A good reminder to always treat props as 'live'

[training wheels]

One of the first things I learnt when I started flying was to always treat props as live..

https://www.facebook.com/CivilAviationSafetyAuthority/videos/447427165450310/

And not even a high vis vest would have helped ..

[Ultralights]

very stupid and very lucky man indeed..

[Shagpile]

I recently had a starter motor engage when turning on the boost pump (ignition OFF and Mixture full lean, first flight of the day).

Turns out a blocking diode had failed allowing reverse current into the starter relay.

I would have never thought it could happen until I saw it with my own eyes.

[RobRW]

Not a stupid man at all Ultralights. If you read the article, its just bit of bad luck mixed with low hours on type and could happen to anyone. Even if the key/master batt. is off, the magneto can still fault and go open circuit, we always learnt to treat every prop as live. Good on him for sharing the story.

[Centaurus]

The CASA video misses the golden opportunity to explain why it is dangerous to attempt to hand start an aeroplane that has a unserviceable starter motor or a flat battery. An aircraft like the one showed in the video including powerful engines in light piston twins.

These aircraft are not designed to be hand-started because of their high compression engines compared to a Tiger Moth, Chipmunk and similar old aeroplanes that do not have starter motors.

If a battery is flat then install a new battery. If the starter motor is inoperative, then it is safer to replace the starter with a serviceable one rather than chance one's arm (literally) by hand starting with the propeller. Being impatient to get away is not a valid excuse.

Nowhere in any POH will you see instructions on how to start the engine that has an inoperative starter motor or a flat battery. An aviation lawyer would be quick to pick that up and if an accident occurs when hand-propping, place full responsibility on the injured or dead pilot. Of course if it is a medical emergency then you have to weigh up the priorities between the patient's medical situation as against risk of the pilot losing an arm or a leg if the hand starting goes wrong. You can think up all sorts of reasons to attempt a hand start if you are stuck somewhere because of a flat battery or u/s starter motor.

But I am sure any insurer would think twice about paying out if someone got maimed or killed trying to hand start an engine simply to save the cost of flying in a LAME to fix the starter or replace a battery. That was the flight safety point the CASA video should have made.

[onetrack]

With age and familiarity, often comes complacence. If he was 19 or 20, you could blame it on inexperience - but at his age, it can only be complacence.

"Just treat a prop like an 8ft machete, and you'll do just fine." :D :D

Comment Award of the Year! :ok:

[mickjoebill]

In the article the pilot says he rotated the prop to check the leading edges for stone damage. But the video shows that he can touch the tip of the most vertical of the blades. Why was it necessary for the prop to be turned if he can touch all the blades?

General point; whilst it is reasonable to assume the presence of a film camera can encourage one to demonstrate "best practice" it also can be a distraction, especially if one is taking directions from a member of the production team.

Mickjoebill

[Aussie Bob]

Has it occurred to any of you that this video could well have been deliberately staged?

These aircraft are not designed to be hand-started because of their high compression engines compared to a Tiger Moth, Chipmunk and similar old aeroplanes that do not have starter motors.
That is nonsense Centaurus, these engines are just as easy to hand start as a Tiger Moth and the compression ratio is also similar. The props are also lower. I don't recall my Tiger Moth flight manual having great instructions on hand starting the engine either. Work long enough in the bush and you will hand start most piston engine types. Done correctly it is not that hard. Get it wrong at your peril.

[Ultralights]

i have seen a rotax 912 hand started. every time i touch my prop, im standing behind it, and treat it like i would if trying to hand start.

[Lookleft]

Hand swung a Duchess once during the year that shall not be forgotten or mentioned. The POH stated that you had to prime while you cranked but all that did was wear out the starter motor so the skills to hand swing were required on a regular basis. Thankfully I now have access to x-bleed starts.:ok:

[spinex]

Having seen a daisy chain of suitably motivated national servicemen, get a DC-3 to start, I am loathe to call impossible on hand starting any aero engine, however some would require a pretty urgent need before I'd try. A 912 is one of those - particularly if it's a bit chilly, the prop needs a fair amount of force to turn and given that most are fitted with lightish composite props, I can imagine the temptation would be to get up close an personal to exert sufficient force to swing one at the required rpm.:hmm: Indeed most Rotax engines fall under that category, I've swung a variety of engines, but the closest I got to being bitten was a 2 stroke Rotax with a very sharp 4 bladed carbon prop, those blades come around rather quickly!

All of which said, it is still a very useful skill to have, I guess being farm bred, I battle with the modern approach of "call the RACQ" for every minor mechanical mishap.

[Car RAMROD]

Never had that problem with my PT6 :E

[sheppey]

Work long enough in the bush and you will hand start most piston engine types

Remove the starter motor before flying planes in the bush and save big bucks in maintenance costs. Why didn't I think of that, before. Thanks Aussie Bob - a brilliant idea.

[Centaurus]

Done correctly it is not that hard. Get it wrong at your peril.

Thanks OB. My point exactly:ok:

[Aussie Bob]

Sheppy, most of the aircraft I have hand propped in the bush have been other peoples. I am quite comfortable with the fact that most pilots will not try a prop start.

Next time you see a Continental powered seaplane, look at the panel and note the manual plunger primer. Then ask why it is fitted.

[currawong]

On this occasion I agree with Aussie Bob.

Any part of flying will kill you if not done correctly.

Some people should probably not attempt it, just as some should not fly, or drive for that matter.

Pulling the prop through before first flight is SOP in some organisations. Prop is handled with same caution as hand starting.

Regarding size/ compression etc, I used to hand start a 300 hp IO-520 on occasion without any trouble at all.

As pointed out already, cock it up and you are dead.

[Squawk7700]

Those of us that have been hand starting Tigers for years are wondering what all the fuss is about :-)

[REDRPPL]

As a young lad I was certainly taught to pull the prop through on a Cessna before the first flight. It seemed to make sense as that action could possibly make it easier for the starter motor and thus conceivably prevent the necessity of having to do a real propeller start.


Now, it also seemed logical to do that first hand swing in the opposite direction of normal propeller rotation. Could somebody please remind me (in gentle language) why this is not a good idea, thanks.

[DeRated]

.... many vac pumps are single direction rotation. Pulling the prop through against that direction will snap the pump vanes or shear the drive.

[training wheels]

Love the advice given at 0:16 s of this clip on how to hand prop an airplane.. :E

7UhX6uXU8X8

[Lead Balloon]

As with so many other areas of aviation, hand starting engines is one in which a detailed understanding of the specific fuel and ignition system fitted to the specific aircraft is essential for success and safety. AB touched on this issue earlier, when he said:....Continental powered seaplane, look at the panel and note the manual plunger primer. Then ask why it is fitted.If your aircraft is fitted with e.g. an injected Conti and the only way to prime it is an electrical auxiliary pump, it's going to take an enormous amount of hand swinging to get that baby started if the battery's so dead that it won't run the aux pump to prime it. At hand swinging RPMs, the EDP isn't doing much at all. (The last time I hand started an IO520 the battery still had enough charge to run the aux pump slowly, but sufficiently to prime the injection system. As noted by currawong, they start easily when swung. Very - and dangerously - easily. But only when the F:A in the induction system and the spark are correct. Speaking of the spark....)

Some ignition systems use retard breakers in the magnetos and electric aids to starting, like "Shower of Sparks" vibrators and 'SlickStart' boosters. They have complicated wiring at and from the ignition switch. That wiring is different than if the magnetos each have just a mechanical impulse coupling. The electrically boosted ignition circuits are rarer these days - at least on 'traditional' GA piston engines - but not extinct. Trying to hand start one of those engines with a flat or low battery may be, at best, impossible, and at worst, deadly, no matter how competent you are at hand swinging in general. And note that the generic model of the same engine can have different magnetos and start systems. Not all e.g. IO520s have the same ignition systems.

For my part, I listen for the 'snap' of mechanical impulse couplings unwinding in both magnetos, while pulling the prop through slowly (with the mags off but assuming they are 'live'), before attempting a hand start. I'm not aware of any esoteric starting aids that still retain mechanical impulse couplings in the magnetos.

[Sunfish]

The Rotax 912 Operators manual requires that the propeller be rotated by hand to build up compression in the crankcase to force oil into the oil tank. You do this until you hear the engine oil tank "burp". You then check the dipstick.

[Ultralights]

yes, but after making sure the ignition is OFF, and keys/master is Off, even then i always stand behind the prop.

[kkiwi]

You shouldn't rotate a Rotax 912 backwards though, and they are of course more difficult to hand start because of the gearbox.

[Band a Lot]

What step of this "mandatory way" magneto timing is remove vacuum pump?


http://www.tcmlink.com/pdf2/msb94-8d.pdf

The prop is required to be turned backwards.


Turn the propeller slowly in the direction of normal rotation until the piston lightly
but positively touches the TDC locator.
4. Rotate the disc of the timing indicator until 0 degrees aligns with the pointer. A light
tap of the finger against the dial will ensure that the pointer is centered.
5. Slowly turn the propeller in the opposite direction of normal rotation until the piston
lightly but positively touches the TDC locator.

[REDRPPL]

De Rated, Band a Lot


The PPrune search function reveals that the same points were being made in 2006 with some suggesting dire consequences to the vacuum pump if rotating the prop backwards with others pointing out that rotating the prop backwards was standard practice when setting ignition timing, presumably with no damage to vacuum pumps.


For a specific set of circumstances: Cessna 172 with cold engine (first flight)- if we rotate prop backwards by hand is it possible to cause damage to engine or engine components ?

[onetrack]

An engine can run backwards by itself, to a small degree, when it hits compression as it stops spinning, on shutdown.
So the suggested component damage (such as to a dry vacuum pump) being caused by turning backwards - at first glance, doesn't seem likely - as one would expect engine manufacturers would have taken this into account in the design of components.

However, the CASA airworthiness bulletin below, is very pointed about the dangers of possible dry vacuum pump damage, due to rotating an engine backwards.

You will note that the vanes in the dry vacuum pump are angled, unlike many vacuum pumps, and they are designed to run in one direction only.

As they run dry, relying only on lubrication from graphite dust from the vanes themselves, it is immediately obvious that the chances of vane damage caused by reverse rotation, over more than a relatively low number of degrees, are high.

CASA Airworthiness Bulletin 37-003 - April 2015 (https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/airworth/awb/37/003.pdf)

[Lead Balloon]

Interestingly, the recommendations in the AWB do not include one to the effect: "Don't move the propellor in the opposite direction to normal rotation", despite reverse rotation as being mentioned as one possible cause of damage to vane-type vacuum pumps.

If you do the calculations on how much reverse rotation a vacuum pump would 'suffer' during a normal timing check or other ground handling activity, that's not surprising. If those pumps are indeed that delicate that they'd suffer damage at ultra-slow rotation a few tens of degrees in the opposite direction to normal rotation, they shouldn't be fitted to aircraft engines in the first place (or there should be a big placard in the cockpit and in the POH and the maintenance manuals that says: DON'T EVER ROTATE THE PROPELLOR IN THE OPPOSITE DIRECTION TO NORMAL ROTATION

[Band a Lot]

Not one to put much into CASA AWB's (I love the compass one!) THERE ARE A NUMBER OF THEM THAT SIMPLE GET REMOVED/CANCELLED.


If the reverse rotation of prop were true for vac pumps, then most failures should be during or on ground run after 100 hr maintenance, where doing timing of mags requires reverse rotation of prop a little or a lot. If the vane was to chipped then it will self destruct on start up (contamination).

Most vacuum pumps DO NOT fail at this time not from my experience within an hour or 3 after timing check regardless of starts.


I have noticed over the years that when there is more smoke around from bush fires there seems a lot of vac pump changes happening, also if a vac pump is swapped at engine change it fails soon after within 50 hrs often.

[Band a Lot]

"For a specific set of circumstances: Cessna 172 with cold engine (first flight)- if we rotate prop backwards by hand is it possible to cause damage to engine or engine components ?"




On the camber in the vac pump, that is at the vent fitting and exposed to the atmosphere in a tropical upto 90% each day. How is the rust on the steel wall of vac pump after 29 days standing and still cold on said C172.

[A Squared]

For my part, I listen for the 'snap' of mechanical impulse couplings unwinding in both magnetos, while pulling the prop through slowly (with the mags off but assuming they are 'live'), before attempting a hand start.

Many aircraft have only have an impulse coupling on one of the magnetos.

[Seagull V]

Little point in hand starting an alternator equipped aero engine if the battery is flat, as the alternator requires excitation to come on line. No radio, no navaids, no lights and maybe no flaps or undercarriage. However I understand that the GA-8 Airvan has a battery in the alternator circuit to provide the initial excitation.

[Aussie Bob]

Assuming the battery is OK and just run flat by say leaving the master on, it will quickly regain enough power to excite the alternator simply by leaving it with zero load for 10 or so minutes.

[Band a Lot]

Why have magneto (independent ignition source) in fact why have 2? Aircraft are and must count on battery failure and still fly.

Rumour has it they can also start with out a working starter system and still fly, even if one magneto fails rumour is it can still fly all be it less power on most occasions.


Fact is a engine can and will start even if TCM forget to put both impulse couplings on a Barron engine. It was only notice at a routine removal and started like a champ each and every time from factory NEW.

[Lead Balloon]

Fact is a engine can and will start even if TCM forget to put both impulse couplings on a Barron engine. It was only notice at a routine removal and started like a champ each and every time from factory NEW.That is quite amazing.

No impulse couplings and no retard breaker circuits?

Bendix or Slick mags?Many aircraft have only have an impulse coupling on one of the magnetos.Just goes to show that it's very important to understand the specific systems fitted to the specific aircraft we fly! :ok:

[Aussie Bob]

That is quite amazing

I agree but I have also seen aircraft start easily with no impulse. 20 degrees of advance is no impediment either, just a bigger risk of kickback.

[Lead Balloon]

S'pose so. The starter motor is rotating the prop a little quicker than a hand swing.

Band a Lot may be able to answer this: How many degrees advance on the magnetos fitted to those Baron engines? I thought 22 or maybe 24, but that's just a guess.

[Band a Lot]

Bendix,


Willie, Hannas, Noel, Aaaron and a few others can confirm. Out of box from TCM to Kalahari Air Services - company policy their to remove and check mags each 100 hrs.

22 degrees.

Noel I think still current owner, call and ask him he will confirm. (smart guy remembers lots).

[Tee Emm]

Most accept there is some risk if an amateur attempts to hand prop without instruction. Even Aussie Bob, the expert pilot from the Bush alludes to that fact.


Question without notice. If an aircraft flat battery is discovered, is it possible to undertake a "jump Start" from a car if one is handy, rather than taking the risk of becoming a one-armed wall paper hanger?

[Aussie Bob]

Most accept there is some risk if an amateur attempts to hand prop without instruction. Even Aussie Bob, the expert pilot from the Bush alludes to that fact. Actually Tee Emm, I am not convinced there is any risk at all. What old mate in the video demonstrates with aplomb is just how easy prop starting is. Next time the lads are hanging around having a few quiet ones after work, perhaps I will get a demo "I will hold your beer, you try this" happening.

Runaway aeroplanes aside, has anyone ever heard about anyone hurting themselves doing this operation? I haven't but I guess there are some.

Moving on to the jump start though, no problem at all. With three leads and two cars, even a 24 volt blat flattery can be fixed this way. :ok: I should add as an afterthought here though, on some types it can be a wee bit tricky getting the cowl back on with the engine running.

[Lead Balloon]

Question without notice. If an aircraft flat battery is discovered, is it possible to undertake a "jump Start" from a car if one is handy, rather than taking the risk of becoming a one-armed wall paper hanger?Of course it's possible. But...

Jump starting is not risk free either. You had better know what the aircraft's battery voltage is, what terminal is connected to earth (airframe) and what jumper lead goes where and in what order. And as AB notes, if you have to have e.g. a cowl panel open or removed and the cover removed from the battery box, what's the plan to get them back on/closed? Note also that there's going to be a fair bit of wind and vibration - could be very bad if a jumper lead shakes/blows loose and touches the wrong thing in the engine bay ...

(Note too that some aircraft have auxiliary power sockets. A much better solution, if available. The POH will explain the correct procedure for using it.)

[Band a Lot]

Mostly a ego injury.

https://www.atsb.gov.au/publications/investigation_reports/2002/aair/aair200203171.aspx

[A Squared]

Little point in hand starting an alternator equipped aero engine if the battery is flat, as the alternator requires excitation to come on line.

That's true for a dead flat battery, but there's a a pretty wide range of territory between "not quite enough juice to turn the engine thru a compression stroke" and "too dead to exite an alternator field"

No radio, no navaids, no lights and maybe no flaps.... There's a whole bunch of GA airplanes which fly quite nicely without any of that.

[A Squared]

Moving on to the jump start though, no problem at all. With three leads and two cars, even a 24 volt blat flattery can be fixed this way. :ok:Yep, I've twice jump started a DC-6 using two vehicles. Haven't ever hand-propped one though. :eek:

Fact is a engine can and will start even if TCM forget to put both impulse couplings on a Barron engine.

The aforementioned DC-6 had an ignition boost similar to "shower of sparks" except that it was controlled by a separate switch. You could start the engines without using the ignition boost, which is the equivalent of starting without an impulse coupling.

[kaz3g]

Aussie Bob mentioned runaways...

http://www.pprune.org/pacific-general-aviation-questions/460396-pilotless-auster-over-sydney-1955-a.html

Great aeroplanes these Austers!

Kaz

[Lead Balloon]

A very fine Chapter in the illustrious history of the RAAF! :E

[Band a Lot]

Ever started an AN2?

"The aforementioned DC-6 had an ignition boost similar to "shower of sparks" except that it was controlled by a separate switch. You could start the engines without using the ignition boost, which is the equivalent of starting without an impulse coupling."


Not a 1 hand job.

[kaz3g]

Lead Balloon...
A very fine Chapter in the illustrious history of the RAAF!


The ignominy of it...shot down by the Kiwi Navy!

Kaz

[gerry111]

"(Note too that some aircraft have auxiliary power sockets. A much better solution, if available. The POH will explain the correct procedure for using it.)"


I seem to remember, a while back, seeing how this jump starting is done on a GA8 Airvan. IIRC, somewhere in the S.A. outback...


I was there helping. :E :ok:

[Band a Lot]

At around 30 years in the game, I do not recall a person coming to me saying I hand started to get here can you fix it.

I do know more than a handful that have attempted and started but failed to do lets say controlled flight, then asked the insurance company to ask me to fix it.


If possible yes jump start or charge battery - never will I suggest a hand swing. I certainly never will do one.

[Pinky the pilot]

I hand started the left engine (260hp) of a Bongo van one time when stuck on the wrong side of the Owen Stanleys one Friday afternoon. Posted here about it once.

Also hand started a 235hp Lycoming in a Pawnee a few times.

Glad I was taught how to do it safely but do not care if I never have to repeat the procedure.

[Judd]

never will I suggest a hand swing. I certainly never will do one. Couldn't agree more. Like cutting the mixture after take off to "simulate" engine failure in a light twin. The more you get away with it, the more the perceived risk is diminished. Also known as Practicing Bleeding.
Judging by some of the replies on this thread, it has become a badge of honour to scorn the risk.

[Lead Balloon]

Or ....

The objective risks are understood, and those risks are adequately mitigated by proper systems knowledge and implementation of proper procedures.

Maybe one day you'll be out in the middle of nowhere, and get dropped back a your aircraft, kilometres from the nearest civilisation, on a Sunday, and realise the aircraft's battery is nearly dead because you didn't notice the map light in the cockpit was accidentally left on when you tied her down two days ago. When that happens, I assure you that you will rue the fact that you did not learn how to swing the prop safely.

But I hope it never happens to you. :ok:

[Pinky the pilot]

The post to which I referred;


When I started my first job in PNG with DZ; after doing the endorsement on the BN2 the Chief Pilot raised an interesting scenario.
"You're on a bush strip the other side of the Owen Stanleys and it's near enough to 'beer o clock on a Friday afternoon so all you want to do is get back to Moresby for the Friday night BBQ and have a few drinks and the starter motor on an engine goes u/s.......what do you do?
He then proceeded to demonstrate how to hand start the BN2's 260hp Lycomings. Brakes on, engine primed with both mags on and throttle fully closed. It fired on about the third swing.
Around 18 months later and with another company in PNG one Friday afternoon about 1630hrs local I found myself in precisely that situation!!!! I set everything up as I had been shown and started swinging, much to the amusement of the locals who were lined up along the side of the strip pointing and laughing at the 'long long balus man.' At somewhere around the 16th or 17th swing away it went and about 3 minutes later I was airborne and climbing for 9500' to slip through the gap back to PY leaving behind a strangely silent mob of villagers whom were busy picking their jaws off the ground!

As lead Balloon said; ''But I hope it never happens to you."

But what if the scenario he outlined in his post above actually does occur?:uhoh::hmm:

[Band a Lot]

A fine line in training at times. Often it is the Bendix drive not the starter MOTOR that fails on a BN2. Some times they will fail in a nasty way, seen more than 1 cracked lyco case due jammed bendix.

[Pinky the pilot]

Band a Lot; In the event I described there was no doubt as to the problem. I hit the starter, heard it spin but the prop did not move!. It failed to engage.

And so.....

[baron_beeza]

You were lucky the bendix didn't engage. In your case it sounds like the bendix drive pin may have sheared.
I have had similar in an Islander and there was no-way you could safely swing it with the starter bendix engaged. In the event I removed and probably replaced the starter, I can't recall swinging the prop to get the start. Again I was in the wops but as a LAME/CPL I was being paid for the skills anyway.

Most pilots can't get their head around the left mag only selected on for a start, well for hand propping. You need to know the type of ignition boosters you have fitted, ie the number of impulse couplings or shower of sparks etc.
No-one needs to be swinging a prop with an advanced mag still live.
Anyone even contemplating swinging a prop has to be confident only the retarded spark is active !
If you can't guarantee that then only a mug would be touching the prop blades. I have heard some rationale that the slow spinning mag doesn't produce enough of a spark to be an issue.... 24 degrees before TDC is a long way to go all the same. The prop WILL come back..
(If that spark proved to be sufficient).

Some Islanders and Trislanders still have the couplings, and generally on the left mag.

[Band a Lot]

"You were lucky the bendix didn't engage. In your case it sounds like the bendix drive pin may have sheared."




A sheared pin is a fully floating bendix drive head, nose down attitude it is possible to engage the flywheel.




And so I don't. TCM "generally" when starter spins but not prop is "safer" to hand start than a Lyco for mechanical reasons. A Friday arvo beer has killed many a willing highly trained pilot from experts that will never pass a LAME test, by fly real well.

[Band a Lot]

Ladies and Gentlemen,

Lets be clear, if on a TCM or LYC piston engine you hear a wizz sound but propeller does not move. Your starter motor is working fine. You have another issue!!!!!!!!!!!!!!!!!!!




That needs to be confirmed before you think it is a great idea to hand start.


It seems the folk that have done here seem lucky, not well informed or WELL INSTRUCTED at all.


But I hope you are never in that position - I have been, I wait for the rescue team and rink beer on the Monday if need be.