Too fast for a c?

[Igor_U]

2 hours ago, Echo said:

So an unmodded C with a powerflow exhaust at 24 squared and 5500’ is doing 150knots?

It's actually about 161 KT true speed (assuming 0deg C) as 150 is indicated speed. I wonder what's the fuel flow but regardless of that, it's very fast.

[Hank]

@Alan Fox, I just flew my 1970 C today, 4+ hours into the wind at 6500 msl.

This is what I had:

• 22"/2400, leaned 50° ROP
• 42°F OAT
• 30.47" barometer
• 6500 msl
• Full tanks (52 gal), me and an overnight bag
• Empty weight = 1606; useful load =969 lb. 
• Call takeoff weight under 2200 lb.

These were the results:

• 150-152 mph indicated 
• or ~170 mph true
• Groundspeed = 126 knots into the wind

I'll know total fuel burn later, no self serve in this here part of Tejas, gotta let the FBO do it. 

Once upon a time, call it 7-8 years ago, I took off one beautiful fall morning in Sweet Home and climbed to 1500 msl, around 1200 agl. WOT/2700, Full Rich, she hit 165 mph indicated. 

But in a 500 fpm descent, indicated airspeed has always been right on 165 mph; higher descent rate gives higher indicated speed. With a fresh allover wax, it may hit 170 mph at 500 fpm; super dirty, it won't go above 160 mph. 

[Echo]

1 hour ago, Igor_U said:

It's actually about 161 KT true speed (assuming 0deg C) as 150 is indicated speed. I wonder what's the fuel flow but regardless of that, it's very fast.

Seems legit. 

[bonal]

Some years ago we did a three heading gps and produced a 149knot tas that was at 8k with two on board.  My recent 24 24 was solo so I can believe the 154k it produced fuel was also just under 50% overall fairly light load.  At 5500 ft my 24 inch mp was with wide open throttle and full rich on a very cool morning but as I mentioned in my previous post the air was pretty bumpy. I’ve seen the pictures Alan posted and don’t doubt the speed he recorded I just wonder how 160 knots is possible in an unmodified C I don’t see how a power flow exhaust would make any difference 24/24 should be the same regardless of the pipe. Perhaps knowing what prop is on that C might explain the performance.  speaking as a proud C owner I’m more than willing to accept his claim.  Go Mooney.

[Echo]

Almost 175mph indicated. What was fuel flow?  I have NEVER in over 25 years of Mooney ownership seen that indicated on ASI in level flight. Over 800 hours. I guess my planes are out of rig…

[MikeOH]

18 minutes ago, Echo said:

Almost 175mph indicated. What was fuel flow?  I have NEVER in over 25 years of Mooney ownership seen that indicated on ASI in level flight. Over 800 hours. I guess my planes are out of rig…

Yeah, mine, too!

I had to check the date of the original post; thought it might have been April 1

[Gilt]

[Igor_U]

All this talk about speed makes me want to wash and polish my plane.... 

 

[Fly Boomer]

@Gilt that's a super-clean panel.  Nice!