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Cruise performance?

Jesse

Jesse

Well Known Member
I am going to be ferrying a -9A across the country. It has a fuel injected 160HP IO-320 and a non-blended-airfoil constant speed prop. I know there are more variables, but we will be close to gross weight. It does have all wheel and gear leg fairings installed.

I just need some ideas for flight planning.
 
Hey Jesse,
I have the RV-9 with IO-320 and P-mags. It loves altitude. CC I will use about 10 k and lean of peak. 6-7 GPH @ 155ktas. I gain about .5 GPH for each couple of thousand altitude and same speed.
 
Decisions

I am really trying to decide between a 9A and 14A. The 9A seems like it is an extremely economical cc machine. That works out to be about 25 statue mpg at 176 mph. Will the 14A be able to match this?
 
MarkW said:
Hey Jesse,
I have the RV-9 with IO-320 and P-mags. It loves altitude. CC I will use about 10 k and lean of peak. 6-7 GPH @ 155ktas. I gain about .5 GPH for each couple of thousand altitude and same speed.
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Mark's numbers match what I see at lower power settings on my O-360 and are my typical cruise numbers.

Bring a bottle and go higher, the -9 is still flying nose down at 17.5.
 
PS. When it comes time to land, slow it down before entering the pattern, drop all the flaps abeam the touchdown point and trim it for 60 kts (you are still well above stall) and fly the pattern at 60 Kts.

I know it sounds nuts but it will make landing much easier.
 
Unfortunately I don't think there is a bottle available.

Sounds like I should be safe planning 150ktas at 7gph with room to spare. I don't have a fuel computer unfortunately.
 
N941WR said:
PS. When it comes time to land, slow it down before entering the pattern, drop all the flaps abeam the touchdown point and trim it for 60 kts (you are still well above stall) and fly the pattern at 60 Kts.

I know it sounds nuts but it will make landing much easier.
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This part I already know. I used to have a -9A, but it was 150hp, carbureted and fixed pitch. We could get 145-150ktas at 6gph if careful and leaned out, but I was speaking mainly of the 160HP fuel injected engine with constant speed.
 
Jesse said:
Unfortunately I don't think there is a bottle available.

Sounds like I should be safe planning 150ktas at 7gph with room to spare. I don't have a fuel computer unfortunately.
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I don't know that I'd call that safe. That's more like a leaned out at cruise figure. And remember the 9's have smaller tanks than others in the fleet.
 
Dbro172 said:
I don't know that I'd call that safe. That's more like a leaned out at cruise figure. And remember the 9's have smaller tanks than others in the fleet.
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Why isn't 150 kts at 7 GPH a safe cruise setting? I cruise there all the time. That's four hours of cruise with eight gallons left in the tanks.
 
I don't think he's saying that's and unsafe cruise setting, just not maybe a safe expectation without having a fuel computer. I won't be doing max range, so I don't need to know exactly. Dbro172, would you call 150ktas at 8gph safe?
 
Ignition

Hi Jesse,

Mags or EI? It seems EI really helps save some fuel per hour if set up correctly. I see numbers similar to the other guys here with my EI, but with mags, I'd be more conservative.

My ranting of a madman.......worth what you paid for it.

Have a safe flight!
 
Fly it high, lean it out LOP, and you'll be able to easily go 4 hours at 150Kts burning less than 7 gallons per hour. I did a flight from San Diego to Logan, UT that was 4 hours and landed with about 1.5 hours of fuel left according to the computer.
 
Jesse said:
I don't think he's saying that's and unsafe cruise setting, just not maybe a safe expectation without having a fuel computer. I won't be doing max range, so I don't need to know exactly. Dbro172, would you call 150ktas at 8gph safe?
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Correct on the first statement.

Perhaps 145ktas at 8gph. Tough to bank on anything without the fuel computers most of these guys are running, I really liked the fuel rings on my G3X. One of my 3.5 hour legs flying across the country i went low because of winds and only had 7 or 8 gallons left after 3.5 hours, which is quite a bit different than what BruceH is used to running up high.
 
Got it.

Truth is, that is not much difference than having stronger headwinds than forecast. All good pilots must be flexible.

I was struggling with your comment regarding the -9 holding 36 gallons of fuel, while I wish it had more, I find 3 hour legs more than adequate. On a delivery, like he is going to fly, that is plenty long enough, regardless of the tank size.
 
Jesse said:
I don't think he's saying that's and unsafe cruise setting, just not maybe a safe expectation without having a fuel computer. I won't be doing max range, so I don't need to know exactly. Dbro172, would you call 150ktas at 8gph safe?
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Yes you would be safe at that providing you lean. After each leg you can calculate actual fuel burn for future legs.

I flight plan my 160 HP constant speed prop (Hartzell 7663 blade) RV-6 at 150 KTAS and 7.3 GPH @ 23 squared. 3,066 hours on the -6 and over 1,700 Cross Country Hours.
 
This group is great. I posted last night and the thread has 18 replies. I'm now just hoping the winds hold out. I'm staying Thursday night at Pecan Plantation then home on Friday.

I guess if I need to go above 12,500 for better winds, I'll just hold my breath. :p winds right now would average 40kts on the tail for the 1,100nm trip home.
 
Cruise

Jesse: Please post some perf numbers after your trip.

Don Broussard

RV 9 Rebuild in Progress

160 HP roller cam IO-320, Hartzell, 1 Slick 1 EI

N14DB reserved
 
I just had the whirlwind trip. It happened so fast I almost blinked and missed it. Left the house at 3:00AM. American Airlines from MCO to DFW at 6:00 arrived at 8:00. Boutique Air PC-12 left DFW at 9:30 and arrived Clovis, NM at 10:15. A quick once-over and a short test flight and we headed east. Wheels down at The Landings in Pecan Plantation at 4:00pm. Good Texas BBQ and a good night sleep. Wheels up at 8:15 and wheels down at X35 at 1:55PM.

Leg 1 - 11,500' 20.5" 2400rpm leaned out and burned 14.4gallons in 2 hours. 155-157ktas calculated. 7gph.

Leg 2 - 11,500' 20" 2400rpm leaned out a little further and burned 30.2 gallons in 4.9 hours. 150ktas calculated. 6gph.
 
Good numbers!

That -9 wing does like it up high!

Good to hear it was a safe and uneventful trip!
 
Cruise Perf

Thanks Jesse: Does this plane have a Hartzell CS? Except for having 1 mag/1 ElectroAir my 9 will be equipped the same FWF. Always good to get real world numbers and to see different builds delivering the same great performance.

Don Broussard

RV 9. Rebuild in Progress
 
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