Empirical Evidence - Why buy a C/S prop

[TJoyner]

If I remember correctly it was raised to 200 kts sometime in the early 90's. Maybe the change had something to do with converting to ICAO airspace classifications..?

[JBW]

If a given fixed pitch RV cannot fly a profile as outlined above, I submit their fixed pitch prop is not nearly as efficient as my faster than a constant speed and nearly bulletproof Sensenich.

I wonder how much longer it took your "faster" fp prop to climb to 8000', and also how much faster the Hartzell would be if you wound it up to 2730 RPM? BTW, I though the Sensenich was limited to 2600 RPM?

[hecilopter]

At a towered airport, just ask for an overhead approach. You can come in at cruise speed and be at flap speed by the time you roll out on downwind. Works with either prop

[N427EF]

One more good reason for a CS prop.
This observation is based on actual experience selling my FP Sensenich Prop RV-8
When its time to sell, everybody wants a CS Prop.

[RVbySDI]

Originally Posted by JBW

I wonder how much longer it took your "faster" fp prop to climb to 8000', and also how much faster the Hartzell would be if you wound it up to 2730 RPM? BTW, I though the Sensenich was limited to 2600 RPM?

I cannot answer for others but I can for my airplane. With my IO-340 with 3 blade fixed pitch Catto prop from a field elevation of 1300' it takes me 2 minutes to 4500', 4 minutes to 6500', 6 minutes to 8500'.

[n5lp]

Originally Posted by JBW

...BTW, I though the Sensenich was limited to 2600 RPM?

Sensenich makes many different models. The referenced 72FM8 has no published RPM limitations.

[David-aviator]

Originally Posted by Jamie

I am based at a towered airport (LZU) with a 6000ft runway. Yesterday evening I went out for some "therapy" as I like to call it. In spite of a light breeze across the ground and some serious winds at altitude, the air was smooth as silk. Heading back to home base I was northeast of the field and I was told to make a left downwind to runway 7. I was the only one around. When I was abeam the departure end on downwind I was doing 185kts TAS, 195kts groundspeed. Abeam the approach end I was doing 80kts TAS.

That, ladies and gentleman, is why you get a C/S prop. It's also why I sort of chuckle when people talk about putting speed brakes on these airplanes.

BTW: Before someone scolds me about this...I don't make a habit of this. I know it's not 'good' for the engine. Believe it or not, I did pull the power off slowly. Also, I would never do this at a non-towered airport.

Cool maneuver, but I remain unconvinced.

When compared with no other factors maybe CS is the way to go. But factor in weight (plus 50#) and cost (plus $7000) and complexity (moving parts that can fail) boat anchor performance (with an engine failure), forget it.

These airplanes do just fine with simple FP, 10,000' in a little over 8 minutes.

[mike newall]

So when I hoof it downwind in an A320 -1500'agl at 340kts IAS, am I breaking a rule somewhere.......

It slows down really well, by base turn you are at 210, flap 1, half way round base, 185, flap 2 then gear down, turn final at 800', 170, flap 3, then flap full, stable at 500', checks complete.

[Jamie]

Originally Posted by David-aviator

boat anchor performance (with an engine failure)

I find that to be an exaggerated, unfounded claim as well. I have intentionally dead sticked my airplane a number of times. It glides perfectly fine with the red knob all the way back.

[Kevin Horton]

Originally Posted by Mel

Besides, FARs only use "odd" numbers. You won't find an even numbered FAR.

Not quite true. There have been many amendments that added even numbered FARs, such as 91.126, 91.130, 91.138, 23.2, 23.302, 23.1322, etc.