Emergency prop

[JG3]

This is for anyone flying far from home with a 912s and having an incident that destroys their prop. It can happen in a minor incident, and can lead to a real problem waiting for a replacement.

 

I keep an old Brolga 4-blade prop all packed up and ready to ship anywhere same day or next day at latest. Complete with pitch blocks matched to a 100hp Rotax. The advantage of the Brolga is that you don't need a protractor and testing to get the pitch correct. Just bolt it together and it's ready to go. All I ask is that it be shipped back to me when a new prop has been acquired.

 

Keep my number handy and I'll help when I can. 0429 943 508.

 

JG

 

 

[Guy s]

What a nice gesture JG and I have your number in my ph just in case but not planning on using it for that Lol. I sent you a email which did lack a little finer detail I know on a trip I'm planning out to Marree and many thanks for your kind reply and info and have taken it onboard, We still have a few months before we head off but will ring you closer to the trip to pick your brains.

 

Cheers Guy.

 

 

[Sav 4352]

JG just wondering why did you replace your Brolga 4 blade and what did you replace it with?

 

Is the replacement as good or better?

 

Sav.

 

 

[Neil_S]

This is for anyone flying far from home with a 912s and having an incident that destroys their prop. It can happen in a minor incident, and can lead to a real problem waiting for a replacement.I keep an old Brolga 4-blade prop all packed up and ready to ship anywhere same day or next day at latest. Complete with pitch blocks matched to a 100hp Rotax. The advantage of the Brolga is that you don't need a protractor and testing to get the pitch correct. Just bolt it together and it's ready to go. All I ask is that it be shipped back to me when a new prop has been acquired.

 

Keep my number handy and I'll help when I can. 0429 943 508.

 

JG

Hi JG,

 

That is extremely thoughtful of you - thanks! I have noted your number, but hope I never need to use it.

 

Best Regards,

 

Neil

 

 

[JG3]

JG just wondering why did you replace your Brolga 4 blade and what did you replace it with?Is the replacement as good or better?

Sav.

I replaced the Brolga with a Kool, as per these prop comparison tests StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft

As you will see, there was very little difference in performance, but on a long trip alongside an identical Savannah, the Brolga used one litre per hour more fuel, as would be expected because a 4-blade prop is inherently less efficient than a 3-blade. The Brolga company was by then out of production, and I really liked the Kool so have been using it ever since.

 

JG

 

 

[JG3]

This weekend we tried to use that Brolga prop to replace a Bolly damaged at Cawarral on the way to Lakeside. But it turns out that it won't fit the S and XL Savannahs because they have that prop hub extension with bolt holes only 100mm spacing....  The Brolga is 80mm and fits the Rotax hub because it has bolt holes for both 80 and 100mm sizes.

 

In this instance we managed to borrow a new Bolly from Ray at Rods Bay. Many thanks for Ray's generosity and to Greg who arranged the contact. It's a great flying community we enjoy!

 

 

[old man emu]

"The beast laid schemes o' mice and men

 

Gang aft a-gley"

 

I bet you were somewhat perturbed when you found out about the bolt spacing.

 

Still, your friendly offer is most appreciated.

 

 

[kaz3g]

How do you ensure no shock damage done to engine before flying again?

 

kaz

 

 

[old man emu]

How do you ensure no shock damage done to engine before flying again?

kaz

Good point.

 

If the aircraft is VH- registered, the engine has to be stripped down and inspected after a prop strike. Isn't what is good for those gooses good for an RAAus gander?

 

 

[facthunter]

 The procedure varies for different engines. I'm not sure it's just a VH thing.. Sometimes just a flange run out check is enough as an initial check. CHECK what your engine  needs. The nature of the strike is important and the type of prop.  Nev

 

 

[kgwilson]

If the prop is wood it disintegrates easily. I did one. Bits flew off everywhere but the engine never stopped & there was little rpm degradation at the time & it was just above idle. As recommended by Jabiru I pulled the engine out, the flange runout was perfect & I replaced the flywheel bolts. The check was to clean the female thread thoroughly & put in the new bolts 3 full turns & wiggle them. Any movement of 0.05mm or more & they had to be retapped. There was no movement at all so all good. The new bolts are not loctited in like the old ones which were a mission to get out but have nordloc washers.

 

 

[eightyknots]

Very generpus of you John!