How to repair a crashed airplane: My approach

Frank v B · October 22, 2015, 10:20:18 PM

These were my notes covered at the first repair/build class last night:

When you crash:
- gather all the pieces... no matter how small... You may need it and you don't want to be accused of littering.
- put the airplane in the corner of your workshop. It starts to repair itself. It is amazing how some terribly crashed planes can be quickly re-built.
- establish the cause of the crash so it does not happen again.
- make sure the cause does not affect other planes in your hanger. (radio, battery, building error)

Re-building an airplane. Any repaired airplane will fly again. Keep the following in mind:
- wing and stabilizer must be true (parallel) when viewed from the front (head-on) or the back (tail view)
- fin and rudder must be 90 degrees to the stabilizer.
-build all errors and corrections symmetrically. I usually re-build one wing half and duplicate the repair on the other half.
- re-balance. Any work on the tail will shift the CG so re-balance.
- any repair involving there motor and motor mount: 1) Correct to zero down thrust and 2) zero side thrust. If you are going to be off in your guess, err to down thrust and right thrust (when viewed from the top and looking from behind). Never up thrust or left thrust (single engine airplane).

Repair Approach:
- piece the airplane together no matter how frail. Then strengthen it for flight either from the inside where possible by using wood (balsa or ply) doublers, fibreglass cloth, or from the outside by using glue, fibreglass or wood.

Remember: many repaired airplanes fly well and last a long time. Don't fuss too much about the appearance. If you can't see the repair at 50 feet and 50 miles an hour.... who cares. As well, ugly airplanes last longer.

Happy re-building.....if you lost an altercation with gravity and the earth.

Frank

sihinch · October 22, 2015, 10:53:23 PM

Thanks Frank, this is brilliant.

Plus, when you repair an aircraft I think you tend to develop more of a bond with it. A certain fondness. It has a piece of you in it.

Andy Hoffer · October 23, 2015, 08:22:06 AM

Quote from: sihinch on October 22, 2015, 10:53:23 PM
Thanks Frank, this is brilliant.

Plus, when you repair an aircraft I think you tend to develop more of a bond with it. A certain fondness. It has a piece of you in it.

Especially when you CA your fingers to it!!

Frank v B · October 23, 2015, 08:25:24 PM

Simon,

"...you tend to develop more of a bond with it."

Use de-bonder!*

Frank
* actually crashing is a version of de-bonding... in both senses of the word.

Wingnutz · October 25, 2015, 02:57:15 PM

"-put the airplane in a corner of your workshop. It starts to repair itself."
I must be doing something wrong. I have several battered indoor models sitting in a pile in one corner of the basement...no matter how long I leave them, they still look battered!

Frank v B · October 25, 2015, 03:49:52 PM

Dear Mr. Nutz,

re:"no matter how long I leave them, they still look battered!"

The difference between a beginner and an experienced crasher is the size and therefore the number of the pieces. You need to crash in larger pieces. It comes with time... guaranteed!

Frank

Skyking · October 26, 2015, 08:09:52 PM

Hi Frank,

I sent a message but maybe you didn't get it.
Can I borrow the Seadart plans/outlines?
Will you be at the Wed build class?
Thanks,

Ken

Wingnutz · November 20, 2015, 05:52:18 AM

Quote from: Frank v B on October 25, 2015, 03:49:52 PM
Dear Mr. Nutz,

re:"no matter how long I leave them, they still look battered!"

The difference between a beginner and an experienced crasher is the size and therefore the number of the pieces. You need to crash in larger pieces. It comes with time... guaranteed!

Frank

Frank,
Winning TEMAC's 2014 Crash of the Year Award puts me squarely in the 'Beginner Crasher' category. There were so many small pieces, I didn't put the DH2 pieces in a corner and wait, but instead, bought another one. I made a number of changes to Maxford USAs DH2 which I posted on the RC Groups thread and to date, the new one has survived four flights unscathed. Roger Mason was at the field for the third and fourth flights and kindly agreed to shoot this video with my phone.
http://youtu.be/KARgl0BoCYY

Roger also generously shot the video of my e-Flite B777 airliner, another repair project, which I inherited after the previous owners had given up on trying to re-power the model. Roger used his new iPhone and some slo-mo wizardry to get some pretty realistic video...thanks Roger!

http://youtu.be/jpsSY8sCh_Q

piker · November 20, 2015, 09:56:52 AM

A couple of awesome flights!

Congratulations, Bill. Well done!

Andy Hoffer · November 21, 2015, 01:42:18 PM

Quote from: Wingnutz on November 20, 2015, 05:52:18 AM
Quote from: Frank v B on October 25, 2015, 03:49:52 PM
Dear Mr. Nutz,

re:"no matter how long I leave them, they still look battered!"

The difference between a beginner and an experienced crasher is the size and therefore the number of the pieces. You need to crash in larger pieces. It comes with time... guaranteed!

Frank
Frank,
Winning TEMAC's 2014 Crash of the Year Award puts me squarely in the 'Beginner Crasher' category. There were so many small pieces, I didn't put the DH2 pieces in a corner and wait, but instead, bought another one. I made a number of changes to Maxford USAs DH2 which I posted on the RC Groups thread and to date, the new one has survived four flights unscathed. Roger Mason was at the field for the third and fourth flights and kindly agreed to shoot this video with my phone.
http://youtu.be/KARgl0BoCYY

Roger also generously shot the video of my e-Flite B777 airliner, another repair project, which I inherited after the previous owners had given up on trying to re-power the model. Roger used his new iPhone and some slo-mo wizardry to get some pretty realistic video...thanks Roger!

http://youtu.be/jpsSY8sCh_Q

Great orchestration!! We should put up speakers at the field - if the music doesn't miss a beat, maybe the pilots won't either!

Andy