Official FlightLine 1600mm B-25J Mitchell PNP Thread

[davegee]

I had a great morning under near-perfect weather conditions to do the maiden on my Flightline B-25J model today. I started by taking up my "weather ship" the E-Flite Beech 18 to get a feel for the winds aloft and as a warmup before the main event. We have some weird extremely local micro weather conditions at our flying field which is on Bureau of Rec land with lots of sagebrush, rocks, and not much else. No excuses to run into a tree, because there are none! But I have found that just two miles away at reliable weather stations, or flags flying in front of buildings, the weather can be 180 degrees out of phase at the field, usually with discouraging results. But this morning, everything lined up and I was ready to fly!

I did some tests yesterday like taxi tests, turns, etc., just to get a feel for how this model behaves. Did a full power test and range test too. This morning I did the same prep, checking flaps, gear and retraction, and security of the removable wing panels. All was good.

So I took off using low rates and 30% expo per the assembly manual with an Admiral 5000 6S battery pushed all the way forward. All control throws were book values, and I flew most of the 5 flights I flew in low rates.

I've had a couple of Flightline B-24s, a DeHavilland Mosquito, and Flightline P-38, not sure if I've had other multiengine prop planes, but I was reasonably assured that this would go relatively well. First takeoff was scale, low climb angle with takeoff flaps. and then I cleaned up the gear and flaps for several laps checking out trims. Needed hardly any correction, maybe one up-click in elevator at level flight with the gear up, but nothing else.

The first landing was actually not bad, however I was a bit alarmed as I almost ran out of elevator authority in the roundout to landing pitch attitude on the mains with a little nose up and a bit of power right into the touchdown. I did other flights with just a little more power and it was a bit better, but I decided to do just one more flight with the elevators in the mid-rates position. This made a BIG difference as I had adequate pitch control and a slightly nose up landing about as good as I could ever do with this airplane. I hope to make the landings more consistent with this setting,
and I think it will work out ok.

I did load three of the little foam bombs that came with the kit, and dropped them from a low altitude as it passed by me. There was a little left to right wind, and the bombs took off with the wind a bit. I tried to find them afterwards, but never did. But I think they looked pretty cool coming out and the bomb bay doors worked great. Fortunately, I have access to my 3D printer and can print up a ton of these little bombs for future use. I think I'll paint a set of them fluorescent orange so I can find them more easily. Plus, these will have the screws in the nose so I think they'll drop closer to the aim point, than the kit foam bombs. We'll see.

In conclusion, I'm delighted with this new addition to my "fleet." You still have to stay on top of it as with any plane, but this one with its great suspension gear for our rough runway, mid-wing position and elevators that clear contact with the ground even if you get into a bit of a pickle on a landing or two.

I usually don't fly on the weekends so I will work on the airplane this weekend with some scale details like a removable pitot tube and a few scale drainage tubes on the engines. I'm going to try and make some scale looking panels on the inside of the bomb bay doors that have round lightening holes in them for a more scale appearance when the doors are open. And I'll print up a bunch more bombs to use to practice with my little bomb rack, design courtesy of Fast N Light.

Callie is set to ship my specific markings for this plane, called Cactus Kitten. I should get them next week to finish up the markings part of the model building. Lots of weathering and other details to go.

I highly recommend this airplane, for those interested in multi-engine warbirds.

Cheers

Davegee

[davegee]

Great job, Davegee. Onward and upward!

Thanks, Rex. I'm looking forward to getting the maiden done soon. Still a lot of detailing, decals, weathering, etc., but that can be done later this fall/winter.

[jetfool]

Great job, Davegee. Onward and upward!

[davegee]

While waiting for my B-25 to arrive via FedEx tomorrow, I printed a few items I plan to use on my plane on occasion. These are bombs and a bomb rack, and a tray to put small parachute items in so they hopefully don't snag on the airplane coming out of the bomb bay.

These designs are courtesy of Fast N Light. The bombs have holes drilled through them and mount onto 12 aluminum 1/8" diameter tubes. When the bomb bay doors open, they will fall out by gravity. Or that's the plan, I'm thinking it will work. Per Fast N Light, a 3 g. M5 screw 16mm long is screwed into the top to give it more stability and realism during the drop to the ground. You can drop from 1 to 12 bombs simultaneously. I have 6 made up now for Initial tests. I'll try to drop them in the ground just off to the side of the runway so that they don't break and I can find them again!

The tray that I printed up is designed to put soft items in, like parachutes. The hope is that they will fall out of the bomb bay without getting caught on some structure of the airplane.

The aircraft I am going to replicate, Cactus Kitten, was in a unit in the Pacific Theater that did strictly low level work; strafing and low altitude bombing. One thing I read they did was tie a parachute onto bombs that were going to be dropped at very low altitudes, hopefully giving them enough time to escape without "fragging" themselves on their own bombs! Unfortunately, this happened many times to pilots and aircraft doing dive bombing and low altitude bombing during WWII.

I'm hoping my B-25 will be ready for its maiden flight sometime this upcoming week. Once I have a few successful flights on it, I'll add the bombs and other scale details to the plane. I'll post developments here as they happen.

Cheers

davegee

I made some progress on assembling the plane yesterday. Got the wings on for the first time, painted white stripes on the outboard wing sections that this unit had, and did a test bomb drop in the shop just now. The main purpose for today's test was to be sure that the bombs (6 of them in this test) would drop clear of the airplane when the doors are opened and the bombs slide down the aluminum tubes.

I took note of the unfortunate accident that our friend Arthur from France had on his maiden flight of his B-25. I don't know exactly what happened there, but I did take away that is is possible for the pilot to get distracted watching the bombs or parachutes drop out of the airplane during flight. I took that to heart, as I could see I could be distracted for a glimpse of this just long enough to lose control of the aircraft. I'll be sure to keep my eyes on the plane at all times, and if a friend is around to snap some pictures or video that is a much better way to go for me.

I'll include a photo of the bombs in the airplane. I tried a10 second video of a static drop in my shop but it was too long. I might try another one later, but this one proved what I needed to know for now.. Each bomb (up to 12 max load) has a 5mm 16 screw that is screwed into the nose. This will hopefully give some stability and realism when they are actually dropped on a flight. We'll see.

Possible maiden has slipped to sometime next week, weather permitting. It will still be a work in progress for several months as I do some additional detailing and weathering of the airplane. So far, I'm liking this airplane.

[TiredIronGRB]

DUDE! It's been a minute!

I still fly, new runway, living off-grid over in the woods for a few years

[Aros]

I might get one of these…

DUDE! It's been a minute!

[davegee]

I just started in on my new B-25J that arrived yesterday via FedEx. The only things I've dome so far is add the extra header printed exhaust fairings onto the cowlings (now 14 per side as this was a 14 cylinder R2600 engine) and they came out pretty well. I also repainted the yellow cowls to red, per my intended replica of Cactus Kitten when I get done with it. In my reading, I found that the crew chief of this aircraft was from Wyoming, so he painted on a sexy cowgirl as the logo for the plane on the right side of the fuselage. Always like having a connection with Wyoming wherever possible!

The other minor painting detail I did was repaint the crankcase cover from silver to semi-gloss grey. I masked off and found that Tamiya spray Ocean Grey was a pretty close match to the bluish-grey crankcase covers on rotary engines at the time.

Thanks, Elbee. The printed fairings from Fast N Light were a very close match to the foam ones molded on the cowls.

davegee

[Elbee]

Very nice work, Dave.

[Elbee]

RRHandy, yours, too. Best, LB

[RRHandy]

I might get one of these…

Good to see your Avatar here again,

[davegee]

I just started in on my new B-25J that arrived yesterday via FedEx. The only things I've done so far is add the extra header printed exhaust fairings onto the cowlings (now 14 per side as this was a 14 cylinder R2600 engine) and they came out pretty well. I also repainted the yellow cowls to red, per my intended replica of Cactus Kitten when I get done with it. In my reading, I found that the crew chief of this aircraft was from Wyoming, so he painted on a sexy cowgirl as the logo for the plane on the right side of the fuselage. Always like having a connection with Wyoming wherever possible!

The other minor painting detail I did was repaint the crankcase cover from silver to semi-gloss grey. I masked off and found that Tamiya spray Ocean Grey was a pretty close match to the bluish-grey crankcase covers on round engines at the time.

[Elbee]

I might get one of these…

Hey TI, great to read your voice, Sir! I have yet to start working on mine. It is really a good-lookin' aircraft. Best, LB

[TiredIronGRB]

I might get one of these…

[Elbee]

Maybe others have seen this one already? The distraction begins ~12:50

Oops.

[Fast N Light]

Maybe others have seen this one already? The distraction begins ~12:50

https://www.youtube.com/watch?v=5AeKV1wPMZk

[Elbee]

Fast N Light

Parachutes are a crowd-pleaser due to the lengthy hang/observation time. I give control to the bombadeer (aka SAFE) during the bomb run, which gives me just a moment to observe the release without flying the plane into the ground. Be careful folks. Common for models to be lost due to pilot distraction during drops



Best, LB

[Fast N Light]

FNL, ahh, a builder/designer after my own heart.

Very nicely done and thank you for your effort and the STL files.
Your picture showing all of the previous variants of the nose is very familiar to me.

It is part(s) of the process. Again, great work.

Best as always, LB

LB,
When I started the gunship nose, I decided to track the waste driven by my design process. A number of factors have made it a more challenging than most project. Eg having to eyeball the external shape, conforming to the 'greenhouse' attachment surfaces, printing a large overhung thin (0.9mm) shell and structurally capable gun barrel supports. A full size print is 10 -14 hours on an X1C. Plenty of 'that didn't work, lets try it another way ..." on this one. Frustrating in the moment, rewarding it the long run.


Thanks for your complements/contributions

These designs are courtesy of Fast N Light. The bombs have holes drilled through them and mount onto 12 aluminum 1/8" diameter tubes. When the bomb bay doors open, they will fall out by gravity. Or that's the plan, I'm thinking it will work. Per Fast N Light, a 3 g. M5 screw 16mm long is screwed into the top to give it more stability and realism during the drop to the ground. You can drop from 1 to 12 bombs simultaneously. I have 6 made up now for Initial tests. I'll try to drop them in the ground just off to the side of the runway so that they don't break and I can find them again!

The tray that I printed up is designed to put soft items in, like parachutes. The hope is that they will fall out of the bomb bay without getting caught on some structure of the airplane.

Cheers

davegee

Credit to Tom Hunt for the original design work for the ordnance and storage rack. With 3g nose weight, my drops have been flawless (meaning they released and 'flew' scale like😄)... Best to salvo before landing. Also scale for one or 2 to deploy on landing or other high G maneuvers.... Save the touch and gos until after the drop mission is completed.

I am pleased with how the M5 screw, basket and quick release modifications came out. Highly recommend using the printed fixtures to set the retainer clips precisely in the bay. Hope you like them as well.

As always, there is room for improvement. The tail fins on the ordnance tend to break on hard surfaces. I think they tumble after initial impact. Mine are ASA. Maybe a tougher filament (eg nylon?), a little less then 3g in the nose, design change to reinforce that location, reduced airspeed on release? Parachutes are a crowd-pleaser due to the lengthy hang/observation time. I give control to the bombadeer (aka SAFE) during the bomb run, which gives me just a moment to observe the release without flying the plane into the ground. Be careful folks. Common for models to be lost due to pilot distraction during drops.

[davegee]

Hi Fast N Light: great ideas there! I have printed up the exhaust header covers already, not knowing you had already designed them and put them on Thingiverse. They came out great!

I've settled on a glazed nose version of the B-25 I mentioned in a previous post, but I love the solid nosed B-25 covers with machine guns that you have come out with. If I ever get another B-25 after this one, or change the version of the one I'm waiting on delivery on Monday, I'll definitely use your designs on those. I'll probably do something like what you show for bomb racks later down the road when I get this plane together and some flights on it.

Thanks for all your magnificent designs.

Cheers

Davegee

While waiting for my B-25 to arrive via FedEx tomorrow, I printed a few items I plan to use on my plane on occasion. These are bombs and a bomb rack, and a tray to put small parachute items in so they hopefully don't snag on the airplane coming out of the bomb bay.

These designs are courtesy of Fast N Light. The bombs have holes drilled through them and mount onto 12 aluminum 1/8" diameter tubes. When the bomb bay doors open, they will fall out by gravity. Or that's the plan, I'm thinking it will work. Per Fast N Light, a 3 g. M5 screw 16mm long is screwed into the top to give it more stability and realism during the drop to the ground. You can drop from 1 to 12 bombs simultaneously. I have 6 made up now for Initial tests. I'll try to drop them in the ground just off to the side of the runway so that they don't break and I can find them again!

The tray that I printed up is designed to put soft items in, like parachutes. The hope is that they will fall out of the bomb bay without getting caught on some structure of the airplane.

The aircraft I am going to replicate, Cactus Kitten, was in a unit in the Pacific Theater that did strictly low level work; strafing and low altitude bombing. One thing I read they did was tie a parachute onto bombs that were going to be dropped at very low altitudes, hopefully giving them enough time to escape without "fragging" themselves on their own bombs! Unfortunately, this happened many times to pilots and aircraft doing dive bombing and low altitude bombing during WWII.

I'm hoping my B-25 will be ready for its maiden flight sometime this upcoming week. Once I have a few successful flights on it, I'll add the bombs and other scale details to the plane. I'll post developments here as they happen.

Cheers

davegee

[davegee]

Davegee,

Both FW-190 and Tigercat require 40%+ throttle on landing leg to a 2-point landing , I don't want to get behind the curve and stall. learning more about throttle management each flight and know the Corsair requires this also.
Today club had a display at our city airport day and the airport manager asked me to taxi my Corsair ( have a sound system installed) around the display area for people to see a model and hear a P&W sound. Pretty neat w/lots of videos being taken. Most people didn't realize the complexity that can be involved in this hobby.

A Day in Paradise, Rex

How Fun!! And How Fun for all who got to see and hear your Corsair!! Well Done!!👍👍👍

[jetfool]

Davegee,

Both FW-190 and Tigercat require 40%+ throttle on landing leg to a 2-point landing , I don't want to get behind the curve and stall. learning more about throttle management each flight and know the Corsair requires this also.
Today club had a display at our city airport day and the airport manager asked me to taxi my Corsair ( have a sound system installed) around the display area for people to see a model and hear a P&W sound. Pretty neat w/lots of videos being taken. Most people didn't realize the complexity that can be involved in this hobby.

A Day in Paradise, Rex