Propellers are DANGEROUS
 

Maybe I'm a little old fashioned. Maybe I'm a boring old nag.

During my basic training it was drummed into me that props are inherently dangerous. A prop that is momentarily rotated can flick over and it is not unheard of or even that rare for the engine to burst into life

You turn the mags off and the prop is only safe if both mags ground at the P lead.

Ergo - it is best to treat all props as "live and dangerous".

Over the past two or three weeks, I have seen people pull and push aircraft using the propeller blades as the lever.

Today I witnesed a whole family pose for the photographic reminder of their aerial baptism - fantastic, but no one warned them to avoid the propeller. Two wee boys were "hanging" off the blades and the photo was taken. It is statisically highly unlikely that the engine would have started, however as alluded to above, it is not uncommon.

Please, please, please - think about the inherent danger and brief your pax accordingly.


Boring old Hector/Stik

Indeed, which makes it all the more important on those occasions when you *do* have to pull the propellor through - those of us with radials in particular - to act in the same way as you would if you were trying to swing the prop for a start. High compression engines can brain you with a prop blade without any internal combustion being required - even in the complete absence of fuel, or HT leads being connected to spark plugs - luckily, on that occasion the blade missed my head by miles - did deliver a glancing blow to the b0llocks though. Not the sort of lesson you forget.

I was there when our mutual Uncle was pulling the prop through on his previous S2 which decided to fire a couple of cylinders - he might have short legs, but by God he can move fast when required....almost a blur, in fact.

Just thinking about club types that I've hired in the past - C150s, C172s, PA28s - all the usual stuff. On most of the Cessnas the parking brakes don't really work yet most people just stand there, in front of the aircraft, pulling the prop round as part of their walkround. If it burst in to life what would stop it moving forward turning poor Johnny PPL into coleslaw on the way?

How should we do it? Well to one side, from behind, chocked with someone in the cabin? I don't mind it taking more time - always better to be five minutes late in this life than early in the next. So, how should it best be done?

Always treat the prop as LIVE but in addition never get into or out of an aircraft with the engine running.

I was just about to start a SE aircraft one afternoon and when i say start I mean a millisecond away from turning the starter and someone popped up in front of me grabbed the prop and shouted. "I will just push you back a bit further"!

Thats why you always shout CLEAR PROP STARTING and I always did after that!

:eek:Who on earth teaches people to do that? I don't even touch the prop unless it has acquired a new dink and then only VERY gently to feel how rough it is and how far it seems to extend before getting it checked by someone better qualified.

Its a must on DC3s first flight of the day!!! especially if you were up all night with Birch and Bramson

Propper Prop Pushing
 

Hi Everyone,

A very dangerous thing these things are, I know of someone who prop swung a C402 successfully and only noticed that his watch had been removed by the prop when he was doing the runups! :eek: (watch was found smashed against the hangar wall!)

I have prop swung a few aeroplanes in my time, Piper J3, Cessna 182, Cessna 150 to name a few.

Some basic rules a few of which have already mentioned :-
1. ALWAYS treat props as LIVE (even ones hung at a bar! <-- face it if the prop falls off the wall and you fall off the bar as a result you could end up buying many a beer for many a month)
2. NEVER cycle the prop as part of your pre-flight
3. NEVER prop swing alone
4. NEVER trust just the parking brake, or the parking brake + toe brakes, ALWAYS use chocks
5. Children + Props - NO!
6. PAX + Props - NO!
7. You and Props - NO! (unless for the sole purpose of starting the aircraft)

Some aircraft have written procedures for prop swinging and if you're part of a club, the club will have it's rules to suit. Never just give it a go please, get someone competent to show you how it's done.

keep safe

sb

A point which is worth mentioning is that when you turn the mags off you are making a circuit by earthing the mag to the engine. This is not fail-safe in the event of malfunction of the "switch" (key etc) so this is another reason why props should always be treated as live.

In short you cannot assume the prop is not live just because the mags are off.

The problem with pilots pulling on the props to move the a/c is usually lack of an appropriate tow bar.

A long time ago, a pilot friend of mine, whom I would trust with my life, asked me to hand prop his flat battery Cessna 150. I was very comfortable hand propping, and happy to help him. It was an aircraft I also regularly flew, so I knew it to be in good mechanical condition, including the live mag check, which I had recently done…

As it was the first flight of the day, pulling it through a few times was appropriate. I called to him "Mags off" and he called back “Mags off”. I swung the prop once, it started, and ran quite nicely. I looked through the turning propeller at my friend in the pilot’s seat, and gave him that look, which he knew was my question to him, “are the mags really off?”. He immediately held up the keys, which I saw through the still turning prop!

This particular 150 was equipped with one of the mag switches which was later AD’d for internal failure which lead to two live mags. What a dangerous co-incidence that the time of the switch’s first failure, was the first time I would hand prop the plane!

If I have to touch a prop, I touch it assuming that the next thing it will be, is running!

Pilot DAR

What's indicated here is a lack of understanding, and training regarding propellers.

You most certainly can safely manipulate the propeller by hand, and in some aircraft, it's absolutely necessary. From the responses thus far, one would easily assume that hand propping an airplane is no longer taught.

I grew up on airplanes without electrical systems, and handpropping was part of every engine start...no engine starter. I've handpropped airplanes over the years that do have starters when the occasion has arisn, and have always done it to teach students about proper propeller handling. Yes, it can be done safely, and yes, it can hurt you if you do it improperly.

Any radial engine pilot knows the necessity of pulling the propeller through by hand as part of the preflight.

As far as leaving the airplane with the propeller running, it's done in some arenas all the time. In ag work, for example, we frequently get out of the aircraft with the engine running. In the turbine airplanes, shutting down the engine and adding cycles is unwarrated and unwanted. In backcountry work, we'd sometimes get out, leave it on the left mag and chocked with a rock, and load our passengers and cargo. There are ways to do it safely and legitimately, but only with purpose and proper training.

Propellers can certainly be dangerous, but no pilot training is complete without being properly trained in the safe handling of the propeller. It is wholly inadequate and irresponsible for an instructor to merely teach a student to fear the prop.

At Liverpool many years ago a Cessna 337 passenger vacated engines running and walked away from the (front) prop, I am sure you can guess the rest.
http://ferryflights.aircraftdelivery.net/14.jpg
Photo to illustrate the point, not the actual aircraft

Guppy
 

Thank you for adding some balance, the best post on this thread so far.

Access to VLAs & Micros close to the prop
 

I note that some of the new VLAs and three axis microlights, notably the Technam Sierra, are accessed over the leading edge of the wing. This is done using a foot rest below the leading edge.

These are very small aircraft and have only a short nose, so when climbing in or out, you are very close to that prop. Clearly, sooner or later someone is going to access or leave the aircraft while the engine is running.

I think this is an accident waiting to happen. Access should always be over the trailing edge.

Broomstick.

I teach my son to never even touch a prop, and explain the reason.

However, manipulating the prop is often necessary (to clear the towbar, to push the plane back, etc) and then I check the keys are out beforehand.

Same is true of the DA 40 :(

Also worth bearing in mind that if the propellor is attached to an enginge with a vacuum pump, very often that pump is designed to turn in ONLY one direction. The consequenses of inadvertantly turning the prop in the wrong direction can be a broken vacuum pump and loss of some of the instrumentation.

Whenever inspecting the prop during a pre-flight check, my old instructor used to say "never put more of your hand on the prop than you are prepared to lose...."

http://img.photobucket.com/albums/v6...t/P1010120.jpg That step is also so high I need to use a caravan step as well. But it is quite a way back from the prop.

Most VLA’s and probably the DA40 do not have old fashioned Mags or vac pumps. Standard operating procedure on a Rotax machine is to pull the prop through until the dry sump oil system “gurgles” normally about 30 – 40 compressions if the aircraft has not run for a while. If the solid state ignition is switched on it should still not fire as the system will not produce a spark below 300 rpm. I have to say I check the switches carefully, but I do move the aircraft by using the prop as it is the only practical way to do it.

Rod1

What's indicated here is a lack of understanding, and training regarding propellers.

First of all Guppy this is not a forum for AG pilots but PRIVATE FLYING. I have seen a pilot flying inverted over an airfield at 100 feet but that doesnt meant its a practice that should be recomended to low hour amateurs.

If you treat the prop as live you are more cautious than if you see it as an implement to move the aircraft around the hangar. Of course you can swing a prop or move it but that is not what treating the prop as live means.

As for getting in and out of an aircraft with the engine running, why is it neccesary and when is neccesarry. Its a habit taught by lazy sloppy instructors who are possibly potential AG pilots.

Turning Vac pumps backwards....... more folklore!
 

This don't turn prop backwards because of the Vac pump is total and utter rubbish that is chured out by people who should know better and belongs in avations dustbin along with "don't lean the mixture below 5000ft".

The prop can be turned backwards by hand without damage to the vac pump, what you must not do is fit a Vac pump from an engine that turns to the right to a left hand turning engine (IE dont swap the vac pumps between engines on counter rotating twins).

If turning the engine backwards did as much damage as the mis-informed say we would all be changing them at the 150 hour check as checking the Mag timing requires the engine to be turned backwards to release the impulse coupling in the Mag(s).