Mustang Flies

Tonight I flew the Mustang for the second night. It is looking quite promising now.

I am running into the normal new plane teething problems. Nothing really too wierd however. Remember this is a new plane and a new design to me so things are going to be a little different.

The first night I discovered I have trouble choking the engine like normal. This is causing a bit of a problem getting the thing started. I think tonight I figured out how to prime the engine right. Instead of putting my finger over the venturi, I have to squirt some fuel in from my pump. I think I have figured out how much to squirt in without flooding it. Because of the scoop under the nose I am having trouble getting my finger on the venturi to choke it like my Stukas. One thing about doing it this way, the engine has been starting out slow but speeds up for about a second. It is actually kinda neat because that is how I always envision a full size plane starting. It is also fun to watch the spinner turn from black and white to a light grey.

The first flights basically have been uneventful. I was right in that the thing has turned out nose heavy. I have put in some tail weight in the back and now it is gliding and turning a little better.

One thing about this design is that it seems to need more control surface deflection than my Stuka's do which I expected. I have a Ted Fancher handle and I have had to flip the arms around in order to get enough width in the handle. If I need more, I will have to get longer arms. Right now the turn does not seem bad with the 5 3/4" spacing.

I also put in a higher ratio of elevator deflection to flap deflection. With these three things the plane is actually starting to get a corner now. Before it just seemed to stall around the corners instead of turn.

I did discover I have to be gentle on take offs. On my Stukas I can pull on the lines a fair amount when I pull the pin and I have no ill effects. Not so with the Mustang. The first time I thought I had a bad angle. The plane rolled just a bit, turned into me just slightly and then the tail came off the ground and it flew level on ground effects for a little bit with the lines slack. It was actually a rather neat take off for any bistander who did not know better. The plane road the ground efects very nicely. I could hear a very rapid clickity clack the whole time. It was the shock gear working very nicely as it bounced on the rough ground. I know of a couple of people that put shock gear on their planes. While theirs worked, it seemed stiff. Mine works quite well and is quite free.

This last take off just elevated my adrenalin just a bit and only made my heart skip a beat. The next time was a bit different. I got a huge adrenalin rush and my heart stopped for a much longer period. I figured out after this next one that pulling on the lines is not a good idea at all. The plane suddenly went up right after I pulled the pin and turned into me causing the lines to go very slack while it was in FF mode. Fortunately I, as Ted Fancher once said, have fast feet. Probably spurred on with the adrenalin rush. I caught it in plenty of time but it is an experience I would not like to repeat again thank you very much.

I still have things to correct should be on the downhill side of things for the most part. I did not have a lot of time tonight but will later on this weekend. I have not done much other than round and square loops. It is not ready for the whole pattern yet but should be shortly.

Ah! Just like the full-sized 'Stang...P-factor raising the pucker factor. Hang in there, Matt. Take it slowly. Too much work went into this one to rush things.

>Ah! Just like the full-sized 'Stang...P-factor raising the
>pucker factor. Hang in there, Matt. Take it slowly. Too
>much work went into this one to rush things.
>
>Mike Keville
>A clear conscience is usually the sign of a bad memory.

Yeah, a 15" 2B prop can throw you around a bit. On the first lousy take off that was my thought so I pulled a bit more on the lines the next time. However, when I pulled the lines, I think I caused the outboard tip to pop up which is why it came in on me the second time.

Yes, it is going purposly slow which is why I have only done some simple loops and a lot of level flights.

This problem is easily solved by adjusting the alignment of the wheels as described in several Stunt News articles. The Mustang will then be completely normal in its take off characteristics, better than normal, in fact. For now launch with the nose pointed out a bit. Gyroscopic precession is yawing the airplane into the circle as the tail comes up on the roll. If you start with the nose out a bit, everything will balance out and you will be able to maintain normal tension at the release. For now you simply aren't used to the prop effects of having a nose high sitting attitude at launch. If you adjust the wheel alignment, you will learn to love it.

Matt,

In reference to your choking problem I may have a solution. I have that same reach problem on several of my models. On a SIG Mustang I used the eraser end of a pencil. The eraser fit the venturi nicely and I could choke it consistantly. On my Gladiator that wouldn't work, so I made a soft balsa plug that I stick in the venturi and choke, pull it out and start. I know that sounds clumsy, but I found that pump priming is both inconsistant and messy. After a few times out I statred remembering the keep the pencil or plug in my pocket along with my booster battery and finger guard. I also found that the balsa plug makes a good storeage plug and have taken to putting them in all my models.

>Matt,
>
>In reference to your choking problem I may have a solution.
>I have that same reach problem on several of my models. On a
>SIG Mustang I used the eraser end of a pencil. The eraser
>fit the venturi nicely and I could choke it consistantly. On
>my Gladiator that wouldn't work, so I made a soft balsa plug
>that I stick in the venturi and choke, pull it out and
>start. I know that sounds clumsy, but I found that pump
>priming is both inconsistant and messy. After a few times
>out I statred remembering the keep the pencil or plug in my
>pocket along with my booster battery and finger guard. I
>also found that the balsa plug makes a good storeage plug
>and have taken to putting them in all my models.
>
>Randy Ryan <><
>AMA 8500
>SAM 36
>BO all my own M's

I am also ahead of you too on something to plug the venturi so I can choke it. That will be tried in the future. A venturi plug like you described would also be best when filling the plane. The fuel tends to drip out of the venturi when filling and getting on the inside of the cowl. I had been putting a paper towel in the venturi but that only works so well. An Actual "hard" plug would probably be best. I will find out in the near future.

>
>This problem is easily solved by adjusting the alignment of
>the wheels as described in several Stunt News articles. The
>Mustang will then be completely normal in its take off
>characteristics, better than normal, in fact. For now
>launch with the nose pointed out a bit. Gyroscopic
>precession is yawing the airplane into the circle as the
>tail comes up on the roll. If you start with the nose out a
>bit, everything will balance out and you will be able to
>maintain normal tension at the release. For now you simply
>aren't used to the prop effects of having a nose high
>sitting attitude at launch. If you adjust the wheel
>alignment, you will learn to love it.
>
>Al

Already ahead of you on that one. After the first incedent, I also thought of a little nose out attitude, I think I just had a little too much and that caused things to bounce on the lines agrivating the problem. Like I said, this is a new plane and new characteristics to me. It is just a matter of learning what it wants to do and how to expect them. Whenever you have a new plane there is bound to be some "exciting" moments now and again.

Matt,

Just go slow. Better to take it easy until you have stuff down. I've lost a couple of planes very early in their lives due to impatience. The plane will usually tell you when it's ready to move to the next step.

Are you running an air cleaner on your engine?

bill
Matt
The engine choker I use on my Mustang is a piece of aluminum tubing with an ear plug in it. I had to make a small notch in the bottom cowl lip but it is well worth it .
All the best Batman

Bill,

I noticed your notch on your cowl. I have a picture of the bottom of your plane with you holding it. And you thought I was getting it for the fun of it. I did have alterior motives.

Anyway, I am figuring on making something here probably this weekend. I shall have to see what I come up with. I have made the modifications to the plane and am now waiting for weather.

I do not have a filter on the Mustang. The thing is it may help because it would trap some fuel in it while filling. This would help with the priming. However, due to the way the cowl is made, I doubt if i could fit one.

Oh, just as a funny side note. One other thing that just happened last night is that the engine bolts came lose. I was actually missing one while the other three were loose. Ah, the fun of having teething problems.

Yes guys, I am taking this slow and methodical. Dad learned the same lesson a long time ago about not stunting a plane before it is ready.

Dad learned the same lesson a long time ago ...
===============================================

The "hard way", we presume.

>Dad learned the same lesson a long time ago ...
>===============================================
>
>The "hard way", we presume.
>
>Mike Keville
>A clear conscience is usually the sign of a bad memory.

Yes, but now I preach the gospel of experience to others.

The game of chess is only won by capitalizing on the mistakes of others. I could play ten games in a night and go back and replay each game move for move. Whenever I lost a game in my younger years I would go back and replay the game to find where I made my mistake. I would then determine not to make that one again. There are enough mistakes we make in life. No sense making the same ones over again.

LAST EDITED ON May-06-06 AT 02:27 PM (CST)
 
Matt,

I have the same problem with priming. Actually, there is no problem, just a change in procedures. There is no way to choke either my Classic Bearcat and Snaggletooth Mustang. I run filters (panty hose) because I fly off hard surface with some loose gravel.

I fill my tank with a pump then use the pump to back the plunger of my syringe back a measured amount for an accurate prime. I prime the first flight with a small syringe spraying it up into the filtered venturi. Then I turn the engine over a couple of times before lighting the plug. I usually get first flip starts. Subsequent starts usually require no priming for first flip starts.

I observe that my starts are just as prompt as anybody I fly with including Richard. About nine out of ten times the engine starts on the first of second flip. If it doesn't, I simply hit it with the starter. No messin' around. No whittlin' on my cowling.