spot it against?
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Perfect example: Old Candelabra vs New Candelabra Walnut grove CA

walnutgrove_02.jpg
 
Henning said:
I'd work under them for three full loads and a partial before I finished that section of wheat, but I was well aware of where every anchor was.
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You must have been spraying in a really small and slow spray plane. I am rather comfortable working around wires and have yet to see a tower I was ok with working under the guy lines. No matter which way you approach it seems like the other wires are in the way. Then the really big towers have guys that anchor at different distances from the base making it a real PIA. In fact you are the only pilot I have ever heard say they worked under guy lines. Im not sure that was a good idea.
 
Tarheelpilot said:
You must have been spraying in a really small and slow spray plane. I am rather comfortable working around wires and have yet to see a tower I was ok with working under the guy lines. No matter which way you approach it seems like the other wires are in the way. Then the really big towers have guys that anchor at different distances from the base making it a real PIA. In fact you are the only pilot I have ever heard say they worked under guy lines. Im not sure that was a good idea.
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Yep, AgCats are not the most efficient fertilizer planes for doing big square fields,but the boss wouldn't send an Airtractor to that one, "You gotta be able to turn really fast on this field, because eventually you'll need to." Tripod guy lines make it a real PITA.
 
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