TURBO FAILURE AND NA CROSS COUNTY MUSINGS

[Brian Scranton]

So...we just made our way from Colorado to New Jersey with some great stops in between. Headed to Dallas to see U2 (great show) to KTUP>KINT>31E.

Would have liked to have gone faster but I saw MP drop from 25" to 13" at 17,000 just past Trinidad. An immediate decent down to Dalhart, Texas to find out that the control arm on the RayJay manual waste gate had snapped off. Damn. Now I had to update Foreflight to read 130TAS vs 145TAS. Flying NA across the country I noticed a few things:

1) Dang my temps stay nice and cool.

2) Dang my compass doesn't shake like a mofo when I run 21" and 2550 (vs 25/2500).

3) Dang I burn SOOOO much less fuel! In the 9-10gph range vs 12.5-13gph with the turbo

4) Dang I go slow NA. 

5) It's nice to fly IFR outside of the mountains. So much smoother. No ice. No mountains. No turbulence. 

6) Air is smooth when you get 500 miles away from 14,000 peaks--that's nice. We've been getting our ass kicked for weeks out west. 

7) Tupelo is a cool town--soul food! And Winston-Salem was GREAT! Nice little city. 

8) Bono and the Edge can still rock pretty hard.    

 

[M20F]

I get 160-165 at FL190-210 running 23/23 at about 11gph and my F is slow comparable to others.  If all you are seeing is 145kts either something really wrong or you are calculating incorrectly. 

[Brian Scranton]

12 hours ago, M20F said:

I get 160-165 at FL190-210 running 23/23 at about 11gph and my F is slow comparable to others.  If all you are seeing is 145kts either something really wrong or you are calculating incorrectly. 

Hi Mike--not sure what my TAS is at FL20, I haven't been that high yet. At FL19 I've seen 157 KIAS. For the most part however, when I am farting around in the 12K to 15K range, I am at 145KIAS per my 430, so I plan 145 in forelfight.

[M20F]

3 hours ago, Brian Scranton said:

Hi Mike--not sure what my TAS is at FL20, I haven't been that high yet. At FL19 I've seen 157 KIAS. For the most part however, when I am farting around in the 12K to 15K range, I am at 145KIAS per my 430, so I plan 145 in forelfight.

Ok in your post you referenced 17000 which 145kts at 25/25 would be off. 

[Brian Scranton]

5 minutes ago, M20F said:

Ok in your post you referenced 17000 which 145kts at 25/25 would be off. 

Truth--I can see how that would be misleading. 17K is typically my IFR altitude over the rockies. I stay there for 30 mins or so because my family fears oxygen  However, I do feel I am on the slow end of the Fs, even with the Turbo. Probably a result of old antennas that really need to come off and the fact that I am always as max gross when flying. Wife, kid, 100#s of bags and full fuel! I don't think I have ever seen a climb rate above 700fpm. Ever! 

[Jerry 5TJ]

4 hours ago, Brian Scranton said:

....,At FL190 I've seen 157 KIAS.....

Pretty darn good speed for an F model, Brian -- that's 210 knots true airspeed on a standard day. 

 

 

[M20F]

37 minutes ago, Jerry 5TJ said:

Pretty darn good speed for an F model, Brian -- that's 210 knots true airspeed on a standard day. 

 

 

I think he meant KTAS ;-)

[Brian Scranton]

Ha. I wish. Yeah...KTAS indeed. 

[thinwing]

So you continued to fly with the waste gate inop?Did I misunderstand your post?

[N201MKTurbo]

1 minute ago, thinwing said:

So you continued to fly with the waste gate inop?Did I misunderstand your post?

Would that be legal? Probably not. Would I have continued? Probably yes. Is it dangerous? No.

[thinwing]

I was thinking more for takeoff...wouldn't he be running seriously lean with throttle open but turbo spooled down...not familiar with his manual wastegate

[M20F]

16 hours ago, thinwing said:

I was thinking more for takeoff...wouldn't he be running seriously lean with throttle open but turbo spooled down...not familiar with his manual wastegate

When the RayJay is off it is just like flying a normally aspirated IO-360, that is a nicety of the system.  

[Parker_Woodruff]

Is your airspeed indicator in mph or knots?  157 KIAS at FL190 is improbable in a TN IO-360 unless you were flying with a sustained negative AOA to maintain altitude due to a significant updraft.  A clean and light M20K would see 190 to 195 KTAS at the same altitude.

[Parker_Woodruff]

On 5/29/2017 at 9:26 AM, Brian Scranton said:

Hi Mike--not sure what my TAS is at FL20, I haven't been that high yet. At FL19 I've seen 157 KIAS. For the most part however, when I am farting around in the 12K to 15K range, I am at 145KIAS per my 430, so I plan 145 in forelfight.

You really need to be planning these long distance flights with more accurate figures.  With an accurate airspeed indicator and OAT, compute your TAS from there and input into foreflight.  Foreflight will do a good job with the winds aloft from there.

Your Garmin 430 also has a TAS calculator you can use.

For flight planning and knowing your bird, it's nice to know how fast you're REALLY flying through the relative air around you which is TAS.