I was looking at another group's website in NH and thought we should plan a bbq like this with the flour bomb contest. It could be open to the community and people could pay for rides and a chance to throw a "bomb". Of course we'd need some power pilots to volunteer their planes, but there could also be a Soaring Rides part of the day too.
It would raise money for the club, perhaps get new members, and be super fun. I will help organize it if we have enough pilots wanting to provide rides-I can't do that part of the schedule. Feedback welcomed.
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Dianne's post referred to a web site clebrating their airport day. Neat.
(http://ossipeeaviation.com/barbe.html)
The page included this advice on flour bombing:
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Hey! Next time, try this on the flour bomb contest:
* First you need to know how long it takes for the bomb to hit the ground
* where h= height and g = gravity (32) Next, you need to know the distance you will be traveling in the time it takes for the flour bomb to hit the ground.
d = v t where v = velocity (fps).
Sound simple? Let's try a sample:
Let's say you're going 80 mph (117 fps) and you're 200 feet agl.
First, let's calculate the time:
Now, let's calculate the distance:
d = v t = 117 fps (3.5) = 409.5 feet
So, if you drop the flour bomb 409.5 feet before you get to the target you'll hit the mark ( or be beside it if you're not lined up correctly and, you're going exactly 80mph and 200ft agl).
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Well, does his airplane have a propellor and a slipstream, or is his bomb out on the wing out in the undisturbed relative wind?
Simple Newtonian physics needs to take into account what happens when that bag of white stuff hits the propwash. In my limited experience, the horizontal velocity of the bomb changes dramatically and may even reverse relative to the ground. You could release it right over the target and get a hit.
Has anyone we know put a wind speed indicator out a Cub window (or a Champ, but no Champ owners would have such a thing) at cruise? I wonder what the propwash
speed would be relative to the airplane and to the relative wind. It certainly is in the opposite direction to ground speed and relative wind (in most cases.)
Unless you are flying a glider of course. Or better, a balloon. Which also reminds us that the real world has non relative wind too.
Not so simple as this suggests.
I guess it all depends on how much power you have on, so to be really
accurate you'd need a new pitot system set up by the release point and calculate the difference in velocities, taking into account of course such variables as dwell time in the wash, drag of the flour bag, and any force impared by the pilot's arm (I mean, release mechanism).
All this assuming that it doesn't hit the landing gear on the way down...
(nothing like a snowy day at a boatyard to encourage desk activities)
The calculation given on the website is correct in a vacuum. I think that the errors due to air resistance are far larger than the errors due to the local flowfield.
If what the website assumes were true, then the bomb would appear (from the airplane) to drop straight down. And we all know that this is far from true.
Setting the physics problem aside, I do think that Diane's suggestion is a good one, and it's never too early to plan for the next Post Mills Airport Day. Another chance to prove the superiority of Cubs over Champs.
(Darn, sure wish I had a Champ.) I'm pretty sure it was lovely green Champ, outfitted with a Norton Bomb Site, that won a bomb-drop competition at Post Mills many years ago. We also had a spot landing competion. And, something to do with throwing a roll of toilet paper out of the plane and trying to cut it with the propeller. Champs Rule!
You folks are funny- with all your mathyness. It is all about the right tool for the job. In this case a helicopter would do quite nicely. Put your flour bag exactly where you want. Airplanes are for towing gliders.
A correction to a previous comment: That bombsite was a Gordon, not a Norton.
Ok all you physics geeks, how bout some volunteers for taking up passengers? :-)
Can't get folks up there with aircraft (altho I did have a really cool flying dream with an umbrella last night, which then became a nightmare when I had to think about landing!). So how many power pilots will say YES to taking up towns folks? I will arrange most of the rest (did I say that??).
Diane
Sign me up. Sign up Andy, too (he tells me that he can't remember to read the News, so I'll just volunteer him). I will work on getting the other Champ. The Chief should be available, too. That makes four. Should be enough.
Thank you Rick!
I hope someone is up there flying now-looks boootuful outside!! Enjoy, DDC
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