Nonstop KPAO to KAPA

[Steve Brown]

This is probably not as thrilling to others as it is to me, but I was completely surprised. I learned some things about my airplane and it forced me to expand my fuel management skills.

825.8nm
5.4 hours
32.48 gallons
ind alt 15,500'
DA ~17,400'
TAS ~ 147

I had planned a fuel stop at KDTA, but before I got there I noticed my fuel burn was well below plan. After crunching the numbers I realized I could make it all the way to KAPA with acceptable reserves. My estimate was that we would make it with about 45 minutes reserve, maybe up to an hour.

I had ran the left tank dry near KEGE. On landing we were showing about 4 gallons remaining in the right tank. The fuel fill implied we had only 3.5, but I think the tank holds a bit more than 18.

Our average fuel burn was 6 GPH, including climb, so even 3.5g was greater than 1/2 hour reserve. We lost some of our tail wind on the second half of the trip that ate into our margins.

Some notes:
I've been experimenting with running LOP for the past few months. When the MP is pulled back to an inch or two below max it works great. For this trip I only pulled back a bit more than 1/2 inch. My leaning procedure was not very scientific. I leaned until roughness, then enriched it just a bit. I noticed this was just LOP on #3, which I think was my leanest cylinder.
**
Running a tank dry was a first for me. I was a bit apprehensive, but being within glide of an airport made it emotionally easier. When I was showing about 1 Gal remaining, I switched on the fuel pump. When fuel pressure started to drop I switched tanks. To my delight the engine never missed a beat.

My wife was not happy with this procedure at all. Adding to the apprehension is that it ran a long time, maybe 10 min while pegged at zero. Anyway, it had to be done. Using all the fuel in that tank is what allowed having acceptable reserves on arrival. Now that I've done it, I wouldn't hesitate to do it again.

Another note on this procedure: pay attention to the fuel pressure gauge! I was watching it close and got distracted by ATC. I heard the pump struggling and by the time I looked at the pressure it was falling fast. Not a catastrophe if the motor quit momentarily, but its drama I don't need.
**
I've been checking the fuel gauges on this airplane since I bought it. They are very accurate. That gave me the confidence to use them for in flight fuel planning
**
The GPS496 is what tipped the balance on making this trip non-stop. Otherwise, I wouldn't have had the nerve. Continuously updated ETE + weather. Weather means wind, so I new what to expect. We also had to skirt several small thunderstorms. The XM weather allowed doing that, and in an economical way.

[rv7charlie]

So, can your wife give my wife lessons on how to avoid a DEfueling stop on a 5+ hour trip?
Car or plane, 2.5, 3 max is all I can plan for.

Charlie

[Steve Brown]

Originally Posted by rv7charlie

So, can your wife give my wife lessons on how to avoid a DEfueling stop on a 5+ hour trip?
Car or plane, 2.5, 3 max is all I can plan for.

Charlie

We filled about 4 of those altogether on this trip. The gel is due to chemical reaction, so up where its cold let it sit on the glare shield in the sun before using. Otherwise it takes a long time to gel.

My last airplane (M20J) had very long legs so it forced us to perfect the in flight relief technique. It takes practice and planning.

-Avoid turbulence. do over flat rather than mountainous, in clear sky areas rather than under cumulus clouds.
-For the pilot, go right after a frequency change. Otherwise I've found that invariably they give me a freq change right in the middle
-Make rules about when, because it causes a little chaos in the cockpit. For me that's level cruise only

My wife has no problem doing it, but she had to learn to plan ahead since at some points in the flight she has to wait.

[Mike S]

Originally Posted by Steve Brown

My leaning procedure was not very scientific. I leaned until roughness, then enriched it just a bit. I noticed this was just LOP on #3, which I think was my leanest cylinder.

Are you sure you are LOP with this technique??

What do you have for EGT monitoring?

[Danny7]

Is there a web based program that will tell me what airports kpao and kapa are that you guys like to use?
palo alto to arapahoe county colorado?

and what oxygen system are you using?

what is DA?

[Steve Brown]

Originally Posted by Danny7

Is there a web based program that will tell me what airports kpao and kapa are that you guys like to use?
palo alto to arapahoe county colorado?

and what oxygen system are you using?

what is DA?

Those are the right airports:
http://www.airnav.com/

I think my O2 is 24^3 feet. It is a 4 place system, but obviously I only use 2 now. We use cannula

DA is density altitude

[Steve Brown]

Originally Posted by Mike S

Are you sure you are LOP with this technique??

What do you have for EGT monitoring?

This was LOP on at least one cylinder. Since I have a switch between cylinders its difficult to tell what happening on the others.

[turbo]

steve, i always run a tank dry on long legs where i dont want to leave any fuel in the tank. my tanks were set up to have 2 gal left when they read 0. knowing my fuel burn i watch my egts which start to fall off when the tank is empty. the engine doest quit. i did this last month running from hartford ct khfd to columbus co sc kcpc. i had 4 gal left. next stop was stuart fl ksua. my burn at 150kts tas is 8 gph leaned to rough then 1 1/2 turns in. keep on flying. my hobbs turned over 3,300 hrs on my last trip which covered 13,000 miles. fl/ca/fl/ct/fl. ;love these rvs.

[Mike S]

Originally Posted by Steve Brown

This was LOP on at least one cylinder. Since I have a switch between cylinders its difficult to tell what happening on the others.

O.K., makes sense, by your signature block it appears your a/c is carb, not FI.

Coupled with limited EGT monitoring,I think you are doing it the right----read as safest---way.

[339A]

My wife has no problem doing it, but she had to learn to plan ahead since at some points in the flight she has to wait.

OK Steve,

Longest flight my wife and I have made to date was 4.2 hours. She has the smallest bladder on the planet so I try not to plan for more than 3 hour legs. My wife has tried and just can't seem to overcome some of the obstacles in the way. Mostly the stick, but postioning is difficult also. Curious which gel pack/system are you using for this? Our wives need to talk.
I have no problem with the little john and agree with you on your rules for going.