Good Day All,

Lets Talk Gravel Opearation in a 182.....

Ok...I know all the techniques and done lots of reading on this subject over the years...as well as listened to all the masters of Gravel Operation. But....after all the proper techniques are used and the precautions are taken...what is the expectation of damage and to what extent to the aircraft? Now when I talk damage I mean of course mostly cosmetic, Paint, etc. To narrow it down....what would one expect after about 50 Landings and departures from loose gravel strips and what will the damge be to that "brand new paint job and prop"?

I cringe just asking the question!!


Cheers


Macdon221

It'll beat your horizontal stabilizer no matter what. Prop survives if you're always moving.

After a dirt strip landing threw a big rock into the underside of my tail I invested in these gravel deflectors. They cost about $1700, but are worth it if you fly into the BC regularly. AeroTwin claims no loss of airspeed and that's been the case on my 206.

http://www.aerotwin.com/products/main_g ... ctors.html

If you do much gravel strip work at all, the gravel deflectors are indeed worth the cost of admission.

Secondly, good pilot technique and keeping your head out of your butt will prevent a LOT of gravel damage. I'd get a set of the gravel deflectors, that'll take care of the paint for the most part. Then just use some common sense with the prop. You're going to get some dings in the prop.

If you need to do gravel ops, just do it.

MTV

Gravel deflector are not a bad idea. I do swear by the nose wheel scraper. Props are expensive. If you use the strip a lot, one thing we did was bring a broom. We would sweep a 10' x 10' strip at the end of the runway. It would get most of the loosest gravel out of the way, leaving the hard pack. Then add 50% of the power until you get to a brisk walking pace, then the rest. If you do this consistently (gets faster each time you do it), you get very little gravel interactions. We would also dump waste oil, I know not very green, but it was Africa, in the same spot we swept.

If your model aircraft has an option for abrasion boots, get them (185's have the boot, and a sacrificial aluminum cuff for the stab). You can glue or clamp, inner tube rubber in spots that get affected (front of brakes get beat to shit, tail wheel stinger and on nose wheel aircraft we would also put some of the inner tube rubber at the lower portions of the oleo. The prop can occasionally throw a high speed rock onto it chipping the chrome (the shaft is very expensive to replace or to have re-chromed). Secure it with zip ties top and bottom. The cylinder will just push the upper zip tie down the oleo to the bottom, collapsing the rubber, cheap insurance. Just pull it back into position before take off.

learn to file a prop, it is the price of admission to the fun places to fly.

We operate almost exclusively off gravel: it beats up the prop, the lower cowling, and the horizontal stabilizer leading edge. After a while our oil coolers look like someone has been shooting at them with birdshot! We use the gravel deflectors on most of the planes and leading edge tape on the horizontal stabilizers of all the planes. To minimize damage we try to park facing into the wind and facing downhill. You'd be surprised how much facing downhill helps: the amount of power needed to get the plane moving is much lower. Rolling run ups are better than stationary ones. If you have enough runway and can pick where you start your takeoff roll you can try using the part of the runway that has been blown the hardest and most often by other planes - it's usually pretty easy to see where that is. Slow power application can help, too.

If you operate off gravel you're going to get some prop dings and some chips in the paint. It's inevitable, but it isn't the end of the world by any means. As others have mentioned, it's good to know how to dress the prop correctly, and you can proudly view the paint chips as testimony to the fact that you don't fly a hangar queen.

Damage could depend on the type of gravel and the hardness of your tires. I have found that harder tires tend to spray gravel, especially on touchdown. There are times that the gravel will spray laterally off the tires and ding your fuselage. There is a video on you tube of a 170 making a splashdown in water on approach to a gravel bar. I am not tech savvy or would try to post the video. The video clip filmed from a camera on the bar clearly shows this lateral deflection of rocks into the fuse. Unfortunately, gravel deflectors will probably not help here. But I have found that the softer bushwheels tend to roll over gravel without scattering it out from under them. With 8.50x6 tires on my 185, I was getting little "scratches" all over the underside surface of the horizontal. With 26" bushwheels at 12psi, there is little evidence of gravel dings. I may go with 29" tires when the 26's start cording.

With relation to gravel size, pebbles of the golf-ball sized variety could require you to fix a large crack in the outboard horizontal fairing (been there). If you are unlucky enough to twang the leading edge of the horizontal leaving an unsightly dent you will wish you could go back to the days when that newly-painted airframe had those innumerable 1" long "scratches" that you could only see by crawling down and looking under the horizontal.

On YouTube, search for "splash down landing in a Cessna 170"

Guy's gonna get a shitload of rocks on the tailfeathers, just from starting and taxiing with the elevator flopping down instead of pulled back like it's supposed to be...

Gump

GumpAir wrote:Guy's gonna get a shitload of rocks on the tailfeathers, just from starting and taxiing with the elevator flopping down instead of pulled back like it's supposed to be...

Gump

Amen.....makes me cringe. I see students all the time who taxi with one hand on the throttle and the other in their lap. I "explain" to them that this is not proper technique......been instilled by a wannabe airline pilot primary instructor and a Piper Warrior. Great airplanes, but let you get away with a lot of "stuff".

MTV

mtv wrote:Amen.....makes me cringe. I see students all the time who taxi with one hand on the throttle and the other in their lap. I "explain" to them that this is not proper technique......

MTV

My very first time sitting in an airplane as a student. My very first engine start. The absolute microsecond my hand touched that starter button, not knowing any better with the stick just sitting there...

That stick came whizzing back towards my nuts, powered by that calloused old bush pilot/rancher's hand sitting in the backseat of my Super Cub, and a greasy ball cap smacked me across the back of the head...

I got THE LECTURE about where that stick was gonna be if'n it wasn't where it was supposed to be at all times.

42 years later, I don't think I've made that mistake ever again.

Gump

GumpAir wrote:Guy's gonna get a shitload of rocks on the tailfeathers, just from starting and taxiing with the elevator flopping down instead of pulled back like it's supposed to be...

Gump

On gravel bars with loose rock, I find myself pushing forward to lighten up the tail so I'm not dragging my tailwheel half buried in rock. Less power... less rock damage?
The Bushwheel made a big difference.
I have picked up horizontal damage on the leading edge and underneath, but none on the elevator....yet.
Maybe I better rethink all that.

mtv wrote:Amen.....makes me cringe. I see students all the time who taxi with one hand on the throttle and the other in their lap.

MTV

I fly rotary wing primarily... Taking hands off the controls gives me the heeby-jeebies.

Amen.....makes me cringe. I see students all the time who taxi with one hand on the throttle and the other in their lap.

Not me I like to steer isn't that what the yoke is for the bottom of my horizontal looks like I've been upside down in a hail storm

Terry wrote:On gravel bars with loose rock, I find myself pushing forward to lighten up the tail so I'm not dragging my tailwheel half buried in rock. Less power... less rock damage?

This ^^ is a good point. The smooth tires probably make all the difference in this case. You pretty much have to use down elevator to get that tailwheel off the rough stuff.

Very true, but there is a big difference in mindset when using a specialized technique to get your airplane to do what you want it to do in a specialized situation, to just being untrained or oblivious, and letting parts of the airplane get dinged up for no reason.

To get back to the original post...

But....after all the proper techniques are used and the precautions are taken...what is the expectation of damage and to what extent to the aircraft? Now when I talk damage I mean of course mostly cosmetic, Paint, etc. To narrow it down....what would one expect after about 50 Landings and departures from loose gravel strips and what will the damage be to that "brand new paint job and prop"?

50 take-off/landings would have been about two or three days work for those of us up north flying off gravel almost exclusively. I think most of us could go months without picking up a ding in the prop, or anything but minor bangs to the tail. It was all in having situational awareness, and adjusting for what kinds of surface and winds were going to let shit blow against the airplane.

On the other hand, one trip with sloppy technique can ruin a prop and make your tail look like someone took a sledgehammer to it.

Gump

Another made for fadebook video by a short peter society member driving our collective insurance cost up.