First Flight N90AK, the Monster Cub takes off

[Litecub]

February 12, 2021 completed first flight for another Mackey Cub, N90AK. It started as a wide body Cub with Javaron wings and part way through the project I met Wayne and he gave some good suggestions and ultimately essential help to morph the cub into a monster. The wide body fuselage was cut at the aft fittings and 2 more feet welded on, full box(no gingerbread ) large electric trim motor for the stabilalator and large tail feathers to help balance out for the Lycoming YIO-390 and Wayne's up sized cowling to fit the big motor up front. It has 8" extended cub gear with Black Ops shocks on the front and the Black Ops Stinger on the tail, Whirlwind ground adjustable 3 blade composite prop, 3rd seat with huge extended baggage and baggage door. Wayne had some spare SQ 2 ailerons so those went on, Keller 3 hanger flaps and Backcountry slats for the leading edge. More to come as I work out the performance parameters after engine break in.

[Litecub]

[stewartb]

Congrats, Bob. I hope it makes lots of smiles.

[aktango58]

Wow!

Congratulations!

[Bill Rusk]

A huge congratulations Bob. Well done!


Can’t wait to see it fly. See you in May


Bill

[gpepperd]

Congratulations Bob, awesome job!

[vj88]

Awesome cub. Whats it weigh as configured? 2300 gross? Oversized tail feathers?

[Litecub]

Awesome cub. Whats it weigh as configured? 2300 gross? Oversized tail feathers?

With 35" Alaskan Bushwheels and the bigger cargo pod it is 1,355 pounds. On the skis as configured in the picture 1,335 pounds. It has does Javaron oversize tail feathers. I gave it a 2,200 pound gross weight as had to transition the aileron cables through the rear spar which I reinforced with .090" doublers riveted as well as the brackets for pulleys so not any higher gross weight.
After first flight I had to move an oil cooler line and get a couple of the probes to register so will fly again tomorrow and see what's next to fix. It has put a smile on my face, my father-in-law, George Pappas was out during the first flight and a friend who was visiting with him heard him say after 45 minutes of flying they were going to have to shoot me down to get me back on the ground.

[skywagon8a]

There's a name from the past. I met George 40 years ago. A very clever fellow. He is one who knew how to wrap the FAA around his little finger.

[mam90]

It has put a smile on my face, my father-in-law, George Pappas was out during the first flight and a friend who was visiting with him heard him say after 45 minutes of flying they were going to have to shoot me down to get me back on the ground.

So great to hear another Alaska aviation legend is still with us and hanging around the airport. Growing up on Merrill Field in the 70’s allowed me to meet many of these men.

[Litecub]

There's a name from the past. I met George 40 years ago. A very clever fellow. He is one who knew how to wrap the FAA around his little finger.

George drove over in his Tesla to upload the latest update and had to wait for 45 minutes for the system to reboot so got to see the first flight We both were commiserating about computers later as I put an EFIS in this Cub and have the same problems. I would not do the EFIS again.

[Dan Gervae]

Congrats on the completion of your Cub....It's a beaut. What EFIS did you put in it? Give us a nice PIREP once you get some hours on it!

[stewartb]

My G3X had an internal communication hiccup during commissioning. Mike figured out that the Can Bus wasn't terminated. I wouldn't have figured that out on my own. I don't know a can bus from a school bus.

[akavidflyer]

My G3X had an internal communication hiccup during commissioning. Mike figured out that the Can Bus wasn't terminated. I wouldn't have figured that out on my own. I don't know a can bus from a school bus.

I dummied up with the G5 install on mine and couldn't figure out why the magnetometer wouldn't work. They should put different ends on so you cant plug into the instrument without have the terminator on it for those of us who hate to read the instructions and look at pics closely. Had to call a buddy who tried his best to not make me feel too stupid to figure it out.

[Litecub]

Congrats on the completion of your Cub....It's a beaut. What EFIS did you put in it? Give us a nice PIREP once you get some hours on it!

The panel is powder coated in sections so can remove portions to access behind. I used the MGL Challenger Lite EFIS, their recommended probes and support boxes. Will get the Stratus and WiFi connect to the iPad mini running ForeFlight to get some traffic. Still staying close to home and on skis so feel very comfortable buzzing around the Meadow Lakes area while the engine gets broken in. As I get more experience with it will report how it performs. So far when it slows down it is a rudder controlled plane.

[stewartb]

What CG are you operating at? My plane works better if I get the CG aft of 15". It makes it a more comfortable plane to fly.

[Litecub]

What CG are you operating at? My plane works better if I get the CG aft of 15". It makes it a more comfortable plane to fly.

Full fuel, myself and 100 pounds in rear seat gives CG at 15.5" aft of leading edge. I have 2 hours in 2 flights so little to reference but it does fly well at this loading with heavier feel to the controls than a stock cub. My tail is light at 62 pounds when level and empty so that is why I have 100 pounds in the back for initial flights.

[stewartb]

My tail's about the same on the W&B. But tey to lift it when the plane has gas and a little gear in it. Yowza!

[Kodiakmack]

What iPad mount is that?

[Litecub]

The iPad holder is a RAM mount that is made for an iPad in a protector so thicker slots. It retains the iPad with a spring that pulls down the top portion or the iPad. It works well and I have a second one I use in two other planes retained with a RAM ball and their clamps.

[Kodiakmack]

Thanks! That’s awesome. Any issue do you know with putting that on a certified AC panel?

[Litecub]

Not that I am aware of. I have a Garmin 296 mounted on the panel in an Airgizmo with charger cord. Hard wire might raise an issue. Others please chime in.

[Dan Gervae]

Its just a piece of plastic screwed to your panel , should be no issue....I have basically the same mount in my build....I'm Experimental, but i believe my statement still holds

[Litecub]

Well the cylinders have broken in with the CHT initially running 320 degrees to a peak at full power climb of 340 degrees. On the third flight all cylinders dropped to below 300 and I cut the flight short as the oil temperature was running 130 degrees and it dropped to 115 degrees while keeping power above 65%. I needed to get the engine to run warmer so used duct tape to block air inlet as a test similar to what has worked for me on my other aircraft with cold temperatures.

With the cylinders blocked off much happier with these temperatures and next flight will have some aluminum winter fronts on and uncover the oil cooler to see how the engine likes the inlet airflow. My preference would be to block or restrict the outflow with cowl flaps but that would be a major undertaking with my current cowling.

[Kodiakmack]

I want to find out the why for sure, but my IA implied that screwing something into the panel could be considered installing. We will go with that for now and will use 3M dual lock. We’ve used it in other settings and it is rock solid. If it’s bumpy enough to remove my iPad mounted with dual lock I’m having bigger problems lol.

https://www.amazon.com/3M-Dual-Lock-...NsaWNrPXRydWU=

[stewartb]

What cruise speeds are you seeing?

[Litecub]

[QUOTE=Kodiakmack;797850]I want to find out the why for sure, but my IA implied that screwing something into the panel could be considered installing. We will go with that for now and will use 3M dual lock. We’ve used it in other settings and it is rock solid. If it’s bumpy enough to remove my iPad mounted with dual lock I’m having bigger problems lol.


This is the RAM mount set up in the stock Cub. Charger cord to iPad and also runs out to “temporary mount” on access panel for GoPro camera.

[DENNY]

Well the cylinders have broken in with the CHT initially running 320 degrees to a peak at full power climb of 340 degrees. On the third flight all cylinders dropped to below 300 and I cut the flight short as the oil temperature was running 130 degrees and it dropped to 115 degrees while keeping power above 65%. I needed to get the engine to run warmer so used duct tape to block air inlet as a test similar to what has worked for me on my other aircraft with cold temperatures.

With the cylinders blocked off much happier with these temperatures and next flight will have some aluminum winter fronts on and uncover the oil cooler to see how the engine likes the inlet airflow. My preference would be to block or restrict the outflow with cowl flaps but that would be a major undertaking with my current cowling.

This is the beauty of having a properly instrumented engine. Especially in an experimental setting with new engine/cowling/fuel systems. I remember seeing one custom build advertised that needed new cylinders in under 100 hrs if I remember correctly. Having a good grasp on how the engine is performing the first 5 hours is priceless. Great job!!
DENNY

[Litecub]

What cruise speeds are you seeing?

Will show some panel pictures of the EFIS screen to answer your question. Currently still roaring around the valley at 9 to 12 gph breaking the engine in, changing engine rpms and mixture frequently. The prop is set course pitch and I don’t get full rpm redline of 2,700 in level flight and only 2375 on liftoff. It does get off quick about 3 seconds and 52 yards the one time I paced the tracks in the snow.

[Litecub]

Winter fronts on today and CHTs OK. I did uncover the oil cooler for the flight and the oil temperature was down again so will make a plate to cover for winter ops too.

[stewartb]

I’ll admit I’m curious about your prop. Very interesting.

[Litecub]

I’ll admit I’m curious about your prop. Very interesting.

Stewart;
Too early to really tell as I will be flattening the pitch and cruse lean of peak once I’m sure the rings are seated. I’m along ways from getting it dialed in. Today I finally looked at the moving map and it had me in Girdwood as I went by Palmer. Computers🤷*♂️. I’m more focused on the engine and airframe for the first flights.
Cheers,
Bob

[stewartb]

I don’t understand your EFIS display in the pics. What MP are you seeing?

[Litecub]

Stewart
That makes two of us. The EFIS is a MGL Challenger Lite which is user programmable and that is where the problem lies. I now regret putting a flipping computer in this airplane as I do not do well with such unreliable electronic devices and am dependent on others to “fix” it. The last flight as I was going by Palmer and looked at the moving map which had our location in Girdwood. The engine monitor page has the manifold pressure in increment that do not make sense as you pointed out and I have made one attempt to change it with limited success in that I was able to change the range in which it reads but now get the MP heading which overlaps on the readout number one still on top of the other. This whole system has caused a delay in my completing the project with a hardware problem that is still in the ECB (electronic circuit breaker) and should have been flying last spring. As it is I get to fly it and the engine monitor is working and use the iPad mini for navigation until such time as the flipping EFIS get tuned up buy someone who knows the program as I just want to remove it and put in steam gauges that are reliable and do not require programming and may do so next winter.

[stewartb]

I'm sorry to hear about your struggles. I'd think MGL could diagnose your problem from your description. Side story- I was struggling with a function on my G3X and was frustrated enough to call tech support. I told them what it would and wouldn't do and they asked a few odd questions. Then they told me I had two wires pinned into an incorrect connector. WTF? How did they come up with that? Not the wrong pin location but the wrong connector? They were right, too. When this stuff works it sure is impressive. I hope you get it sorted.