Gazelle and 3 bladed props?

[Admin]

Hi All

 

I have a query - I was under the belief that whilst 3 bladed props can be fitted to Gazelles they are technically illegal as the Gazelle was only certified with the 2 bladed wooden prop. Also that 3 bladed props could certainly not be used for training.

 

Has the rules changed and I didn't know about it?

 

 

[Guest brentc]

I'm yet to hear of a 3 Blader that is legal on a Gazelle. You need an engineer order from a Reg35 (not just a LAME). Same goes for any factory built aircraft. eg. an Allegro is fitted with a 2 or 3 blade wood-comp brand, however you can't change this unless the type certificate includes the alternate prop. It's a pity, but there for the safety of pilot and passenger. If you are using a 3-blader for a training aircraft without an E.O. the aircraft is technically illegal and if you crash you won't be covered by any insurance. It's the same in GA and any certified aircraft.

 

 

[barandbrew]

Hi

 

I was under the impression that the RAA was turning a blind eye to private aircraft but all for hire aircraft had to have wood props. However does the RAA insurence become void if you use a comp prop for private use?

 

 

[Admin]

John

 

I just spoke to Glenn Turner who handles the insurance for RA-Aus and he has advised that it wouldn't be a problem as the Insurance Company just deals in "added" risk and there wouldn't be any added risk to a 3 bladed prop as long as the prop itself was a certified prop - not just 3 pieces of sheetmetal tied together with a piece of bail twine .

 

In the event of an accident it would have to be completely proven that it was the fitting of the 3 bladed prop to the Gazelle that caused the accident but I generally got the impression from Glenn that this would be extremely unlikely.

 

I have both my Gazelle and CT insured through Glenn Turner

 

 

[Guest brentc]

My question then is, what certified props are available that will fit a Gazelle?

 

Most Gazelle's that have glass props are fitted with Warp Drive propellors from the US. These propellors are not certified and are only for experimental aircraft. There are very few certified carbon or fibreglass props that are certified. I know that there are some glass ones around on certified aircraft, however as a rule I believe the aircraft is certified with the propellor as is, however the individual propellor is not necassarily certified.

 

It's a tricky area and one to try and avoid getting involved in. Insurance companies can be difficult to deal with come claim time.

 

Ian, I believe you made the right decision on purchasing the timber prop.

 

 

[Guest brentc]

HiI was under the impression that the RAA was turning a blind eye to private aircraft but all for hire aircraft had to have wood props. However does the RAA insurence become void if you use a comp prop for private use?

I once found out that there is no such thing as a 'blind eye' when something went wrong! It may have looked like it was looking elsewhere, however it was firmly looking - at me!

 

 

[Guest brentc]

I don't write the rules, I just follow them :-)

 

I ran a timber prop on my Gazelle for 500 hours and it did 1,500 hours total before I departed with the aircraft. Based on the logbook, 1,500 trouble free hours!

 

 

[Guest ozzie]

If i remember right as it is with GA types is that whoever does the hard yards to gain type approval for the three blade prop will own the STC and then receives a royalty from those who convert to the new prop.

 

maybe not enough gazelles used for training to make it worthwhile.

 

Comments?

 

Ozzie

 

 

[barandbrew]

What surface was the airstrip you opperated from. From personal experience dirt/grass strips do horrible things to wood props and we were always repairing chipsand splits

 

 

[Guest brentc]

I operate off all surfaces and always have. I've always been super careful with runups and taxi. I'm paranoid about damage. When entering bitumen off grass as an example, I build up speed, then back off power as I coast over loose stones. Sometimes runups are done when cruising down the runway or on a known safe piece of grass. If grass is damaging your prop I'd say it's too long!

 

There was a great demo video doing the rounds for the original Gazelle promotional stuff from Fraser Anning that showed a Gazelle taxiing into a 6 foot deep ditch and then out the other side! Because the Gazelle prop is so close to the nose wheel, it gives it a very high descent and departure angle. It was most impressive and I'd love to know where to get a copy.

 

I once landed on a small strip and tried to turn around at the end, however it was a bit steep and I couldn't turn around as I didn't have enough power so I was stuck between a rock and a hard place as they say because there is no handbrake on a Gazelle so I couldn't get out for fear of the aircraft rolling backwards down the hill. I just had to sit there and yell out for someone! Glad I got out of that one.

 

 

[barandbrew]

Thanks Brentc

 

On reflection the wood props were on the Gazelle when she was online and I like you am very carefull with my aeroplanes mybe I should get one of the old wood props refinished and give them another go.

 

I would love to see that video if you ever find a copy please let me know

 

John

 

 

[Guest Stkin0]

i think you may have to get special permision from casa if they say no then thats it, you cant do anythink about it then.

 

 

[rick-p]

As a point of interest for all some Skyfox's are certified for three bladed props and in respect thereof can any of the prop engineers out there tell me why where and how. Just a little knowledge test.

 

Regards,

 

rick-p

 

 

[rick-p]

Would anyone like to know the answer to my previous post in this thread?

 

rick-p

 

 

[Guest Crash Lander]

I asked this very question about 3 bladed props on gazelles a few weeks ago during a lesson. A guy has a yellow taildragger Gazelle with a 3 bladed prop. My instructor said she didn't believe that 3 blades really made much difference to the performance of the a/c, but she did say that an a/c must be bog standard if it is to be used as a trainer, and therefore this yellow 3 blader was not suitable. It also had something else minor, that excluded it from being a trainer but I cant remember what that was. Maybe no spinner or something.

 

 

[rick-p]

Three bladed props on Skyfox's are legal if an Aeropower engine and a three bladed wooden All-Size prop.

 

I don't even know if Tony Kerr makes 3 blade props but the previous owners of All-Size did.

 

Maybe a point of interest to some, I know Factfinder would like it.

 

 

[Guest brentc]

It's the carbon / glass props that aren't legal on the Gazelle / Skyfox. Legally you can't make any mods, such as ferry tanks and prop without approval which won't come easily and without great expense.

 

If you are contemplating the purchase of any certified aircraft you need to make sure that it is still in original format. Usually a condition report by a valid inspector prior to purchase should find this out. Make it a condition of sale before handing over the cash to be safe.