Airmaster Pirep

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Airmaster Pirep

Postby rpigeek » Wed May 15, 2019 1:46 am

I thought I’d share some feedback with the Airmaster on the Highlander.
TL;DR Takeoff negligible, greater rate of climb, 10% faster cruise

First, I have the following configuration.
1. 912 ULS w/Zipper
2. Extreme Gear, Shock Monster, 29” Tires
3. T3 Tail
4. Leading Edge Cuffs, VGs

I installed the Airmaster AP430 and that added about 16-17 lbs to the nose (vs the Kiev which is very light). I was way nose heavy and out of CG (6”) and must have been before adding the Airmaster (calculated it was probably 7.25” with the Kiev). I added 20 lbs to the tail which brought the CG to 9” when empty.

I had the Kiev setup for a 5500 static RPM, so I already was generating 95% of the horsepower of the engine. As a result the 5% increase in HP at 5800 RPM was counteracted by the 5% increase in weight (prop plus tail weight). This was confirmed as I didn’t see any difference in the takeoff roll at 5800 RPM.

However, I did see much better climb rate as I was able to hold RPM and not over speed in the climb. I could hold 1000 FPM with the Airmaster.

I did see a noticeable difference in cruise speed. Typically, in cruise I have to throttle back to maintain 5300 and usually see 79 KIAS. I don’t know what MP was as I didn’t add a manifold gauge until I installed the Airmaster. With the Airmaster at 26” / 5300 I saw 85 KIAS and 27” / 5300 I saw 89 KIAS.

Interestingly, I hit the same KIAS at 5200, 5300, 5500 RPM. It simply is a question of how much strain/load you want to put on the engine. The prop/hp/torque thrust seems to be pretty flat.

It was a lot of fun in the descent. In descent I had to previously power back a lot to keep from over speeding, however with the Airmaster as the prop adjusts it can keep forward thrust. I could easily see 110 KIAS.

As I had the same takeoff roll the main reason to buy the Airmaster is for the speed (vs fixed pitch for 5500 RPM). Only you can decide if that’s worth the money to you.
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Re: Airmaster Pirep

Postby taildrgfun » Sun May 19, 2019 8:18 am

What kind of blades did you get on your Airmaster?
Steve Henry, Wild West Aircraft
(the Dead Stick Take-off Guy)
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Re: Airmaster Pirep

Postby AV8R Paul » Wed May 22, 2019 4:44 am

Any photos?
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SuperSTOL XL - N357TX - Titan 180 HP (Purple Haze)
S/N JA498-11-16
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Re: Airmaster Pirep

Postby rpigeek » Mon Jun 24, 2019 6:01 pm

taildrgfun wrote:What kind of blades did you get on your Airmaster?

The 75" Whirlwinds.
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Re: Airmaster Pirep

Postby Sloney » Sat Aug 24, 2019 1:18 am

Thank you for this. I’m considering going with the same set up. We have the same mods yet I’m still stock 100 hp. Is it about $8000?
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Re: Airmaster Pirep

Postby CanadianSheepHunter » Tue Oct 22, 2019 7:32 pm

rpigeek wrote:I thought I’d share some feedback with the Airmaster on the Highlander.
TL;DR Takeoff negligible, greater rate of climb, 10% faster cruise

First, I have the following configuration.
1. 912 ULS w/Zipper
2. Extreme Gear, Shock Monster, 29” Tires
3. T3 Tail
4. Leading Edge Cuffs, VGs

I installed the Airmaster AP430 and that added about 16-17 lbs to the nose (vs the Kiev which is very light). I was way nose heavy and out of CG (6”) and must have been before adding the Airmaster (calculated it was probably 7.25” with the Kiev). I added 20 lbs to the tail which brought the CG to 9” when empty.

I had the Kiev setup for a 5500 static RPM, so I already was generating 95% of the horsepower of the engine. As a result the 5% increase in HP at 5800 RPM was counteracted by the 5% increase in weight (prop plus tail weight). This was confirmed as I didn’t see any difference in the takeoff roll at 5800 RPM.

Whats w/zipper...never heard the term before?

However, I did see much better climb rate as I was able to hold RPM and not over speed in the climb. I could hold 1000 FPM with the Airmaster.

I did see a noticeable difference in cruise speed. Typically, in cruise I have to throttle back to maintain 5300 and usually see 79 KIAS. I don’t know what MP was as I didn’t add a manifold gauge until I installed the Airmaster. With the Airmaster at 26” / 5300 I saw 85 KIAS and 27” / 5300 I saw 89 KIAS.

Interestingly, I hit the same KIAS at 5200, 5300, 5500 RPM. It simply is a question of how much strain/load you want to put on the engine. The prop/hp/torque thrust seems to be pretty flat.

It was a lot of fun in the descent. In descent I had to previously power back a lot to keep from over speeding, however with the Airmaster as the prop adjusts it can keep forward thrust. I could easily see 110 KIAS.

As I had the same takeoff roll the main reason to buy the Airmaster is for the speed (vs fixed pitch for 5500 RPM). Only you can decide if that’s worth the money to you.
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