Safety around propellers

[Pilot DAR]

A sad accident, perhaps complacency or distraction. This was probably a very experienced pilot, a moment's inattention - it can happen to any of us...

Clark J. Baldwin, 62, of Wasilla, a well-known pilot and flight instructor, was killed Thursday morning when he was struck by the propeller of his plane, National Park Service spokesperson Robyn Broyles told Channel 2 News.
Baldwin, a retired Lieutenant Colonel of the United States Air Force and owner of the Alaska Club Training Specialists flight school, was teaching a class at the Peavine bar strip about 15 miles east of McCarthy Thursday morning, Broyles said.
"Baldwin was the only operator of the plane at the time and was instructing a small group of pilots when he got out of his plane was struck and killed by the propellers of his plane," Broyles told Channel 2 News.



Pilot dead Thursday after walking into propeller of plane in Alaska National Park | Local News - KTUU.com Anchorage (http://www.ktuu.com/news/news/pilot-dead-thursday-after-walking-into-propeller-of-plane-in-alaska-national-park/33425172)

[old,not bold]

Gulf Air carried a passenger one day ('70s) from Doha to Abu Dhabi, in a Fokker F27-400.

Subsequent investigation showed that he (a European) was concerned about his suitcase to the point of obsession. At check-in he wanted to take it in the cabin; when this was refused he wanted assurances from all concerned that it would be safe, and he was visibly distressed by losing control of the bag.

Nowadays he would have been hauled off by security for a thorough going-over, but we weren't so sophisticated then.

In GF F27s ( and most others) the baggage was loaded via a freight door into a compartment forward of the cabin, and offloaded by the same route. Passengers embarked and disembarked via a rear door, using a small set of steps wheeled up by hand.

As soon as the aircraft came to a halt in Abu Dhabi, he was out of his seat to be first in the queue to get off. The door was opened, and the steps appeared. He ran down them, and immediately ran under the wing and nacelle. The conclusion drawn later was that he did that to check on his suitcase.

Unfortunately, he could not assist with the enquiry because the engine was still running down. So the propeller was rotating, perhaps at about 200 RPM, and he was terminally sliced.

For the sake of quick turnrounds it was the practice until that time to place the stairs and start disembarkation even if the port prop. was still turning.

Our SOPs were changed swiftly to forbid any ground activity until both props were motionless, and the UK CAA (Gulf Air was still regulated by CAA at the time) then introduced the rule about placing a tape from the doors to the port-side wingtip on all propeller aircraft before any disembarkation could start.

As they say, most aviation rules are written in blood, and I can personally assure you that there was plenty of that.

On another occasion, a loader lost all the fingers on one hand trying to stop a very slowly rotating prop by grabbing a blade. The F27-400 had the square ended, very sharp tips on the blades. My maths is not what it was, but even at 30 RPM, with a disc of, say, 12M circumference, each tip is moving at 6m/sec (21.6 KPH, I think) with an enormous amount of energy behind it, but will appear to be almost stopped.

[Background Noise]

This happened to an equally experienced pilot over here: https://assets.digital.cabinet-office.gov.uk/media/5422fe93e5274a1314000955/Piper_J3C-65_Cub_G-BHPK_10-12.pdf

[Nightstop]

Another F27 prop accident occurred on stand 5 at EDI years ago when an Air UK GPU driver inadvertently selected reverse instead of forward gear when driving the GPU away after engine start. The cab was struck by the prop and he died instantly. This resulted in the SOP that GPU's must always be parked alongside aircraft in such a way that they are not in line with the prop arc.

[chevvron]

It was instilled in me as a junior ATC cadet to STAY CLEAR of the ARC of the PROPELLOR!
One of my squadron officers told us of the case where a cadet had been too close, had pointed at something, then saw a hand on the ground in front of him. He'd picked it up before shock set in and he realised it was his own hand.
NB: I'm not sure if this was a true story!

[thing]

It's not lack of knowledge of props that kills; it's complacency and that can happen to any of us.

[9 lives]

seat in row 6 where much of my body is directly inline with the spinning prop

It's fun to watch the blades flew, and the tip plane move fore and aft with the application of thrust though!

During my formative years, I came to know pilot Tony. Tony was known for daring beyond the regular (which eventually claimed his life), and grass roots flying. Tony wore a somewhat tattered, but obviously prized leather flying jacket. Rather than a crest on the back, it had a swirly red smeared on stain.I asked....

Apparently Tony was standing, chatting one day, with inadequate regard for the Taylorcraft idling behind him. He was drawn into the turning prop by the suction, and could not lean forward to extract himself. He had to wait until someone ran around and shut it down. During this time, the "skull cap" spinner smeared its red paint into his back.

I can't imagine being that casual about turning propellers, but apparently it was possible!

[west lakes]

Then there as always this incident

BBC News - Gyrocopter pilot cleared over huntsman death (http://news.bbc.co.uk/1/hi/england/coventry_warwickshire/8571913.stm)

http://www.pprune.org/rotorheads/365357-gyrocopter-involved-murder-charge.html

[Pilot DAR]

Added bonus was reverse thrust away from airport terminal buildings. A rare treat in these days of tug pushbacks.

A friend and I had occasion back the '80's to fuel stop in Cairo in a Twin Otter. I combination of events had left us very dis satisfied with the ground handling to get fuel. We were marshalled up to near the terminal building, nose in, and then denied a pushback. My friend said something under his breath, then "get in" to me. He fired up, and backed out. My most vivid memory was a blizzard of garbage raining back down, as we neatly taxiied away...

[27mm]

A late uncle was a Lanc pilot during WW2; after landing from a raid, it was not unusual for crew members to exit while the engines were being shut down. On this occasion, one of the young lads climbed down, but instead of walking to the rear of the aircraft, walked forward into one of the idling props and was instantly killed.

[Maoraigh1]

You don't need to be running the engine. Maintenance, especially if two or more are working, perhaps on separate tasks, can be dangerous.
When a father and son team were working on a C182 in Colorado, the starter accidentally kicked, decapitating the father. Both were fully qualified.

[chevvron]

A late uncle was a Lanc pilot during WW2; after landing from a raid, it was not unusual for crew members to exit while the engines were being shut down. On this occasion, one of the young lads climbed down, but instead of walking to the rear of the aircraft, walked forward into one of the idling props and was instantly killed.
I read an article in a magazine some years ago documenting how people had walked through idling props without being touched, usually big radials. On one occasion, the guy realised what he had just done and fainted!!

[Mechta]

I read an article in a magazine some years ago documenting how people had walked through idling props without being touched, usually big radials. On one occasion, the guy realised what he had just done and fainted!! My school metalwork teacher did his national service in the RAF maintaining Washingtons (Boeing B-29). He described this occurred on their squadron. I've also heard it mentioned in the case of a Vickers Wellington.

Mechta Senior did some trials work on HMS Eagle, and in the relatively short time he was aboard, the cruise included a burial at sea for someone who had walked into a propeller of a Fairey Gannet. Assuming both engines were running, you wouldn't stand much chance with a contra-rotating prop.

[pithblot]

I guess, having been taught to hand swing an engine from an early age, propellor dangers have remained a major concern whenever I'm near them. Propellers worry me, they have no friends.

We are creatures of habit, who see only what is expected so we can tend to naturally place ourselves in danger around Propellors. I'm dismayed now days at the complacency (or is it just ignorance?) I see on the Tarmac by CPLs and instructors: arms and hands passing through the prop arc, photos taken lounging against the prop and head-in-the-cockpit as the starter motor is engaged with a simultaneous cry of "clear prop" - but never a glance at the danger area.

In the days before Hi Vis vests, it was common practice to brief everyone on propellor dangers; especially visitors, passengers and students. I think the lessons, of the sad sad story, related in post #11 should be part of this briefing.

You don't need to be running the engine. Maintenance, especially if two or more are working, perhaps on separate tasks, can be dangerous.
When a father and son team were working on a C182 in Colorado, the starter accidentally kicked, decapitating the father. Both were fully qualified.

[Pull what]

Teaching people to feel the propeller leading edge is the start of teaching no respect of the propeller arc.

Pilots posing for pictures within the propeller arc is another bad habit.

If you never walk into the propeller arc you cant be hit by it unless it flys off!

[JammedStab]

On another occasion, a loader lost all the fingers on one hand trying to stop a very slowly rotating prop by grabbing a blade. The F27-400 had the square ended, very sharp tips on the blades. My maths is not what it was, but even at 30 RPM, with a disc of, say, 12M circumference, each tip is moving at 6m/sec (21.6 KPH, I think) with an enormous amount of energy behind it, but will appear to be almost stopped.

I have in the old days seen a cocky engineer placing his hand on each passing Dowty Rotol blade on the HS-748 as it wound down in its last few rpm. I suppose it caught on as it looked kind of cool.

But there was a petite female apprentice who did this with gloved hand one day. The leading edge of these aircraft had many nicks from gravel operations and when a leading edge blade that had a jagged metal edge caught onto her glove, it picked her up and she went around with the blade. Fortunately no serious injuries.

[JammedStab]

A bit more detail.....

The pilot, 62-year-old Clark J. (Jay) Baldwin, was instructing a group of fellow pilots in Wrangell-St. Elias National Park/Preserve Thursday when the apparent accident took place.

Five small planes, including Baldwin’s, were idling near each other on the Peavine Bar airstrip 15 miles east of McCarthy when one of them began to roll. Witnesses later told Park Service officials that Baldwin attempted to stop the rolling plane and, in doing so, accidentally walked backwards into the propeller of his own Piper PA-18 Super Cub aircraft, according to Robin Broyles, spokesperson with the NPS.

It just shows the danger of being around props that are running. No doubt he was on alert but as soon as something serious happened, all of a sudden the primary hazard can be forgotten. Reminds me of the mechanic near a jet engine inlet that was operating. The wind caught his ball cap and he went after it until he got sucked into the engine.

I have taught two or three people about hand propping techniques. One thing I mentioned was, that even if the most beautiful girl in the world is seen to be walking across the ramp nearby completely naked(well perhaps in high heels), you don't care while you are near the prop. And don't wear a hat.

[HEATHROW DIRECTOR]

I was on watch at Heathrow when a ground engineer walked straight through the prop of a Dash 7 about to taxi. Incomprehensible how such an experienced person could do such a thing.

[JammedStab]

It must be distraction. I remember many years ago as a ground crew guy we used to have a Fairchild metro scheduled flight come in and like all the aircraft, they always used ground power until after engine start.

Guess where the plug-in was? On the engine nacelle behind the prop so we had to walk in front of the wing but behind the prop to unplug it. Strict paranoia is required in this situation when given the disconnect signal by the pilot. Walk far out toward the wingtip and then as approaching, I would keep one hand always on the leading edge of the wing as I approached to unplug and then walked back toward the wingtip as this meant that I was not within range of the prop arc. Then come back to drive the GPU away.

I don't remember any particular direction being given to us by the company on what specifically to do for the various aircraft hazards based on all different types, just a general briefing that there was a hazard and perhaps specifics about the most frequent aircraft serviced such as waiting 30 seconds after a CFM-56 engine shutdown before approaching. I was a licenced pilot at the time and well aware but there was no shortage of young newbies. You have to come up with your own plan for many situations. The first step in the plan is be paranoid.

In more recent times when removing chocks from aircraft such as a light aircraft that has been hand-propped with engine running, I am continuously saying to myself that the prop is running. I think we need to just pre-brief(or remind oneself) for a few seconds that if something goes wrong, such as the plug-in or chock cannot be removed then stop, perhaps carefully move out of the way and consider. And if something happens such as a backfire or aircraft starts moving what will we do. Keep your arms close to your body can be part of that self-briefing. That being said, finding an alternative to chocks near props is a good idea. Why have chocks in if the aircraft has a park brake and pilot on board.

In the Alaska case, it sounds like there may have been multiple airplanes with engines running. Is suspect that if it can happen to this guy, it can happen to any of us. Beware the unanticipated situations.

[mikedreamer787]

Agree with all posts. I was taught from Day One PROPELLERS CAN AND WILL KILL!

The CFI of my training school used to come down like a ton of bricks if ANYONE was observed to disregard even the tiniest points of prop safety. An actual insertion of his flying boot into one's arse was part of the procedure. He used to say most propeller fatalities were not so much complacency but momentary fatal distraction.

The only prop injury I ever saw was a drooling barking mutt get his ear knocked off by a taxiing Cherokee. Stupid canine.

[the_flying_cop]

I had always had good prop discipline instilled into me from a young age. Imagine my surprise and apprehension when I was told that the islander needed a comp wash once a week.

The instruction was to spray water into the intake, whilst balancing one of the prop blades on one's shoulder. This was to take up the strain of the prop as the captain then repeatedly spooled the starter motor for 3-4 second bursts.

Most dangerous thing I ever saw, and also completely pointless. The spray was just a 5l hozelock container with tap water in it.

I raised my concerns to the higher ups, and was told that we HAD to do it or the engines' warranty would not be upheld.

Nonsense!

[Piltdown Man]

I recalling seeing an RAF poster some time ago listing the "Five golden rules" with regard to propellor safety. In typical RAF style they were:

1. Never walk through the arc of a propellor.
2. Never walk through the arc of a propellor.
3. Never walk through the arc of a propellor.
4. Never walk through the arc of a propellor.
5. Never walk through the arc of a propellor.

I think they made their point well.

PM

[Fostex]

I won't go near the business end until I have visually checked the mags. I once hauled my machine out of the hangar with the tow bar and hand on the prop only to find the previous pilot had left the keys in place with mags on both.

I have since had a ****-fit on someone who did the same. It is extremely dangerous, you wouldn't leave a loaded shotgun sitting in the hangar.

[pasir]

During my PPL days at Biggin Hill there was a report of a Cessna 337 twin (engine front and rear) whereby a passenger disembarked, walked around the back of the a/c and into the still rotating prop with tragic consequences.
The other occasion was on the Doolittle raid on Tokyo 1942 where a sailor on the a/c carrier slipped over on the deck and lost an arm as start up orocedures commenced .

[Lancman]

A Chieffie at RAF St. Eval climbed into a Shackleton early one morning and started up one engine, he then climbed out and walked into the propellor. The verdict was suicide, but what a strange way to do it.

[Penny Washers]

#23: "A loaded shotgun." Good one.

I always tell any non-aviating passengers, especially the young ones, that a propeller is really a circular saw. It may have only two teeth, but should be treated with the same degree of caution.

They can understand the circular saw analogy, while a propeller can look so harmless.

[rigpiggy]

in my younger much more foolish days. I ramped on a 748, sop's being no debarkation till the props were stopped. we would time and grab the blades so as to get a lift of 4-6' off the ground. the cakes would fly a good 200' if you tossed them in during rundown" these imbecilic tricks taught to me by the mechanic". heehee, oh well I survived my childhood, barely

[mary meagher]

It is unsafe to walk too close to the front of a fixed wing power plane. There may be a very short pilot whispering "clear prop!"

It is unsafe to walk too close to the rear of a rotary helicopter or a gyrocopter which is already running...and I used to think it was unsafe to walk anywhere near a heli without keeping an extremely low posture....still true or not?

It is perfectly safe to walk all around a glider unless it is attached to some sort of launching line. It is dangerous if you are standing on or near the winch line or the aerotow rope. (once in my former club we nearly launched a chap who caught a foot in a loop) If both wings are level, a glider may be about to be launched. If one wing is on the ground, probably not, though there may be somebody groveling under the glider attempting to attach a winch line to the belly hook.

[Chuck Ellsworth]

When I first started my flying career my first real flying job was crop dusting. ( Aerial application. )

The company had three types of airplanes, we started on the J3 Cub then went to the Super Cub and finally the Stearman with the P.W. 450 hp. engine.

Only the Super Cub had a starter the other two we hand proped.

So we grew up with prop safety as a natural talent.

[Small Rodent Driver]

During my PPL days at Biggin Hill there was a report of a Cessna 337 twin (engine front and rear) whereby a passenger disembarked, walked around the back of the a/c and into the still rotating prop with tragic consequences.

I believe that may have been at Liverpool in the early to mid 1970,s. A stewardess having accepted a lift disembarked the 337 whilst the a/c was being shut down and walked rearward through the prop arc. Resulted in a big tightening of security around the Liverpool apron at the time.

[mary meagher]

Pithblot on page 1 is apparently the only pilot on this thread who has hand propped his plane, and is therefore very very aware of the hazards. Being a weak old woman, when my battery refused to inspire the starter, I put chocks under the wheels and asked a more experienced pilot to pull it through while I was safe in the cockpit.....and once had the honor of Derek Piggot propping GOFER for me...he insisted, though he is even older than I am, but in his career has pulled props through more times than most. A true gentleman!

You chaps should take a trip to Jack Brown's seaplane base in Florida. I got my rating there...we would slide the J3 Cub down the ramp into the water, prepare to release from the dock, and the instructor would step out onto the float and pull the prop through from behind! that really impressed me!
The whole course for the rating was tremendous fun, but they wouldn't let me fly it solo, you have to go and buy your own seaplane.

[Gertrude the Wombat]

but they wouldn't let me fly it solo
Try Canada. Well, I didn't get to fly the floatplane solo either, but only because I wasn't good enough at the time (I'd be better at it now) - it's five solo circuits for the rating.

[Chuck Ellsworth]

- it's five solo circuits for the rating.

Actually it is five solo take offs and landings for the rating.

...which can be done in a straight line in about three or four minutes.

[JammedStab]

Update,

About 11 a.m. on June 4, an emergency call placed via satellite phone reached authorities in southwest Alaska. The caller was on a gravel bank on the Chitistone River in the Wrangell-St. Elias National Preserve, where a flight of four Super Cubs had landed to practice backcountry off-airport operations. The instructor leading the course had been hit by a turning propeller. He died almost instantaneously. Damage to the airplane was classified as “minor.”

The victim was the 62-year-old owner and chief flight instructor of a well-regarded bush-flying school. He was an Air Force veteran who’d flown F-16s and retired with the rank of lieutenant colonel, then gone on to fly for Northwest Airlines before moving to Alaska nearly 20 years ago. By the time of the accident, he’d accumulated 40 years of teaching experience and was deeply respected in the community. Friends described an exceptionally aware and conscientious pilot who never stopped thinking about how to defeat the innumerable risks of bush flying. It’s possible, however, that he hadn’t accorded sufficient respect to the most dangerous animal on the planet: the mosquito. (By communicating disease, these pestilential parasites have caused far more human deaths than attacks by all vertebrate species combined.)

After landing on the Peavine Bar, the training group was swarmed by hordes of the biting insects. To keep them under control, they decided to start the engines on all four airplanes, using their propwash to blow away the infestation. Unfortunately, rather than leaving one pilot inside each airplane to hold the brakes, they merely chocked the wheels. While loading his Super Cub from its right side, the instructor saw that the airplane to its left had jumped its chocks and begun to roll forward. Dashing up to try to stop it, he apparently misjudged the arc of his own propeller and ran into it from behind.

[India Four Two]

I recalling seeing an RAF poster some time ago listing the "Five golden rules" with regard to propellor safety.I remember another RAF poster from the politically-incorrect 60s with an appropriate picture and the caption:
Props are like birds - don't lose your head!

[Midland 331]

From "summer job" days working as a loader at Castle Don., I seem to recall the ground power socket on the BMA 800-series Viscounts being in a pretty dangerous place, and the lads having to inch along the belly between the wing roots to get to it.

An RAF old hand told me that tiredness at one base resulted in a number of his mates walking into props.

[Rhino25782]

There is two occassions where I regularly move near the prop and/or touch it: During the pre-flight and when pushing or pulling a plane back into the hangar. I don't like doing it, but on some planes, it's the only option as far as I know.

[chevvron]

One thing that's puzzled me for years. I was at Brize in about 1970; I had taken some cadets there and scrounged a ride in a Britannia (only a short one, 4.5 hours!) and were waiting for transport back to the terminal. Another Britannia was being readied for departure. Prior to start, one of the groundcrew went over and leaned against the prop of the engine about to be started. He suddenly walked forwards and as he did so, the prop started to turn. He did this with all 4 engines. Why was this? As the mighty Proteus was multiple spool, did he wait until he heard the turbine begin to wind up, effectively 'braking' the prop?

[rigpiggy]

arctic sop was to hold the prop on the twotter until oil temp came up ensuring that there was oil in the gearbox, start #2, hold til captain gave word run over hold #1 for start, with temps let go jump in the back crawl up front while captain was taxiing.

[bingofuel]

Re the Britannis props, I believe it was to stop the propellors windmilling in reverse if there was a tailwind after prop brake release as turning in reverse may cause issues with the gearbox.

[mustafagander]

It was SOP on Britannias as I recall it. When I were but a lad my crew used to service the CP Brits transiting SYD and that was one of my jobs, hold the prop until it pulled away from my hands in the correct direction of rotation.

Always had quite an audience!! :ok:

[Capot]

During the pre-flight and when pushing or pulling a plane back into the hangarOnce again, as we dinosaurs know well, this is fine just so long as you know that turning a prop through a compression can cause a hot engine to fire with the mags switched off.

I shudder when I see students assiduously doing their pre-flight and grabbing the prop to give it a turn on an aircraft that was landed and vacated 15 minutes before by the previous user, and I look away when I see people grabbing a hot prop to move an aircraft that landed 5 minutes before. Trust me; it happens.

It's Darwin Award territory.

[Gertrude the Wombat]

I shudder when I see students assiduously doing their pre-flight and grabbing the prop
My passenger briefing includes "Stay away from props, especially ones that aren't going round. It only takes three things to go wrong at once for a prop to burst spontaneously into life, and we like better odds than that around little aeroplanes. So, no selfies draped across the prop please."

[Thruster763]

On holding props during compressor washes http://www.pprune.org/accidents-close-calls/562596-safety-around-propellers-2.html#post9100126

This was standard practice on PT6's As a free turbine engine its easy at motoring speed. Don't try it with a TPE-331 though.

[DownWest]

We were doing engine runs on a rebuilt Stamp SV4 fitted with the Renault engine. This had an air starter with a little knob on the panel that you pulled out. This in turn had a little spring loaded lock, so both hands were required to operate it.
One of our junior mechs was in the seat and got ready to start, while I put the chocks in front of the wheels. With not much pressure in the cylinder, the knob needed to be pulled out over an inch before anything happened, but I had been running the engine just before, so the cylinder was fully charged. As soon as he moved the knob the engine turned, and fired, as he had the switches on.....The blade went through the hair on the back of my head (had more then..) Choice words followed about not taking anything for granted, and sticking to the rules.
DW

[Geosync]

When I was a mechanic we would do engine runs in the middle of the night on beater Cessnas, huge torch in hand, checking for oil leaks after maintenance. I would ALWAYS have one hand on a strut, and if I couldn't see the front of the engine using that method then so be it. The scarest part was adjusting the carb idle screw while that puppy was running.

One time at a remote airfield I had a dead battery in a Cessna 150. I was deciding how I would hand prop it without anybody around to hold brakes when an old grizzled IA drives up out of nowhere and offered to help. He told me to get inside and hold the brakes while he tried to hand prop it. After a while he was unsuccessful, so he pulled up his car and jumped the battery.

But in order to get the battery box lid back on, this old grizzled IA withstood the mighty wind forces the O-200 was producing and stuck his hands in the tiny access panel to pin it in. The angle was screwy, so he was gyrating all over to get it in, bringing parts of his body within inches of the blade. I was holding the brakes like mad. He eventually was successful, gave me a slight nod, jumped in his car and drove away, leaving me alone with the weeds and coyotes to contemplate life.

[LJP]

Thruster763 obviously paid no attention to maintenance manuals. Cowboy attitude. MM specfically states not to hold prop during compressor wash on PT6. On 331, no advantage derived from compressor wash.

[Wunwing]

I was told when I started on museum aircraft that there was a problem with the Wright powered aircraft, where if a relay stuck on, with GPU applied the starter would turn and as a result the prop would turn.

One day I powered up our Neptune and as the plug went in, the starter engaged. Fortunately on the L/H side where the GPU plug is,so it was obvious immediately.

The other Wright aircraft in our fleet needed power to be selected on the F/Es panel but it was possible with that as well. It took me quite a bit of arguing to convince the others on site that this was a real threat.

Wunwing

[Tankertrashnav]

When I was at Seletar in the 60s we had a squadron of Beverleys. The prop clearance on this aircraft was about 7 feet and although it was forbidden some of the blokes used to take a short cut under the props. This was ok until one of them got a posting across to the Argosy squadron at Changi and tried the same trick there, with predictable fatal results.

[TomU]

I stopped someone walking into a prop.
Arriving a Britannia, I was on the headset as chock man installed the nose chocks, then proceeded towards the MLG to put the chocks. Only problem was that spinning prop was between him and MLG. He was head down with ear muffs on, dragging the chocks on ropes.
He didn't hear my shouting - I managed to rugby tackle him just ahead of the prop.
Far as I remember (it was 40 years ago) he just cursed me for hurting his knee.

[TomU]

It was SOP on Britannias as I recall it. When I were but a lad my crew used to service the CP Brits transiting SYD and that was one of my jobs, hold the prop until it pulled away from my hands in the correct direction of rotation.

Always had quite an audience!! :ok:
Indeed, I remember that. The Brit did not like to start with the prop reverse rotating, so we needed to hold it during start. We had competitions to see who could hold the longest! Silly really, I wonder how we survived it.

[India Four Two]

A further point about the dangers of a live prop.

After shutting down our gliding club's C-182, we always put the keys on top of the glare shield so that someone outside can see them.

However, that is not a guarantee that the engine can't start. Apart from the obvious issue of a potentially broken ground wire, it is also possible with some keys, to remove them from the ignition switch, when it is set to Both.

I have personally had that happen to me with a PA-28 and I've heard that it is fairly common.

[Gertrude the Wombat]

How to get onto a floatplane when parked nose in to a jetty: hold on to the propeller as you step onto the front of the float (there's nothing else you can reach). Never entirely happy with that sort of thing.

[SpannerInTheWerks]

1. Always treat the propeller as being live

2. Never touch a propeller unless you have too

3. pass the message on ... !

I seem to remember a loader was killed at Aldergrove in the mid 90s when he walked into a HS748 prop?

[squidie]

When I was training we were instructed to walk out to the A/C and perform our pre-flight checks and then start the engine and waiting for the instructor to board before calling for taxy. It used to worry me everytime when I watched the instructor climb onto the wing of the HR200 and then open the canopy and climb in. It’s so easy to slip and fall over the leading edge and within the prop arc and I’m surprised an issue hadn’t already pccured to that day.


Eventually (still as a student and after) I decided to simply wait for the instructor before powering up off my own occurred.

[gruntie]

1. Always treat the propeller as being live

Drummed into me while I was in the CCF by a serving RAF officer several decades ago.

A couple of decades later I was watching the Italian AF giving a demonstration of mountain rescue at a ski resort, using a large helicopter. It was sitting at the bottom of the pistes rotors running, when for some reason the co-pilot got out and walked round the back. He slipped on the snow and fell into the tail rotor. 2 stretcher bearers ran over from a parked ambulance: when they reached the scene they just stopped running.
A couple of hours later, having tidied everything up, the helicopter started up and flew away. Without any sort of inspection.

[pithblot]

On another thread. A cautionary tale from Dunnunda. (http://www.pprune.org/pacific-general-aviation-questions/401275-one-nostalgia-buffs-4.html)

Re my previous post.
One of the scars came from an upside down engine, a Queen 30 as fitted to the DH Heron.
I was lining up the props after a flight, asked the PIC if the mags were off and received an affirmative.
Lined up #1 and moved on to #2 which fired up with hardly any movement of the prop by me.
The prop threw me into the fuselage side and I fell back on to the ground just in front of the rotating prop. The aircraft was inching toward me so I rolled out of the way pronto.
I then ran around the wing up the stairs into the aircraft and found the mags to all four engine in the on position. I shut #2 down and switched off the rest.
Walking down the cabin I saw blood all over the floor, I was wearing a raincoat and the sleeve was a bit over long and covering my left hand. I shoved my hand out of the sleeve to find a V between my index finger and the next one along. Could have held a real big cigar and put Winston Churchills V to shame. The prop must have done this whilst I was performing my aerobatic display.
Anyway I grabbed a stray tarmac terrier to run me into hospital where they spent some time reducing the V to v or maybe u. Good job too though the left arm still aches on a cold day all these years later.
I had a massive bruise on my upper arm which could have only come from the prop launching me into the fuse.
Lucky no doubt. Whilst I was cautious around props before this I have treated them like big black snakes ever since. With an excess of caution.
SD

[mikemmb]

Please DO NOT put all your faith in the Mag Switches being OFF.

Decades ago I spent many years as ground crew in the RAF on all sorts of propellor aircraft.
One of the tasks each morning was to turn the engines over using the prop to check for oil leaking into the cylinders (if it did the resulting hydraulic effect on startup could blow the cylinder head off).
We clearly always checked that the Mag Switches were OFF, but still had a fair few engines burst into life in the hanger........certainly catches your attention!

The cause was faulty Mag Switches or associated wiring.

Magneto switch circuitry is different to most other electrical stuff in that the electrical circuit has to be in perfect condition and the switches closed (ie technically "ON") in order to disable the Magneto.

SO IT IS NOT FAIL SAFE - if anything is broken or damaged THE MAG IS ON.

.............Never walk through the arc of a propellor, let alone touch it.

If you do have to turn a prop over, always assume its going to fire and move away from its arc.

[Big Pistons Forever]

However, that is not a guarantee that the engine can't start. Apart from the obvious issue of a potentially broken ground wire, it is also possible with some keys, to remove them from the ignition switch, when it is set to Both.


If this happens then the mag switch is US and the aircraft must be grounded until it is fixed. All of the standard light airplane mag switches are specifically designed so that you can only remove the key when the switch is in the off position.

I check for this at the end of every flight by giving the key a little tug at each mag position as I cycle it to off. I have found a few bad switches over the years, all in high time trainers where the switch is just worn out. My guess is in all cases the switches had been like that for awhile but nobody had paid any attention to what they were doing when they shut down :ugh:

[Lou Scannon]

When a student on No 16 Vampire/Varsity course at Oakington in the 60's I was told about the "civvy" who, in WW2 and before first light, cycled to work round the perimeter track.

They were equipped with Stirling bombers with their extended undercarriage legs that ensured the four engines had plenty of clearance under them. Knowing this he would remain on the taxyway rather than take to the grass to pass them.

Sadly they re-equipped almost overnight with Halifaxes and he still took his usual short cut..... but through the props rather than under them.

[NutLoose]

I always turn props backwards as it reduces the chance of it firing due to the impulse coupling not engaging on those that have it installed.

As for what was said re mag switches, I had one even worse than that, the starter solenoid on one had jammed in and simply turning the battery switch on resultied in the starter turning the prop over.

[Flyingmac]

I always turn props backwards
Presumably you listen carefully for the 'Tink' sound of a breaking vane on a dry vacuum pump?


From another forum.


I know better, being a mechanic and all. I park my little Porsche 914 in front of the wing of the Comanche. To get the best clearance I swing the prop vertical so I can back in or pull out with ease. Well, the last time it was just a little off and i pushed it backwards and thought I heard a little "tink".https://www.pilotsofamerica.com/community/styles/poa/poa_smilies/no.gif Didn't think much of it until I flew down to Eugene, Or. and noticed the vacuum gauge needle flickering a bit. Upon the return trip no vacuum at all. Needless to say the Comanche has a new vacuum pump on it now... Oh and the one inner lower nut, washer and lockwasher was a real pain in the butt too.https://www.pilotsofamerica.com/community/styles/poa/poa_smilies/yes.gif
Dumb-a**
Kevin

[stevef]

I've posted this before a couple of times - turning the prop backwards does NOT damage the vacuum pump. This is from Parker Hannefin, who manufacture them. I've lost the email the service department sent to me years ago confirming this but everyone's free to send their own enquiry. :-)
Anyway, turning the prop backwards is part of the magneto timing procedure and I've never heard of anyone breaking the vanes by doing that.
The pump killer is oil, solvents or water.

[India Four Two]

On the 182 that I fly, you can't turn the prop backwards, due to the construction of the starter adapter.

[Forfoxake]

Turning the prop backwards (over one or more revolutions) on Rotax 912/914 engines can apparently cause ingestion of air into the valve train and require a venting check:

SB-912-036
Service Bulletin: Inspection for correct venting of the oil system for Rotax engine type 912 and 914 (series)
SB-912-036 R1 SB-914-022 R1
Cited in Compliance 1.5 – “engines which have had the prop spun for more than 1 turn in reverse direction allowing air to be ingested into the valve train.”

and

SI-04-1997
Service instruction: Venting of lubrication system for Rotax engine type 912 and 914 (series) SI-04-1997 R3
Cited in 1.3 Reason – “and/or had the prop spun in the reverse direction allowing air to be ingested into the valve train.”

[tonytales]

Even though well indoctrinated in avoiding prop arcs I nearly walked into one. Midnight shift of course, only three mechanics on duty and we had to adjust the hydraulic pressure for the autopilot of a DC-4. The regulator was located in the hydraulic hell hole accessible through a hatch on the starboard side at about the wind leading edge. No pressure gauge down there and no aux hydraulic pump on the ex C-54 so you had to run an inboard engine for pressure. So, one of us in the cockpit to run the engine, ride brakes and observe pressure, one in the hydraulic hell hole to adjust the regulator and one in the cabin above the hydraulic hell hole to stamp on the floor. That was to signal me, the guy in the hell hole to raise or lower the pressure. No maintenance intercoms on this old bird, no hearing protection either in those pre-jet day (1954).
So I stood fire guard wile #3 engine was started and then carefully made my way clear of the props around behind the RMLG and up the short ladder and into the hell hole.
The R2000 engine was not the only source of noise. Being in and among the hydraulic system lines and valves, they were singing loudly too. Screeching was maybe a better word.
Lots of stamping and banging as I adjusted the regulator but it turned out to be faulty, probably worn internally. It would overshoot either up or down but would not settle on the desired 600 PSI (I seem to remember) no matter how carefully I tried to set it. After an eternity we gave up, lots of stomping. Half befuddled by engine noise and hydraulic screeching and midnight shift lack of sleep I backed out of the hell hole, down the steps, turned right, took a couple of steps forward and realized there was a prop whistling by a foot in front of me. My knees almost gave way.
I have been a fanatic on prop safety ever since but, yet, I too am one of those who held the prop whilst a Proteus tried to start up in a tailwind.

[IcePaq]

Turning a prop backwards causes the oil to reverse direction and air to enter.

Depending on where it ingests the air is what determines the severity of the problem that may arise at next start.

I parked a car on a hill and put the manual transmission in a forward gear.

When I came back out, it had moved down the slope about 15 feet.

That was enough to slowly draw the oil out of all the hydraulic lifters and tensioners and the engine almost threw the chain off and the lifters clicked for about 10 minutes afterward.

[Russell Gulch]

Turning a prop backwards causes the oil to reverse direction and air to enter.

Depending on where it ingests the air is what determines the severity of the problem that may arise at next start.

I parked a car on a hill and put the manual transmission in a forward gear.

When I came back out, it had moved down the slope about 15 feet.

That was enough to slowly draw the oil out of all the hydraulic lifters and tensioners and the engine almost threw the chain off and the lifters clicked for about 10 minutes afterward.

What bollocks.

[DANbudgieman]

During the very early eighties nose in parking of aircraft on stand became obligatory at Glasgow airport.

The powers that be decided in their infinite wisdom that it was possible and desirable to use an air bridge in conjunction with the twice daily British Midland Viscount service to East Midland.

The procedure agreed with the BAA was that a heavy duty wooden (nose wheel)chock was installed at gate 17. Used in conjunction with AGNIS light this was intended to ensure that the aircraft would safely be brought to a halt in the required position before contact between the props and the airbridge became "an issue."

This system worked well enough and the dear old Viscounts were eventually replaced by DC9s. The introduction of the DC9 with the removal of the props in near proximity made for a much happier experience for all concerned on the ramp!

How this system came to be regarded as acceptable to both the airport authorities, the Viscount aircrew and the ramp crew god alone knows!

[IcePaq]

What bollocks.


You obviously don't understand how internal combustion engine lubrication systems work.

[Consol]

Having done some flying in the good ol' USA where you are encouraged to yell 'Clear Prop!' (I'm softly spoken so no one ever hears), I found myself back home at my local airfield. About to start my engine I observed an instructor and student at another aircraft parked alongside. I earnestly called 'Clear Prop!', no one heard. I signalled engine starting with hand signals several times to a now bemused looking pair. Then the instructor walked over to my aircraft through the prop arc, put his arm over the front cowl and helpfully asked if everything was alright!
Never earnestly assume that everybody else knows about hand signals and prop safety.

[rnzoli]

where you are encouraged to yell 'Clear Prop!' (I'm softly spoken so no one ever hears). I always open the DV window and literally scream "Clear prop!" to the outside world, because in small airfields, dogs or even small children can easliy approach the lower part of the prop arc without me seeing them.

And then there was one time, when I forgot to turn off the intercom before shouting, and made myself and my passenger deaf for the next 2 minutes.

[mustafagander]

IcePaq, I would love to read your explanation for these assertions. I fully agree with Russ G, utter bollox. Please enlighten us, me especially. If you're right I may have wasted a lifetime as a mechanical engineer by not knowing this stuff. I need science, not anecdotes or assertions mate, I've been in the game over 50 years.

[IcePaq]

How hard is it to understand that turning an oil pump backwards will draw the oil out of the engine through the pump and to the oil pump pickup/sump?

When an engine is sitting you have gravity working on the oil but, you have to have a path for it to move down and out of the engine.

That path is measured in the thousandths of an inch of whatever clearance you have in your positive displacement oil pump.

The flow rate is so low that I routinely start cars that have been sitting for 4 years and only the valves that were open had lifters bled down meaning only two valves clicking until oil can pump the lifters back up and remove the clearance.

Unlike leaving a car sitting for a long period and possibly having oil drainback, turning the engine backwards uses suction to draw the oil out of where it would normally not leave.

So a car placed in a forward gear on a hill with Ebrake not properly applied will slowly roll down the hill depending on how steep it is and what gear the car is in.

I made the mistake of 3rd gear instead of 1st or reverse so the car rolled about 1.5 lengths down in an hour before I came back.

In my case, I had all lifters clacking as if they had zero oil in them for a period you might see when running a new engine for the first time.

Remember that the oil leaving these devices end up being pushed around a bearing or the tip of a lifter in normal operation so............turning the engine backwards now makes any "oil exit" a perfect "entrance" for air to enter.

I have already witnessed it as described above and the physics is quite basic.

Turned backwards at the right speed, you can generate quite a few inches of vacuum (mercury) which will pull oil from wherever it is until one route of air entry empties and increases in flow rate causing the rest of the entry points to nearly stop..

That short amount of time is more than enough for oil to be sucked from the lifters since it only has to travel about 5/16 inch before the lifters are empty.

I do turn engines backward but only to "prime" the oil pump when it is impossible to do it with a tool and then only on engines that don't have a device that would be damaged by reverse rotation or may skip a belt tooth since the tensioner is not pumped up yet..

I hook a clear plastic hose to a long and skinny funnel and run it to the port that supplies the oil filter boss.

This port goes directly to the oil pump.

I fill the funnel with oil and turn the engine backwards and watch as the oil is quickly sucked down through the tube and into the port which leads to the oil pump.

I pump at least a quart to ensure the oil has gone all the way down to the oil pickup.

Now I know that the oil pump is full, and that the gallery leading away from it has a nice column as well so I fill up the filter as much as possible and crank the engine.

It's the same mechanism as what empties an engine except I am using it for the opposite by supplying oil from where the reverse rotated engine would seek air.

I get oil pressure immediately at the pressure sender port so I screw it in and undo the oil supply line to the turbo and crank until it comes out there.

Then I enable ignition/injection and start the engine.

Is it possible that your lifetime as a mechanical engineer never brought you to this exact condition.

I've got plenty of gaps in my mechanical engineering knowledge but my engine knowledge has me working directly in this area my entire lifetime.

Ask me about other things and you may find a hole............but not here.

If you think my answer was harsh, it's simply tit for tat replying to a BS post of "pure bullocks" which had zero scientific merit.

I'm the guy on the right asking "why did you guys run 30 pounds of boost to it without filling the methanol tank?"

http://performancepowerracing.com/wp-content/uploads/2012/10/74g9759.jpg

[tescoapp]

Well as another engineering type I would say its completely dependant on the engine design and component design about what's going to happen.

For some it won't be a problem and others its going to break something.

BTW the ability of vacuum pumps to be turned the opposite way only really holds with new ones. Mid life units which have only been run one way your asking for trouble mainly due to wear profiles and material properties changing. Normally you will get gradual wear but one turn in the wrong direction and you "might" get bigish lumps coming off instead of the normal dust wear erosion.

As for the aero engines what may be ok in a normal utility engine with no inverted capability might do some quite nasty damage to an engine with inverted flight certification. Aero engines will have none return valves where as car engines won't in various systems. So I do actually agree with everything Icepaq says about consumer car engines.

But for me it is quiet dangerous to the wallet to presume that they translate directly to aero engines. All it takes is one none return valve to operate as per design and you have issues. Gravity time flow isn't an issue, but as soon as you get about the valve operation threshold then your into outside design operation.

[cyclic35]

A very close call. :rolleyes:
Always assume the prop is "Live".


https://assets.publishing.service.gov.uk/media/595e409640f0b60a40000129/Piper_PA-28-161_Cherokee_Warrior_II_G-BNSZ_08-17.pdf

[Fostex]

That PA28 isn't that bad, in the same Aug 17 AAIB report is the G-MYUB where the flexwing guy put his head into the prop and amazingly survived!

G-MYUB was an incident which occured during a ground run in which the injured party was doing checks rather than intending to go flying. Easy to drop your guard when perception of risk drops.

[Homsap]

If someone disembarks or boards on a Cessna the door and wing strut generally prevents someone walking into a live prop. like wise on Pipers the door again prevents someone walking into the prop.

The problem is with aircraft with sliding canopies such as the Bulldog, Grob115, Robin DR200, DR400, the poblem is boarding with the engine running, that you could slip on the wing and fall of the front of the wing, likewise upon disembarking an aircraft the danger is 'going the wrong way' and jumping of the leading edge into the propellor. I was warned of this when I started flying DR200s, as I was told this happened with fatal results at Sywell in the eventies and eighties.

During my career on several occasions I have seen people hand swinging aircraft, when there is no occupant in the aircaft, utter maddness!

Historically, the RAF did live changeover of air cadets on on the DHC Chipmunks as the had explosive cartriges and their were only six, but the air cadet was always ecort. It would be interesting to know what happens on the RAF grob? In the instructing world instructors have in the past asked student pilots to start the engine and then board.

As most modern aircraft have electric starters, there is no need for anyone to board or disembark with a live engine. On aircraft where handswing takes, the person who is handswinging and the occupant should be sufficiently qualified, trained and pre=briefed not to walk into the prop,

[Chuck Glider]

...I have seen people hand swinging aircraft, when there is no occupant in the aircaft, utter maddness!
Other opinions are available. I do it all the time. It's even shown in the flight manual for my aircraft.

[edited to add]
Generally solo hand propping is done from behind the prop with the controls within reach.
It's still not a place to be careless in your movements but with reasonable care and attention it is quite safe.

[tmmorris]

It would be interesting to know what happens on the RAF grob?

Engine is stopped for cadet changeover AND the cadet is helped into the aircraft by ground crew.

[mary meagher]

As Chuck Glider says, "Generally solo hand propping is done from behind the prop with controls within reach"

At Brown's Seaplane establishment, Winter Haven Florida, the J3 Cub prop was swung FROM BEHIND by the instructor who was standing on the float, holding onto the struts.
On a strong wind day with ripples or waves,this could have been even more interesting....

They sent me solo - if I bought my own seaplane to fly solo in. That didn't happen.

[ShyTorque]

Engine is stopped for cadet changeover AND the cadet is helped into the aircraft by ground crew.

Good idea. I was once carrying out a "running change" in a Bulldog. I was in the process of getting back in the right side and was standing on the wing. The student, having finished solo circuits, hadn't set the parking brake properly and the aircraft began to roll forwards. The student suddenly saw the aircraft movement and without warning jammed on the toe brakes. I was thrown towards the spinning prop but just managed to grab the screen frame with my fingertips... Very close.

[India Four Two]

They sent me solo - if I bought my own seaplane to fly solo in.

Mary,

You should have done your rating in Canada. Solo flying is a required part of the syllabus. :ok:

[RatherBeFlying]

Batteries and starters are challenged in the cold.

Fuel does not vaporise that well in the cold.

Spark plugs ice up.

FBO staff is scarce; so no preheat or battery boost available.

It all ends up with hand propping.

Best to arrange ahead of time for preheat equipment to be available.

[Maoraigh1]

NTSB report:
"On July 26, 2018, about 1650 eastern daylight time, the private pilot of a Cessna 182P, N1311S, was fatally injured when he was struck by the propeller during a preflight inspection of the airplane at the Cleveland Regional Jetport (RZR), Cleveland, Tennessee. "
"The pilot's wife reported to Federal Aviation Administration personnel that they had flown to RZR earlier that day, and her husband performed a normal shutdown of the engine utilizing the mixture control. They performed errands then returned to the airport. She reported to law enforcement that she was outside the airplane behind the passenger door facing her seat, and her husband was performing a preflight inspection of the airplane. She heard the "propeller move" which she described as unusual and heard the engine like it was starting or trying to start. She looked up and noticed her husband fall to the ground. She thought the propeller stopped at that time, and went inside the fixed-base-operator to summon help. She also indicated that the ignition key was in her husband's pocket at the time of the accident. The airplane's ignition switch and key were retained for operational testing."

[Fostex]

A live mag? Very important to actually check that your ignition key/mag switches actually grounds both the mags in the off position.

[jonkster]

Forgive me if this is a stupid question but how exactly can I check that the ignition key/mag switches have actually grounded both mags in the off position?

I recently acquired a share in a light aircraft and one of the requirements where the aircraft is based is that the prop is left in the horizontal position (for the purposes of the ground handlers moving the aircraft - who refuse to touch the aircraft other than connecting the tow to the nosewheel). This therefore means there's a 50/50 chance that I have to move the prop round 90 degrees..... which I absolutely hate doing! - now I've always been taught to make sure that when I shut a piston aircraft down that I turn the key to the OFF position and make sure the keys are out of the ignition.... but the last two posts on here suggest this might not be sufficient? maybe pulling a circuit breaker would ensure there's no mishaps? (type is a Beagle Pup 150)

magnetos are turned "off" by shorting them. This means if a wire or the switch breaks, the engine will keep running, what you want when flying. On the ground though if a wire comes loose or a switch breaks etc, you may have a live mag, even if the switch is off. There is no circuit breaker or anything else to disable the mags. They are designed so that failures in any switch, wiring etc are unlikely to stop the engine.

It is worth learning how to do a mag check prior to engine shutdown (and get into the habit of doing it each shutdown). If that ever indicates you may have a live prop, get someone to inspect the mags and avoid handling the prop (even put a sign on the prop indicating it is live).

Always treat props as live, always move the prop only if you are in a position to pull your hands away and never leave any part of your body in the arc of the prop when rotating it.

[Maoraigh1]

At idle. Right off - mag drop - back to both. Left off - mag drop - back to both.
Both off for an instant, back on fast covers last possibility.
Could vapour mixture ignite to give a kick, without a plug spark, on a hot engine, at compression? This engine had been shut down for long enough that glowing carbon should not be possible. Outside temp 31°C, and in the sun, higher under the cowling.

[India Four Two]

I don't think this has been posted,

https://www.youtube.com/watch?v=Ypb6fEgLNpY

[Piper.Classique]

He wasn't (I hope) trying to start that engine. Pulling it through to check compressions, more likely.
Personally I wouldn't hand swing anything with more than two blades.
I've had a 180 Lycoming with a four blade prop start with keys in my pocket, first flight of the day, just out of the hangar, temp -10 Deg C. No prime, mixture lean. Throttle at idle. Chocks in front of the wheels
That was because it was normally a cow to start on a cold day and I wanted to unstick the oil before starting it. Ran for long enough to walk round the wing. That was a broken mag lead.

[paulross]

I had a similar experience as a staff instructor/tug pilot at Lasham.

We were pulling all the aircraft out of the hanger at the start of the day. The chief tug pilot was just getting in a Rallye 180 that need to be moved but he realised he had omitted to do a compression check. To save time I offered to turn the prop. We did the normal safety calls and responses. On the second swing the engine picked up at fast idle. I think he was more shocked than I as he immediately beckoned me around to inspect the engine controls whilst keeping his hands in the air. The tumbler switch controlling the mags was off with the key removed. The switch had failed to earth one or both magnetos.

Perhaps it helped that I had done my PPL on Tiger Moths trained by ex-RAF instructors who had drilled into me the danger of swinging any prop.

[double_barrel]

I just stumbled upon the report of a horrific accident involving a student pilot who walked into the prop of a C152. The flight school in question was routinely disembarking one student and embarking the next with the engine running.

That seems insane, and not just because of the prop danger. But the report did not explicitly condemn the practice. Although failure to shut down the engine was listed as a contributory cause (!), the recommendations talked vaguely about the importance of awareness of the dangers of spinning props among students and passengers.

Is it ever acceptable practice to allow people to enter/exit a small aircraft with the engine running? Why would this ever be permitted ? Whatever permitted means in this context.

[tmmorris]

I’d never do it, but do people think the risks are different for high vs low wing?

And how how are the students supposed to learn how to start and shut down the engine?

[A and C]

As an instructor I would be quite happy to leave a PA28 or C152 with the engine running, doing the same thing with a DR400 would require a bit more thinking about but dong this with a DA40 simply would not happen. However I have been working around propellers for years and have a respect for the dangers and always approach or leave an aircraft from the rear.

The problems start when people who do not appreciate the risks of propellers are unsupervised near live aircraft and people new to flying are not trained properly , after all how often do you hear a student call “clear prop,” and instantly start the engine allowing no time for a person to step away from the aircraft ?

Old gits like me consider propellor awareness as part of airmanship but no doubt the new and politically correct title is now T.E.M.

[MrAverage]

Our FOB expressly forbids the practice. The problem is not how good and safe one crew is at doing it, but the easily led who see it being done and try to copy....................

[ChickenHouse]

I just stumbled upon the report of a horrific accident involving a student pilot who walked into the prop of a C152. The flight school in question was routinely disembarking one student and embarking the next with the engine running.

That seems insane, and not just because of the prop danger. But the report did not explicitly condemn the practice. Although failure to shut down the engine was listed as a contributory cause (!), the recommendations talked vaguely about the importance of awareness of the dangers of spinning props among students and passengers.

Is it ever acceptable practice to allow people to enter/exit a small aircraft with the engine running? Why would this ever be permitted ? Whatever permitted means in this context.
You have a link to the report? I know of quite some places where they change students with engine running.
On one side, for scenic flights and unfamiliar pax loading/unloading I would follow the never-ever-do-that.
On the other side, a student on training must have some kind of common sense not to walk in front of a running prop.
I know, I AM an old fart from the days when common sense was more common.

[double_barrel]

You have a link to the report? I know of quite some places where they change students with engine running.

http://www.transport.go.ke/downloads/Accident%20report%20%20Cessna%20152%205Y-BYQ%2007%20April%202016.pdf

[Fostex]

Swapping out students with a running engine, while safe if performed correctly (and depending on aircraft type), is not really the best practice when teaching students. It needs to be emphasised to anyone new to flying that being a pilot is not just about handling the aircraft in flight but rather all aspects of safety around the aircraft when airside. That includes the safe startup and shutdown of the engine as well as the use of mags, throttle, mixture and pitch to manage the prop. By simply turning up to a running aircraft and jumping in the student is missing a lot of the learning experience. Not a good idea in my opinion.

[ivorPhillips]

This report is a about a AA5 Passenger that was smuggling drugs and left the aircraft by going forward over the wing,
https://assets.publishing.service.gov.uk/media/54230074ed915d1374000a4b/dft_avsafety_pdf_501006.pdf

His attempt at a quick exit with engine running lead to his demise,

[mgahan]

Only slightly off topic:

I am becoming increasingly concerned at the number of "professional" pilots I see walking through the prop arcs. Any links to decent educative material relevant to the dangers of this activity gratefully received.

MJG

[Three Wire]

MJG. The only education I got was from crusty old FSGTs at Pt Cook. If you didn't walk around the prop on your walkaround they would belt your helmet far harder than any QFI. And then occasionally, you would hear a cough and see a prop turnover with noone in the cockpit.....

[double_barrel]

Swapping out students with a running engine, while safe if performed correctly (and depending on aircraft type), is not really the best practice when teaching students. It needs to be emphasised to anyone new to flying that being a pilot is not just about handling the aircraft in flight but rather all aspects of safety around the aircraft when airside. That includes the safe startup and shutdown of the engine as well as the use of mags, throttle, mixture and pitch to manage the prop. By simply turning up to a running aircraft and jumping in the student is missing a lot of the learning experience. Not a good idea in my opinion.

Exactly. That was my 'other' concern with the practice. You would loose out on all the essential stuff associated with preflighting, pre-start checks, comms with ground, shut down checks (do they also skip power checks?) and I worry that would change the way a student learns to take responsibility for the whole operation.

[mikehallam]

Untill I read the above discussion before Christmas I 'thought' I was careful when ground handling handling my 80 h.p. Rotax powered Rans at my strip.
It set me thinking on how I might operate more safely and wrote the following proto checklist; it's initially for discussion here - bearing in mind it's one man alone at the strip and not so complicated please that one abandons using any checks.

Precaution Treat the Propeller as Always LIVE - A handling regime.
With hot or cold engine even with both ignition 'kill' switches turned to off, turning the propeller could cause it to suddenly fire either forwards or in reverse due to a hot spot or a single 'kill' switch wiring could have an intermittent open circuit.
Rotax never-the-less require the propeller of a cold engine to be rotated forwards by hand many turns to blow crankcase oil back up into the tank to check oil level, & to ascertain there is no hydraulic lock.
Precautions :-
a) Always chock the main wheels.
b) Tie back stick.
c) Throttle closed.
d) Both Ignition switches OFF.
e) Stand on firm ground and rotate the propeller keeping one's arms, body and clothing away from its arc.
f) Pulling the a/c out of its hangar holding the propeller roots reqires equal care.
g) Once in the cockpit ready for engine start, shout "CLEAR PROP" and wait at least 7 to 10 seconds for it to register to anyone unseen outside before operating the starter..
If possible avoid post flight prop/compression checking, it is even more risky.
But, with care as above, the propeller might need turning to re-position an upwards pointing blade to clear the hangar entrance beam for pushing back inside.

Could readers kindly comment ?

[mikemmb]

Untill I read the above discussion before Christmas I 'thought' I was careful when ground handling handling my 80 h.p. Rotax powered Rans at my strip.
It set me thinking on how I might operate more safely and wrote the following proto checklist; it's initially for discussion here - bearing in mind it's one man alone at the strip and not so complicated please that one abandons using any checks.

Precaution Treat the Propeller as Always LIVE - A handling regime.
With hot or cold engine even with both ignition 'kill' switches turned to off, turning the propeller could cause it to suddenly fire either forwards or in reverse due to a hot spot or a single 'kill' switch wiring could have an intermittent open circuit.
Rotax never-the-less require the propeller of a cold engine to be rotated forwards by hand many turns to blow crankcase oil back up into the tank to check oil level, & to ascertain there is no hydraulic lock.
Precautions :-
a) Always chock the main wheels.
b) Tie back stick.
c) Throttle closed.
d) Both Ignition switches OFF.
e) Stand on firm ground and rotate the propeller keeping one's arms, body and clothing away from its arc.
f) Pulling the a/c out of its hangar holding the propeller roots reqires equal care.
g) Once in the cockpit ready for engine start, shout "CLEAR PROP" and wait at least 7 to 10 seconds for it to register to anyone unseen outside before operating the starter..
If possible avoid post flight prop/compression checking, it is even more risky.
But, with care as above, the propeller might need turning to re-position an upwards pointing blade to clear the hangar entrance beam for pushing back inside.

Could readers kindly comment ?

Not strictly Ground Handling, but regular Mag Checks will reduce the risk of a faulty mag switch or wiring creeping up on you!

[jonkster]

My 2c - I am not overly familiar with Rotaxes but understand many are shut down by turning mags off rather than cutting mixture(?). If so, in that case you would be likely to detect a live mag on shutdown because the engine would keep running so you would know if there was an issue there. Effectively you are forced to do a live mag check every shutdown.

Whilst not impossible, I am guessing it would be pretty unlikely for a mag to cut OK on shutdown and then go live afterwards.

Also for the prop to fire you need a suitable fuel mixture available in at least one cylinder - I would assume that would be unlikely if the aircraft hadn't been recently running. If a warm engine though... I would be more cautious.

I think if you are doing the oil pull-through process you require, on a cold engine that you personally have shut down from the last flight, handling the prop would be unlikely to be a high risk.

Doesn't mean you treat props casually - ie don't stand where you could be struck if moving it.

(NB If hand swinging to start, rather than to check oil or adjust blade position, that should involve more care).

That is me personally. You need to make your own decisions though. Other's may have differing opinions.

[mikehallam]

Twice thanks,

And yes i) I've owned it O.K. thus for 10 years
and
ii) Post flight switch off is done each ignition in turn - no weak cut offwith the Bing carb's.

[Maoraigh1]

"Whilst not impossible, I am guessing it would be pretty unlikely for a mag to cut OK on shutdown and then go live afterwards."
As mag switches earth the mags, any break would make the mag live.
Vehicle ignition switches fail dead - and the engine stops.
Mag switches fail live, so the engine doesn't stop, and you keep flying, still with 2 mags.

[DeanoP]

Engines running crew changes were often done on the RAF C130K fleet. The Air Loadmaster (ALM) would exit first from the crew entrance door and screen the engines off with his very long intercomm lead providing a 'fence' to remind crews not to turn into the propeller arcs. As far as I know without any incidents occurring. The ALM would renter the aircraft last.

I remember, around about 1970, a Britannia aircraft, on engine start at night, one of the start up crew walked in to a propeller with fatal results. (It was necessary for a start crew member to ensure that the hold the propeller during engine start to ensure that it was not turning in the wrong direction at the beginning of the start sequence, so they would always be very close to the propellers). I think that the Board of Inquiry concluded that the bright apron lighting caused the propeller to appear to be stationary due to the stroboscopic effect.

From Wikipedia:
The stroboscopic effect is a visual phenomenon (https://en.wikipedia.org/wiki/Optical_phenomenon) caused by aliasing (https://en.wikipedia.org/wiki/Aliasing) that occurs when continuous motion is represented by a series of short or instantaneous samples. It occurs when the view of a moving object is represented by a series of short samples as distinct from a continuous view, and the moving object is in rotational or other cyclic motion at a rate close to the sampling rate (https://en.wikipedia.org/wiki/Sampling_(signal_processing)). It also accounts for the "wagon-wheel effect (https://en.wikipedia.org/wiki/Wagon-wheel_effect)", so-called because in video, spoked wheels on horse-drawn wagons sometimes appear to be turning backwards.

[jonkster]

"Whilst not impossible, I am guessing it would be pretty unlikely for a mag to cut OK on shutdown and then go live afterwards."
As mag switches earth the mags, any break would make the mag live.
Vehicle ignition switches fail dead - and the engine stops.
Mag switches fail live, so the engine doesn't stop, and you keep flying, still with 2 mags.

Exactly.

I would suspect switches more likely to fail with the engine running (due sustained vibration). Why a mag check on shutdown important.

[mikehallam]

Small beer, but that is where Rotax have an edge as every shut down requires the "kill" switches to earth the two ignitions.

[Fostex]

Surely it is normal shut down procedure to check each mag for cut prior to pulling the mixture? This both identifies a grounding issue and will also show any previously unknown mag issue which may have developed during flight.

[Blackfriar]

If someone disembarks or boards on a Cessna the door and wing strut generally prevents someone walking into a live prop. like wise on Pipers the door again prevents someone walking into the prop.

The problem is with aircraft with sliding canopies such as the Bulldog, Grob115, Robin DR200, DR400, the poblem is boarding with the engine running, that you could slip on the wing and fall of the front of the wing, likewise upon disembarking an aircraft the danger is 'going the wrong way' and jumping of the leading edge into the propellor. I was warned of this when I started flying DR200s, as I was told this happened with fatal results at Sywell in the eventies and eighties.

During my career on several occasions I have seen people hand swinging aircraft, when there is no occupant in the aircaft, utter maddness!

Historically, the RAF did live changeover of air cadets on on the DHC Chipmunks as the had explosive cartriges and their were only six, but the air cadet was always ecort. It would be interesting to know what happens on the RAF grob? In the instructing world instructors have in the past asked student pilots to start the engine and then board.

As most modern aircraft have electric starters, there is no need for anyone to board or disembark with a live engine. On aircraft where handswing takes, the person who is handswinging and the occupant should be sufficiently qualified, trained and pre=briefed not to walk into the prop,

I was one of those cadets, at 15 I would walk up the wing and stand by the pilot in the front seat and get the cadet out one side and the next one in the other side with the engine idling. Then strap them in and exit back down the wing rearwards. We had very strict procedures instilled in us including never approaching a prop, even if the engine was off. I can't imagine the "elfansafety" letting kids do that now.

Fast forward 10 years and I'm stood under the nose wheel of a 747 in the middle of a taxiway, tug has removed the towbar and I'm waiting, hopefully, for the "OK, thanks, see you next time" on the intercom. It's a lonely place and with zero training, except cadet experience around live aircraft.

[Pontius Navigator]

I was taught never to handle a prop unless you knew the mag switches were off. That was enough for me so never ever touched one. What amazed me though on the Hastings and Lancaster was the flight eng aligning all the props the same way.

It looked neat and as the flt eng he probably knew the mags were off.

I think on the Shack someone managed to pass through both prop arcs.

[Donkey9871]

In just over 12 years at first line on helicoptors I saw a number of close calls with tail rotors, fortunately only had one myself due to a Wesex pilot turning before the marshaller gave the signal during a 3 ship 'formation' taxi landing and shut down. At 6'2" it was frighteningly close to my head. Towards the end of my helicoptor first line experience I worked on flat tops in the dark. You know that the tail rotor is there, you can hear it and feel the turbulence from it, you know it is at head hight but can't see a thing. When attaching the tail lashings to a running helicopter the drill is to monkey walk in, knees bent head down, attach the lashing to the ac lashing point and crawl out to the elephant's foot lashing point. Used to scare the last meal I ate out of me every time. How more fatalities don't occur is a mystery and a credit to the training and professionalism of those who operate as ground crew on embarked helicoptors. There is nowhere as dark as a flight deck out in the ocean under 'darkened ship' conditions. The most effecient killing machine known to man has to be the tail rotor of a helicopter, the final twist being a helicoptor tail rotor under 'darkened ship' conditions in a heavy sea. Having said that they tend not to start of their own accord like props on piston engined ac can and do.

[BearForce One]

I have a question, something I've been wondering about for a while..

At my gliding club, our Motor Falke is usually last to go in the hangar. And so first to come out. Routinely, whoever is moving it will pull it forward by the prop. I've done this a couple of times myself, but since reading this thread, I've not touched it. I did ask someone about it, and was told "no, no - prop couldn't possibly turn by itself". There was some mechanical reason given as to why this couldn't happen, possibly magneto-related, but it was a while ago and I can't remember the exact basis.

Could someone please tell me I am not nuts to be leery of this? I just have a nagging feeling that if I'm right, it's something I should be mentioning to our CFI..

[IcePaq]

Exactly.

I would suspect switches more likely to fail with the engine running (due sustained vibration). Why a mag check on shutdown important.

A mag shorting circuit that successfully shut down a warm engine can become open as the engine cools (or after) because of the dissimilar expansion rate of materials used to manufacture the parts.

[DownWest]

Just a question about Rotax 912 and other derivatives. I put together a Merlin GT from a kit and it had dual electronic ignition, so not like a mag with earthing? It was a while back, so I might be fuddled...

[mickjoebill]

We know camera crews and helicopters are a toxic mix. Although I had a ppl when I began a filming assignment with a HEMS operation who were using Dauphans, I was taught in most graphic way how low a rotor can dip. The risk was I would be exiting rotors running and possibly on rising ground whilst being pre-occupied with filming the medical team rushing off to the casualty.

With the aircraft shut down, during the first safety briefing, the pilot jumped up, grabbed the blade and pulled it down to neck height.
That got my attention!

That lesson remained for many years and kept me safe for a few thousand hours of aerial filming assignments. I decided I would always wait until rotors stopped before exiting because a gust of wind has more effect on a blade at startup and shut down.


Mjb

[India Four Two]

An awful propeller accident in Florida:

https://www.flkeysnews.com/news/local/article236092133.html

[B2N2]

There is so much wrong with that accident:

- Did the “pilot” even do a preflight?
- “Pilot” should have shut down prior to exit.
Especially with a passenger.
- “Pilot” should have briefed his passenger which is really easy in a Cessna (stay behind the strut at all times even with the engine off. Walk around the wingtip to get to the door)
- Pax should have listened but was probably just trying to be helpful.

I’m typing “pilot” as he obviously isn’t.
The FAA should investigate and revoke his certificates.
Good luck helping your wife learn to walk again and wipe.

I have no sympathy for these types.

[Pilot DAR]

In piloting, we consider "normal" and "abnormal" conditions. When presented with an "abnormal" condition, we exercise more caution, as an accident is more possible. A turning propeller, with people moving around near it on the ground, is an abnormal condition.

I expect that the FAA will speak to the pilot about the offense of not occupying the pilot's seat with the engine running.

[India Four Two]

- Did the “pilot” even do a preflight?
- “Pilot” should have shut down prior to exit.

B2N2,

I'm guilty of forgetting to remove the chocks during my preflight. However, when I realized what was preventing me from moving, I did shut down prior to getting out and removing the chocks.

Most of my power-flying is on a gliding field where there are often people in relatively close proximity to the tow plane. I am always conscious of the potential need to quickly turn the mags off if anyone is approaching me.

However, I do have a lot of sympathy for the pilot. He has to live with the fact that his wife was severely injured because of his oversight/complacency.

[B2N2]

Everybody has forgotten chocks including me.
Its how you deal with an error or an oversight.
If anything this clearly shows that an accident is a chain of events and some accidents are years in the making (complacencies).

This was a rented airplane, they may have been delayed into a flight after sunset, renter may have been legal for night flight with passengers but not comfortable and so on.

Could have been many additional stress factors including the attitude/behavior of a passenger.

[Teddy Robinson]

The propeller arc is always live. Never EVER go there.

[Auxtank]

It pains me to see some of the ads in the press for modular ATPL with grinning students in their crisp white pilot shirts, student epaulettes and a hand resting on the prop of a PA-28 or in this case a DA-40. Even if that thing hasn't even got an engine under the cowling and prop's a mock up - it's still promoting bad practise.
Here you go. In a popular monthly mag for a major ATO...


https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/500x365/dfdf_dd61613cf248736bfd445b28f09f1cd14a694dab.jpg

[rnzoli]

Hey, it's because they are ATPL students, so in 2 years time they willl fly big jets, without remembering what a prop or magneto is :)
Just kidding of course, but I also watch thes photos, any many happy before / after sightseeing flight photos with the pilots and passengers touching blades, standing right next to blades etc.
While accidents rarely happen that way, it shows disrepspect to a literally lethal part of the aircraft, which WILL develop into complacency and if the circumstances are given, WILL directly lead to a prop accident.
Although not always fatal, aircraft propellers striking humans leave scars for life: missing fingers, amputated or totally paralized arm, very badly difigured face.
And of course you won't see THAT on social media or fancy brochures.

[Big Pistons Forever]

The September Pilot has an article re mag checks. Personally I have a problem with the "dead' mag check. I always taught my students check the mags on shut down by going to 1200 rpm and then checking for a RPM drop with a left - both right -both and then mixture idle cut off. The reason for not turning both mags off with the engine running is that if the student isn't quick turning the mags back on, the engine will backfire and blow out all of the muffler baffles.

I was discussing this with an another instructor recently who strongly disagreed with me. My question to fellow ppruners is; has anyone ever seen a mag switch that would properly ground the mags when selected to left and right but leave a mag live when selected to off ?

Incidentally he did not know that the mag switch is designed so that the key can only be removed when the switch is in the off position. When I teach the shut down mag check I also tell the student to gently pull on the key when in the both, left and right position. On 2 occasions I have found switches that were worn enough that the key came off in the left position. It would be very easy to think you had turned the key all the way to the off position but instead left it in the left position with a mag live and the key out.

I also make a point of not wrapping your fingers around the blade if you have to reposition the prop to put in the tow bar.

[Pilot DAR]

Yes, I have seem several mag switches worn to the point where the key could be pulled out in any selected position, this mode of failure can be easily checked with the engine stopped. Yes!!! I have personally experienced (as the guy hand propping the plane) a mag switch, which when selected off, left the mags live. Happily, my habit of hand propping as though the mags were always live, and the engine could unexpectedly start, prevented an unhappy event that day. After the engine (C150) was wrongly running, and I glared at my trusted buddy in the cockpit - he replied with a surprised look, holding up the keys, which I could see through the running prop arc!

So, though I agree with BPF's observation about the risks to the exhaust of a careless live mag check, I always do these checks - with great care. I am certain to turn the key off only at the slowest possible idle RPM, and for the most brief period. Doing it that way, I've never had an exhaust backfire, but as BPF says, a live mag check conducted at power can certainly damage the exhaust. For those who would like a refresher; if the engine is turning, with the mixture rich, it's pumping fuel through. If it's running while it's turning, the fuel is obviously being burned - no problem. If you (during a successful live mag check) prevent the fuel being burned, it gets pumped through anyway. It'll accumulate in the exhaust after a few strokes, and may be reignited when the mags are turned on again. If the engine was turning fast, and the period of no ignition was many strokes, it'll pump quite a bit of fuel. That cold create a damaging backfire. This also applies in flight, if you must reduce power beyond throttle to idle, move the mixture to cut off, rather than turning the key off, if you intend to return the power in flight.

If the engine has turned over many strokes with the fuel on, and ignition off, if on the ground, it would be wise to let the engine stop, then sit for many minutes before restarting, so fuel may evaporate from the exhaust. If in flight, select the mixture to cut off, and let the engine windmill so as to blow through any fuel accumulated in the exhaust. You'll know you did it wrong if you hear a bang when you return ignition.

There is hardly any damage you could do to an exhaust system which won't be a few thousand dollars to repair. And, any exhaust work introduces the risk that a cylinder stud is damaged during removal, then you're having to change a cylinder as well, which will be many more thousands of dollars. So, it's worth not abusing the engine this way.

[Big Pistons Forever]

Pilot DAR

I have seen a mag switch with a live mag when selected off but it also allowed a live mag when selected to the other mag and so would have been caught by my check. So my question is if the mag switch grounds the mag when individually selecting a mag but then allows a mag to live when in the off position. Has anyone seen that ?

I think that failure mode is essential impossible and so a running shut down check and the normal precautions around props are sufficient and therefore a full dead mag check where the mags are turned off with the engine running is not really required

[Pilot DAR]

I agree that if everyone always treated a stopped propeller as though it could start the engine if moved at all, live mag checks would serve little purpose, other than to confirm "airworthiness" of the mag switch itself. I also agree that the need to hand prop planes is happily becoming less, as non starter equipped planes become more rare. But there can always be reasonably legitimate reasons to pull a prop through by hand, like circulating engine oil after preheating, before starting, so with careful live mag check technique, I'd rather do the check, and have more (not total, more) assurance that the system is airworthy. I will still treat a prop as though it's live all the time.

'Story from the past:

In a past life, I was the O-200 key clutch repair guy, so all the clutches that cam into the engine shop for repair came to me. One of our customers, with a C 150, called back to say that the clutch we'd (I'd) just sent back repaired would not engage, and he was a bit fussed about this, wanting to go flying. I was told to fly down, and make it right. So, I packed up my tools, prepared to rebuild the clutch on site. It was possible I'd made an error, and it would not engage, so I was ready to make it right for the customer. I arrived to his plane after an hour flight, it was the one with the top cowl beside it on the grass. Sure enough, I turned the key, starter ran, prop didn't - problem. I asked the owner what had been done for installation. He replied that he had simply put the clutch back in, and had not fussed with anything else. So, I took the clutch out, and checked it, it seemed to be working correctly. I reinstalled it, and did some more checks, and everything seemed to be working correctly, I could feel it engage and disengage the starter motor with slight, and careful rotation of the prop. But still, the starter motor would not turn the prop. In diagnosing, it got to the point where I had the owner engage the starter, while I wiggled the prop with a bit of light rope, intended fly off the tip if the prop started to turn, it didn't. I was puzzled, and this was getting less safe to experiment with, as everything seemed to be working as it should. Then in desperation, I re-asked the question I'd already asked, just a little differently: "Are you sure that you haven't taken anything else apart here?". Then the reply (he knew I was really frustrated now); "Well... I did take the back plate off the starter motor to look inside...". The bugger had put it back on 90 degrees out of phase, and the starter motor was turning backward, of course my correctly repaired one way starter clutch would not engage! A quick fix, and the whole thing worked just fine. I could have saved an hour of frustration if I'd known to check the starter motor for misassembly. I must have looked like a fool wiggling a prop tip when the owner held the starter running!

It's worth understanding how your starter should work, and getting it fixed if it doesn't. And still, I support careful live mag checks....

[TLDNMCL]

Having done some flying in the good ol' USA where you are encouraged to yell 'Clear Prop!' (I'm softly spoken so no one ever hears), I found myself back home at my local airfield. About to start my engine I observed an instructor and student at another aircraft parked alongside. I earnestly called 'Clear Prop!', no one heard. I signalled engine starting with hand signals several times to a now bemused looking pair. Then the instructor walked over to my aircraft through the prop arc, put his arm over the front cowl and helpfully asked if everything was alright!
Never earnestly assume that everybody else knows about hand signals and prop safety.
I remember during my initial groudcrew training, when we were being introduced to a new topic where verbal warnings were required, the instructors would make each of us stand up and shout the appropriate warning or instruction.
Some of the shrinking violets in the class would go red, mumble and sit down. "Get back up."
This went on until satisfactory volume was achieved,
"If you are working on aircraft, you'd better learn to shout and not be embarrassed by it, or you'll kill some poor **ck** one day."
Funny how the simplest of lessons stick even after 40+ years

[TLDNMCL]

Having done some flying in the good ol' USA where you are encouraged to yell 'Clear Prop!' (I'm softly spoken so no one ever hears), I found myself back home at my local airfield. About to start my engine I observed an instructor and student at another aircraft parked alongside. I earnestly called 'Clear Prop!', no one heard. I signalled engine starting with hand signals several times to a now bemused looking pair. Then the instructor walked over to my aircraft through the prop arc, put his arm over the front cowl and helpfully asked if everything was alright!
Never earnestly assume that everybody else knows about hand signals and prop safety.
I remember during my initial groudcrew training, when we were being introduced to a new topic where verbal warnings were required, the instructors would make each of us stand up and shout the appropriate warning or instruction.
Some of the shrinking violets in the class would go red, mumble and sit down. "Get back up."
This went on until satisfactory volume was achieved,
"If you are working on aircraft, you'd better learn to shout and not be embarrassed by it, or you'll kill some poor **ck** one day."
Funny how the simplest of lessons stick even after 40+ years.

[punkalouver]

Just read an interesting one today on a Gipsy Major last year. The pilot’s hand was injured by the prop while turning the prop to prime the engine(a requirement).

He had actually done a live mag check on the previous shutdown with no issue. Yet the ignition was intermittently live. Something to do with the earthing cap which is a different design from modern mags. A wire doesn’t always have to break for the mag to be live, just a single lack of continuity in the earthing circuit.

Just shows the importance of being paranoid even if the mag was just tested. Best to just make it a policy to always have the same level of paranoia when turning the prop.

[punkalouver]

Was pulling a Gipsy Major through the other day for priming. It has a Fairey Reed prop and for me, requires quite a stretch to reach. Because of this, I found that I would be moving the prop in two separate movements for each pull through. The first is the big reach to be able to just get the blade to a position of about 2 o’clock, which is just prior to the click of the impulse coupling. I find that I have to grab the prop near the hub to do this.

Once positioned at the 2 o’clock position, then I pull it through carefully and start over again. But I did notice that I was pulling through with my hands about mid-way between hub and tip as that is where they were for the initial positioning of the propeller. While doing this, I was thinking about the incident mentioned in the previous post.

I noticed that even though I was only just wrapping the very tips of my fingers onto the trailing edge of the blade, because of the increased twist of the blade at the mid-point versus near the tip, it seemed I was more vulnerable to having my fingers struck by the next blade if the engine started suddenly. Therefore, for the rest of the pull-throughs, I made sure to take the time to make sure I was pulling from as close to the propeller tip as possible, even if it took a bit longer to do the whole procedure. As a benefit, the prop requires less force to pull through when hands are close to the tip.

Update Nov 17/2022:
Well folks, it actually did happen. I ended up with a live mag on the Gipsy Major and had it fire on me.

The pilot flying the aircraft came in and did a pre-flight. Part of his pre-flight is to actually remove the earthing cap for each mag and lake a look at the interior of the cap(it has a spring and carbon brush and he once found the spring broken on a pre-flight). Both caps were placed back in position. I was the ground crewman for the start. What neither of us knew was that the mag on the starboard side of the engine was live. As the pilot was setting himself up in the cockpit, I confirmed that the throttle was closed, brakes set, fuel selector off, and mag switches off. I carefully pulled the prop through several times as a standard(but unlikely to find) check for a hydraulic lock. All seemed normal with a few clicks heard to confirm impulse operation. The pilot said that he was ready for the engine to be primed. I pulled on the cable to overflow the carb which allows fuel to flow into the intake manifold. When I saw fuel coming out the intake manifold drain, I proceeded to the prop to start turning it which allows the suction from intake strokes to suck in fumes for start,

Because the prop is quite high and in a near vertical position(a blade at 1 o'clock position), I have to reach up and grab the inner part of the prop and move it clockwise to near the horizontal position which is just prior to an impulse click - which is a spark in one of the four cylinders as each sequential click fires a different cylinder(keep in mind that most British engines turn in the opposite direction to American engines). I don't have to worry about the non-impulse mag, even if is live, as prop is being turned too slow to activate it. But unknown to us, the impulse mag is hot.

I pull the prop through twice, each time it ends up near vertical and has to be re-positioned to near horizontal for the next pull through. On the fateful pull, I grab the prop with both hands near the tip as there is less twist at that location meaning my hands are further forward a bit from any sudden, fast start(like Kinners tend to do). My fingers are not wrapped all the way around the trailing edge but just enough to be able to pull the prop through. And then it happens. There is a single fire and the propeller kicks backward(not 100% sure why yet) but for a fraction of a second, I thought it was a hydraulic lock I hit but the prop pulls away backwards out of my grasp. There is no pain or issue as I did not have my fingers wrapped around the prop(remember, the trailing edge is sharper than the leading edge).

The engine is started and there is a live mag as it has to be shut down by turning the fuel selector off. It turns out that there is an exposed wire on the starboard earthing cap, that perhaps became exposed when it was removed for inspection.