Rock your wings - on the preflight inspection

[pelmet]

The discussion is for light aircraft of course.

Do you rock your wings on the pre-flight inspection? I do. There can be more than one reason to do so. For example, to move water contamination in fuel that may be trapped.

But there is at least one other important reason, at least on some types of aircraft. If the wing is structurally unsound, it may be revealed at this point. Admittedly, your typical C172 or Piper Cherokee is unlikely to be loose but what about on those fabric covered aircraft such as the Citabria you rent or some biplane, etc. That being said, I do it even on the Bonanza, 172,Grumman, etc. Rock the wing up and down while looking at it for anything unusual.

You may just find out that the spar is broken or an attachment fitting is missing.

This pilot obviously didn't do that and he paid for it with his life. The struts on one side were not secured to the airframe....

http://www.kathrynsreport.com/2019/06/l ... ident.html

[jakeandelwood]

I've heard this is especially true for planes with bladder fuel tanks as small wrinkles develop on the bottom further preventing water from finding its way to the drain.

[PilotDAR]

Yes, water trapped in wrinkles was an issue in the C 310 I used to fly, I rocked the wings.

When I first started getting to know my new 150 32 years ago, I rocked the wings. I heard the rattle of a screwdriver handle inside the wing as it rolled around. After a few attempts, I was able to see it, and pick it out. It has "HITCH" scratched into the yellow handle, so Hitch, if you're missing a slotted screwdriver, I have it!

Following the PA-28R wing separation last year, a Youtube video was posted showing another PA-28 which the pilot rocked the wing preflight, and it was noticeably loose.

I used to fly an SW300Cbi helicopter. I would "rock" the tailboom preflight. Over time (as I flew it over years) a "creak" developed in a bolted joint, which once I reported, was attended to with some alarm.

Have respect for what you're grabbing to rock the airframe, some parts aren't intended for that, but yes, apply suitable manual force to the airframe preflight. Do not press on stabilizer tips with force enough to lift a nosewheel of, they're not designed for that, and can be broken. Unlike a wing, the stabilizer is designed for symmetrical forces only. Gentle on those, hand forces can crack ribs.

[J31]

During an annual inspection on a Cessna 185 years ago, my father found a large screw driver where the upper strut to wing bolt should be. Upon grabbing the wing tip we could move the wing up and down with the accompanying clunk. We called the owner over to show him. Visibly shaken, he said he had wondered for a while why there was a clunking noise when flying in turbulence!

Apparently the airplane had been flying for some time with a screwdriver holding the wing.

[pelmet]

Following the PA-28R wing separation last year, a Youtube video was posted showing another PA-28 which the pilot rocked the wing preflight, and it was noticeably loose.

Thanks,


The video is here proving that a Cherokee can have a loose wing. Which is why you should rock your wings during the pre-flight. It might save your life......

https://www.youtube.com/watch?v=GFYf42UE9gk

[bodyflyer2]

my father found a large screw driver where the upper strut to wing bolt should be.

I remember a Canadian incident report that was similar. It was on some light aircraft, can't recall if it was some advanced ultralight or Aeronca Champ style plane, but after some rigging work, a circuit was flown with a screwdriver in place of a wing strut bolt somewhere...

[switchflicker]

How many of us have had a loose horizontal stab on a DC3?
I personally got screamed at for 'shaking' the stab and discovering a loud clunking noise.

How many of us have had a loose float? Especially on a Beech 18.

[cncpc]

The discussion is for light aircraft of course.

Do you rock your wings on the pre-flight inspection? I do. There can be more than one reason to do so. For example, to move water contamination in fuel that may be trapped.

But there is at least one other important reason, at least on some types of aircraft. If the wing is structurally unsound, it may be revealed at this point. Admittedly, your typical C172 or Piper Cherokee is unlikely to be loose but what about on those fabric covered aircraft such as the Citabria you rent or some biplane, etc. That being said, I do it even on the Bonanza, 172,Grumman, etc. Rock the wing up and down while looking at it for anything unusual.

You may just find out that the spar is broken or an attachment fitting is missing.

This pilot obviously didn't do that and he paid for it with his life. The struts on one side were not secured to the airframe....

http://www.kathrynsreport.com/2019/06/l ... ident.html

Always do it, up to a certain size.

Same with the stab.

[pelmet]

Good point about the stab as well using an appropriate level of force.

[cncpc]

Good point about the stab as well using an appropriate level of force.

Yes, you don't want to break that which ain't broken. Or start something small which becomes big.