Propeller protection in sandy conditions

[Sam Rutherford]

I have spoken to the man at Hartzell:

Officially not approved (not needed)
Unofficially, put some sticky tape on there and see how you go

Anyone any advice on this? It's a feathering, aluminium prop.

Thanks, Sam.


PS They do have a protective tape for their wooden props...

[Mariner9]

Light Aircraft Spares sell purpose-made propellor tape (http://www.lasaero.com/article/a-proptape)

[NutLoose]

The people to ask are your Engineers, they should be able to check with your prop overhaul company. Incidentally this is the stuff you mean.

LAS Aerospace Ltd (http://www.lasaero.com/article/a-proptape)

[SNS3Guppy]

I've used tape quite a bit on big aircraft and small. However, much of the time, it's not the tape that's required, but proper operation of the engine and propeller that makes the difference.

When you say sandy, do you mean blowing dust or sand in the air, or are you operating from hard packed beaches or a desert floor?

If you're operating from a sandy surface or loose chips, the best thing you can do for your propeller is minimize ground operating time, add slow power for takeoff, leave the flaps up until you're ready to break ground, and do runups before you land so you don't have to operate the engine at high power settings on the ground.

In flight, sand isn't a big problem for your prop.

[Doodlebug]

Further to Guppys' good points:

1/ Sweep the area beneath the prop/s, or at least tow the thing to a bare patch prior to startup.
2/ On towing out (or on taxiing in), try not to park facing uphill. Ideally park on an incline facing downhill. This allows you to begin rolling by applying much less power.
3/ On startup, do not immediately advance to 1000 RPM (unless the manufacturer expressly advises against this, the C404 Titan should not idle below 1000 if it can be avoided, for example) Idling at 1000 will sandpaper your prop/s most effectively whilst you sort yourself out in the cockpit before finally taxiing off.
4/ Prepare well before start, so as to minimise time at idle and taxiing prior to departure. Ideally you should start, stabilise temperatures, and get airborne. Every minute on the bad surface hurts the blades.
5/ When taxiing, stay outside the cockpit. Plan the route, avoiding soft patches and shingle/shale/small pebbles. Dodge ruts or bumps that may slow you down.
6/ A heavyish light aircraft, particularly a single, will sit at a slightly higher nose-up attitude when taxiing with the yoke pulled back. Any hairs' breadth you can get the blade-tips further away from the surface will help. Keep that yoke back throughout, even(especially) on initiating the run. (bear in mind that this will influence performance)
7/ Runups can be done on the roll, utilising a long taxy or the backtrack so as to minimise braking. Back-pressure held on the yoke throughout. NOT to be attempted unless you know the aircraft well. Eyes needed outside as well as quick glances at relevant instrumentation during the checks. (certainly a bush-procedure, certainly not to be preferred to a unhurried static runup, but it can be done and definately saves props)
8/ Avoid tight turning-circles. They slow you down and you'll need to feed in lots of power.
9/ If operating on really soft sand consider tire-pressures. If fatter tires are not an option, lower tire pressures can avoid 'digging-in' and the consequent need for higher power. Check the AFM as to low tire-pressure limits! Nosewheels generally more prone to digging in. (if you ever feel the nose suddenly dropping noticeably, immediately pull mixtures. Shockload inspections are expensive)
10/ Don't come to a complete stop before beginning the takeoff-run, performance permitting, of course.
11/ Feed in the power gently, slowly, as the airspeed builds. Again, performance permitting.

Hope this helps, props are expensive, and dinged, scarred props don't deliver the advertised numbers, either.

Bug

[SNS3Guppy]

On startup, do not immediately advance to 1000 RPM (unless the manufacturer expressly advises against this, the C404 Titan should not idle below 1000 if it can be avoided, for example) Idling at 1000 will sandpaper your prop/s most effectively whilst you sort yourself out in the cockpit before finally taxiing off.


Running on one mag at idle (and leaned out) is a good way to knock off some engine RPM when operating on sand, gravel, loose chips, etc, too. I'll do the mag checks on the downwind to avoid needing to do them on the ground and just do idle mag checks on the ground while taxiing.

[Doodlebug]

Hi Guppy, new tip for me on the mags :)

Hey Sam, impressive website! Methinks that's a Maule you're poling? Tricycle-advice obviously not needed! Interesting firm you've set up, envy you your trip down south in december :{
Enjoy! :ok:

[Pilot DAR]

Simple vinyl electrical tape will work, but I suggest that you really evaluate why you need it. As mentioned, operational cautions are your best defense. Most common planes, for with sand operation would be appropriate can be carefully operated so as to avoid the damaging conditions.

If you need to use tape, plan for it to come off during flight and make a funny noise. Keep the lengths the same to affect balance the least. If one piece stays on a long time after the other departs, you'll be running out of balance for a while.

It is a float plane trick to reduce water damage to the prop, but again, proper handling will be of more value in damage prevention in the long run.

Pilot DAR

[172driver]

Sam, I guess this question relates to your upcoming little African adventure, right? If so, you'll find that many strips in Africa have hard stands where to perform a runup, typically just big enough to get the front of the plane onto. Sweep this area clean before engine start. Other than that, I think Guppy and Doodlebug have pretty much covered it :ok:

[Radar]

Sam,

My 2p worth. When we operated the Arrow down to Senegal in 2003 we were a bit concerned operating into the couple of desert strips which were scheduled. Slow use of power on the initial part of the run and we had no problems. (... and the Arrow has a lot less tip clearance than NSN, I should imagine..)

[RatherBeFlying]

Good advice above.

While beginning the takeoff with stick all the way back in a tricycle, once you have some speed you may find the a/c will no longer accelerate, you then need to lower the nose a bit to get to flying speed.

That worked for me in a C-172 with four aboard and full fuel in soft sand.