N112B

N112B

Active Member
I do a lot of cross country flying up high. I made a trip today from KMGW to FD04 at a cruise altitude of 12,500 ft in 3 hours and 36 minutes gear up to gear down, thanks to a good tailwind. Not a record setting pace, just real numbers. I burned 28 gallons on the 642 nautical mile trip.

From time to time I document my performance numbers. I did today and am sharing them with you. Or bragging... Yeah that's it! BRAGGING!

RV-7A with Superior XP-IO360 and Hartzell constant speed blended airfoil prop.

05/23/2010
11:30AM Eastern

KMGW->FD04
642 Nautical Miles
3:36 takeoff to landing
28 gallon fuel burn

Altimeter: 30.19
OAT: 2C
Altitude: 12,500
Density Altitude: 13,780

RPM: 2400
Manifold: 19.0 (WOT)
Mixture: Slightly lean of peak
Percent of power: 61%

CHT: 1-367, 2-359, 3-371, 4-365
EGT: 1-1404, 2-1409, 3-1367, 4-1386
Oil Temp: 161

Fuel Flow: 7.4 GPH

Knots Indicated: 132 to 138
Knots True: 163 to 171

(Reducing RPM to 2300... Fuel Flow: 6.8 GPH, Knots True: 158 to 162, 56% power).

All numbers taken from my trusty Dynon EMS D-10 and EFIS D-10A.

NO! The plane is NOT for sale! :)

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Bob, good numbers but I think your %HP numbers may be out. I stand to be corrected on this but the "Part Throttle Fuel Consumption" graph for a 180 hp I0-360 shows that leaned to peak EGT and 2,400 rpm at 7.4 g/hr, the engine would be producing about 97 hp or around 54% rather than 61%.
Likewise peak EGT, 2,300 rpm and 6.8 g/hr would give about 88 hp or 49% rather than 56%.
I would think that being slightly LOP would not change the HP much as Lycomings "Representative Effect of Leaning....." graph shows that Specific Fuel consumption is pretty much constant from around peak to about 70 degrees LOP.

Fin
9A
 
Good numbers pretty close to my -8 with IO-360. I too, can't get past the tail, I'm looking to do a military paint scheme, where did you get the graphics, or are they airbrushed?

Jeff Riblet
RV-8 643RV
PVG Virginia
 
WXMeister...

Says that same trip today in my -6a would take 3:52 at 10.5K and burn 30.7 gals, very little wind. Do you know what your wind was? Good numbers in any event. Pretty economical air travel, huh? This is cruise at WOT/2300.


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The tail is just too big on the 7...Now folks look at his plane and ask if he wants a little tail.
Anyhow, flying a 6A and just installed a Skyview so for the first time I have known manifold pressure. Two 100 mile trips yesterday at 3500'..TAS of 170 knots at 23.5 inches. Definitely happy with the performance.
 
Come on guys, get past the tail! :)

Maybe I should've left the pic of the plane off here. Screaming Aero Graphics in Ocala, FL did the graphics.

Since the first flight, I've documented performance numbers at every cruise altitude, using the info listed below and doing four turn GPS runs on the cardinal headings to confirm. (My indicated airspeed can be a few knots slow).

I talk to folks all the time that say "My plane does 200". I say Knots?? "No, miles". Then I just have to reply... Well mine does 300....KILOMETERS!

Or, "We did 200 knots on the way to Key West the other day". ....ground speed....

Some may not have the ability to accurately gather enough info to compute all of the numbers below, but for those of you that do, I'd like to see your real numbers!!

Airframe
Horsepower
Prop

Altimeter
OAT
Altitude
Density Altitude

RPM
Manifold
Mixture

CHT
EGT
Oil Temp

Fuel Flow

Knots Indicated
Knots True
 
You are asking for a lot of numbers as if they are constants

Every flight is different and NOBODY tests the same as anyone else. Out of the box my maximum speed at 6,000 ft density altitude was 170.67 kts, I have modified my RV-6A many times to increase the speed and the best number I have achieved at 6,000 ft density altitude was 184.4 kts. My test method is the one specified by the U. S. Air Race organization for handicapping when they were still running races. Basically it is a three direction procedure requiring recordings every 20 seconds with no variation in excess of 1 knot between readings. I trim the plane for hands off level flight then activate the autopilot with altitude hold for GPS tracks of 000, 120 and 240 degrees and manually record the data. After the flight I average the five recordings for each track and input those numbers to the National Test Pilots School spread sheet and it mathematically determines the wind direction and the actual true airspeed in knots. I try to test the same way every time but lately I am thinking that Because I race at low altitudes (500 ft AGL) I need to do some testing at low level so I can evaluate the effect of some mods that may be more effective at low altitudes. In other words just because a mod shows no gain at 6,000 ft density altitude does not mean that it will have no gain down where I will be using it. I have a file folder full of test data sheets and I could dig them out but I'm not going to waste our time because every mod effects some small change and operating numbers are simply not directly comparable without a lot more information.

Bob Axsom

P.S. RV-6A Lyc O-360-A1A, 180 HP, Hartzell C/S 72" F7666 blades
 
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