How Low Can You Go? (1 Viewer)

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I have no personal video because I was doing it, but I have 4 seasons of hooking aerial banners @10' or so, playing the AOD ( angle of the dangle ) of the grapple hook line down to ~2' without skipping it off the ground and bouncing over the pickup loop @3'
 
Thanks. It is odd. I have taken a ton of pictures over time, but when I was aviating I did not collect much. I was busy :)
I made some fine "high speed go-arounds" in the 310 but it was a bit like strafing. Only 1 pass, and nobody was taking videos. That second pass netted you a call from the friendly local Flight Standards District Office (FSDO), complete with a good solid ID of your tail number. I never got that call.
We had 3 planes working the big events. The boss flew his 170B, I was in his C175, and the other guy was a contract 150/150 taildragger with a single hook.
The two bigger planes were purpose assembled with Western Airways leading edge cuffs, the 180 HP Lycoming and constant speed prop from the E model Mooneys, battery relocated aft for CG, no interior or back seats.
Each had 3 glider tow hooks at the tail and 3 levers between the seats.
You tied a grapple hook to each wing tie down,
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brought the rope through the open window and tied it to the grab handle here.
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We had windows fitted that hinged at the top and opened a bit at the bottom.

Then you attached the 3rd grapple hook set to the middle release, brought it around carefully and through the open window and hung it on that yellow handle.
Carefully because if you weaved things wrong, the hook set would not release. You'd be "foul hooked" as we called it, and you were landing rather abruptly with your rag still attached.
Then you would take off, toss that hook out the window and swoop over if it was north flow and grab your sign.
Approaches were half flaps and 60. With the STOL wing and big engine, you could pitch to nil on the airspeed because the angle was so steep.
Big events were a lot of letter signs mostly, easy towing with 165' lead ropes laid off on an angle like that video.
5 passes on site, then back to drop and get another.
Come in as steep as you please with full flaps and sign drag. At 100' AGL pull the release and pitch up and come around for another after loosening the knot on the grapple.
You brought it low so it would stack in where you wanted it. A little cross wind and too high, and the sign ended up on the active runway or in the Cedar river, both bad things.
We had a ground crew on big events setting up and folding up, so we would tow 3, stop for more hooks, get another at least.
That sign in your video was a baby billboard with some letter copy at the lower edge.
We towed a lot of 20x50 billboards. All of them you laid out straight away on a 400' rope, and peeled them off the ground like a bandage.
The biggest was a Schucks Auto parts sign that measured 30x100 and the plane could not climb straight away with it.
 
...wait a minute...I know where the Cedar River is...is that airport you mentioned in Renton?
...we might be neighbors...sorta.
 
Yes it was out of RNT.
Nobody took the bait on my last line up there. :)
This 3 minute video is a good explanation of billboard towing. We did a few things differently but that is the tribal nature of barnstorming. You do what the guy who started you out did, until you figure out a better way.

View: https://youtu.be/uLNC9w1j6HQ?si=YLHLni23jmNNDmYc

Differences of our operation:
They are using a Piper Pawnee, a plane originally built for small cropdusting operations. It has a 6 cylinder 235 HP Lycoming O-540.
We used Cessna 17x with the 180 Hp O-360 from the Mooney M20C.
They approached with high energy at 85 and just motored away. This was due largely to the 50% bigger engine. Drag is exponential and nothing drives that lesson home like an underpowered aircraft pulling a giant drag bucket behind you.
We approached at 60 and pitched up quite steeply.
They had the pickup poles at 5' high and 6'5' apart??
We had 4' poles, set them about 12' and the rope was about 3'
They left the sign by the poles and ran with 300' of rope.
We took the sign all the way out to the end of a 400' rope and peeled it off the ground like peeling a bandaid.
On that second pickup @ 1:50 you can see the hook skip off the ground as he pitches up. That frequently results in a skip over the rope and a miss.
So back to my comment : " the plane could not climb straight away with it".
I'm not kidding. you hooked, pitched up, the sign peeled off and drug you back down ~100' and you pitched for 55 MPH indicated and the vertical speed indicator (VSI) hung out at a -50 ~100 FPM as you headed out over Lake Washington.
That sounds pretty sketchy eh?
This is when some barnstorming aerodynamics comes into play.
I'd call the tower "Signbird2 doing left turns climbing 1500" and the tower guys would munch their popcorn and watch what happened next.
I'd roll into a middling steep bank about 35 degrees and hold 55, and the VSI would reverse and show a decent 600 FPM climb, then 700 and 800 as the plane accelerated and climbed.
From all your pilot and sim training, the basic knowledge is turning is bad for climb performance. The old horizontal component of lift thing.
When you have this 30' tall lead pole and 3000 SF of ripstop with drag chutes on the back 400' behind you, your package is quite variable. When I started that tight turn it dropped almost back to the earth, and then dangled there like a flag on a slack wind day as I spiraled up around it. That 400' rope was all I was moving, plus the sign weight. It was quite a tug downward at the tail but manageable. No more drag.
You overshoot target altitude by at least 150' because when you straighten out, the pair of you equalize quite a bit lower.
Our assignment was Seattle International Raceways (SIR) out by Covington to the SE.
I was still at a performance deficit at that point, but we rode the thermals and ridge lift along the hills to the east of the valley with great effect. It was a rare day when I had to stop forward progress and spiral back up.
Once on station, the vast parking lots of hot pavement provided plenty of updraft to play with. I would frequently throttle back to keep the 55.
We towed it there and at the races in Portland, and the Rose Parade down there.
 
Yes it was out of RNT.
I don't know how long you lived around that area but I worked at the big U-Haul maintenance facility that was, more or less, across the street from the end of the runway of that airport (my shop was formerly the old "B&B Dodge" dealership).
Used to watch planes fly in and out all the time.
That was in '92.
One day the morning news mentioned that the freshly restored B-29 was coming in, to be on exhibit at the Boeing Museum. They must've buzzed our shop about 1/2 a dozen times.
One B-29 + four P-51 escorts = LOUD. Even at, what I guesstimate to have been about 400'-500'.
I didn't get much done that day because I kept running outside every time they flew over.
Eventually, I thought I better get to work or the boss was gonna fire me, but I never saw him. I figured he was probably standing outside of his office doing the same thing I was. :)
skyking1 said:
Nobody took the bait on my last line up there. :)
This 3 minute video is a good explanation of billboard towing. We did a few things differently but that is the tribal nature of barnstorming. You do what the guy who started you out did, until you figure out a better way.
Differences of our operation:
They are using a Piper Pawnee, a plane originally built for small cropdusting operations. It has a 6 cylinder 235 HP Lycoming O-540.
We used Cessna 17x with the 180 Hp O-360 from the Mooney M20C.
They approached with high energy at 85 and just motored away. This was due largely to the 50% bigger engine. Drag is exponential and nothing drives that lesson home like an underpowered aircraft pulling a giant drag bucket behind you.
We approached at 60 and pitched up quite steeply.
They had the pickup poles at 5' high and 6'5' apart??
We had 4' poles, set them about 12' and the rope was about 3'
They left the sign by the poles and ran with 300' of rope.
We took the sign all the way out to the end of a 400' rope and peeled it off the ground like peeling a bandaid.
SMART. Whether you got oodles of power or not, that just seems like a much less stressful way of handling the load. Less stress on the airframe, and the towing equipment.
skyking1 said:
So back to my comment : " the plane could not climb straight away with it".
I'm not kidding. you hooked, pitched up, the sign peeled off and drug you back down ~100' and you pitched for 55 MPH indicated and the vertical speed indicator (VSI) hung out at a -50 ~100 FPM as you headed out over Lake Washington.
That sounds pretty sketchy eh?
I'm not a pilot, but it seems you'd just use a gentler climb slope (departure angle?), instead of hooking the sign and shooting for the stars. Wouldn't that allow you to maintain more speed and/or accelerate faster?
skyking1 said:
This is when some barnstorming aerodynamics comes into play.
I'd call the tower "Signbird2 doing left turns climbing 1500" and the tower guys would munch their popcorn and watch what happened next.
I'd roll into a middling steep bank about 35 degrees and hold 55, and the VSI would reverse and show a decent 600 FPM climb, then 700 and 800 as the plane accelerated and climbed.
From all your pilot and sim training, the basic knowledge is turning is bad for climb performance. The old horizontal component of lift thing.
When you have this 30' tall lead pole and 3000 SF of ripstop with drag chutes on the back 400' behind you, your package is quite variable. When I started that tight turn it dropped almost back to the earth, and then dangled there like a flag on a slack wind day as I spiraled up around it. That 400' rope was all I was moving, plus the sign weight. It was quite a tug downward at the tail but manageable. No more drag.
You overshoot target altitude by at least 150' because when you straighten out, the pair of you equalize quite a bit lower.
That last part about overshooting your target altitude reminds me of navigating an intersection in a tractor-trailer rig. Another mechanic job I had was working for a truck leasing outfit and we had to have a CDL so we could pickup and deliver thee trucks after working on them.
When you're turning at an intersection, you can't just turn around the corner like you would in your car. If you did, the trailer would take out everything on the inside of the corner, so you shoot past the spot where you'd normally start the turn, so you can bring the trailer wheels close enough to the corner than when they pivot, you can make a clean turn. Sometimes, this puts you in one or more of the opposite lanes...so you just pray for light traffic. I did run over an ice cream truck once, but it turned out to be his fault, so I dodged that bullet.
Anyway, in the same way you overshoot where you want to be, in order to end up where you want to be, I had to overshoot the lane I intended to be in, in order to end up in the lane I intended to be in.
Interesting.
skyking1 said:
Our assignment was Seattle International Raceways (SIR) out by Covington to the SE.
They changed the name back to "Pacific Raceways" a while ago, but I still call it SIR too. :) Met race car driver Dan Gurney there once.
skyking1 said:
I was still at a performance deficit at that point, but we rode the thermals and ridge lift along the hills to the east of the valley with great effect. It was a rare day when I had to stop forward progress and spiral back up.
Once on station, the vast parking lots of hot pavement provided plenty of updraft to play with. I would frequently throttle back to keep the 55.
We towed it there and at the races in Portland, and the Rose Parade down there.
 
I know right where you were and flew out of RNT during that time and after. I got my float rating there also.
My work involved using a CDL to move equipment. I hear ya on getting around.

I'm not a pilot, but it seems you'd just use a gentler climb slope (departure angle?), instead of hooking the sign and shooting for the stars. Wouldn't that allow you to maintain more speed and/or accelerate faster?
We did not have the power to just "drive away" with the sign like that Pawnee in the video. When the sign comes off the ground at 60, it hangs really low behind you and a simple attempt at climbing away would result in a drag and then settling into the ground rather quickly.
The Pawnee was hooking at 85. It is a world of performance difference. We were the only ones who would tow the complete sign with only 180Hp.
The sign was in two parts:
Top 20' was the main Message "SHUCKS AUTO SUPPLY"
Zip tied along the bottom was " WHERE AMERICA LOVES TO SHOP"
The sign came to us Fedex in huge duffles and I asked why are we adding this additional 10'? Because we can was the answer. LOL.
 
I know right where you were and flew out of RNT during that time and after. I got my float rating there also.
My work involved using a CDL to move equipment. I hear ya on getting around.


We did not have the power to just "drive away" with the sign like that Pawnee in the video. When the sign comes off the ground at 60, it hangs really low behind you and a simple attempt at climbing away would result in a drag and then settling into the ground rather quickly.
The Pawnee was hooking at 85. It is a world of performance difference. We were the only ones who would tow the complete sign with only 180Hp.
The sign was in two parts:
Top 20' was the main Message "SHUCKS AUTO SUPPLY"
Zip tied along the bottom was " WHERE AMERICA LOVES TO SHOP"
The sign came to us Fedex in huge duffles and I asked why are we adding this additional 10'? Because we can was the answer. LOL.
OK, I see what you're getting at now.
Thanks for taking the time to explain that further.
 

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