SWEEPING UNDER PROPS

[Doc]

To sweep, or not to sweep? That is the question.
I've swept. I haven't swept. It makes NO difference. At all. Sometimes you'll pick up a stone. Sometimes you won't. Whether you sweep or not.
Sweeping creates little loose piles of stones. Theses ARE easily picked up by the prop of "the other" guy. These little piles of stones are also easily blown into paint jobs, spinning props and passenger's faces by arriving and departing aircraft.
I ask pilots why they sweep. Most common answer: "My boss tells me to..." Your boss doesn't have a clue.
I can't count the number of you I've seen sweep your little hearts out, only to spark up and taxi five feet, then come to a stop and just sit there.
I don't sweep. None of our guys do. We're not any better than any of you. We do get the odd nick in the props. It's a cost of doing business. I do, however only start moving ONCE. I make sure I can "go" before I start to taxi. Many of you don't.
To sweep, or not to sweep. Your call. But you're wasting your time. And you're creating potential damage for other aircraft. But most won't listen. Most never do.

[ragbagflyer]

Two points; you can't pick up rocks when you pull away that aren't there (swept away), and who says you have to sweep into a neat little pile? That said, I fly a Caravan exclusively on rock, dirt and gravel into places where brakes alone won't cut it so If I stressed out over every nick I'd be a ball of nerves. Rarely do I sweep but I wouldn't berate somebody who does.

[Maynard]

Kind if depends on the aircraft. It actually does make a difference. Maybe not on a king air, but a caravan, 207, 206 etc it sure does. Of course your going to get a nick here and there even with sweeping, but I had a picture of a prop from maintenance of a guy who never swept, vs mine and it was night and day. If you sweep properly and push through the stones so they scatter out, you won't make a pile to endanger other aircraft...again this is based on individual airmanship. If you want to talk about useless things, how about the guys putting engine tents on "unplugged" engines overnight in -30...

[flyinthebug]

You cant sweep under a floatplane prop...and water does FAR more damage to a prop then any small stones you may encounter on the ramp. Sweeping is huge waste of time for the tiny amount of "knicks" you might keep off the prop. We fire up Navajos and King Airs on gravel everyday in this country, and water is truly far more corrosive than a few peebles on the ramp.

[Doc]

Kind if depends on the aircraft. It actually does make a difference. Maybe not on a king air, but a caravan, 207, 206 etc it sure does. Of course your going to get a nick here and there even with sweeping, but I had a picture of a prop from maintenance of a guy who never swept, vs mine and it was night and day. If you sweep properly and push through the stones so they scatter out, you won't make a pile to endanger other aircraft...again this is based on individual airmanship. If you want to talk about useless things, how about the guys putting engine tents on "unplugged" engines overnight in -30...

Got quite a chunk of Caravan time as well. Sweeping does no good at all. Doesn't hurt.....but it's basically "kool aide" that some drink, because they're told it works. Your example has no validity. I've seen props chewed to crap as well. Proves nothing, except you may be a little gentler while applying power initially.
As far as engine tents go....leaving them tented overnight without a heat source is another waste of time. Might keep some snow out (although, it doesn't snow at -30, now does it?) but your engine will be as stiff as it would have been uncovered.

[Doc]

You cant sweep under a floatplane prop...and water does FAR more damage to a prop then any small stones you may encounter on the ramp. Sweeping is huge waste of time for the tiny amount of "knicks" you might keep off the prop. We fire up Navajos and King Airs on gravel everyday in this country, and water is truly far more corrosive than a few peebles on the ramp.

No problem. Just use a bailing can to move the water under the prop to the side. But don't make little piles of water. The next guy will jus blow the little piles over. Once you've bailed about 6" of water out from under the prop, you're good to go. Another problem on floats is the ineffectiveness of the bloody park brake.

[Siddley Hawker]

Another problem on floats is the ineffectiveness of the bloody park brake.

There's that, but I found if you held all the doors open on landing it was just as effective as brakes.

[flyinthebug]

LMFAO Doc!!! Thanks for makin me smile first thing in the morning! How goes the battle in YQK?

[Caracrane]

When I could't use a concrete pad,it actually made a difference especially with very low ground clearance like the PC-!2 since you cannot move right away because of the AHRS unless you made a quick turn-around and leave the batts ON.

[Caracrane]

Forgot to mention not only under the prop but at least a good 4 to 6 ft in front, takes only about 1 minute!

[single_swine_herder]

With extreme deference to my aviation colleagues who poo-poo the concept of sweeping under props, I'm "The Boss" and yes .... I tell my guys to do it not "because it feels good," but because at the very least, while it may not eliminate all potential damage, it at least reduces the risk of sucking in FOD. For those of us that have to track that kind of stuff to explain why we need new props, taking steps to decrease the probability is a big deal.

And, why anyone would sweep under the props, then taxi forward 3 feet and sit there at high power settings over "unprotected ground" is beyond my reasoning .... but suppose its done every day without anybody getting fired on the spot, so I guess its just fine.

Our airplanes have the Raisbeck mod which increases the idle speed, and with reduced prop clearance over a "standard King Air," it assists with the process of getting to "commit aviation."

Like Caracrane, we have to sit for awhile waiting for the AHRS to settle down before moving.

[Doc]

With extreme deference to my aviation colleagues who poo-poo the concept of sweeping under props, I'm "The Boss" and yes .... I tell my guys to do it not "because it feels good," but because at the very least, while it may not eliminate all potential damage, it at least reduces the risk of sucking in FOD. For those of us that have to track that kind of stuff to explain why we need new props, taking steps to decrease the probability is a big deal.

And, why anyone would sweep under the props, then taxi forward 3 feet and sit there at high power settings over "unprotected ground" is beyond my reasoning .... but suppose its done every day without anybody getting fired on the spot, so I guess its just fine.

Our airplanes have the Raisbeck mod which increases the idle speed, and with reduced prop clearance over a "standard King Air," it assists with the process of getting to "commit aviation."

Like Caracrane, we have to sit for awhile waiting for the AHRS to settle down before moving.

Well, "Boss", they're your airplanes. Tell your guys whatever you want. Most stone damage that comes home (not necessarily yours) is due in a large part to excessive reverse on landing. I see more than a few PC12's, Metros, etc., chasing a cloud of gravel down the runway on landing. The lads don't like to back taxi? Want to really protect your props? Tell your guys to roll to the end to dissipate the energy, instead of braking or reverse thrust. Again, it's not your guys. I have no idea who your guys are. Generally speaking, this is where the majority of prop damage occurs. This, and high speed turns on gravel where the nose wheel slings stones into the props. Again, I've been doing this for a long time (maybe you've been doing it longer) and I have seen no difference between sweeping and not.
Love to see more concrete pads in the north.

[single_swine_herder]

Correct "Doc," they're my airplanes.

Sure, if you've got an under-trained, poorly supervised, and ham-fisted lout with almost zero respect for equipment that jumps onto the brakes, pulls the props over the gate and into reverse a quarter second after the mains touch, then of course there will be damage. We aren't talking about that at the moment, from my reading comprehension, the is thread dealing with the value of sweeping under props.

[Liquid Charlie]

Add more crew --- saweeeeeeeeeeep yes yes -- no no --- sweeeeeeeeeeeeeeeeep

[Siddley Hawker]

Christ!! Eigil Ramsfjell is turning over in his grave!

[Doc]

Correct "Doc," they're my airplanes.

Sure, if you've got an under-trained, poorly supervised, and ham-fisted lout with almost zero respect for equipment that jumps onto the brakes, pulls the props over the gate and into reverse a quarter second after the mains touch, then of course there will be damage. We aren't talking about that at the moment, from my reading comprehension, the is thread dealing with the value of sweeping under props.

We'll just have to agree to disagree on this one.
Love the "ham-fisted lout" comment, though. Seems they're everywhere.

[2R]

Does taking a whizz on the gravel help or does it just scare away the seagulls and crowes ?

[AOW]

Does taking a whizz on the gravel help or does it just scare away the seagulls and crowes ?

It sure scares away the passengers... except for that one toothless Kashechewaner who gives you an unexpected increase in headwind........

[Doc]

Does taking a whizz on the gravel help or does it just scare away the seagulls and crowes ?

All kidding aside, peeing, or emptying your day old coffee under a prop would tend to keep the dust down. Probably as good as sweeping. As long as it decaffeinated coffee, of course. BTW, there's no "e" on crows. Or potato, for that matter. Or tomato.

[AOW]

All kidding aside, peeing, or emptying your day old coffee under a prop would tend to keep the dust down. Probably as good as sweeping.

A practice I have advocated for several years...
On that note, I won't sweep wet gravel, frozen gravel, or solidly imbeded in clay gravel. However, on those hot, dusty summer days, I do like to sweep the loose gravel away, if I don't have a decent supply of water/coffee/urine available. If I follow proper procedures, I shouldn't pick up any of the medium to large sized rocks. It is the small rocks and dust that I am most worried about, not just for prop damage, but also for clogging engine and oil cooler intakes. The way you see some people sweep, you would think that they are actually making things worse, by moving away all the big stones, and leaving just the small light ones that now have no big stones to hold them down. If you are going to bother to sweep, make sure that you sweep right down to a solid, "clean" surface, preferably damp enough that huge clouds of dust aren't going to be kicked up when you start.

No problem. Just use a bailing can to move the water under the prop to the side. But don't make little piles of water. The next guy will jus blow the little piles over. Once you've bailed about 6" of water out from under the prop, you're good to go.

Should you bail side to side, or front to back (or back to front)... does having a left-turning prop make any difference?

Another problem on floats is the ineffectiveness of the bloody park brake.

Had the same problem on skis... although I did keep my feet firmly planted on the brakes while the owner of the Chief on skis demonstrated the ArmStrong starter... As it turned out, we needed almost full power out of that little C85 just to get moving....

[Doc]

AOW, you are SO obviously uneducated in the ways of the bailing can. You bail left to right in the northern hemisphere, and right to left in the southern hemisphere. DOH!. Of course everything is reversed if the engine is British. Twice as much must be bailed if the engine is German!
NEVER bail front to back, OR back to front.
Read the bloody memo!

[Lost Lake]

If all these planes are coming and going on a pad, where is all the build up. Should be in near full beta and coasting when you hit the pad. Like others, I haven't seen the damage on start up, but on landing. Heard of 1 caravan guy, who screwed up the landing. watching from the apron, all anyone saw or heard was a huge cloud of dust and a bit of stones on metal.

[AOW]

AOW, you are SO obviously uneducated in the ways of the bailing can. You bail left to right in the northern hemisphere, and right to left in the southern hemisphere. DOH!. Of course everything is reversed if the engine is British. Twice as much must be bailed if the engine is German!
NEVER bail front to back, OR back to front.
Read the bloody memo!

My float training was so lacking! I must some day go and actually get a float rating!
What is the procedure for a Russian engine? Does the "hit it until it works" mantra from other Soviet machinary (and possibly women, too;) apply here?

[Lost Lake]

Doc, you are ssooo behind the times. To start a plane on floats, you wait for the trough in the wave. If the water is calm, you throw the f/o in to make waves. Taxi in the trough until ready to take off. Duh!!!

[Meatservo]

[quote="Doc" This, and high speed turns on gravel where the nose wheel slings stones into the props.[/quote]

Shhuurre.. And Santa Claus slings coal into our stockings at Christmastime when we've been naughty.