1st. Flight report on the Panzerflug twin

[John Miller]

Today was the day. The baby has taken it's first steps in the air.

I'm so fortunate to fly with Gordan (Mr. Twin) Delaney, and Norm Whittle. They were invaluable help to me today.

First, the plane seems to have a lot of potential. Level flight both upright and inverted seemed to groove well. Turn rates seemed pretty equal on first rerview. Line tension seemed good at all altitudes flown. The wing seemed to be pretty level upright and inverted. The ploane has a good power off glide, and the gear appears to be located optimally.

Now the items that really need to be addressed.

As the engines are currently set, the 9X4 APC props seem to be loading the engines more than they seemed to like.

I need to do some more work getting the tank height set proper for both engines.

I will need to make up a new set of lines dedicated to this plane. The ones I'm using are setup for my Pathfinder Twin, and I need to legnthen the up line slightly. I dont want to mess up the settings by making changes to this set of lines.

The most imnportant area, of course is getting the engines properly dialed in. Electric would be easier to setup, but I love the smell of castor in the morning.

Here's whats been done, and is going to be done before Sundays flying session.

Since I'm getting about 6+ minutes of flight from only 2 ounces of 10% fuel, we're betting that the venturiis need to be opened up some. We've already adjusted the depth the spigot goes into the throat of the vebturii. This should increase the size of the venturii's opening. I'm also going to change from the highly efficient APC 9X4 props, to the Master airscrew S2 style props of the same size. Norms experience was good with these props, and my Pathfinder twin did well with them also.

If the pesponce to the above change is good, but I still need more, I can open up the venturiis a bit, and, or up the nitro.

I'm quite happy so far, I think the plane may have a bright future.

[wwwarbird]

 Thanks for the update. What engines are you using again John?

[John Miller]

I'm using a pair of Magnum .15XLS from Hobby People. Nicely built engine.

[john e. holliday]

9-4's sound like a lot of prop for .15's.  You are so lucky to have the guys you have to help.   

[John Miller]

I agree about being lucky to have the guys who help me. There's a lot of knowlege about the sport spread between them.

It seems that modern .15's, set up properly, can turn those 9 inch props efficiently. I just need to find the right combination.

On the Twin Pathfinder, Gordy is using the 9X4 APC with about 1/4" clipped off each tip. Using 20% nitro on a pair of OS .15 fp's, he had to lengthen his lines out to 66 feet. The plane flies with authority. Norm was using a pair of OS .15's, I think they were the AX versions, dual ball bearings. Anyway, he could run the same props, at the same speed, while using 10% nitro. My PF Twin used a pair of OS .15LA's, and turned the Master Airscrew 9X4 Scimitar style props to the same speed on 20% nitro.

I believe the Magnums, which seem to be a clone of the engine Norm was using, should equal the performance. As stated before, I just need to find the right combination of prop and venturri's.

Thanks for your interest, support, and encouragement guys.  

[ChrisSarnowski]

Nice work, John, looking forward to hearing more reports.

-Chris

[John Miller]

Sadly, the Panzerflug is no more. It was progressing so well too. I changed to the Master Airscrew Scimitar style 9X4's. They guaged out as 9X3+ with their phillipd entry.

The engines liked the change, but about 90 percent through the flight, the nose dropped and I had no control. I watched it plow into the ground and break up.

It was a control system failure. The 4-40 bolt holding the elevator pushrod ball link was missing. I'm checking the photos from the build, I may have forgotten to use a jam nut.  

It was showing a lot of promise, so much so, that I'll either re-build, or build another.

Edit: Well, I checked the pictures from the build, and it deffinatly shows that there was indeed a jam nut. Not just any jam nut either, but a locking version. I'm not sure what happened to the screw, but it wasn't there in the wreckage.

[Martin Quartim]

John,

I feel for you my friend.

Take care

Martin

[john e. holliday]

Very sad news.

[Bill Little]

BUMMER!  I really hate that for you, John.  I could sense the excitement in your previous post.  Build another!

Big Bear

[WhittleN]

John

Stop building twins, although they fly nice and I watched yours develop nicely - all twins (except Gordan's) do not have a long life span.  Mine lasted about 25 flights, Bart's less and yours about the same.  Sorry for your lose.

Norm

[John Stiles]

Sadly, the Panzerflug is no more............... Well, I checked the pictures from the build, and it deffinatly shows that there was indeed a jam nut. Not just any jam nut either, but a locking version. I'm not sure what happened to the screw, but it wasn't there in the wreckage.

Gremlins

[Mark Scarborough]

It was the damn spitfires, I knew it,, somehow they have an insider on the skunkworks, and find this stuff out,,

John, very sad, I feel fortunate that my Avenger has survived trim flights so far,, knock on wood,,

[Dalton Hammett]

I also sorry to hear that that plane was wrecked,  it was a very interesting looking project.  Are you planning on repairing or rebuilding

Dalton H.

[John Miller]

Thanks guys. I've got the remains sitting next to my work bench while I acess the damage, before making the decision over repair, or build a new one. I don't think a re-build would be too difficult, but a new build would allow me to make a few changes that might make for a better design. I'll know in a few weeks or so.

[Howard Rush]

Too bad, John.  It was a cool plane.  I hope it's easier to fix than it initially appeared.