HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Apr 29, 2010, 08:47 AM
Registered User
Joined Dec 2005
712 Posts
Discussion
My wowplanes B26 Marauder before it seconds before it crashed!

Hello fellow flyers,
I maidened my B26 Marauder yesterday-didn't go well.Within seconds of taking off she banked to the left,I applied opposite aileron but she keeped on going left if anything the turn tightened then she plowed in,I should add my ailerons worked in the correct sense-you can see in the photo I was applying opposite ban to the last moment.
I'm thinking maybe the torque of both engines turning the same direction might have been too much,was one wing producing more lift than the other,or were my engines mis-aligned with a bad thrust line ? I'm thinking of buying another kit and building her again. If you guys have any comments would be great to hear from you,I should say I have flown lots of planes mostly ARF's this is my first kit build,so I must have built something wrong to have such a reaction.
redtail is offline Find More Posts by redtail
Reply With Quote
Sign up now
to remove ads between posts
Old Apr 29, 2010, 09:04 AM
Registered User
GiusedtoBe's Avatar
Tennessee
Joined Apr 2009
5,518 Posts
Wow! I feel your pain. I'm amazed you are ready to build another one so fast. I don't want to insult your intelligence so this is a dumb question I'm sure but did it have sufficient speed on take off? It looks like a stall from the fact that it is not responding to your input. I would not think the same rotation would cause this but the real plane was known for being really tricky because of the small wing area to the size of the plane.

Is it a total loss?

Good Luck on the rebuild
Alan
GiusedtoBe is offline Find More Posts by GiusedtoBe
Reply With Quote
Old Apr 29, 2010, 09:45 AM
Registered User
Joined Oct 2009
79 Posts
Were you using any rudder? In the photo it looks straight.
howlingriffon is offline Find More Posts by howlingriffon
Reply With Quote
Old Apr 29, 2010, 09:52 AM
Registered User
stacker's Avatar
Salt Lake City Utah
Joined Mar 2004
3,307 Posts
redtail,

Did you check both motors to make sure current draw was the same? Also, was it possible that you had a large warp in one outer wing panel? The wing cores on mine were super thin out at the tips and took a lot of care to keep straight. Differential thrust from miss-matched motors are more likely. What motors and speed control did you use, and did you run both motors off one battery?

Sorry to hear about the crash ---Stacker
stacker is offline Find More Posts by stacker
Reply With Quote
Old Apr 29, 2010, 09:58 AM
Registered User
Joined Dec 2005
712 Posts
Quote:
Originally Posted by GiusedtoBe View Post
Wow! I feel your pain. I'm amazed you are ready to build another one so fast. I don't want to insult your intelligence so this is a dumb question I'm sure but did it have sufficient speed on take off? It looks like a stall from the fact that it is not responding to your input. I would not think the same rotation would cause this but the real plane was known for being really tricky because of the small wing area to the size of the plane.

Is it a total loss?

Good Luck on the rebuild
Alan
Thanks Alan and Howling Griffon,
Yes the rudder is straight,it happened just after take off-had plenty of power on as she lifted of the grass in a short distance,I wasn't airbourne long probably 10 seconds - guy at the model shop said might be a wing warp problem-I might order a new kit as I have all the gear for her,plus I know the build procedure-wasalso looking for an ARF twin which will take 2 x Eflite power 15 motors and spring air retracts-still looking lol!
redtail is offline Find More Posts by redtail
Reply With Quote
Old Apr 29, 2010, 10:16 AM
Registered User
GiusedtoBe's Avatar
Tennessee
Joined Apr 2009
5,518 Posts
Redtail would you recommend the Wowplanes kits? I've had my eye on the ME-110 for awhile as I love those planes and they don't seem to be modelled frequently.

Thanks
Alan
GiusedtoBe is offline Find More Posts by GiusedtoBe
Reply With Quote
Old Apr 29, 2010, 11:42 AM
Registered User
Joined Dec 2005
712 Posts
Quote:
Originally Posted by GiusedtoBe View Post
Redtail would you recommend the Wowplanes kits? I've had my eye on the ME-110 for awhile as I love those planes and they don't seem to be modelled frequently.

Thanks
Alan
Hi Alan,
Yes,despite my little mishap lol! Wowplanes are very good kits and yes they do some very good subjects like the Marauder,this was my first foamy kit build,tell a lie and I built a foamy kit A7 Corsair from X-flight. You must have a little experience of building as alot of the decisions are left to the builder.I was rather gutted as it took me awhile to put my plane together,mind you we all have experience of righting planes off lol ! You just move on and build another plane. I should add Fahim of Wowplanes always emails you back with advice when you need it-excellent communication.
redtail is offline Find More Posts by redtail
Reply With Quote
Old Apr 29, 2010, 02:02 PM
Registered User
makemcool's Avatar
Lansing, Michigan
Joined Oct 2003
610 Posts
looks like there is a lot of down aileron. You should have aileron differential either built, or programmed in. { down aileron is MUCH less than up]. Especially with tapered wings, and high wing loading, down aileron produces high drag, and possibility of stall, causiing it to increasingly roll in the opposite direction you have input. I am building a highly tapered wing De Havilland Comet, with which I am VERY worried about this effect.
makemcool is offline Find More Posts by makemcool
Reply With Quote
Old Apr 29, 2010, 04:31 PM
diligentia vis celeritas
gunracer's Avatar
Corona, CA
Joined Feb 2006
3,547 Posts
sorry for the loss...she was a beauty and hopefully she can be repaired...for multis, definitely check each motor's output with a wattmeter and rpm with a tachometer...
gunracer is offline Find More Posts by gunracer
Reply With Quote
Old Apr 29, 2010, 04:51 PM
Storm Runner guy
Slider2732's Avatar
USA, OK, Muskogee
Joined Nov 2008
3,581 Posts
Although I have as much experience flying one of these, as I do with paint stripping oil tankers, i'm in agreement with makemcool's observation.
That's a lot of down aileron travel straight after takeoff...if anything, I would have expected to see almost zero deflection in this nearside one. Perhaps then I wouldn't have been studying the picture and have learned from this discussion though !

Or, as mentioned in the car earlier. Did you check the fluid level for the indicator lights ?

Best wishes for the rebuild/remake/redo
Slider2732 is offline Find More Posts by Slider2732
Reply With Quote
Old Apr 29, 2010, 11:37 PM
Registered User
Joined Aug 2004
365 Posts
I'm quite sure that's a tip stall - you mentioned it took off after a short run. Because of the accelerated airflow of the props over the wing, a multi to an extent generates it's own lift - over the inboard section of the wing. The outboard section, with the ailerons isn't quite flying yet. On the next one, make sure you have plenty of speed before lift-off.

The B-26 has a pretty high wing loading and isn't a park flyer. My HL B-25 exhibits exactly the same behavior if I horse it off the grass before it's ready to fly (I get off the up elevator pronto!)

BTW, there is no torque associated with a twin with wing mounted motors - torque acts along the centerline of the motors, and airplanes roll along their fuselage centerline. There is P-factor, at high angles of attack and high power settings, but that won't have any effect if you have flying speed (which in this case you didn't!) Sorry about the accident and I hope you build another, love the B-26 - keep 'em flying! Russ Farris
pookielips1954 is offline Find More Posts by pookielips1954
Reply With Quote
Old Apr 30, 2010, 02:33 AM
Registered User
Joined Dec 2005
712 Posts
Quote:
Originally Posted by pookielips1954 View Post
I'm quite sure that's a tip stall - you mentioned it took off after a short run. Because of the accelerated airflow of the props over the wing, a multi to an extent generates it's own lift - over the inboard section of the wing. The outboard section, with the ailerons isn't quite flying yet. On the next one, make sure you have plenty of speed before lift-off.

The B-26 has a pretty high wing loading and isn't a park flyer. My HL B-25 exhibits exactly the same behavior if I horse it off the grass before it's ready to fly (I get off the up elevator pronto!)

BTW, there is no torque associated with a twin with wing mounted motors - torque acts along the centerline of the motors, and airplanes roll along their fuselage centerline. There is P-factor, at high angles of attack and high power settings, but that won't have any effect if you have flying speed (which in this case you didn't!) Sorry about the accident and I hope you build another, love the B-26 - keep 'em flying! Russ Farris
Hi Russ,
And all the other guys who have given me advice on my maiden flight,I am definitley going to build another B26 as I have all the equipment to go in her.Russ,you had me thinking about my take off,I did throttle up fairly quickly and maybe put a little too much elevator as she leapt into the air.I'm so glad for peoples advice as I now have a better understanding of the dynamics.
Thanks again.
Paul Johnson - New Forest U.K
redtail is offline Find More Posts by redtail
Reply With Quote
Old Apr 30, 2010, 05:50 AM
Registered User
Joined Dec 2005
712 Posts
Quote:
Originally Posted by stacker View Post
redtail,

Did you check both motors to make sure current draw was the same? Also, was it possible that you had a large warp in one outer wing panel? The wing cores on mine were super thin out at the tips and took a lot of care to keep straight. Differential thrust from miss-matched motors are more likely. What motors and speed control did you use, and did you run both motors off one battery?

Sorry to hear about the crash ---Stacker
Hi Stacker,
Sorry about the late reply,I was using 2 x Eflite power 15 motors and 2 x Boss 26amp ESC all off one 11.1v 3900 3S battery.
redtail is offline Find More Posts by redtail
Reply With Quote
Old Apr 30, 2010, 10:48 AM
Registered User
stacker's Avatar
Salt Lake City Utah
Joined Mar 2004
3,307 Posts
redtail,

Was there any undamaged parts? Maybe you can order just the damaged parts from Wow to save money and speed up the build. Might be able to cut on the fuse seam and re-glue new sections.

Take care -- Stacker
stacker is offline Find More Posts by stacker
Reply With Quote
Old Apr 30, 2010, 11:11 AM
Warbird E-Pilot / Hack Builder
Peoria, Arizona
Joined Feb 2009
366 Posts
I'd piece it back together, no mater how ugly, and make it fly. Then maybe build another airframe. When I see a plane flip over like that I fist suspect a stall which is made worse with aileron input. Maybe there is too much aileron travel. You neeed to get it up in the air and dialed in.
Larry076 is offline Find More Posts by Larry076
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product B26 Marauder awrightbrother Scale Kit/Scratch Built 522 Jun 14, 2012 06:02 PM
Gallery My Wowplanes B26 seconds before it crashed. redtail Electric Combat 7 Jul 24, 2010 06:34 AM
Discussion Wowplanes B26 Marauder 60 inch wing span. redtail Electric Warbirds 7 Apr 09, 2010 05:17 AM
Discussion EPF Hobby digital retracts-Wowplanes B26 Marauder redtail Electric Warbirds 5 Jan 03, 2009 06:01 PM
Discussion B26 Marauder or Ju88 Flyer88 Electric Warbirds 4 Aug 18, 2007 05:13 PM