4kilo

4kilo

Well Known Member
I got mine to 24,370 feet last Friday.

Normally aspirated, Superior XP-IO-360 (180 HP) with blended airfoil prop.

Pat
 
Yup, that's fairly typical with a 180hp motor. I cruise at 17,500 & 16,500' quite happily fairly often. Just bring the right oxygen equipment & tailwinds!
 
So...

Good question cus I'm going to Denver from Western OR next month and I got my new altitude demand O2 system and there are some firece westerly's up there this time of year..

So how do you know if its worth it?..I mean we all know an RV is happiest (i.e best speed in still air for least fuel flow) at 8 to 10k'

What would be your calibration for going to say 14, 16, 18k?...is a 20 knot tailwind worth flogging up to 18k on say a 3 hour X country?, assuming a typical price to refill the O2 tank etc.

Thanks

Frank
 
frankh said:
So how do you know if its worth it?..I mean we all know an RV is happiest (i.e best speed in still air for least fuel flow) at 8 to 10k'
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I look at the winds & if I can get the same groundspeed by going higher, I climb. My plane does roughly 200mph TAS at 10k & 170mph TAS at 16k, so If there is 30 knots more tailwind in the high teens, I climb. The fuel savings ends up being about even with the O2 usage.

There are other reasons to climb too. Crossing areas like the 14,000 footers in Colorado, I like to be at 16.5 or higher. There's also not much traffic up there & you seem to get some instant credibility with Center. I've found that flying through flatlands (Texas, for example) in the teens leaves you very alone in the big sky. The air is usually smoother up there too. YMMV.
 
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Everything that Groucho said!

Higher is better in many ways, but not always - one way I decide if I've done any better by going up (and losing TAS) is to check the miles per gallon readout on the EFIS. Once i get above the convection layer into the smooth, cool air, the question is "how much higher", and maximizing mpg is a good measure to use. I love the high teens, but love overall efficiency the most, and will go there only when it makes sense - or if I need to vault building cumulus (this IS Texas after all.....)

Paul
 
Duh...

groucho said:
I look at the winds & if I can get the same groundspeed by going higher, I climb. .
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Ok I must be slow this morning Bryan..But why would you climb higher to get the same groundspeed?...Is it because you use less fuel (cus you got less mp) ...??

Frank
 
frankh said:
So how do you know if its worth it?..I mean we all know an RV is happiest (i.e best speed in still air for least fuel flow) at 8 to 10k'
Click to expand...

I guess we don't all know that...I will always fly extended legs above 10,000 unless head winds or weather make it undesirable.

I get my best speeds / fuel flow at about 11,500.
 
frankh said:
OK I must be slow this morning Bryan..But why would you climb higher to get the same groundspeed?...Is it because you use less fuel (cus you got less mp) ...??

Frank
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Exactly Frank - if you can get the same ground speed, but burn less fuel doing it,. your trip is less expensive AND, you might be able to eliminate a fuel stop, which will REALLY make the trip faster (extra range is a very cheap way to increase your trip speed). That's why I use the mpg read-out to fine-tine my altitude.

Paul
 
Great idea

Ironflight said:
Exactly Frank - if you can get the same ground speed, but burn less fuel doing it,. your trip is less expensive AND, you might be able to eliminate a fuel stop, which will REALLY make the trip faster (extra range is a very cheap way to increase your trip speed). That's why I use the mpg read-out to fine-tine my altitude.

Paul
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I like the idea of that...I never even thought of doing that...Mind you I only just got my O2 setup together so the big trip to Denver in June wll be the test!

Thanks

Frank
 
duats

Run the flight plan on duats at a few altitudes and see which one is fastest.
Eastbound, going high is usually a good idea. West not so much.
Duats will save you gas and time.
DM


frankh said:
Good question cus I'm going to Denver from Western OR next month and I got my new altitude demand O2 system and there are some firece westerly's up there this time of year..

So how do you know if its worth it?..I mean we all know an RV is happiest (i.e best speed in still air for least fuel flow) at 8 to 10k'

What would be your calibration for going to say 14, 16, 18k?...is a 20 knot tailwind worth flogging up to 18k on say a 3 hour X country?, assuming a typical price to refill the O2 tank etc.

Thanks

Frank
Click to expand...
 
How high will "it" go?
Since every "it" is different, you will only know what "it" will do by taking the "it" and doing IT.
Be sure you have the proper high altitude endorcements and some time with someone who knows about "it" before doing it. There are many safety considerations that come with messing around with high altitude work in our planes.

If you really want to know, then get some experienced help and go get er done. Its a hoot. I have had some really cool flights in my RV in the mid 20's.
Upper 20's gets spooky. My 1st rv got spooky in the lower 20's. Thats because the "its" were so different.

best,
 
Dennis Madden said:
Run the flight plan on duats at a few altitudes and see which one is fastest.
Eastbound, going high is usually a good idea. West not so much.
Duats will save you gas and time.
DM
Click to expand...

Weathermeister.com takes it another step further and tells you the best altitude for economy or fuel taking the forecast winds into consideration - just put in departure and destination and you don't have to run multiple cases.

Takes all the challenge out of it.....;)
 
I want to see frank go for a max alt run in his RV and then set the "most consecutive spins" record on the way down!!

Some guy in a 150/152 did somewhere around 50 spins over Burgstrom ?sp? in Austin IIRC.

Bet Frank could get 100 or better from 25k.:eek:

Anyone know the record?
 
grantcarruthers said:
Anyone know the record?
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I was watching a guy in Reno perform at the air races in '06 doing something similiar, he was doing a spin series from about 15,000 down to about 1000 AGL and talking to the crowd over the radio while spinning, counting them and making other chit chat on the way down. If I remember correctly, he spun 40-some-odd times and said the record was 76.

Can anyone verify that?
 
17,800

intothinair said:
What is the highest altitude anyone has been in a RV9/A?
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I was trying to top some clouds over the grand canyon. I didn't make it because they were climbing as fast as I was, so I bailed out the side though a "valley" in the clouds.

It was still climbing about 400 fpm (I think) when I leveled off. It was still handling solid and could have went much higher. That was at over 1700#. We didn't have a lot of margin in our O2 that flight so I went back down ASAP.
 
grantcarruthers said:
Some guy in a 150/152 did somewhere around 50 spins over Burgstrom ?sp? in Austin IIRC.
Click to expand...

I'm sure that Louise will chime in sooner or later....it was a GAL (Louise knows her - writes interesting music...) in the left seat of that 150/152 over Austin (there was a guy riding along in the right seat counting) when they did the 50 spins....;)
 
Ironflight said:
I'm sure that Louise will chime in sooner or later....it was a GAL (Louise knows her - writes interesting music...) in the left seat of that 150/152 over Austin (there was a guy riding along in the right seat counting) when they did the 50 spins....;)
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It is Barb McLeod that Paul is referring to. She has video of a 52 turn spin she did but I can't get it to work from the web page
http://www.avweb.com/news/profiles/182926-1.html

She says the record is 125 upright and 80 inverted.
 
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