epsilon
Active member
So... about my PBY crash here's the post I made about it when it happened.
PBY Water Ops preperation and bonus! Post flight(cough, crash) analysis...
Flown@
MidWest AirWing R/C Club Videos and Photos
Contributing factors...
1. CG (Center of gravity):
I may have been a bit too far forward with the CG. This would help explain the trouble with the nose being so low in the water. This also can cause issues with flaring which I'll get to in a bit...
2. Thrust angle:
I'm not 100% convinced I got the nacelles glued on right. There was a noticeable clearance difference between the two props and the canopy, meaning they weren't both attached the same. This is due to a... not necessarily a flaw but more of a short coming of the design imo. There's not really any guide or markings to help with alignment. Compounding the above problem in water whenever thrust was applied, further driving the nose down.
3. Elevator travel:
The geometry of the guide tube for the elevator pushrod seems to be a bit off. This puts an excessive amount of strain on both the rod and the servo controlling the elevator. As a result, I had limited up elevator throw and inconsistent response from that control surface; which is a huge problem when trying to "flare" a plane coming in for landing.
4. My own experience:
I have very limited experience flying a bird in this weight class and 0 experience before today on water.
While coming in for landing that last time I was struggling to control the decent rate and air speed. I inadvertently bled off too much speed which caused the plane to stall and begin to simply fall from the sky. I added power and attempted to pull up to slow my decent but with all the above factors, it was simply too late. Lol, I've been watching waaaay too many episodes of Air Disasters on Amazon prime! It's rare that any one factor leads to a crash. It's usually a string of events which lead to catastrophe.
In reality, the damage isn't that bad... the wings broke clean at the glue joints. I could likely dremel off the front damaged portion of the fuselage, reprint, and replace and with a bit of work, could probably get it to look as good as it ever did. All that said, I've learned so much since beginning this build that I'm not sure repairing is the best way forward here. There are many things I would do differently to get a better print in general and there's also the question of some of the design short comings, some of which I think I could fix now with my current skills... others, I'm not so sure. I might just check everything out once it dries out and salvage the components for now. Either way, I got 3 flights out of this thing and really could get it in the air again if I really wanted to.
PBY Water Ops preperation and bonus! Post flight(cough, crash) analysis...
Flown@
MidWest AirWing R/C Club Videos and Photos
Contributing factors...
1. CG (Center of gravity):
I may have been a bit too far forward with the CG. This would help explain the trouble with the nose being so low in the water. This also can cause issues with flaring which I'll get to in a bit...
2. Thrust angle:
I'm not 100% convinced I got the nacelles glued on right. There was a noticeable clearance difference between the two props and the canopy, meaning they weren't both attached the same. This is due to a... not necessarily a flaw but more of a short coming of the design imo. There's not really any guide or markings to help with alignment. Compounding the above problem in water whenever thrust was applied, further driving the nose down.
3. Elevator travel:
The geometry of the guide tube for the elevator pushrod seems to be a bit off. This puts an excessive amount of strain on both the rod and the servo controlling the elevator. As a result, I had limited up elevator throw and inconsistent response from that control surface; which is a huge problem when trying to "flare" a plane coming in for landing.
4. My own experience:
I have very limited experience flying a bird in this weight class and 0 experience before today on water.
While coming in for landing that last time I was struggling to control the decent rate and air speed. I inadvertently bled off too much speed which caused the plane to stall and begin to simply fall from the sky. I added power and attempted to pull up to slow my decent but with all the above factors, it was simply too late. Lol, I've been watching waaaay too many episodes of Air Disasters on Amazon prime! It's rare that any one factor leads to a crash. It's usually a string of events which lead to catastrophe.
In reality, the damage isn't that bad... the wings broke clean at the glue joints. I could likely dremel off the front damaged portion of the fuselage, reprint, and replace and with a bit of work, could probably get it to look as good as it ever did. All that said, I've learned so much since beginning this build that I'm not sure repairing is the best way forward here. There are many things I would do differently to get a better print in general and there's also the question of some of the design short comings, some of which I think I could fix now with my current skills... others, I'm not so sure. I might just check everything out once it dries out and salvage the components for now. Either way, I got 3 flights out of this thing and really could get it in the air again if I really wanted to.
