information "Airmaster" Propellers

[skippydiesel]

I am interested in an aircraft fitted with an "Airmaster" CS electrically motivated/ controlled, 3 blade "Warpdrive", propeller.

Having only GA experience of hydraulic CS props, I am unfamiliar with any problems/issues relating to electric CS props fitted to RAA level aircraft, so do not know what I should be looking for/questions to ask.

So if it pleases the "Brains Trust", I would very much like to receive input/comments, regarding electrically controlled CS props in general and" Airmaster/Warpdrive" in particular, from my more experienced Forum friends.

[M61A1]

As previously mentioned, I have a few hours behind a 912ULS fitted with a 3 blade Airmaster. The owner has put a few hundred hours on it so far and it had about 300 on it when he purchased it.

It is still going well so far with no obvious issues. I found it easy to operate and fairly intuitive. It has TAKE OFF, CLIMB, CRUISE and MANUAL settings and can be feathered if desired. To my knowledge parts and service are readily available and different blades can be installed (Sensenich and Bolly) if you want a more efficient blade than the Warp Drive. It greatly enhances the performance envelope of this aircraft. Solo cruise is often up around 130 kts or more with full power available on takeoff and climbout.

[facthunter]

A variable pitch prop is easy to handle if you use sense. You can have a car in too high a gear where the engine will slog and not rev enough to get It's potential power. Same with a prop. A C/S (Constant speed) has a governor of some kind. The inflight variable pitch doesn't. There are often RPM and manifold pressure limits for your engine/prop combo and there should be pitch stops in the ACTION. The fine pitch stop should be such as to enable flight comfortably above stall without over revving the engine. As YOU set the revs the RPM alone won't tell you how much power you are getting from the engine. You need Manifold pressure and/or a torquemeter. , as well as an accurate tacho. A prop capable of being feathered should have a lock to prevent inadvertent feather action. It's more important in multi's to have a prop that can be feathered for you to get the full benefit of having more than one engine.

A free to turn prop blade will normally want go to FINE..You have to drive it to other positions electric hydraulic or Manual..Nev

[M61A1]

The feather action requires a set sequence of switching on the Airmaster. I would consider it very difficult to do inadvertently. They are usually set up with a manifold pressure gauge. The Rotax operators manual has a chart for manifold pressure and power with defined limits.

Here is a link to the Airmaster manual.

https://propellor.com/Content/Images/uploaded/Documents/Manuals/AP3%20and%204%20series%20Operator's%20Manual%20V4.pdf

[409tonner]

I run an airmaster with warp drive blades on my 912uls Sting and the performance is exceptional. In take off mode the engine revs to 5700 rpm and the acceleration pushes you back into the seat . I switch it to climb mode 5500rpm about 100 ft off the ground and put the flaps away as it will quickly accelerate through max flap speed 77knts and climb out solo at 80knts at 1300 -1500 ftpm depending on the day And fully loaded it will climb out at 1000 + and temps stay in the green . In the cruise mode 5000 rpm at 24in manifold pressure I get about 115ktas at 15-16l hr and at 26in I get about 125 ktas at 18lhr I plan on 115knts and 18lhr. It is also very good slowing down the aircraft when I put it back to climb mode when I am setting up for landing on down wind . I have also had the misfortune of using the feather mode when I had an engine failure due to oil pump drive pin breaking and locked the engine during my BFR of all things we were 5 miles to the SW of the airport at 2500 agl and made it back to airport with ease . Passed my BFR ? and rotaxs do break. It is also very easy to service . Hope this helps

[skippydiesel]

Thanks 409 a very complete response. I am reassured that should I follow through with the purchase the prop will be a positive attribute not a negative.

 

Are there any propeller matters at all, to investigate/look into, when viewing the aircraft & questioning the vendor ?

[Sam the Swiss]

Electric CS propellers adjust slower than hydraulic CS propellers. The only time I can see that this really matters is when you do aerobatics, however.

[facthunter]

C/S props with aerobatics are something else to have to deal with. IF the governor "hunts" it can give the engine a workout it doesn't need. I prefer fixed pitch although technically there are advantages like overspeeding, but you may be at Vne before that anyhow. There's giant gyroscopic loads possible with some manouvers so heavy props might be well avoided.. Nev

[tuffnut]

From Experience...

 

Airmaster props with the current specification change pitch just as fast as hydraulic propellers.

 

Part 5.8.Manifold Air Pressure Gauge The manufacturer does not require that a Manifold Air Pressure (MAP) gauge be fitted as part of an installation of an Airmaster propeller onto a Rotax or Jabiru engine. As these engines have no published MAP limits, operators do not need to be concerned with exceeding the limits, as they do with some other aircraft engines.

 

You can't accidentally feather an Airmaster prop.

 

You have to remove the blades from the hub and regrease every year which adds some expense, but is not a difficult operation.

 

This is a prop that shines. Designed for aircraft and pilots who require the best performance posible in all operations.

 

TN.

[facthunter]

Draggy or high(er) altitude planes may benefit from wider blades. There may be an option. Nev

[skippydiesel]

My reserch into Airmaster would suggest that they fit third party props (dont make their own) to their hub.

 

At the time of purchase, you can select from - Whirlwind,, Bolly ,Kiev,Sesenich, Warpdrive (may not apply to all aircraft or hubs).

 

It would also seem treat the AC Airmaster prop combination is significantly heavier than hydraulic competitors.

 

Airmaster has an enviable reputation and I can certainly vouch for their quick, comprehensive and processional responses to my enquiries.

[Mhalc]

My reserch into Airmaster would suggest that they fit third party props (dont make their own) to their hub.

 

At the time of purchase, you can select from - Whirlwind,, Bolly ,Kiev,Sesenich, Warpdrive (may not apply to all aircraft or hubs).

 

It would also seem treat the AC Airmaster prop combination is significantly heavier than hydraulic competitors.

 

Airmaster has an enviable reputation and I can certainly vouch for their quick, comprehensive and processional responses to my enquiries.

I hope the “shutdowns world wide” don’t impact their “enviable reputation”. I ordered a new Airmaster hub/computer with Sensenich blades for my lightning the first of March. I hope to have it someday, but reply’s have be slow and dodgy. Hopefully once some of the restrictions are lifted it will improve.

 

But someday I hope to have some performance numbers :).

[M61A1]

I hope the “shutdowns world wide” don’t impact their “enviable reputation”. I ordered a new Airmaster hub/computer with Sensenich blades for my lightning the first of March. I hope to have it someday, but reply’s have be slow and dodgy. Hopefully once some of the restrictions are lifted it will improve.

 

But someday I hope to have some performance numbers :).

New Zealand was put into an extreme lockdown by Saint Jacinda, probably slow due to covid restrictions.

Maybe very slow if they had to order the Sensenich blades from the USA.

[Mhalc]

New Zealand was put into an extreme lockdown by Saint Jacinda, probably slow due to covid restrictions.

Maybe very slow if they had to order the Sensenich blades from the USA.

Fortunately the blades I wanted, they had in stock from Sensenich. But I am sure your are correct about the “extreme lockdown” measures.

[Downunder]

I'm still waiting for an order from the US from late March which should be here this week.

An order from mid March from the UK took two months, so it's a bit of a worldwide thing....

[eightyknots]

Fortunately the blades I wanted, they had in stock from Sensenich. But I am sure your are correct about the “extreme lockdown” measures.

 

New Zealand came out of the Lock Down into Alert Level 1 on Tuesday, three days ago. People can now go back to work so I think you'll have your Airmaster in the near future.

[Mhalc]

New Zealand came out of the Lock Down into Alert Level 1 on Tuesday, three days ago. People can now go back to work so I think you'll have your Airmaster in the near future.

If they did not fold as a result of being out of business 2.5 months? I sure hope not, they have a very nice product.

[eightyknots]

If they did not fold as a result of being out of business 2.5 months? I sure hope not, they have a very nice product.

 

Hi Mhalc, I have just called them with some questions and they are definitely still in business.

[Mhalc]

Hi Mhalc, I have just called them with some questions and they are definitely still in business.

Thats great, I hate to see business go under because of this.

[walrus]

The only cautionary comment I’ve had was from a LAME who warned to keep a spare set of carbon brushes handy as they do wear down in service. Apart from that, the quality of mine is superb and all ground testing has been perfect. I checked blade tracking yesterday and the total difference is less than a quarter of a millimeter or less - too small to even measure accurately unless I wanted to use a dial gauge.

 

You MUST fit a MAP gauge AND a fuel flow gauge. The first is required by Rotax because you CAN overload the engine if the prop is mishandled. SL - 912 -016R1 section 3.1.3 refers.

 

The second is a matter of safety. It is possible to have an engine producing takeoff rpm and correct MAP but producing SFA power if fuel flow is restricted. You must see correct fuel flow and MAP to assure required power.

[Downunder]

I know the Rotax spec is a minimum of 5200 rpm at WOT, so that would give something of a limit as to how "coarse" you can go....

[facthunter]

Response to # 20.......Even that is not a guarantee. You could have a cylinder out and the fuel flow won't alter nor the RPM, MP. Revs(CS prop) Only a torquemeter will prove the power loss.

To # 21 ...At what airspeed?. A static would cover it with that or another figure which was appropriate . Over propping a motor besides reducing the Power available doesn't help the motor. Jabiru have consistently warned against it.....Nev

Edited June 23, 2020 by facthunter

[skippydiesel]

Rotax 912 ULS minimum static (tied to a fence) RPM is 5200

[Downunder]

To # 21 ...At what airspeed?. A static would cover it with that or another figure which was appropriate

At both climb and level......

[skippydiesel]

.......................................................................

 

The second is a matter of safety. It is possible to have an engine producing takeoff rpm and correct MAP but producing SFA power if fuel flow is restricted. You must see correct fuel flow and MAP to assure required power.

 

Please explain how you can have TO RPM & correct MAP if fuel flow is compromised??