RCU Forums

RCU Forums (http://www.rcuniverse.com/forum/)
-   Tips & Techniques (http://www.rcuniverse.com/forum/tips-techniques-180/)
-   -   First bipe (http://www.rcuniverse.com/forum/tips-techniques-180/11315765-first-bipe.html)

fly20 12-01-2012 08:05 AM

First bipe
 
I just finished my first biplane build. A BUSA 1/6th pup. The build itself was very enjoyable [aren't they all]. My auw including batteries [it's electric] is just under 6lbs and gives me just under a 100 watts per pound [more than enough I'm guessing]. Anyway I've flown numerous small electrics and a telemaster 40 and have gotten pretty confident with my 4*40 but have never flown a biplane. Any thing bipe specific that I should set up /watch for? Thanks for the help. Gary

flyallday 12-01-2012 08:25 AM

RE: First bipe
 
I love to fly my bipe but it did take some getting used to. Best thing would be to fly in very calm conditions until you get the hang of it. Take off and land into the wind as cross winds are a challange, land with power on and until it stops. I have found that too much rudder on the ground will get you in trouble and will result in a nose - over or worse. I fly off pavement so a nose over can bend the motor mount and need to check that consistantly - I found out the hard way a few weeks ago.

Harry

LesUyeda 12-02-2012 08:28 AM

RE: First bipe
 
"Any thing bipe specific that I should set up /watch for? "

YES. Your bipe is NOT going to float the way you are used to. Bipes are way draggy, and will have a tendency to drop as soon as you cut the power. You would like to FLY them to the ground, then cut the throttle.

Les

acerc 12-02-2012 09:26 AM

RE: First bipe
 
More of the same here. I have a Waco, Stearman, Ultimate, and all of them do not like to land slow. Generally 4-6 clicks of throttle trim does real well. Once the wheels are on the ground I bring the clicks back down. Of course I don't use that method anymore since getting a feel for it. The only other attribute I have found is useing rudder really helps in turns. For me without rudder the tail seemed like it wanted to loop around. Kinda slide outward away from the turn.
Good luck.

speedracerntrixie 12-02-2012 10:52 AM

RE: First bipe
 

Quote:

ORIGINAL: acerc

More of the same here. I have a Waco, Stearman, Ultimate, and all of them do not like to land slow. Generally4-6 clicks of throttle trim does real well. Once the wheels are on the ground I bring the clicks back down. Of course I don't use that method anymore since getting a feel for it. The only other attribute I have found is useing rudder really helps in turns. For me without rudder the tail seemed like it wanted to loop around. Kinda slide outward away from the turn.
Good luck.
Most of this sounds like trimming issues. Yes a bipe is draggy and will require some power on final but have more wing area then a mono so should slow down nicely. The rudder in the turns thing is most likely an adverse yaw caused by a lack of aileron differential.


flyallday 12-02-2012 11:19 AM

RE: First bipe
 
Not so much being able to slow a bipe down, but once on the ground is when you need keep up the power allowing sufficient airflow across the elevator and rudder. At least that is what I have learned.

Harry

speedracerntrixie 12-02-2012 11:35 AM

RE: First bipe
 

Quote:

ORIGINAL: flyallday

Not so much being able to slow a bipe down, but once on the ground is when you need keep up the power allowing sufficient airflow across the elevator and rudder. At least that is what I have learned.

Harry

I can see where this may be helpful on a WW1 airplane where the gear is narrow and a little bit aft but on what I would call a " normal " bipe it really should not be any different then flying a mono. Landing fast is usually caused by having the CG too far forward.


flyallday 12-02-2012 11:39 AM

RE: First bipe
 
Yep, you have a point and I was referring to WWl aircraft. I have no experience with a "normal" bipe.

Harry

jester_s1 12-02-2012 11:51 AM

RE: First bipe
 
Assuming a properly balanced and trimmed plane, the biggest thing is managing your momentum. The plane will slow down in a glide much faster than you are used to, so stalls come on quite suddenly. You have to really have your eyes on the plane and know how to recognize a stall coming on so you can be ready with the throttle. If you want to prepare, take the 4 star and practice doing landings at maybe 1/4 throttle, keeping the plane fast enough that you could just pull it back up if you wanted to.

acerc 12-02-2012 12:29 PM

RE: First bipe
 
Speedracer, I was giving advice to a beginner, at least that's how his post reads. If you want to give him lessons on aileron differential, adverse yaw, climb and descent in relation to throttle, adverse torque on power up, etc.etc.etc. be my guest. My post was based on a beginner's perspective. You and I know quite well all those parameter's and what to do with them, he may not yet. I'll be waiting for your book.

speedracerntrixie 12-02-2012 12:36 PM

RE: First bipe
 

Quote:

ORIGINAL: acerc

Speedracer, I was giving advice to a beginner, at least that's how his post reads. If you want to give him lessons on aileron differential, adverse yaw, climb and descent in relation to throttle, adverse torque on power up, etc.etc.etc. be my guest. My post was based on a beginner's perspective. You and I know quite well all those parameter's and what to do with them, he may not yet. I'll be waiting for your book.

I was commenting on the characteristics described by you about your airplanes in an effort to assist you. I guess no good deed goes unpunished.


acerc 12-02-2012 12:45 PM

RE: First bipe
 


My apoligies speedracer. I misunderstood your meaning. And thank's for the attempted advice. I usually welcome all the advice I can get.
Those were problem's I had years ago and good advice from people like yourself helped me thru it.</p>

fly20 12-02-2012 01:28 PM

RE: First bipe
 
Thanks for all the advice.

speedracerntrixie 12-02-2012 01:30 PM

RE: First bipe
 
No worries. I remember when I started flying, getting trimming information was very difficult. Now with these forums I like to share what Ihave learned after 35 years of R/C. I still do learn as well.

acerc 12-02-2012 01:43 PM

RE: First bipe
 
fly20- here is the best advice you will get. Find someone local that is capable and let them teach you the intricacies of set up. A club would be a good place to find such a person.

hairy46 12-02-2012 02:35 PM

RE: First bipe
 
Once again person came to right place for advice!

OliverJacob 12-02-2012 03:07 PM

RE: First bipe
 
I don't want to hijack this thread, but can anybody recommend a nice bipe for a 70 FS ?
It should be small enough to fit in a Trailblazer or should be easy to set up at the field quickly...

acerc 12-02-2012 03:26 PM

RE: First bipe
 


I had one in a Great Planes Super Skybolt. It was sweet.</p>

eddieC 12-02-2012 05:13 PM

RE: First bipe
 
The Sig Hog Bipe is good for a 70 FS, plus you can bash it to look like most anything.

mickeyrogers 12-02-2012 06:21 PM

RE: First bipe
 
You can't beat the great planes super skybolt. It flies great,is very stable and lands like a butterfly with sore feet.

JPMacG 12-02-2012 07:42 PM

RE: First bipe
 
Great Planes Ultimate Bipe 40 for a 70 four stroke. Mine has a Saito 72. Very nice combination. It fits in the back of my Forester assembled.

flyallday 12-02-2012 08:21 PM

RE: First bipe
 
Great info on off topic here.. but how does this help the OP? Start another thread.

Harry

CARDFAN 12-02-2012 09:50 PM

RE: First bipe
 
Probably the most important set up condition you should follow is wing incidence. Check it then check it again. Usually the top wing is set with a slight negative incidence to the lower wing but, whatever the plans say, is what to follow(let's NOT open that can!). Get it wrong and things can really get screwed up. Keep your speed up as everyone suggests on approach. It's also been my experience that MOST bipes like rudder or at least respond more to rudder input. Last, and this could just be my perception, but a bipe seems to have a slightly faster response to control input than a monoplane. Once it's initiated everything seems the same but that initial movement always seems quicker to me. AND alwaysremember, REAL AIRPLANES HAVE ROUND ENGINES AND TWO WINGS!!:D

rgburrill 12-03-2012 03:47 AM

RE: First bipe
 
I agree with wing incidence - especially the difference between the two wings.  I just finished my second bipe and it has ailerons on both wings where my first one didn't.  I am kind of anxious to see what happens there.

Note that the tail moment on a bipe is very short making the elevator and rudder very quick to respond.  Ground loops are quite common as is takeoff pulling to the left.  I found getting the tail up quickly was very important to get better control.  And that is also a reason to land faster than a monoplane.

drac1 12-03-2012 04:57 AM

RE: First bipe
 
All good advice in these posts. Even though a bipe has more wing area, they do require more power on the landing approach to keep the airspeed up. You need to fly a bipe in. Hold about a quarter throttle, and when you are over the threshold and a couple of feet off the ground cut the power and it should settle nicely.


All times are GMT -8. The time now is 04:33 AM.