InboundLZ

My Feedback: (10)

OK I am convinced that crow is the ticket. I have never used it so Ryan expect a email when it is time to set it up. I have a 12X so I should have the channels required....

furloughed ual

My Feedback: (31)

hard to see, but the crow is active and the ailerons are up in this slow pass.....

avicom

My Feedback: (14)

Congratulations Gonzalo for your nice new bird. With Michel at your side you just can't go wrong. Nice job guys. Michel try to shoot a video of that bird as soon you can specially can't wait to see those nice landing you made.[sm=wink_smile.gif]

Alex

Gonzalo38

The supplied cockpit is of bad quality.... you touch it and it almost brakes immediately, so we used some fiber to stiffen the sides. The cockpit was installed inside the canopy because in that way, is easier to install.

Hope the picture help you.

avicom

My Feedback: (14)

Are your plane was one in a hundred o with a lemon cockpit? So that means that spending $500.00 for that cockpit is like throwing my money to the trash can. Thanks for the update. I guess I got no other option but to keep my other brand 339 with out cockpit. Now I understand why they are offering the cockpit for $99.00 to the guys who buy the complete combo. But $495.00 for just a cockpit that bad quality? I don't get it.

Best Regards,
Alejandro

Gonzalo38

Alejandro:

The plastic tub that is used for constructing the cockpit is very fragile and that's the one that breaks easily. Once you put the fiber to reinforce it, you shouldn't have any problems. That's another reason for placing the cockpit inside the canopy........ once you do it, you don't touch it too much and you avoid problems. Details of the cockpit are OK.

I must be honest and say that this is not the best cockpit I've seen, but for me a jet needs to have one.

The pilots supplied are terrible....... I'm currently looking for ones that would look more scale.

I got the cockpit for US$ 100 so at the end of the day, it wasn't a bad deal.

Why don't you didn't buy the Fei-Bao cockpit when you bought the plane ?

avicom

My Feedback: (14)

Gracias Gonzalo for clarification. At least you didn't spent the $495.00 US for the cockpit. I agree a plane with no cockpit looks empty. As far I know till today there is no scale cockpit available yet for the FeiBao version. I do have the original plain plastic one that came in all kits. And it goes inside the canopy as yours. I guess I will need to find a way to make some customs details to it. But I'm not so good making cockpits. Lets see what can I do when the time to start the build arrives. Got two more projects first. awaiting for too long now.

Alex

Gonzalo38

Alejandro:

http://www.fbjetspain.com/magento/de...-t-mb-339.html

avicom

My Feedback: (14)

Thank you again Gonzalo. Need to talk to Wagner to see when they will be available in the US. Did the conversion and it's about $592 US dollars. More pricey than the SM alone. If it's not a SM one I hope they cost less for the US when available.

Alex

Gonzalo38

I finally flew the plane on Saturday...... Great plane and easy to fly.

This is my first jet so I'm still taking it easy. Michel was flying with me and he was doing the landings. Hopefully during my next flight, I will start doing some approaches and we'll see how it goes.

It looks great when you are doing a slow pass at low altitude.

avicom

My Feedback: (14)

Gonzalo tha's great to hear. Congratulations for your firt flights. Michel will guide you to a perfect landing. That way you will have a lot fun time with the 339. Nice choice for a very first scale jet. Wish you a lot fun with it. Don't forget to post some video when available. Mine will not be ready for a while.

Alex

Gonzalo38

Some pictures from last weekend









* Pictures taken by Oso

princesse

Today,I did the maiden flight of my new Skymaster MB339 ARF Plus.It flys like a dream.
It is powered by a Frank Turbine TJ74S (16Kg thrust).Weight is 20Kg empty and 24Kg with fuel.
The jet is very stable and very easy to fly.It flys very low with the flaps.

Jerome.

richbran

Hmmmm, I fell off this thread obviously, good to see it goes on.

I have bad news.
Laste saturday, after 2 immaculate flights by my son, I took the controls on the 5th flight. It flew like a rock, not difficult at all. Visibility on the model is fantastic, the white line over the wings is extremely good visible, especially in darker skies.
All went OK, made a touch and go also. Already the I noticed the floating tendency.

Then came the last landing, I came in again a bit fast, nothing to worry about. Overshot my target touchdown point. Possibly I got impatient and allowed the MB to settle with (as other pilots state) with the nose somehow lower as should be. Once You get further away from the touchdown zone, it gets harder to estimate the height of the model.
At touchdown it suddenly it started to bounce. That kind of bounce I recognize from my Hotspot when it still had the original eurokit gear.
I made the decision not to try and pull it out by engine (spool up time, lack of propellor wash) and let it settle. It did about four nasty bounces before sliding to a stop.
I felt awful.
Nosegear has been pushed back into fuse thus damage to the hull, underside. Luckily all in the silver area, so a one colour paint job will do. Landing gear formers in the wings also damaged.
Exact damage I did not look into yet, coming home I setthe model aside, I will open it when I have courage to do. No pics yet, till I feel better.

In hindsight:
I should have gone round before the second landing, maybe even after the first bounce. But I be honest, I never expected the MB to bounce with those nice trailing link gears! It caught me unaware!
I should have used the speedbrake. Due to a limit on my FC28's channels I have the speedbrake pop out at full flaps. But there is a definite nose UP tendency with speedbrake, which I want to blend out with an elevator mixer later. So I used about 90% flaps in landing, to bypass the speedbrake. I might go for crow also, I have had good results with other planes.
Fuel tank was still quite full, plus smoke tank also due to a failure of the smoke pump, so landing weight was quite a bit.

So, guys, be careful in landing and make those flares close to full stall, nose high.

Btw I have sacrificed one saddle tank for smoke which is OK, I estimate I can make safe 7min flights on the main and ONE saddle tank, using a P160.
For the rest:
The lighting system is awesome, a real eyecatcher.

Rollrate is not extremely fast, I would say very scale like. Loops no problem. Knife edge indeed just not enough rudder authority to maintain level flight. I might try more rudder later.
There was turbulence when we flew it, but this bird just eats them raw, it flew like on rails.
I told myself it will be restored to mint condition again, but that might take a while...keep You guys posted.

Gonzalo38

Richard:

Good to hear that your MB-339 can be repaired.

As you said, this plane is a real floater and if you don't cut the turbine way before for landing, the speed won't come down.

Last weekend we had a minor accident with my MB-339. Michel was bringing the plane for landing and he was coming a little bit too fast. When applying full power to go around, the turbine died and the airplane had an emergency landing. After a couple of big bounces, the airplane came to a stop. We inspected everything and the only damage we were able to found was one of the landing gear doors gone and also one landing gear a little bit loose (the landing gear didn't suffer any damage, it was the wood inside the wing).

After a closer inspection to try to determine why the turbine shut off, we noticed that the top tank started sucking air and that didn't allow the pump to suck from the bottom tanks. The bottom tanks were almost full and the top tank was absolutely empty, so there was no more available full for the turbine when Michele tried to go around.

We are checking all the hoses and we discovered that there were two that were loose. The airplane should be ready for flying this coming weekend.

richbran

Hola Gonzalo,

Hmmm You too had this bouncing act.... I guess we need a nose gear that has a real shock absorber..... The normal spring action throws the nose uncontrollabe back into the air....Much like a Piper cub does!

I too had once an engine out with another model, still on the ground, however. Just plain forgot to close the refuelling ballvalve, so after it used up all the hopper fuel, the engine died, just at the moment I throttled up for the take off!!! Since then I carefully look each time after I refuel if I closed it.

In the MB I use Tygon fuel lines, which fit very tight over nipples, plus I added tie wraps around all joints.

I like the link with the FB Jetspain Feibao cockpit. Would that one fit our MB too?

Gonzalo38

Richard:

From what I understand, both the SM and FB are almost the same....... so the cockpit should be able to go in without too much hassle. I guess that the people from FB can tell you exactly if this cockpit would fit. It looks very nice and just by the pictures, better than the SM one.

I'm also using Tygon but I guess that the we didn't make sure it was tight enough.

avicom

My Feedback: (14)

Hello Richard, the answer to your question can be yes off course. I saw Carlos's (RTI) FB MB-339 in person in the firts Dominican Republic Jet Rally. His was fitted with a SM scale cockpit. Like Gonzalo did to his, just few mods to make it fit. Looks that all this cockpit needs some little work to make them fit all. That's why I'm looking for the SM one for the one I have. But will wait to see what is the US price for the FB when available in USA to make my decision. There is a video of Carlos's one in rcjetmodel site, the video is from Kentuky Jets. You can see the Sm cockpit in that video and some tips about engine modification to eliminate the need of 4 pounds of lead in the nose.

Regards,
Alex

avicom

My Feedback: (14)

Now I got a question. How this plane handle the cross wings? I heard this plane hates cross wings more that other models. But I like to know more feedback form others who are flying this beauty.

Alex

richbran

Avicom,
I will keep an eye on the FB cockpit also. But first repairs!

If You mean cross WINDS (cross WINGS You might get when You pull too much G-'s, no plane likes toooo much G's... )

I am a professional pilot, flying all sizes, from a Piper Cub to a 747-400 (that is, I retired 3/4 years ago...), but believe me, I find it extremely difficult to land a model in a good crosswind, in the way You land a Cessna or a B747: decrabbing by rudder with upwind wing a bit low.

Theoretically the shape, not even the weight is of no importance for the effect of cross wind. The angle at which the airplane is transported off its normal straight ahead course we call drift angle. If this crosswind influence is corrected, by turning to a heading that results in following the original planned track (as we need to do on final) the angle is called crab angle.
It is the same as drift angle, only at the opposite side.

The drift angle of an airplane is ONLY dictated by 2 factors: The crosswind (vector) itself and the speed of the airplane on final. The faster You fly, the less drift angle, and therefore the less crab angle needed.
On a given day with cross wind, a Lear jet flying at 140 knots on final, has the SAME crab angle as a B747 at the same speed.

Normally very short before touchdown, this crab agle is removed, we call it the decrab manouvre. There are bacically 2 techniques which can be followed:
You keep the crab angle almost all the way till You touch the runway, keeping wings level all the time. Just before touchdown You put in just enough rudder to line up the nose with the runway centreline. Make sure You keep the wings level. Touchdown HAS to come very soonafter You initiate this one, otherwie the plane will start drifing again.

The other way to do it (you can do it on a 747 perfectly) is at about 100 feet You start adding rudder into the good direction, while at the same time adding a bit of opposite aileron, thus giving a bit of bank into the wind. In fact You are making a sideslip manouvre. You WILL touchdown on the upwind gear first!

In the case of the MB it can therefore be a factor that if You land at a low speed (slower than many other jets can), the more problems You will have in lining up the nose with the runway. General aviation aircraft like a Cessna You tend to fly faster in a crosswind landing with less flaps as normal (if runway allows longer landings). The higher speed makes it all easier plus, as a result of the higher speed, the ailerons are more effectively for counteracting turbulence.
Because IF You have a good crosswind, You will also have more turbulence!
The MB has no astronomical rollrate, therefore an upset because of turbulence might turn Your crosswind landing into an ugly one, if running out of roll authority.
Things like underslung fueltanks etc make things even more complicated as they are vulnerable to touch the runway at excessive bank angles. A B747 already scrapes an engine at only 8 degrees of bank (with compressed oleo's..)

I hope You understand it all!

So in effect for You flying the MB: Try to avoid heavy crosswinds, basically it is difficult for ANY model. The more experience You gather, the higher winds You can handle.

furloughed ual

My Feedback: (31)

I would disagree...the Mb does very well in strong crosswinds with the wide landing gear and very effective ailerons at low speed....I would fly mine with no reservations is a strong crosswind.....it's all about your ability level and understanding of the proper technique, which I have only seen about 2 guys do it properly in about 10 yrs of RC flying....it is definately more difficult in a model that doing it in a fullscale......

here's something that will help with the bouncing on the Mb, and it does bounce....the only reason it bounces is too much speed....here's what I used as a guide....if the plane is not in a nose high attutude when it crosses the end of the runway for landing, you're too fast.....go around at that time.....even with the spool up time, the plane has enough speed/energy to stay flying untill the turbine bites....

erbroens

My landing technique for this plane:

About 35 degrees of flap, no crow, no speedbrake, no pitch trim change.. final approach done in a "flat" attitude, never with the nose hanging up. I never try to land putting the wheels on ground, but instead I try to "land" on the strong ground effect this airplane has at about 1 feet of height. This means flying paralel to the ground as long as 50 meters letting the plane land by itself as the ground effect dissipates. (watching the plane doing this is absolutely beautiful). A very short rollout happens after doing this so the landing distance for this particular plane is average, even with his size and weight.


About crosswind, just pay attention on where is the plane is going and not where the nose is pointing.. keep the wing on the side of the wind low, and there should be no problems.

avicom

My Feedback: (14)

Thanks Richard for the typo correction. And all of you that all ready experienced the crosswinds in this model. I know no model likes the x winds, but some handles better than others. We ususally do not have many x winds situations but knowing the behavior of this particular model will help in taking wise decision about going up or not in a case the x wind. I asked cause Carlos told me that this model is a pig in cross winds while others planes are more forgiving. He just told me to be carefull if I get in to this heavy cross winds.

Alex

chtalbert

My Feedback: (3)

First, only 10 years of flying? More like 25. Next, thanks for the compliment.

furloughed ual

My Feedback: (31)

Nope.....u wern't one of the 2....thanks for playing....