A biplane can bring you down

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pelmet
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A biplane can bring you down

#1 Post by pelmet » Sun Sep 03, 2017 6:47 pm

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PilotDAR
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Re: A biplane can bring you down

#2 Post by PilotDAR » Mon Sep 04, 2017 4:30 am

This is very true! While following a friend (both C-150s) in the wrong position, his wake stood me on my wingtip. Happily, at altitude, there was no problem, but lesson learned!
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Re: A biplane can bring you down

#3 Post by pelmet » Mon Sep 04, 2017 6:39 am

PilotDAR wrote:This is very true! While following a friend (both C-150s) in the wrong position, his wake stood me on my wingtip. Happily, at altitude, there was no problem, but lesson learned!
Have to admit, I wouldn't expect that. I used to do close-in formation flying for skydiving runs in Cessna 180 and Cessna 182 aircraft. It was common to encounter wakes but while a bit of a surprise, it was never close to doing what you experienced. Perhaps it was combined with some general turbulence as well.
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Re: A biplane can bring you down

#4 Post by AirFrame » Mon Sep 04, 2017 8:01 am

PilotDAR wrote:This is very true! While following a friend (both C-150s) in the wrong position, his wake stood me on my wingtip. Happily, at altitude, there was no problem, but lesson learned!
It's fairly common for someone with no formal formation training to find themselves in this situation. When you don't know what to expect, you can be half-way to knife edge before you realize what's happening... Especially if you hit a turbulent patch, or take your eyes off of lead to look at something in the cockpit, etc. etc.
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Re: A biplane can bring you down

#5 Post by Chris M » Mon Sep 04, 2017 1:45 pm

I've gone through the wake many times while being towed in a glider, both as demos for students and while moving from high to low tow position. At 2-300 ft it's a rough ride but not alarming if you're ready for it. Still, some heavy aileron input can be needed to keep things stable. Being in the center of one of the vortices would get exciting pretty quick.
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Re: A biplane can bring you down

#6 Post by Adam Oke » Mon Sep 04, 2017 2:13 pm

Chris M wrote:I've gone through the wake many times while being towed in a glider, both as demos for students and while moving from high to low tow position. At 2-300 ft it's a rough ride but not alarming if you're ready for it. Still, some heavy aileron input can be needed to keep things stable. Being in the center of one of the vortices would get exciting pretty quick.
Do keep in mind, that there is a rope pulling you through the wake. A similar, yet very different scenario then encountering wake turbulence when not attached. That rope does wonders keeping the nose pointed in the right direction...as it should.
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Re: A biplane can bring you down

#7 Post by cgzro » Mon Sep 04, 2017 2:37 pm

Very sad.

I have a few of hours logged formation against an AN-2. Despite horror stories about its horrendous wake it did not seem all that horrible although it was probably not at max gross when we did the shows. Its very similar to water skiing and then crossing the boats wake. You have to fight a bit to keep things level as you cross but nothing too horrific, bit like strong gusty winds on landing. Of course if you are close to stall speed it can induce a stall and if you are not careful that could get out of hand quickly. In fact I noticed the Robin had opposite aileron, no rudder and no obvious elevator input, if the wake upset stalled him, as opposed to just rolling him, thats a sure fire recipe for the incipient that followed.

[attachment=0]AN2-ZRO.jpg[/attachment]
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Re: A biplane can bring you down

#8 Post by AuxBatOn » Mon Sep 04, 2017 3:04 pm

Your roll control power in a Pitts is a bit better than a Cessna and most GA aircraft... Not a fair statement, given what you fly.
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Re: A biplane can bring you down

#9 Post by cgzro » Mon Sep 04, 2017 3:49 pm

Fair enough, I should amend my comment by noting that I never used anywhere close to full roll inputs. Just relatively minor amounts of aileron and rudder at a speed of about 80Mph , which is only ~10 above my stall. Was a bit like landing on a gusty day. Any more roll would be a bad idea anyway as the adverse yaw at that AOA gives a very nice spin departure. Not sure how the Robin behaves but full aileron at high AOA and full power may not be all that wise either but is no doubt a hard temptation to resist.

In my limited experience the Harvard is much worse (very pronounced) and twin helicopters worse still.

Anyway I'm not saying anybody is wrong (I've not flown a Robin in years) I'm just describing my experience for what its worth, certainly wise for people to give a bit of space between themselves and an aircraft that is 10x your weight and give big helicopters a very wide berth.
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Re: A biplane can bring you down

#10 Post by pelmet » Sun Sep 10, 2017 6:16 am

cgzro wrote:Of course if you are close to stall speed it can induce a stall and if you are not careful that could get out of hand quickly. In fact I noticed the Robin had opposite aileron, no rudder and no obvious elevator input, if the wake upset stalled him, as opposed to just rolling him, thats a sure fire recipe for the incipient that followed.
I find this statement very thought-provoking. I wonder if he could have been "thrown" into a stall because he was already somewhat close to one as opposed to strictly having his roll control capability compromised.
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