Lessons Learned – Mass Launch Fun

Maybe the title for this should be “So You THINK You Can Fly”…

This will be a cautionary tale of mistakes I made yesterday that caused me to be less than competitive.  I will also include two examples that can show how YOU can win a local mass launch.

Lesson One

When time rolled around for the WWII Combat mass launch yesterday, I pulled out my Guillows #905 P-51 Mustang (more on this model in a bit).  It hadn’t been flown since the fall, but the surfaces were straight.  But it was missing a motor.  I quickly made one out of 3/16″ rubber.  I tied the knot, lubed it up, and installed it.  As I was loading it, I told Jack, “you know, I forgot to tie the ‘new’ knot and went with the ‘old’ knot.  Now my words cannot describe the knots.  Just let it be known that my old style is what I had been doing for 20 years, but they occasionally come untied.  Last year, Winn Moore showed us a new knot that locks on itself so it will not come untied.

We had six flyers in WWII.  I made it through the first round easily.  And I outflew everyone in the second round.  It was down to me, Jack with his Wildcat, and Winn with his Tony for the finals.  I was confident.  Jack broke his motor winding.  That left me and Winn.  As I was winding – my motor broke!  Inspection revealed it hadn’t but that it had come untied.

I failed myself in that I knew that I had not done the proper knot before I loaded the motor.

Lesson Two

When I have a new plane I test fly, test fly, test fly, gradually working up to full power.  Everyone does this (right?)  But what about your small modifications on your existing planes?

Over the winter, I needed to replace the lost spinner on my Elmendorf Special.  I went from a balsa to a vacuformed spinner.  and I needed to add a backing plate to the prop.  Well, I wasn’t happy with the old prop, so I made a new one.  It was the same diameter but a different blade shape.  I was trying to optimize performance.

I gave the plane a few low-to-mid power test flights to get it retrimmed and I was satisfied and ready for the races.  I would the motor up to a base-line performance torque; somewhere between 2 and 2.5 in-oz on a loop of 3/16″ rubber.  Max safe torque would be 3+ in-oz, so I had a ways to go before that.  No worries (first rule of mass launch – just fly safe in the first round – someone will always screw up).  Unfortunately, I hadn’t tested at that torque – my plane streaked away and to the left – hard.  It made about 1/4 circuit and hit the ground with the left wing and nose.  I believe the only damage is detached wings and broken center section and associated belly tissue (I think it can be fixed).

Again, I failed myself by not following the practice of test, test, test – my different prop reacted differently to the torque and I nearly destroyed my plane.

For You – How to Win a Mass Launch

As illustrated above, mass launches are unpredictable – mostly due to the lack of human preparation.  I could write pages and pages about how people fail themselves and their models in a mass launch.  It will always happen.  We even joked before the first one that anyone can win a mass launch and I quipped how I have won them with planes that cannot fly an “official” 20-second flight.

But this is about how to win.  You need to build a good model and you need to test, test, test until you know what to expect out of the model.  You need to prepare yourself -don’t do anything different in the mass launch than what you would do in a solo flight.  If your model likes a certain power and a certain launch attitude – do that, don’t change just because of the pressure.

What you need is a consistent flyer.  In local contests and on small fields, if your plane has repeatable performance in the 1-minute range – you WILL win some over the season.  You might not win every contest, but you can rely on people – even the better flyers – to eliminate themselves.  Fellow Cloudbuster, Ron Joyal, has been flying for maybe 4 years.  But he has been learning and he will fly and fly and fly a certain model; testing and trimming.  He and his Mr Mulligan are not the best racers on our Cloudbuster field, but he has won twice in the last 3 or 4 outdoor contests because he has the most predictable performance and “some of us” can’t follow our own rules  Well done, Ron.

For You – A Good Local Mass Launch Fighter

I wrote about this plane before – the Guillows Kit #905 P-51 Mustang.  If you are just getting started in WWII and think Scale Planes are difficult – or if you are just looking for a simple and good flying fighter for your local contests, you really owe it to yourself to give this kit a try.  Mine has turned out to be a fine flyer – very easy to fly with very good characteristics.  It won’t compete at the national level, but it is my go-to local fighter.  It builds quick, it is durable, and I am not afraid to break it or lose it on our small field.

I did do some minor modifications to the kit.  Here they are:

1: The Wing:  I built it to plan, but I added 3/32″ square along the leading edge.  I am pretty sure I just cut off the rib tips and laid the square on top of the recommended leading edge.  This allowed me to sand in a rounded “entry point” too the airfoil.  I don’t know how this affects low-speed aerodynamics, I just know it makes me feel better.

2: The Horizontal Stabilizer:  I added about 1/2″ to each tip of the stab:  I just moved the provided tips out wider and built per instructions.  I read somewhere that a greater span has more effect than a deeper chord.  Again, I don’t know if this has made mine more stable than built-to plan, but mine flies well.

3: The Nose: You will have to add and/or replace wood at the nose.  make is a little stronger and make a removable nose plug.  In addition, replace the nose bearing and the prop (and the rubber).  I used a Gizmo Geezer nose button because it is adjustable.  I swapped in a 7″ Chinese prop and a long loop of 3/16″ rubber.  I also added a Nason Clutch to the prop; that is hiding under the spinner.

Of course, as detail above in the sad, cautionary tales, you need to test your plane a lot.  start at extremely low power to adjust your glide and CG.  The work gradually increase the power to get your flight pattern, using only thrust adjustments.  You will be rewarded!

 

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3 Responses to Lessons Learned – Mass Launch Fun

  1. Duke M. Horn says:

    Can’t blame you for putting a Hason Clutch on the prop, George, ultimately the plasic cam on plastic props, fail.

  2. Tom Arnold says:

    Your lessons for the mass launches made me cry bitter, bitter tears. If only I would follow them.

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