Whirlwind Ground Adj Prop SB ——- What facts do you know? Whats your plan?

[BH1166]

Hartzell, on April 7, 2025, issued an Alert Service Bulletin that there have been user reports of bolts breaking and cracks around bolt holes in the mounting shell/clamp. Read the full ASB link below . To date, more specifics have not been made available that I am aware of. I did a disassembly and visual inspection after 4 years 600+ hours in use and found nothing. I did replace all mounting and clamping bolts with new, from Sam @Saber Manufacturing vs from Hartzell. My plans are to keep flying the prop….it does what I want. I plan on removing spinner and front bulkhead and validating bolts are torque appropriately every 25 hours, and visually inspecting the shell/clamp. I do NOT plan on loosening, resetting prop pitch, but validating there has been no change using the vendor approved method, an inclinometer.

What facts do you have to share on your WW GA200L and what have you learned from others using this prop? Catto is field testing their new RV ground adjustable prop, Sensenich has one available for the past 20 years. Who knows, maybe I’m the only one using a Whirlwind/Harzell ground adjustable prop on a RV. Thanks sharing what you know and your plans.

https://whirlwindpropellers.com/aircraft/wp-content/uploads/2025/04/WW-ASB-61-001.pdf

 

[jabarr]

The prop that I am familiar with cannot be torqued without the hub halves contacting each other. Hartzell states in their document that there MUST be clearance when torqued. They have been very elusive with answers to the issue. Even if a new hub is purchased, it still requires the 25 hour inspection. The design/ materials is just inferior and a trusted engineer friend agrees it’s just a failure waiting to happen. We, like many others, have elected to not fly this prop any longer. Currently having a fixed pitch Catto being prepped.

 

[jrs14855]

The prop that I am familiar with cannot be torqued without the hub halves contacting each other. Hartzell states in their document that there MUST be clearance when torqued. They have been very elusive with answers to the issue. Even if a new hub is purchased, it still requires the 25 hour inspection. The design/ materials is just inferior and a trusted engineer friend agrees it’s just a failure waiting to happen. We, like many others, have elected to not fly this prop any longer. Currently having a fixed pitch Catto being prepped.

I strongly disagree with the inferior design/materials statement. I don't trust the new ownership of Hartzell and don't believe anything they say. I have about 200 hours on the prop on a non RV. I retorque, visually inspect and keep[ flying.

 

[jrs14855]

I strongly disagree with the inferior design/materials statement. I don't trust the new ownership of Hartzell and don't believe anything they say. I have about 200 hours on the prop on a non RV. I retorque, visually inspect and keep[ flying.

Hartzell: the magicians who turned a $150 alternator into a $1650 profit center.

 

[jabarr]

I strongly disagree with the inferior design/materials statement. I don't trust the new ownership of Hartzell and don't believe anything they say. I have about 200 hours on the prop on a non RV. I retorque, visually inspect and keep[ flying.

Just going by an engineers assessment. I have to agree as I’ve seen the hub distortion during torque up.
What else would explain the 25 hour inspection requirement?
I hate the situation as it has proven to be a great performing prop.

 

[BH1166]

Just going by an engineers assessment. I have to agree as I’ve seen the hub distortion during torque up.
What else would explain the 25 hour inspection requirement?
I hate the situation as it has proven to be a great performing prop.

Thats an awful lot of aluminum to twist with 30-40 ft lbs . I can’t say not doable, but would think not tightening in steps, crisscrossing if that happened. Thanks, wish Hartzell would release more of what is KNOWN, not hyperbole, or stuff from you tube entertainers. I think the 25 hour thing is due to being conservative and not knowing what they dont know. Thanks for your input.

 

[Freemasm]

A question and apology for any drift or if already addressed. Do the referenced installation instructions call for torqueing the halves in stages? It appears from the illustrations that the mating flanges are relatively thin. If so, it would be very easy to get uneven loading across such. If not specified, I'd strongly consider a 30/30/30/10 % torque increments in whatever torque pattern they recommend. Even finer % increments can only help.

 

[jabarr]

The one in question was carefully torqued in 1/16 increments maintaining an even gap on both halves. It wasn't an installation error. The flex in the hub is what has us changing directions.

 

[auj4]

I bought a secondhand GA200L, with 250 hours on it. I had the hub NDT’d & the blades IRAN’d. I put it on our standard O-320-D1A powered RV-6 23 hours ago. I replaced a Bernie Warnke wood prop that had taken a bit of a beating (unavoidably) flying through rain.

Keeping the GA200 on the plane isn’t something I want to do, so I’m in the early stages of thinking about what to do. I seem have two options;

1) Refinish the Bernie Warnke prop and go back to it. It’s a fantastic prop that gets me 2400RPM static and cruises at 163ktas @6500’ 2450RPM. It does make life harder in formation energy management wise though.

2) Bite the bullet and go to a CSU prop. A CSU prop will make life easier for the formation flying I do. Here it seems that there is really only Hartzell to deal with. I could go with the HC-C2YL-1BF & F-7663-4 blades, or I could go to the WW300-3B. Either way I’m dealing with Hartzell. The Hartzell prop is tried & true, every prop shop and A&P/IA (& LAME) would be familiar with it, but is an older design and appears to leave some performance on the table. The WW300-3B props generally seem to be liked by anyone here on VAF that fly behind them, and they seem to give good performance. I haven’t found any references to putting them on an 0-320 though. Do I trust Whirlwind, (Hartzell really).

I haven’t really considered an MT prop, mostly due to cost here in Australia and not getting a huge amount of increase in weather/stone damage resistance.

I’m happy to read and consider any other ideas & opinions.

Don H
Sydney, Aus.

 

[BH1166]

A question and apology for any drift or if already addressed. Do the referenced installation instructions call for torqueing the halves in stages? It appears from the illustrations that the mating flanges are relatively thin. If so, it would be very easy to get uneven loading across such. If not specified, I'd strongly consider a 30/30/10 % torque increments in whatever torque pattern they recommend. Even finer % increments can only help.

Yes, criss cross, and in 10 ft lb or so increments

 

[BH1166]

The one in question was carefully torqued in 1/16 increments maintaining an even gap on both halves. It wasn't an installation error. The flex in the hub is what has us changing directions.

1/16 of what ? 30 or 40 ft lbs at 1/16 of a foot pound per ? Finger tight there isn’t 1/16 of an inch gap in my installation. Thanks

 

[jabarr]

1/16 of what ? 30 or 40 ft lbs at 1/16 of a foot pound per ? Finger tight there isn’t 1/16 of an inch gap in my installation. Thanks

1/16 of a turn. Probably 5 ft lbs at a time. And yes, in a criss cross pattern. Install instructions say 1/8 of a turn at a time until torque is reached. Installation instructions state there is to be a gap between halves when fully torqued. In big red letters! Could not be maintained in this instance.
If you have zero gap after torque is reached, you are no longer in compliance with the installation instructions.
In our case, a .002 feeler gage will barely fit in the area between bolt locations and gap is zero at bolt locations. The hub is flexing! The continued flexing WILL result in cracks eventually.
I find it odd that the SB doesn’t include the cautions but it does refer you to the install instructions which state in no uncertain terms that the gap must be maintained.

https://whirlwindpropellers.com/aircraft/wp-content/uploads/2025/01/GA200L-Universal-Rev20.pdf

 

[BH1166]

1/16 of a turn. Probably 5 ft lbs at a time. And yes, in a criss cross pattern. Install instructions say 1/8 of a turn at a time until torque is reached. Installation instructions state there is to be a gap between halves when fully torqued. In big red letters! Could not be maintained in this instance.
If you have zero gap after torque is reached, you are no longer in compliance with the installation instructions.
In our case, a .002 feeler gage will barely fit in the area between bolt locations and gap is zero at bolt locations. The hub is flexing! The continued flexing WILL result in cracks eventually.
I find it odd that the SB doesn’t include the cautions but it does refer you to the install instructions which state in no uncertain terms that the gap must be maintained.

https://whirlwindpropellers.com/aircraft/wp-content/uploads/2025/01/GA200L-Universal-Rev20.pdf

Thank you…..

 

[IO390]

I bought a secondhand GA200L, with 250 hours on it. I had the hub NDT’d & the blades IRAN’d. I put it on our standard O-320-D1A powered RV-6 23 hours ago. I replaced a Bernie Warnke wood prop that had taken a bit of a beating (unavoidably) flying through rain.

Keeping the GA200 on the plane isn’t something I want to do, so I’m in the early stages of thinking about what to do. I seem have two options;

1) Refinish the Bernie Warnke prop and go back to it. It’s a fantastic prop that gets me 2400RPM static and cruises at 163ktas @6500’ 2450RPM. It does make life harder in formation energy management wise though.

2) Bite the bullet and go to a CSU prop. A CSU prop will make life easier for the formation flying I do. Here it seems that there is really only Hartzell to deal with. I could go with the HC-C2YL-1BF & F-7663-4 blades, or I could go to the WW300-3B. Either way I’m dealing with Hartzell. The Hartzell prop is tried & true, every prop shop and A&P/IA (& LAME) would be familiar with it, but is an older design and appears to leave some performance on the table. The WW300-3B props generally seem to be liked by anyone here on VAF that fly behind them, and they seem to give good performance. I haven’t found any references to putting them on an 0-320 though. Do I trust Whirlwind, (Hartzell really).

I haven’t really considered an MT prop, mostly due to cost here in Australia and not getting a huge amount of increase in weather/stone damage resistance.

I’m happy to read and consider any other ideas & opinions.

Don H
Sydney, Aus.

Don, I have a WW 300 3B on my O320 RV6. Same as yours. Performance is about the same as the Hartzell but it’s smoother and lighter. Whether it’s worth the extra over the 2 blade Hartzell I don’t know, but when I ordered it my choice was made by the short lead time on the whirlwind. I want to fly not wait months for parts.

I have had some issues with the whirlwind, namely the plastic shims at the base of the blades coming out. Seems to be a known problem and WW sent me thicker ones which have stayed in place so far.

 

[KentI]

The prop that I am familiar with cannot be torqued without the hub halves contacting each other. Hartzell states in their document that there MUST be clearance when torqued. They have been very elusive with answers to the issue. Even if a new hub is purchased, it still requires the 25 hour inspection. The design/ materials is just inferior and a trusted engineer friend agrees it’s just a failure waiting to happen. We, like many others, have elected to not fly this prop any longer. Currently having a fixed pitch Catto being prepped.

Same here, and one that I am aware of developed crack(s) in about 56 hours of service. Hartzell was kind enough to give the owner a 25% discount on the new hub, that is still subject to inspection every 25 hours.

 

[auj4]

Don, I have a WW 300 3B on my O320 RV6. Same as yours. Performance is about the same as the Hartzell but it’s smoother and lighter. Whether it’s worth the extra over the 2 blade Hartzell I don’t know, but when I ordered it my choice was made by the short lead time on the whirlwind. I want to fly not wait months for parts.

I have had some issues with the whirlwind, namely the plastic shims at the base of the blades coming out. Seems to be a known problem and WW sent me thicker ones which have stayed in place so far.

Thanks IO390,

I recall reading posts about the plastic shims coming out, possibly posted by you. Weight is always a factor and in this case a slightly heavier prop could benefit me by moving a somewhat aft empty weight CG forward. I need to measure an accurate arm for the prop and do some preliminary W&B calculations for the different props.

Smoothness is a bonus. The wood Bernie Warnke prop was very smooth compared to the GA200L even after dynamic balancing. Its good to know the performance difference between the Hartzell & Whirlwind isn’t that great.

Picking what is listed at Vans, the Hartzell 2 blade & MT governor, vs the WW300 & Jihostroj from WW/Hartzell, the price comes out as a wash with an estimated AUS$500 difference in favour of the Hartzell, (assuming similar shipping costs). If I get the Hartzell & Jihostroj governor its a lot less expensive. I’ve emailed Vans asking for estimated shipping costs and lead-time, but no reply yet. I’ve been quoted US$14500 & US$1950 for the WW300 & Jihostroj with 8-10 weeks leadtime. Shipping to Australia would be an estimated US$2000.

Don H

 

[amckeen]

I bought a secondhand GA200L, with 250 hours on it. I had the hub NDT’d & the blades IRAN’d. I put it on our standard O-320-D1A powered RV-6 23 hours ago. I replaced a Bernie Warnke wood prop that had taken a bit of a beating (unavoidably) flying through rain.

Keeping the GA200 on the plane isn’t something I want to do, so I’m in the early stages of thinking about what to do. I seem have two options;

1) Refinish the Bernie Warnke prop and go back to it. It’s a fantastic prop that gets me 2400RPM static and cruises at 163ktas @6500’ 2450RPM. It does make life harder in formation energy management wise though.

2) Bite the bullet and go to a CSU prop. A CSU prop will make life easier for the formation flying I do. Here it seems that there is really only Hartzell to deal with. I could go with the HC-C2YL-1BF & F-7663-4 blades, or I could go to the WW300-3B. Either way I’m dealing with Hartzell. The Hartzell prop is tried & true, every prop shop and A&P/IA (& LAME) would be familiar with it, but is an older design and appears to leave some performance on the table. The WW300-3B props generally seem to be liked by anyone here on VAF that fly behind them, and they seem to give good performance. I haven’t found any references to putting them on an 0-320 though. Do I trust Whirlwind, (Hartzell really).

I haven’t really considered an MT prop, mostly due to cost here in Australia and not getting a huge amount of increase in weather/stone damage resistance.

I’m happy to read and consider any other ideas & opinions.

Don H
Sydney, Aus.

I suggest you consider the Airmaster Propeller electric constant speed. The conversion is simpler. It uses modern carbon fiber blade design. Because you are accustomed to fixed pitch, aerobatics can be flow in fixed mode. New Zealand is much closer to you too.

 

[IO390]

I suggest you consider the Airmaster Propeller electric constant speed. The conversion is simpler. It uses modern carbon fiber blade design. Because you are accustomed to fixed pitch, aerobatics can be flow in fixed mode. New Zealand is much closer to you too.

Doesn’t Airmaster use Whirlwind blades?

Personally, I would strongly discourage the use of an electric prop if your engine can take a proper hydraulically controlled unit.

 

[BH1166]

IO390, amckeen, aju4……. Off topic from the post intent….. this is NOT about WW CS but their ground adjustable prop and the service bulletin. Not a blade issue. Thanks

 

[auj4]

IO390, amckeen, aju4……. Off topic from the post intent….. this is NOT about WW CS but their ground adjustable prop and the service bulletin. Not a blade issue. Thanks

Hi Butch,

It wasn’t my intention to hijack or introduce thread drift.

You finished your original post with;

“Who knows, maybe I’m the only one using a Whirlwind/Harzell ground adjustable prop on a RV. Thanks sharing what you know and your plans.”

I’m a new user of the WW GA200 and as such I don't have a great deal of experience with it, so I don’t know a lot about the prop or SB related issues. You did however ask for what my plans were and this is what I’ve shared.

I appreciate that you started the thread so others can also chime in. As you said we can’t be the only ones flying behind the GA200.

Don H
Sydney Aus

 

[danny]

FWIW...I got my new hardware kit yesterday and all the bolts are 1/2" plus longer than what I have and since I have an early serial number hub my clamping bolts are 5/8" but they sent 7/16". Thought I was going to take care of it today. Guess not.
danny

New...it only took three tries to get the hardware straightened out. It's a smooth prop and seems to work well enough for me. I'm deciding my best move.
danny

 

[adrianolsantos]

I spoke to Whirlwind a few weeks ago and this is their answer:

“At this time, we are recommending that those aircraft owners who currently own a GA-200L continue to perform inspections as recommended. If a crack develops in the hub, we are not issuing replacement hubs of the previous design, and those affected will be instructed to ground their aircraft until the new hub is available.”

It doesn’t seem fair in my opinion. What do you think?

 

[J Crate]

This thread has been quiet for a while, so wanted to share an update. In Feb 2026 there was a revision made to the original SB (WW-ASB-61-001). It appears that the SB is now only applicable to hubs mounted with 3/8 bolts. I called WW/Hartzell and they confirmed that my GA-200L-72 is no longer subject to the SB. Hoping to get more clarity on the rationale for the revision at Oshkosh.
J. Crate
RV6A

 

[danny]

This thread has been quiet for a while, so wanted to share an update. In Feb 2026 there was a revision made to the original SB (WW-ASB-61-001). It appears that the SB is now only applicable to hubs mounted with 3/8 bolts. I called WW/Hartzell and they confirmed that my GA-200L-72 is no longer subject to the SB. Hoping to get more clarity on the rationale for the revision at Oshkosh.
J. Crate
RV6A

I'll be looking forward to an update.
Good to know.
Thanks, danny

 

[TParker]

To the best of my knowledge, the rationale was that, with the ASB being in effect for a while to drive owners to inspect and report issues, all reported cracks were in hubs using 3/8" bolts with no reports of cracks in the other hub configurations.

 

[danny]

To the best of my knowledge, the rationale was that, with the ASB being in effect for a while to drive owners to inspect and report issues, all reported cracks were in hubs using 3/8" bolts with no reports of cracks in the other hub configurations.

I just read it again and saw it applied to 3/8" mounting bolts. I have 1/2" but still took it apart and inspected just because I didn't read carefully. My bad but it never hurts to look.
Thanks (for the pmag too)
danny