[iowaflyer]

I am flying to Leadville, CO this week. RV-4 with IO-320 and standard mags. Any suggestions for starting at high altitude? Instead of the mixture full rich, should I try to start it partially leaned?

Also, should I expect try any different procedure for a hot start? Normally it is mixture full lean, full throttle and then advance mixture while retarding throttle once it fires.

Thanks in advance.

Andrew

 

[Ron Lee]

I am flying to Leadville, CO this week. RV-4 with IO-320 and standard mags. Any suggestions for starting at high altitude? Instead of the mixture full rich, should I try to start it partially leaned?

My plane is carbed but I START with the mixture out about an inch. I know from experience where the approximate proper mixture is.

Suggestion. I assume that you will lean the engine while in flight. Use that setting as your mixture starting point. Perhaps note where it is around 9000' in flight.

Then verify the proper mixture setting at runup. I do it by moving the mixture in towards rich (not all the way) then slowly pull towards lean watching the RPM increase then decrease as you pass the ideal mixture. Set at the highest RPM or maybe just a little rich.

If you are new to mountain flying go to the AOPA website and take the mountain flying course.

Fly using your normal INDICATED airspeed. You ground speed will be higher than you are used to. Do not let groundspeed references dictate your landing flare or take-off rotation!!!!

Consider making a low approach first to get a feel for the landing. Most RVs have plenty of performance at Leadville, especially now that temps are getting cooler.

 

[leaker311]

not a big deal with RV's

I have a IO-360 so not really sure how that relates to carb'd engines but I just started it like I always do. I guess the mixture Idle/cu start makes it universal since the engine goes from rich to very lean and starts at the sweet spot.

I flew into Leadville about 3 weeks ago, my first time EVER in a piston aircraft above 1000' elevation. Like you I was wondering what I could expect but it is a non issue especially with RV's.

The big thing is what is mentioned before is to fly IAS! Do not use your seat-of-pants feeling because you will land hella fast (like landing with a 10 knot tailwind) and the landing roll will take forever, do not stomp on the brakes since you have lots of room to slow down, take your time. Likewise the takeoff might seem forever because of the decreased performance but on Leadville's runway you will still takeoff with PLENTY of runway remaining.

As far as engine ops go, I have a CS prop so I have not found a good way to lean at the runup before takeoff; but, what really was an eyeopener for me was the rough engine while taxiing. Some peeps have mentioned "lean for smooth engine operation" didn't really knew what that meant until taxiing at 10k. The engine runs rough and stumbles but smooths out when leaned, pretty cool actually once the "WTF is wrong with my engine" feeling subsides.

I ran the engine up and pulled the mixture until I found the peak rpm and then screwed it back in and took off. I am no expert by any means so I figured since I have plenty of runway I shoot for safe engine ops (little richer than too lean) vs max performance.

Have fun! Find a day with calm winds and clear skies and you are gonna have a blast!

Oh btw what got me was the runway turn off for the pump vs ramp. Both are not connected and when you turn off at the taxiway to the pump and FBO you will not be able to get to the ramp without entering the rnwy again.

Marco
IO-360
RV-7

 

[Ron Lee]

You can park south of the hangars near the fuel pump. Not sure of time limitations/tiedowns.

Call ahead if you have questions.

 

[iowaflyer]

Thanks for the tips. I've been looking forward to this trip. It been on my aviation "bucket list" for a while.

 

[DakotaHawk]

Can't help with the engine questions - my -7 is fuel injected.

Regarding Leadville - the airport has a courtesy Jeep parked in front of the office. The town of Leadville is a couple miles north of the airport. The main street has a couple of nice diners, and if you continue through town, you'll find a couple of fast food (Burger King) and Pizza (Pizza Hut) options. There is no gate code when you get back to the airport - just pull up to the expensive (paid for with your aviation infrastructure tax dollars) gate and push the button.

Make sure to get your certificate of achievement from the office staff. No charge $$$. Mine is occupying valuable wall space in my hangar!

My son and I have flown into Leadville twice, and found it to be a great overnight stop. The altitude will make you appreciate the nimble RV!

 

[flion]

Can't help with the engine questions - my -7 is fuel injected.

So's his -4. However, it may depend on the injection system. Here at 7000 feet with an Airflow Performance system with the purge valve, I leave my mixture where it was when I shut the engine down (engine is shut down by putting the purge valve in ICO, not by pulling the mixture). Start is with the mixture and throttle untouched and the AFP hot or cold start procedure as appropriate.

While we're on the subject, do not go full rich for takeoff or landing. One of our CFIs loves to repeat the story of the lowlander in a 182 who flew into terrain off the end of the runway because he followed the procedure he had learned down low and didn't develop enough power for takeoff.

Don't forget about density altitude, either. But your RV can handle the altitude easily. We have a displaced threshold 900' and I am usually airborne in less than half that, well before I get to the runway. I was shown to lean the engine at run-up, after the prop and mag checks. Pull mixture until the engine fades and then enrich it a few turns to set for takeoff. I typically see EGTs about 200 degrees below my cruise peak EGTs when I'm leaned properly for takeoff.

 

[jrs14855]

mixture

When you descend to land at leadville lean the mixture at pattern altitude as you normally would for cruise, richen the mixture just a bit and note the position of the mixture control. Then use that position as a starting point for setting mixture for takeoff. If you have a fuel flow, set the mixture on takeoff until the engine starts to lose power and then richen it about 2 gallons hour. Normally aspirated engines MUST be leaned for takeoff and landing at altitudes above 4-5000'. You will give up a lot of power if you try to takeoff full rich at Leadville and the engine may not even run at part throttle. Don't go full rich on start and lean for all operations.

 

[jbDC9]

Don't forget about density altitude, either. But your RV can handle the altitude easily.

Good point... one thing to remember though, even though it's a high performance RV, it still helps to keep an eye on weight and fuel load. Last month I crossed one more item off my RV "to-do" list; I flew it to Telluride. It was a gorgeous cool day, but since it was my first time there in a light single, I stayed fairly cautious; just my wife in the back seat, no baggage and half tanks on fuel. The plane did fine and performed well (leaned!), but I had a "holy cr@p!" moment while taxiing out and seeing the Density Altitude readout sign indicating 11,300' DA at just past noon. I'd already checked the DA (yea for iPhone apps!), but to see it on that sign, yikes.

As for starting, on my carbed O-360 I pulled the mixture back maybe an inch for a normal start, then leaned for taxi/t.o. as others have described, no issues.