johnls

I wondered what is the concensus of opinion with regard to installing undercarrige in a wing. I know that with ARTF aircraft you have little choice, but where you do have a choice is it best to make the whole undercarriage bay as strong as possible and bolt the landing gear in, or is it best to accept that not every landing will be perfect and a weak link should be built in to save the wing, ie screw the gear in, etc? in the hope that in a bad landing the screws would give first.
Any thoughts?

John

acw

My Feedback: (1)

I have a lot of experience with bad landings, finally, here is a question I can answer with confidence

The best way to go is to have a solid LG mount with some machine / metal screws tapped into the wood. Start with 4/40 / or 3-4mm. If a bad landing get the screw loose, you can always remove the screw, add CA and tap again. Worst case, you can go to a larger screw. This works for me but I fly relatively small jets (17-24 #) and from tarmac. I suspect this won't work from a grass field.


Arnaud

KC36330

use trailing link struts and it'll soften most of the hard landings.

DelGatoGrande

My Feedback: (23)

i saw some photos last year where a guy had used a bolt with washer and spring to hold down the retract to the wood..
i guess he fine tuned the tension so the force to move this springs is biger than the one to compres the leg full in...

this way you can save trunion and wood mount....but you know what they say...if you are good you can brake anythink!

hysol your woods ..get trailing link struts and "abort + go around " if nesecery for a better landing

sorry for the bad english

highhorse

My Feedback: (2)

The designer of the hugely successful Boomerang series swears by the "screw" method as a built in "fuse" that will blow before the rails get ripped out. Even on the XL version (35+lbs) he specs servo screws for mounting the gear. It just didn't seem right to me so I asked him specifically about that point, and he re-affirmed the method. I have read EVERY post regarding EVERY Boomer in the series and cannot recall the gear mounting ever being an issue, so I suppose it's safe to believe that the man knows what he's talking about

sidgates

My Feedback: (2)

Where the space is available I prefer the carbon flex plate with wood screws holding the carbon to the wood rails front and back. Not my original idea, I got it from the BVM T-33. First the flex plate has some give and as a last resort the flex plate pulls the wood screw out of the wood rails.

Once I ran my Boomerang intro off the end of the runway and hit a praire dog hole. That pulled the wood screws out of the mounting plate and no other damage. In this case the Spring Air nose gear is screwed to the wood plate.

ianober

My Feedback: (12)

Practice practice practice and you wont have to worry about your landing gear. No system obviously is bullet proof but I have been moving to self tapping wood screws. They provide more than enough grip for the gear but in case you dork it they would pull out easier than bolts and maybe, just maybe, leave your rails in there.

I would first suggest solving the ultimate problem though, land proficiently each time

Boomerang1

If undercarriage damage is a concern my answer is just 2 words: wire legs.

I persevered with solid struts for a while & was forever fixing something after less than perfect landings & rough strips. Once I built a bender that can bend coils in 1/4 wire the rest was easy.

Obviously you cannot bend big wire to a very small radius so you will need an axle adapter at the bottom of the leg. If you like fancy looking undercarriage legs the adaptors can be made pretty. - John.