How to make a plug for Composite Amphibious Floats

Ever wanted to fly on water?

First of all, this is a work-in-process.  The plug is not yet complete. In fact, as I write this, it is in storage, ready for next steps. That next step would be to finish the plug, and then use it to either make a mold or start making parts.

Secondly, this is just a pictorial journey.  

As a brief overview, I created a design for a float in CAD, then exported into slice files for cutting in foam. They were stacked and shaped, then glued to a plywood bottom base. Fiberglass was applied for strengthening, also some aluminum rails.

And that is where the project sits now. It's in storage.  :-/

Breaking the Landing Gear Bulkhead on my Chipper 2

Stupid Pilot Tricks...

I had just installed the new oil thermostat in my Chipper 2.  I pulled the plane out of the hangar, eager for a break in the routine.  (I was early in the process of installing shock absorbers on the plane.) It was a beautiful afternoon, the sky was blue, the grass was green, and the plane was gorgeous.  

Chipper 2 N318KW stock photo, before recent events.

As usual, my UL350iS powered up without a hitch. My goal was simply to warm up the engine and check oil pressure & temps. The process of warming up was taking a long time (it was a little chilly) and I advanced power while keeping the brakes engaged.  This went on for several minutes. I edged the power up a bit more. My brakes were having a hard time keeping the plane from creeping forward. I'd ease back on the power, hold the brakes a little tighter, and advance power again.

All of this was extremely poorly thought out.

After advancing power again, the plane started to list to the left and settle down to the ground, like it was kneeling. Realizing that a prop strike was imminent, I retarded throttle. The tip of the prop cut into the soft grass and dirt, carrying through several blades before all became silent.

I broke my plane.

I did not take a picture. I was flaming mad. My hangar mates swiftly emerged from a hangar backroom, having heard the commotion, and walked towards me as I got out of the kneeling airplane and looked at one gear leg bent backwards. I realized that I had twisted the gear attach bulkhead. (The gear leg was not hurt.)

Then I realized I had forgotten to re-install the trailing links, so I had just ripped my gear out because of my forgetfulness.

With the help of my friends, we rolled the wounded bird back into the hangar. 

The inside of the cockpit looked like this:

And after several days of drilling out rivets, chopping out aluminum bulkhead, and cutting / pulling / fussing / fuming, the removed bits looked like this:

Over the course of the Thanksgiving holiday, I will be stepping you through what I have learned on how to repair this problem in my Chipper. I have also been using this opportunity to solve some other problems.

1) Improved bulkhead assembly for potentially higher gross weight

2) Shock absorber installation for potentially higher gross weight

3) Improvements in mounting techniques for bolts in honeycomb

4) Improvements in bonding techniques

5) General proof that this structure is repairable

And as I head into the Thanksgiving break, things are much improved. Here's a photo of how things were looking earlier this afternoon.

I do all my airplane stuff at 29KS, which is the Wichita Gliderport. It has many very smart aviation people who hangar there and build / rebuild / repair things there.

The benefit of this unfortunate event is that I am receiving honeycomb repair and assembly advice from another of these hangar mates. 

I'm going to take a moment out to brag on some of my aviation friends:

    N.: ex-CTO of Mooney Aircraft

    CW.: A&P/IA, formerly with Textron, traveled the globe fixing King Airs, versed in everything including honeycomb

    D.: A&P/IA, formerly built parts for Mosquito Helicopters, currently starting a Piper Cub parts company, currently rebuilding 3 Cubs, has built 7 Pietenpols lifetime to date, with the last one nearly done right now

    CP: 50 years with Cessna engineering, knows everything about any piston aircraft they designed. He can tell you why various Skylanes had weight changes, cabin changes, structure changes, feature changes. He is the walking and talking encylopedia of Cessna singles. 

    K: Designed composite propellers for McCauley, currently working for Textron special ops.

 

In particular CW has taken an interest in Chipper 2 and its proper repair. 

Bottom line: after this rebuild, I believe that the gear mounting bulkhead will be strong enough so that failure will not occur when the trailing link is not installed.

Thanks for reading. Please "Follow" this blog by clicking on the Follow button.  You'll be advised every time I post the next article.

Live & Learn.

Is Now the Time for Electric Ultralights?

 The biggest use of ultralight aircraft is to enjoy flight. To that end, is now the right time for an electric ultralight aircraft? I've been there and done that and want to share my history with you.

My History with Electric Ultralights

I've designed and flown electric aircraft. I threw a lot of money into this one, which featured a carbon fiber fuselage and wing. It is called "SkyDock". I developed it with a gas engine as well.

A couple of years before that, I adapted an electric motor to a classic Belite ultralight.

To help answer the question:

1. Ultralights are flown for fun; and electric flight is super fun!
2. Electric motors are available with incredible value and excellent power;
3. The best batteries ever are now available;
4. U.S. ultralight law allows individuals to do this experimentation easily;
5. Even a company or two (eg: Chip Erwin and Merlin) are publicly showing their work with electric ultralights.

Electric Installations:

Consider a single vs dual motor installation. The SkyDock was setup with two motors, while I flew the Belite with one motor. One of my customers used a very interesting single motor design for his converted UltraCub.

Want to see the electric motors on Skydock doing their thing?:

And even more details of how the Skydock Electric motor installation was designed:

Is Now the Time for Electric Ultralights?

Yes, it is.

• Electric flight in ultralights is proven by myself and others.
• Batteries can produce acceptable flight times for ultralight aviation.
• FAR 103 and Experimental rules allow it.
• Bonus: Electric motors are less expensive than gas motors. (Although offset by battery acquisition costs.)
• Electric flight has a unique sound signature, better and different than any gas motor.  It's just the prop and the airframe, no combustion sounds!

For further exploration:

I recommend you join this Facebook group, run by Bill Esker:

Ultra-electric: do it yourself electric ultralight conversion | Groups | Facebook

The Curious In-Flight Engine Failure of N3748 in Alabama

I was flying N3748, the very first Chipper 2, and I was in cruise, home-bound from a successful Sun-N-Fun in a stiff headwind. One moment, a very choppy but normal aircraft experience. The exact next moment, the propeller was dead-still, and had come to that dead-still position in just one or two revolutions of the crankshaft. It was the kind of violent engine stoppage that screams that all is not well, and that your 'full and undivided' attention needs to be on resolving the emergency of the moment. I looked down, as I scanned the area for a place for an immediate dead stick emergency landing.

I took some critique recently for editing and posting a YouTube video which was described as click-bait. This article is not that; I will tell you exactly what happened, how I responded, and what we found in the engine. I have witnesses who were there, and I have photos of the aftermath of the engine. I won't belabor this story; I've kept this as a short and easy read.

Sun-N-Fun, 2018

But the first order of business for this curious tale is to backup just a few days, to Sun-N-Fun, 2018. I was there with Chipper 2, and it was a success story. Chipper 2 N3748 performed without flaw, showing outstanding takeoff and landing capabilities.

To my delight, it even got the cover of General Aviation News. Describing the airplane as "Chipper in Paradise", it helped fuel good PR, sales, and momentum for Chipper Aerospace, my company.

Engine Changes

Chipper had started out as a two place aircraft project. I originally saw it as an airframe powered by a 60HP engine. To that end, I'd purchased a used Japanese HKS 700e engine, installed it on the plane, and discovered that the engine needed an overhaul. So Chipper never flew with 60HP.

After much consideration, I purchased a new Rotax 912UL, an 80HP engine, brand and spanking new. Everyone who flew it loved it. It did not disappoint at 80HP, and was bucking the trend that light sport aircraft needed to have 100HP engines. Hogwash; I showed them otherwise and proved it.

Yet there was that lust for power, for an improvement in ground roll, for an increased angle of climb. Without changing to yet another engine, the only way I could squeeze more performance out of my Rotax was to upgrade it using an aftermarket kit. When the engine had about 150 hours of use on it, I decided to purchase an engine upgrade from Edge Performance. 

The kit was ordered and received. It was principally installed by a local A&P mechanic. I never touched anything; I'm not an engine guy.

The upgraded engine on N3748 was what I took and showed in Florida.

And its performance was fairly phenomenal. Here's video proof, which I took in-cockpit while taking off in front of a crowd at Sun-N-Fun:

The Flight Home

This is what I remember about the flight home. First of all, the wind, blowing on the nose of the airplane, making every effort to slow my progress.  I tried low altitudes. That increased airspeed, at the expense of bitter, angry jostling of the airframe. I tried high altitudes. A smoother ride, at the expense of speed. For a long while, I was just a few hundred feet off the Alabama forests, with no landing options but with faster speeds. For whatever reason, before I reached Evergreen, Alabama, I climbed up several thousand feet.

When it Gets Real

While in cruise at approximately 4000' altitude, I experienced a sudden and complete loss of power of N3748. One moment all was well, and the next moment, the propeller was fully stopped. My body told me that a restart was not possible due to the shaking experienced while it shut down. Perhaps I touched the starter; perhaps I checked fuel.  I am not certain and I knew it didn't matter. The engine had failed.

I had been traveling over endless miles of forest, with low or non-existent options for emergency landings. I knew I had been playing my odds wrong (I'm always looking for emergency locations.)

This time, I looked straight down, and I realized that I was over the midpoint of the east-west runway of KGZH, Evergreen Regional Airport (AKA Middleton Field). Having already established glide, I made a left turn to reverse course and establish a dead-stick pattern downwind. I looked up the frequency for the airport, and quickly dialed into my radio.

I said: "Evergreen, are you there?"

An angel said back: "This is Evergreen Regional, I read you."

I said: "Evergreen, I am dead-stick overhead your airport now, landing. Can you observe my landing?" I don't remember using the emergency word, but I know that my language conveyed emergency, urgency, and fear, all in one.

The angel said: "Wilco, I'll hop in the truck and see you on the ground."

I think I got all that done while on downwind. A little voice in my hide was nagging me on the irony of dead-sticking into a huge paved airport, and then ending up short on final. That would be an insult wrapped in a tragedy inside of an emergency. I didn't want that to happen.

Adjusting glide, I added flaps and also added a little droop aileron. I listened to the electric linear motors driving the flaps and droop mechanism. I listened to the air flowing around the aircraft.

I turned base.

I turned final.

I passed over the threshold, probably 100+ feet off the ground.

I touched down. It was a pretty good landing. I was one-third down the runway, with a thousand feet behind me and two or three thousand ahead of me.

I rolled to a stop, and off to my right the Angel drove up in a pickup truck.

Tears / crying, but I was alive and unhurt.

Engine Teardown

Let's cut straight to the cause: the engine failure was caused by a failure of and/or improper installation of a clip. The engine had clearly been operating for some time with the failed condition.

Aftermath

After the teardown, the plane was loaded into a rental truck, and I drove it home. It eventually was repaired and received a couple more upgrades, before I flew it to Alaska, and it was destroyed after another engine failure. (Another story for another time.)

Curious Questions

1) Why did the engine fail when I was mid-field over an airport?

2) Why did I upgrade the engine in the first place?

3) What could have been done to prevent this from happening?

The Angel

The airport manager was a wonderful woman, whose name was Terri. She was emotionally and resource-wise helpful to me and spared no effort to make my stay in Evergreen comfortable. I got the use of the airport car, of course. :-)