Big cross-country today at high altitude for me

grantcarruthers · #1 11-23-2012, 06:24 AM

Planning a noon local departure from 3K6 (St Louis) for KMYR (Myrtle Beach) and flight planning for 17500 so I can finally get a full PIREP out to VAF for the cheap pulse ox vs medical grade pulse ox I borrowed from a local source.

My question for the VAF brilliance this morning is what TAS and GPH to expect at 15500-17500 today as I'll be approaching minimum fuel on landing. I have perfect tail winds of 30-50 knots which DUATS is giving me a 3:06 ETE and 28 gallon burn leaving exactly my daytime required reserve. That Duats calculation is programmed for 160kts and 9gph. Other Duats assumptions will also be way off as my programmed climb rate will be a myth after I pass 9000 but the tail winds there are epic so we'll see how it all works out

Weather is near perfect so no cowboy moves today. I'll likely be over the top briefly around Nashville but I'll have tons of fuel at that point if I have to bail out for plan B and a refuel. If I'm not in decent by 6 gallons remaining I'll be stopping for fuel. With these fantastic tailwinds I could pull back the throttle too to extend range and let the tailwinds do the work but not sure if there'll be anything left to pull back at that altitude. I think mother nature will have already pulled it back

The plane is a 160hp fp Warnke RV4 that has proven itself a 160kt airplane at 8000 density altitude. So if we assume 10gph for that to be conservative what should I expect at 17,500 and -17C for TAS and GPH? We'll see if I can do the whole climb on the right tank and then switch to the left and run it dry for some real data on this experiment. There'll likely be some switching for balance and split time/speed/distance calculations in that but I'll try to report back an estimate.

Thanks for the input and I'll post results for the whole adventure later.

tkatc · #2 11-23-2012, 06:34 AM

Sounds like you'll have plenty of fuel with those tailwinds. You have obviously thought this through but be careful!

I'll probably be fighting slight headwinds today enroute from Florida to NJ.

grantcarruthers · #3 11-23-2012, 06:40 AM

Quote:

Originally Posted by tkatc

Sounds like you'll have plenty of fuel with those tailwinds. You have obviously thought this through but be careful!

I'll probably be fighting slight headwinds today enroute from Florida to NJ.

Thanks, I'll be very careful for sure. Good luck on your flight today

grantcarruthers · #4 11-23-2012, 06:44 AM

STL 3126 3236-04 3238-06 3141-10 3069-22 2993-30 279947 770453 287557

^^^^^^

Gives me a nearly direct 26kt TW at 3000 and 36kt TW at 6000 in the climb heading ~120 so off to a good start if the ceiling cooperates

Ron Lee · #5 11-23-2012, 07:03 AM

I would expect closer to around 7 GPH fuel burn but you will burn more getting to altitude than I would (starting at 6800' MSL).

If you have a fuel monitoring system that tells you have much time you have left to empty, you can monitor fuel burn time left versus time to go.

Often I have over 4.5 hours fuel endurance once I get to cruise altitude and lean out.

You may want to check winds at lower altitudes. A quick glance suggests that the tailwind improvement from 13,500' to 17,500' may not be worth the climb. Of course if going to 17,500' is an objective regardless, enjoy the view. I strongly suggest using flight following.

fixnflyguy · #6 11-23-2012, 07:32 AM

I look forward to the report after you make this trip, as I have a 160hp FP (Sterba) RV-4 and I am starting to strech my legs a bit also. I dont have ox, so I stay below 12K. If you end up with any WX issues or maintenance needs on your journey, I am at 8A7 in central NC .

grantcarruthers · #7 11-23-2012, 10:40 AM

Quote:

Originally Posted by Ron Lee

I would expect closer to around 7 GPH fuel burn but you will burn more getting to altitude than I would (starting at 6800' MSL).

If you have a fuel monitoring system that tells you have much time you have left to empty, you can monitor fuel burn time left versus time to go.

Often I have over 4.5 hours fuel endurance once I get to cruise altitude and lean out.

You may want to check winds at lower altitudes. A quick glance suggests that the tailwind improvement from 13,500' to 17,500' may not be worth the climb. Of course if going to 17,500' is an objective regardless, enjoy the view. I strongly suggest using flight following.

Quote:

Originally Posted by fixnflyguy

I look forward to the report after you make this trip, as I have a 160hp FP (Sterba) RV-4 and I am starting to strech my legs a bit also. I dont have ox, so I stay below 12K. If you end up with any WX issues or maintenance needs on your journey, I am at 8A7 in central NC .

Thanks all, headed to the airport, reports to follow.

grantcarruthers · #8 11-23-2012, 10:44 AM

From: 3K6 -- St Jacob IL (St Louis Metro-East/Shafer Field)
To: MYR -- Myrtle Beach SC
Alt.: 17,500 ft. Profile: RV4
Time: Fri Nov 23 18:13 (UTC)

Routing options selected: Great circle.
Flight plan route:
ENL030003 VNN210001 PXV210001 OWB210005 BWG030022 LVT030010 VXV030015 SOT
SUG SPA030011 FML210012 CTF210013 FLO210008
Flight totals: fuel: 28 gallons, time: 3:05, distance 607.1 nm.

Ident Type/Morse Code | | Fuel
Name or Fix/radial/dist | | Time
Latitude Longitude Alt. | Route Mag KTS Fuel | Dist
---+--------+---------+-----| Winds Crs TAS Time |------
1. 3K6 Apt. | Temp Hdg GS Dist | 0.0
St Jacob IL (St Louis M |--------+----+---+------| 0:00
38:44.0 89:48.4 5 | Direct 2.7 | 607
---+--------+---------+-----| 314/41 116 120 0:14 |------
2. Wpt. 115.0/030.0/003.1 | -6 C 110 158 36 | 2.7
ENL . -. .-.. |--------+----+---+------| 0:14
38:27.7 89:07.3 107 | Direct 1.1 | 571
---+--------+---------+-----| 277/61 113 120 0:05 |------
3. Wpt. 113.8/210.0/001.4 | -10C 123 175 16 | 3.8
VNN ...- -. -. |--------+----+---+------| 0:19
38:20.5 88:49.4 148 | Direct 2.6 | 555
---+--------+---------+-----| 272/69 115 151 0:16 |------
4. Wpt. 113.3/210.0/001.1 | -13C 126 211 55 | 6.4
PXV .--. -..- ...- |--------+----+---+------| 0:35
37:54.7 87:46.5 175 | Direct 1.2 | 500
---+--------+---------+-----| 271/75 115 160 0:08 |------
5. Wpt. 108.6/210.0/004.7 | -15C 127 223 31 | 7.6
OWB --- .-- -... |--------+----+---+------| 0:43
37:40.4 87:12.5 175 | Direct 2.3 | 469
---+--------+---------+-----| 262/75 122 160 0:15 |------
6. Wpt. 117.9/030.0/021.9 | -15C 138 215 55 | 9.9
BWG -... .-- --. |--------+----+---+------| 0:58
37:14.3 86:12.0 175 | Direct 2.6 | 414
---+--------+---------+-----| 260/75 117 160 0:18 |------
7. Wpt. 108.4/030.0/010.1 | -14C 134 212 62 | 12.5
LVT .-.. ...- - |--------+----+---+------| 1:16
36:44.0 85:04.1 175 | Direct 3.4 | 352
---+--------+---------+-----| 269/46 122 160 0:22 |------
8. Wpt. 116.4/030.0/014.8 | -14C 130 198 73 | 15.9
VXV ...- -..- ...- |--------+----+---+------| 1:38
36:07.5 83:45.3 175 | Direct 1.8 | 279
---+--------+---------+-----| 264/48 123 160 0:12 |------
9. SOT ... --- - | -14C 134 196 39 | 17.7
d108.8 Snowbird |--------+----+---+------| 1:50
35:47.4 83:03.2 175 | Direct 2.0 | 240
---+--------+---------+-----| 259/50 125 160 0:14 |------
10. SUG ... ..- --. | -13C 137 194 45 | 19.7
d112.2 Sugarloaf Mounta |--------+----+---+------| 2:04
35:24.4 82:16.1 175 | Direct 1.2 | 195
---+--------+---------+-----| 260/53 123 160 0:08 |------
11. Wpt. 115.7/030.0/010.5 | -14C 136 196 25 | 20.9
SPA ... .--. .- |--------+----+---+------| 2:12
35:11.3 81:49.6 175 | Direct 2.0 | 170
---+--------+---------+-----| 270/47 123 160 0:13 |------
12. Wpt. 112.4/210.0/012.3 | -14C 132 199 44 | 22.9
FML ..-. -- .-.. |--------+----+---+------| 2:25
34:48.5 81:04.3 175 | Direct 1.8 | 126
---+--------+---------+-----| 279/41 124 160 0:12 |------
13. Wpt. 108.2/210.0/013.0 | -14C 130 197 39 | 24.7
CTF -.-. - ..-. |--------+----+---+------| 2:37
34:27.5 80:23.6 175 | Direct 1.4 | 87
---+--------+---------+-----| 275/33 125 160 0:12 |------
14. Wpt. 115.2/210.0/008.2 | -6 C 131 188 39 | 26.1
FLO ..-. .-.. --- |--------+----+---+------| 2:49
34:06.6 79:43.9 116 | Direct 1.6 | 48
---+--------+---------+-----| 271/31 126 160 0:16 |------
15. MYR Apt. | +5 C 131 185 48 | 27.7
Myrtle Beach SC |--------+----+---+------| 3:05
33:40.8 78:55.7 0 | | 0
---+--------+---------+-----| |------

NOTE: fuel calculations do not include required reserves.
Flight totals: fuel: 28 gallons, time: 3:05, distance 607.1 nm.
Average groundspeed 197 knots.
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Wayne Gillispie · #9 11-23-2012, 07:59 PM

I was showing 55 kt TW on Foreflight at 17.5'. It was a little gusty on the ground and frontal passage at 12:00 EST here in E. Ky. Clear skies by 1:30 PM. How was the view and turbulence downwind of the mountains?

rzbill · #10 11-24-2012, 05:28 AM

Quote:

Originally Posted by grantcarruthers

9. SOT ... --- - | -14C 134 196 39 | 17.7
d108.8 Snowbird |--------+----+---+------| 1:50
35:47.4 83:03.2 175 | Direct 2.0 | 240
---+--------+---------+-----| 259/50 125 160 0:14 |------
10. SUG ... ..- --. | -13C 137 194 45 | 19.7
d112.2 Sugarloaf Mounta |--------+----+---+------| 2:04
35:24.4 82:16.1 175 | Direct 1.2 | 195

Right over my house.