I decided to post some info on the Royal B-25 that I would have loved to read while I was building it.

I have about 18 flights on her now and let me tell you she flies GREAT. I am using two O.S. 40 Surpass engines which have plenty of power at my 2500 foot elevation. Total weight is about 9 lbs.

Today was a real eye opener for me with this being my first twin. I lost my first engine. Not only once, but three times. The first time was in flight just after a flyby. I brought it back around and landed with no problems. After tinkering with it I thought I had fixed the problem. Just after takeoff I lost the left engine again. Any of you full scalers know that the left engine is the critical engine who's loss will most adversely affect Vmc due to P-factor (in other words losing the left engine is worst case scenario). I originally was going to pull the throttle back and land straight ahead off field but I decided to suck the gear up and try to bring it around. The B-25 has lots of rudder and that lone O.S. 40 was able to actually climb and bring her in for a landing. In this scenario speed is life. Even more so than altitude. I accelerated and flew the pattern at about 20 feet.

I was originally told that the O.S. 40 surpass engines were under powered but that is not the case. Also I read that scale aircraft make lousy first twins. I'm sure this is true but the Royal B-25 so far has flown great with an engine out.

Oh yeah, the third flame out was a up high again. It failed after flying for about 8 minutes(plenty of fuel left). That was enough single engine work for the day. The engine has come off and will get a good look over. I am no longer terrified of the engine out scenario. Its is still a tense moment but I know that my B-25 will no fall out of the sky like I had thought.

Like I said, I just wanted to share my experience with this plane. So far it has been a pleasant one.

Sean

Sean

I am just now finishing off my Royal B25 and it was good to hear your experience flying on one engine only. Mine will have Webra Speed .40's - hope to have it in the air in the next couple of weeks.

Brian

PilotKelowna:

I guess your going to take some time off if you're going to finish your B-25 in a couple of weeks.

Can't wait to see it when it's done though. You better make sure I'm there for the first flight though.

hummmzzz, interesting.......i have a Aerotech B25, about 72" with 2x OS35FP engines. Mine also flys ok on one engine, must be the nature of the planes......i hope my royal B17 will fly ok if i get an engine failure.

cheers

Andrew, from the rainy UK

I have read the comments on the b-25 being hard to fly on one engine but i have also done several one engine landings and in my opinion the b-25 is easier to fly than the 38 on one engine . I also think that they fly better with about 50 to 60 size four cycle engines . I have flown them both ways and i prefer the four cycles because they seem to run more reliably . I flew my original royal b-25 on two old K and B 40 TWO CYCLES AND LANDED IT SEVERAL TIMES ON ONE ENGINE , UNTILL A JOKER AT THE FIELD TURNED ON HIS TRANSMITTER AND SHOT ME DOWN ON THE 13 th FLITE. No problem with the b-25 Tom

I just ordered a Marutaka B-25 (same as the old Royal) and I plan to use YS .63s in mine. I have been flying a Great Planes Corsair powered by a YS .63 for over a year and the engine has been perfect right out of the box. Ultra reliable. The only flameout I have experienced has been due to running out of fuel. Can't blame that one on the engine.

That's great news embpic1. I just had the first flight on my b-25 yesterday and I must say it is one smooth flyer. Mine is a little heavy at 11.4 lbs. But it has 2 .46 fx's and pulls just fine. Everyone on here said that B-25's are worse than a P-38 with an engine out, just looking at the plane this didn't seem to be right, I glad that you posted your experience here now the engine out doesn't seem as intimidating. Although I will use great caution if this does happen..... How about everybody show pics of there royal B-25?

Michael

One thing some guys try to do on a twin is to get maximum power out of the engines . You should not do this Get one engine fairly close to max R.P.M. and then richen it about two to three clics and then bring the other engine up to it . You dont need to scream the engines , you just want them to run reliably. FLYBABY

Here is a pic of my B-25. It it is a work in progress. I ultracoted it but have plans to glass it next year if it survives that long. I plan on flying it about 10 to 15 times a week for the forseable future.

Hi guys well I have a B-25 but its not a Royal its a Wing B-25 and last week end was suppose to been its maiden flight. Just wasn't in the card though had too many grimlems so I hope that in a couple weeks that maybe it may happen. First of all could not get enough RPMs out of the engines. Found a fuel line pinched have to remove fire wall to fix. One of the alerions didn't quite work like it was suppose to so have to repair it. Backup battery pack had a cel go bad and it was new. Burnt out both landing lights and mechanical brakes didn't work quite rite a little more repair work needed here. My plane weights in at about 18# dry and the wing lode will be a little high. But I have cofedence that she will finally fly just have to get the wind gods to cooperate. And tell the grimlens to take a vacation.

That looks good emb, come on lets see everyone's B-25. Here's a pick of mine.

Here are a few more pics taken today

Sean

flyby

.

Done for the day.

SWEET SEAN!!! I wish we could fly them together. I bet that would look real sweet. I noticed the big platue in the background do you live in Arizona?

Wow! That was a good guess. I just moved to Tucson, AZ. I fly at a field called TIMPA. I flew her 5 times today with no real trouble. The left engine acted up a bit again but it did not quit. Not too worried if it does. This thing flies great on one engine. My only problem has been with the gear. I have Spring Air retracts with 3/16 gear legs and they bend easy. After about three or four flights I usually have to take out the main gear legs and bend them back. I plan on tempering them soon. Hope that fixes the problem.

I am going to fly her again tomorrow. I love this plane!

Sean

It realy looks good and i bet it is warm out there too. My next twin will be my zirolli b-25 and i will s.t. 2500s for power as per twin man. flybaby

My buddie snapped this shot of my b-25 a week ago I had to share it.

Michael

That is a very good picture . If it is a digital camera i would like to know what type of camera it is as i am about to replace mine with something with more pixels . Let me know if you can . [email protected] Thanks Tom

That looks nice mugenkidd. Have you had any engine failures yet? I have a total of 35 flight on my B-25 with about 6 failures. All have been the left engine. The funny thing is that the left engine is brand new and the right engine is an old one I have had for many years. I started to suspect fuel lines or maybe the fuel tank but they both checked out ok. It will run at full throttle just fine for about 30 seconds and then it will start to act like it is rich. I also noticed the needle valve is not very sensitive. I can turn it quite a bit with no noticeable effect on the engine at full throttle. It runs fine when at 3/4 throttle or less. So what I have been doing is taking off at full throttle then reducing to about half throttle after takeoff. I have flown it for 10 Minutes at half throttle with no problems. If I leave it at full throttle for too long, the engine quits.

Sean

I've put about 30 flights on my WM F-82 with 2 left engine failures. Once halfway around before landing and the other at the end of the runway and flying all the way around with no problems.
A couple of OS FX .46's.

embpic1, knock on wood no engine outs so far, I really try and double check everything before I fly. My B25 is pretty heavy at 11.5 lbs so I am really dreading the engine out. Your engine problems sounds like it may be an airleak somewhere, that would explain why the needle valve doesn't have a lot of effect, check all of the seals and see if you can see if any exhaust or residue is around the cylinder head(leaky head gasket), there also could be dirt in the carb on that engine, but engine problems can be a very large pain and its hard to say. Good luck.

Michael