Fuel reserves

Tom-D

Tom-D

Taxi to Parking
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Tom-D
How close have you pushed your fuel reserves
 
I had an hour of fuel left but sure didn't like looking in that tank and not seeing fuel slosh around. I now 'always' make the extra stop, peace of mind I guess, along with the what if factor.

From my flight journal - Nags Head, NC flight october 2008.
....Back to my planning, winds favored the short hop for lunch but it looked like a good head wind the whole way home. I decided that we would top off and make the run to both locations (Ocracoke then home)with a non-stop. All my calculations pointed to 11 gallons remaining upon arrival at Wilmington (ILG).

....I made my last tank switch about fifteen miles out of ILG, I was changing on a thirty minute schedule religiously. I know my left tank gauge reads more then whats in the tank but the right side is really pretty close. The right side read ten gallons and the left, when I switched, was bouncing between five and ten. Once on the ground I called for fuel and topped off exactly where I initially had been filled. Right tank took 17.3 and the left tank took 20 for a total of 37.3 gallons. A 48 gallon usable and some basic math tells me I had 10.7 gallons left. I was happy to see my calculations and trip times were on the money especially with the constant headwind all the way home but I rather make my extra stops and keep more fuel in the tanks.

 
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45 minutes remaining (1.8 gallons) after 3.1 flight time (day, VFR, Chief, 12 g tank, 3 GPH)

My ironclad rule until that point was 1 hour reserve. But with such a small tank, that's tough to do on a cross country.

I will stick to the 1 hour rule, though -- just not fun wondering seeing the bobber that low.
 
VFR: 45 minutes remaining

IFR: 1 hour remaining.

...but those were isolated times. Typically it's 1.5+ hours remaining. I prefer this because it gives me more time in the event of getting vectored around without having to say "Low fuel."
 
Far enough to scare myself once. It was a case of going straight to the answer without all that mucking about with learning curve nonsense. Some things don't need a second lesson.
 
I refuse to answer this question on the grounds of self incrimination.
 
In the Cherokee I stop when I hit 12 gallons, which is about an hour and some. That's what I have when the gauges are on quarters, and stop no matter how close to home or destination I may be.
 
Even if you were directly over CMH and headed home?
 
Richard said:
Intentionally: hard against FAA required reserves.
Unintentionally: 15 minutes of flight at full power ROP setting. 65% LOP resolved the issue.
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This is a misnomer, you are not required by the FAA to have any reserve on landing. You are required the reserves on takeoff in case you need more fuel for some reason.

The worst I ever got I landed with about 15minutes of fuel left, but I had multiple options for landing prior to my destination and had a Hoskins Fuel Flow/Totalizer to monitor the situation.
 
Tom-D said:
How close have you pushed your fuel reserves
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Close enough that if I hadn't diverted to the airport I did, I would have diverted to a field instead a few minutes later. It is not my most proud moment, especially considering some of the other boners I committed on that flight.
 
Henning said:
This is a misnomer, you are not required by the FAA to have any reserve on landing. You are required the reserves on takeoff in case you need more fuel for some reason.

The worst I ever got I landed with about 15minutes of fuel left, but I had multiple options for landing prior to my destination and had a Hoskins Fuel Flow/Totalizer to monitor the situation.
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You'll appreciate this:

When working for the cropduster, I had a pilot land for his next load. I went out to hook up the water line before fueling (as normal) and he waved me down and said "Bring the fuel and hurry!" He was low enough that he was worried about running out while I loaded him.
 
SkyHog said:
Close enough that if I hadn't diverted to the airport I did, I would have diverted to a field instead a few minutes later. It is not my most proud moment, especially considering some of the other boners I committed on that flight.
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That's why I make such an ironclad rule, and stick to it no matter what. Maybe I'll be OK if I just judge it on the fly, but better pilots than I have come to grief over fuel issues. Thus I take out all the thought and judgement, and make a rule not to be broken. I'd rather make the occasional extra fuel stop than wind up in a field (or lake, or trees...) some day.
 
Only once, to hop from a field with a broken pump to another field 10 minutes away with a working pump, have I ever taken off without an extra 45 min on board. I REALLY didn't like it.
 
The most I've ever put in the 182 was 56 gallons (79 usable), so I had nearly 2 hours remaining. Even that was low enough that Kate got nervous and it rubbed off on me so we had diverted to pick up more. But that was pre-JPI...

My "rule" is an hour, and I've only actually cut into the hour once. Unfortunately, I don't know for sure how much was left because a partial tank was added, the plane flew for a while, and then it was finally topped off. But, based on its normal consumption and the two amounts added, I still had 45 minutes remaining.

In airplanes I don't know, situations that are new to me, etc. I'll keep even more. I went with a minimum 2-hour reserve on the west coast trip because with all those wide-open spaces, if one airport's fuel pump was broken, it'd be a while to get to the next one.
 
CJones said:
You'll appreciate this:

When working for the cropduster, I had a pilot land for his next load. I went out to hook up the water line before fueling (as normal) and he waved me down and said "Bring the fuel and hurry!" He was low enough that he was worried about running out while I loaded him.
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I've worked when it was hot enough you carried minimum fuel for the load and fueled each load with just what you need and carry a 10 minute buffer.
 
It really depends on the flight. I go down to 30 minutes while flying skydivers (need that useful load).

On cross countries - it depends on the airplane and the weather and lots of other factors but I've never dipped below a hour.
 
jesse said:
It really depends on the flight. I go down to 30 minutes while flying skydivers (need that useful load).

On cross countries - it depends on the airplane and the weather and lots of other factors but I've never dipped below a hour.
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Skydivers is a whole nother matter, as long as I have fuel to get them to altitude, I'm good. I don't like carrying any more fuel with jumpers than I absolutely have to, and I can glide back to the runway from any point I'd run out of fuel. Skydiver crashes are typically ugly, I want to keep the fuel load to a minimum to try and prevent roasting a bunch of people who are most likely injured. The highest risk in a skydive operation is the take off. Once you're above pattern altitude, you can shed ballast quickly and glide to the runway.
 
Henning said:
Skydivers is a whole nother matter, as long as I have fuel to get them to altitude, I'm good. I don't like carrying any more fuel with jumpers than I absolutely have to, and I can glide back to the runway from any point I'd run out of fuel. Skydiver crashes are typically ugly, I want to keep the fuel load to a minimum to try and prevent roasting a bunch of people who are most likely injured. The highest risk in a skydive operation is the take off. Once you're above pattern altitude, you can shed ballast quickly and glide to the runway.
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If you run yourself out of gas, you screwed up. They're not going to appreciate you running out of gas at 1500AGL or even higher and telling them to boot the students or tandem loads out the door RIGHT NOW. Someone could very easily get very hurt.

I just keep an eye on the upcoming loads and adjust the fuel as per that. Never more than 30 gallons, never less than 8. Adding fuel for every load would delay the operation and cost them money. Need to run that elevator up and down as efficiently and quickly as possible.
 
The responses so far have made me feel more comfortable with my own rule of 1hr. I though I was being paranoid. Lowest Ive been on cross countries is a 1hr 15min remaining.
 
jesse said:
If you run yourself out of gas, you screwed up. They're not going to appreciate you running out of gas at 1500AGL or even higher and telling them to boot the students or tandem loads out the door RIGHT NOW. Someone could very easily get very hurt.

I just keep an eye on the upcoming loads and adjust the fuel as per that. Never more than 30 gallons, never less than 8. Adding fuel for every load would delay the operation and cost them money. Need to run that elevator up and down as efficiently and quickly as possible.
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I never ran it out of gas, I'm just saying that the potential for running out of gas are minimal and the consequences are low so I don't need to add a reserve buffer. On the other hand, adding a reserve buffer has negative consequences operationally and in safety. Skydiving is an instance that breaks the general rule of reserve fuel being a safety factor because in this instance the nature of the operation makes reserve fuel a liability.
 
Henning said:
I never ran it out of gas, I'm just saying that the potential for running out of gas are minimal and the consequences are low so I don't need to add a reserve buffer. On the other hand, adding a reserve buffer has negative consequences operationally and in safety. Skydiving is an instance that breaks the general rule of reserve fuel being a safety factor because in this instance the nature of the operation makes reserve fuel a liability.
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I do agree that extra fuel is a liability but running out is too. It's an interesting balance. It'd be nice to have a fuel totalizer to help further balance that relationship. But that won't ever happen.
 
I once put 80gal in meaning that I had 8 left. With a 12-13gal/hr burn I was low but the last flight of the tank was a pair of landings to warm the oil before annual.
 
I had a sobering experience flying to SnF once. I landed my old Tomahawk in Ocala, Fl to refuel. Based on estimated fuel burn and time aloft, I expected to have burned maybe 24-25 gallons, leaving slightly less than a one hour reserve. IIRC, refueling the airplane took almost 30 gallons. It supposedly held 32. :eek:

In the RV, the airplane burns 8 GPH at the power settings I use for X/C. That's been proven time and time again. So I fly a max of 4 hour legs, using 32 of the 38 available gallons and leaving a 45 minute reserve.
 
Any one run their tanks completely dry before selecting the last tank?
 
Tom-D said:
Any one run their tanks completely dry before selecting the last tank?
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Twice.

One time I was with two other pilots and we were trying to make sure we knew exactly how much fuel we had on board before going into a very short strip. Even though we knew it was coming, it was still a bit freaky.
 
Tom-D said:
Any one run their tanks completely dry before selecting the last tank?
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Yes, I like to do that to know exactly how much fuel a tank holds in hours (which is consistent since I fly the same power settings all the time). However in two out of the three twins I fly, I effectively can't run the mains dry because I need to take off and land on them, and so I always want to have fuel there for landing.
 
Tom-D said:
Any one run their tanks completely dry before selecting the last tank?
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I've done it on all the tanks in some of the plane's I've owned and/or flew regularly to determine what the actual fuel capacity was. I haven't tried this in the Porterfield since there's only one tank and running that dry could be problematic. Also in the Baron it's OK to run the aux tanks dry but since you're supposed to take off and land on the mains I'm reluctant to empty them completely.

Some folks seem to think that stopping the engine in flight either by running a tank dry, pulling the mixture, or switching both mags off is "scary" but there's no reason any engine that was running before the fire went out wouldn't start up immediately as soon as it has fuel and spark.
 
Tom-D said:
Any one run their tanks completely dry before selecting the last tank?
Click to expand...

Sure. Better to know that all 45 minutes of your reserve is in one tank than to wonder if you have 5 minutes of fuel in one and 40 in the other. Running that 5 minute tank out on short final could be embarassing.

So on longer flights, I'll run a tank dry at altitude, wait for the fuel pressure to wobble (or the engine to sputter) and change tanks to the one with the remaining fuel.

I find that it is best to tell my wife that the engine may sputter than to explain what happened after it sputters.
 
kyleb said:
I had a sobering experience flying to SnF once. I landed my old Tomahawk in Ocala, Fl to refuel. Based on estimated fuel burn and time aloft, I expected to have burned maybe 24-25 gallons, leaving slightly less than a one hour reserve. IIRC, refueling the airplane took almost 30 gallons. It supposedly held 32. :eek:

In the RV, the airplane burns 8 GPH at the power settings I use for X/C. That's been proven time and time again. So I fly a max of 4 hour legs, using 32 of the 38 available gallons and leaving a 45 minute reserve.
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If we are fessing up.

I left 4 corners regional with the C-170-B with 42 gallons on board, (37 usable) landed at Logan Ut. and loaded 38 gallons.
 
Tom-D said:
Any one run their tanks completely dry before selecting the last tank?
Click to expand...

Well, of course - however always had fuel in the last tank.

Not yet, a couple more minutes, not yet, a little longer, not yet, wait, getting close, wait, YEP, it's definitely empty now, twist click.
 
jesse said:
It really depends on the flight. I go down to 30 minutes while flying skydivers (need that useful load).

On cross countries - it depends on the airplane and the weather and lots of other factors but I've never dipped below a hour.
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I've seen jump planes dead stick back to the runway. :yikes: The jump zone is 4 miles from the threshold. :nono:
 
Once on the way to OSH I had to descend to get under weather - fair weather cumulus with some showers. No CB's. I then made climb back to original cruise alt.

Id planned fuel and weight and winds meticulously but never planned or done two climb profiles before. Was running fuel to tabs in a pa-200r. I leaned and was conscientious about my burn.

Can't remember the exact numbers now but it was probably 15-30 mins of fuel split between tanks. My OSH buddies said I got pale when I found out how much fuel got put in to bring me to tabs again.

Lesson learned.
 
In the 1993 Aircraft Spruce race, I burned my left tank dry about 30 nm west of DPA. That way I knew I had 10 left in the right tank, ALL of it there. The whole midwest was 200-1. Then I lost my Vac Pump and made the ILS 1 stick.

Many moons ago in another solar system, I took so much fuel on a pacific crossing that my Ops Officer admonished me to NEVER do that again (Like I had a real choice then - I did prior, but that was hours earlier). This is the trip where I kissed the ground at NAS Whidbey and I NEVER got close again.
 
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