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  #11  
Old 10-24-2012, 09:06 PM
RV-4 RV-4 is offline
 
Join Date: Oct 2007
Location: St-Jerome,Quebec,Canada
Posts: 1,165
Thumbs down Hand Propping

''Catto Prop and it got me on a backfire''

''decided to mount my Catto Tri-Prop ''

Well there must be something with the Catto Prop...??( Just kidding )

I've got a Catto 3 bladded on my RV-4 and on May 15th of this year, I hand propped it so I could get the battery recharged ( after extensive used of the battery ) and with 2 Lightspeed ignition on my -4, it has always started on the first or second swing but not this time..

I tried numerous time and it just wouldn't start so after a last try where the engine almost caught, I decided to give it one more try and as I was at the point where I would normally release my grip on the prop,it kicked back....

With my left arm fully extended and with the strain of the kick back, my left bicep couldn't take the load and ripped right of the bone....

I don't need to tell that it hurt a tidy bit... and I ended up with an arm that looked like it belonged to Popeye...

With emergency surgery and 6 months of extensive physiotherapy, I'm finally going back to work in a couple weeks...

No more hand propping for this puppy, I now carry a battery booster in the aircraft and if it doesn't start...Marriott will be glad to have my business if I can't find a boost on the airport....

Be careful out there folks..

Bruno
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  #12  
Old 10-24-2012, 09:15 PM
John RV8 John RV8 is offline
 
Join Date: Feb 2005
Location: Watauga, TX
Posts: 153
Default Hand-propping

I have hand-propped a lot of different types of planes over the last 25+ years. Some types are certainly easier than others. I don't think it matters if the plane has a lightweght prop with little flywheel effect, as you will almost never get a healthy (good compression) engine past the compression stroke of a single cylinder (two if your lucky) by hand-propping. As long as the ignition fires at TDC the engine hopefully will start.

I think the often overlooked thing about hand-propping, is if/when you get the engine started you are about to take-off with basicly a dead battery (the most likely reason you hand-propped in the first place) So now if you take-off and have an Alternator failure you have VERY LITTLE or NO Back-up electrical power for things you may really need to complete you flight.

Be Careful out there Folks
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RV-8. N6279G
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  #13  
Old 10-25-2012, 01:02 AM
scsmith scsmith is offline
 
Join Date: Jan 2008
Location: Ashland, OR
Posts: 2,805
Default Lots of good experiences/lessons here

Ron has the right idea. Dead battery from leaving master on.

So, I put the charger on it, and after an hour, the battery was partly charged, but not enough to crank the engine. So, we are still waiting around.
This is when the thought comes, to hand-prop or not.

The LIght Speed will fire at TDC when hand propping PROVIDED there is at least 6 volts to run the controller. If the voltage drops below 6 volts, I'm pretty sure it reverts back to the static timing, 25 BTDC. So that is the risk.

Having a very light-weight prop was the deciding factor for me - there is just not enough inertia to reliably get it to follow through, so you have to be that much more positive in your 'connection' to the prop, which increases the risk of bad things happening, among the experiences cited here.

So my decision was to wait another 2 hrs ( I have a small charger) and then it started. My wife was not very happy about the 3 hr delay, but I was happy to still have all my fingers, no dent in my forehead, and my biceps muscles still attached to bone.

Funny, a wood prop on a C-85 never seemed like a problem, but a 72" carbon prop on an IO-360 just isn't enough.


Quote:
Originally Posted by Ron Lee View Post
Steve, if that occurs, charge the battery. How long would that take?

Then to prevent the change of it happening, install some sort of warning system if the master is left on.

Replace battery before it becomes marginal.

Consider this like get-home-itis. You have two options:

1) Do what is needed to avoid hand-propping even if it means a delay in getting somewhere, or

2) Risk serious injury or death.
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Aeronautical Engineer
RV-8 N825RV
IO-360 A1A
WW 200RV
"The Magic Carpet" Flying since Sept. 2009
Hobbs 635
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  #14  
Old 10-25-2012, 03:12 AM
Ron Lee's Avatar
Ron Lee Ron Lee is offline
 
Join Date: Jun 2005
Posts: 3,275
Default

Good to hear a positive outcome Steve.

I have had enough delays traveling commercial aircraft and my 6A that I accept delays. You can't let a trivial three hour delay lead you down the decision tree to a bad outcome.

Monday I was flying United from Michigan to COS via O'hare. A delay leaving Michigan resulted in me having to overnight in Chicago. Such is life. It did give me the opportunity to help two Russians get to a gate in another concourse, eat at Johnny Rockets (not up to par) and try a White Castle burger for the first time (probably the last time).

It was also the first time I stepped outside the O'hare airport terminal.

Lots of good discussion from people who can competently hand prop when the situation is right...and those who had less positive outcomes.
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  #15  
Old 10-25-2012, 05:47 AM
JDRhodes JDRhodes is offline
 
Join Date: Feb 2008
Location: Taylorsville, GA
Posts: 748
Default

Quote:
Originally Posted by jrs14855 View Post
Also Navajo Chieftain several times.
Wow - you da man! I've seen charter pilots run the batteries dead and burn up starters trying to start those from the cockpit.

It's like anything, I guess. Once you know how...
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RV-9, 7 - going fast
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  #16  
Old 10-25-2012, 05:55 AM
Walt's Avatar
Walt Walt is online now
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,959
Default

Quote:
Originally Posted by John RV8 View Post

I think the often overlooked thing about hand-propping, is if/when you get the engine started you are about to take-off with basicly a dead battery (the most likely reason you hand-propped in the first place) So now if you take-off and have an Alternator failure you have VERY LITTLE or NO Back-up electrical power for things you may really need to complete you flight.
And to add to this, you are seriously taxing the ability of your alternator at this point, it will be outputting maximum current until the battery is recharged. Your poor little alternator is not designed for charging a dead battery, alternator distress in high, failure is very possible (or at least a shorted life).
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EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1900+ hrs, New Titan IO-370, Bendix Mags
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  #17  
Old 10-25-2012, 06:56 AM
Bob Axsom Bob Axsom is offline
 
Join Date: Mar 2005
Posts: 5,685
Default Ultimately you have to get home

You can't just say trying to get home is a bad thing and I will just sit here. You can get into some pretty helpless life threatening settings with these airplanes so it is good to know what options you have, what you have to do to make them work and start implementing the best option as soon as practical. Several times I had to hand prop out Archer over 22 years of ownership and I hand proped my friend's 182 coming back from a trip in Mexico once. It scared the H___ out of me every time but worrying about such things as strain on the alternator was so far down the list of concerns that it is not an issue. I agree that it is one of the least desirable options but if I were stuck in the middle of nowhere with no communication, food or water I think I would give it a shot. I try to pull it through the compression stroke with finger pressure on the blade surface but I know that if it doesn't work I am going to have to "Grab" the prop. My ignition system is a non-bush kit LASAR and it will not start with hand proping but it will air start from a fast windmill (yes I have had to do it). I can envision an emergency attempt at a catapult launch if the conditions made it possible - OK maybe that went too far - but I would consider every option to complete the mission - to survive and get home. The last time it happened to me I had to order a new battery from Aircraft Spruce and wait for it to arrive before I could start up and fly home.

Bob Axsom

Last edited by Bob Axsom : 10-25-2012 at 07:26 AM. Reason: typo
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  #18  
Old 10-25-2012, 07:06 AM
Sam Buchanan's Avatar
Sam Buchanan Sam Buchanan is offline
been here awhile
 
Join Date: Dec 2004
Location: North Alabama
Posts: 4,396
Default Don't cook the alternator

Quote:
Originally Posted by Walt View Post
And to add to this, you are seriously taxing the ability of your alternator at this point, it will be outputting maximum current until the battery is recharged. Your poor little alternator is not designed for charging a dead battery, alternator distress in high, failure is very possible (or at least a shorted life).
Very true. I ran down the battery trying to start a primerless engine on a cold morning (operator error) then jumped the dead battery with cables from the car. The little 35a Vans alternator was putting out 49a recharging the flat battery.....the alternator was dead within the hour.

Lesson learned. If the battery is flat, bring it back with a charger, not the alternator.
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  #19  
Old 10-25-2012, 09:54 AM
aerhed aerhed is offline
 
Join Date: Dec 2008
Location: Big Sandy, WY
Posts: 2,567
Default

Over almost 35 years I've had the "opportunity" to prop Broussards, T-28, tri-motor, all the way down to A-50, O145, and a 1/2 volks. I've always been careful, I've always been scared. You guys make me even more scared. That's good. I always feel safer with a tied plane and nobody inside. That way I KNOW where the mags and throttle are. Most of the 7AC guys don't even get out of the plane. They reach out the door and give the little 65 a flip. There's little margin for error in hand-propping technique. You have to stand right, reach right, and have all your body parts headed in the right direction. This gives you your best odds of keeping all your body parts attached and aligned. Higher compressions and light props make it very tricky and I wouldn't screw around at all with elctronic ignitions. Its one of the reasons I still like magnetos. I "know" what a mag wants to do and where its going to do it, provided it has good P-leads.
P.S. Please don't try it with a 421 or a Duke, and don't do it on ice or snow.
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  #20  
Old 10-25-2012, 10:59 AM
RV-4 RV-4 is offline
 
Join Date: Oct 2007
Location: St-Jerome,Quebec,Canada
Posts: 1,165
Wink Dead Battery

Sam

''If the battery is flat, bring it back with a charger, not the alternator.''
-------------------------
That's one of the reason why I carry this little battery booster,It will take a battery down from let's say 6 volts and boost it up 11 volts in about 10 mins..
At 11 volts, the engine will start every time and my body parts will be all where they are supposed to be..

I've hand propped just about every pistons airplanes before from little Cubs to Single Otters but not anymore unless the strip is on fire and I need to get out of there..
Nothing is urgent enough that it requires hurting yourself, flying at our level is for fun and #2 can wait for me to get home...

Just my $0.02

Bruno
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