Please tell me I'm not the only one...

MAKG1 said:
If the engine wasn't designed for 87 octane, it's either going to detonate at full throttle, or your A&P is a complete idiot and has retarded your timing well beyond what is needed for its rated octane. This substantially reduces available power.

Lean modestly, and avoid full power. Mild detonation is not serious, despite the name. Severe detonation may be quite a lot more expensive than trucking in a tank of 100LL from 100 miles away. But, it doesn't usually cause an engine to quit. Just use a lot of oil and leak compression.
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LOL. I bet you're the type of dude that buys into the idea of premium gasoline for certain cars too, right?

:rolleyes:
 
MoltenLava said:
Ok, after reading this thread now I'm worried. I've trained in C172, and the vast majority of the flying afterward was done in high wing aircrafts. I've just transitioned to Diamond DA40 and put about 10 hours on it. It's a beautiful, safe, and easy to fly aircraft, but this switching fuel tanks every 30 minutes bothered me a little. Yes there is a timer in G1000, and I've heard of the trick to switch the fuel tank to where the minute hand on my wrist watch is pointing. But I need to try really hard not to forget to switch tank, because it's one thing I *never* had to worry about throughout my flying. Reading the responses to this thread tells me fuel starvation due to forgotten fuel tank switch is not uncommon. And it's surprising that fuel tank switch is not automated in this day and age when everything else is electronically controlled. I mean the DA40 has autopilot that can level the wings and trim to assign altitude. Is automatic feeder or tank switcher really hard to design?
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If you're hand flying the DA40 and get an imbalance between the tanks it becomes pretty obvious when you're trying to keep it from turning. However if you're running both tanks low or using autopilot...you're out of luck.
 
SkyHog said:
LOL. I bet you're the type of dude that buys into the idea of premium gasoline for certain cars too, right?

:rolleyes:
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I run what the engine is tuned for. My BMW manual says 91 octane or greater and I won't experiment. My Honda sportbike is tuned for 87. Higher octane only make the temp gauge go up and my pockets lighter.
 
I drive an Audi A8L that requires Premium gas. I guess I'm a sucker because that is what I buy. My wife has put in lesser gas, not really a problem, but I did notice a difference in acceleration in the V8.
 
SkyHog said:
LOL. I bet you're the type of dude that buys into the idea of premium gasoline for certain cars too, right?

:rolleyes:
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If the car has dynamic compression higher than 7:1 or timing advanced without a knock sensor, yes. Most cars, even high performance, do not fit this definition. In a simplified nutshell, if it pings, you need higher octane. If it doesn't ping, you're fine.

In an aircraft, you're unlikely to hear it ping.
 
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MAKG1 said:
If the engine wasn't designed for 87 octane, it's either going to detonate at full throttle, or your A&P is a complete idiot and has retarded your timing well beyond what is needed for its rated octane. This substantially reduces available power.

Lean modestly, and avoid full power. Mild detonation is not serious, despite the name. Severe detonation may be quite a lot more expensive than trucking in a tank of 100LL from 100 miles away. But, it doesn't usually cause an engine to quit. Just use a lot of oil and leak compression.
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I'm guessing that you've never done detonation testing on an aircraft engine, and certainly not on a number of different types of aircraft engines such that you would actually know the detonation characteristics of the fleet. If you had, then you would know that the impacts will vary wildly depending on the engine installed in the aircraft. For example, if you tried this in a Navajo you'd be lucky to get on the runway. Actually you'd be unlucky if you made it that far, since you wouldn't make it much further and would then crash into a heaping pile of rubble.

I'll also guess that the airplane in this case had a lower-powered engine, in which case I'd expect to see no problems.

SkyHog said:
LOL. I bet you're the type of dude that buys into the idea of premium gasoline for certain cars too, right?

:rolleyes:
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I can tell you what will happen if you run 87 in my Mitsubishi, and it won't be pretty. It would probably involve several rods coming out of the side of the block and saying "HI!" or else pistons melting like butter.
 
In Cherokees and Arrows that I flew, it was impossible to forget to switch tanks, because the airplane after a while starts flying differently. It gets heavier and heavier on one wing and makes you put some rudder in (or aileron, to suit). After a while I always stared burning a bit more off left tank when solo, it seemed better that way.

It may only work VFR, and perhaps you can't sense this without seeing the horizon or when the turbulence starts throwing you around in the clouds. Also, some airplanes may have tanks that are closer to the centerline.

However, I'm surprised anyone would fly around with passenger with such small reserves that missing a timer by 20 minutes would unport a tank. I never landed with passengers and less than 10 gallons remaining.
 
Before the university here switched to Cirrus SR-20s for primary flight training there was the occasional student who would forget to switch tanks, declare an emergency and do a forced off-airport landing. I never want to show up in an NTSB report where the words "the [right/left] tank was filled with 100LL aviation gasoline" appear. Reading about that was motivation to develop good fuel management habits.
 
Headspace said:
Before the university here switched to Cirrus SR-20s for primary flight training there was the occasional student who would forget to switch tanks, declare an emergency and do a forced off-airport landing. I never want to show up in an NTSB report where the words "the [right/left] tank was filled with 100LL aviation gasoline" appear. Reading about that was motivation to develop good fuel management habits.
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Hmm... Boilermaker Golf Complex, eh?
 
So this didn't happen to me, running out of fuel, but when I was younger and had my license for almost 5 years, I was at my family's cottage at Winnipeg Beach, Manitoba. A friend of mine who was also a licensed pilot was visiting and suggested we head up to Gimli Manitoba to see ablut renting a plane at a flight school who he had rented from. Gimli was an old RCAF base that my dad had been stationed at in his younger days. I flew into Gimli about 18 months before when i was current. Gimli was about 10 miles up the road from our cottage. The date was July 23, 1983 and after a get together for my sisters birthday, we headed tothe airfield off of Highway 8. Well we couldn't fly that day. Why? The runway was blocked by an Air Canada Boeing 757 or 767. (Can't rember model) that had apparently run out of fuel and had to glide to land. The nose gear had collapsed. Apparently, their was a miscalculation in fuel load due to a multitude of factors. I will never forget that day.
 
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asgcpa said:
Well we couldn't fly that day. Why? The runway was blocked by an Air Canada Boeing 757 or 767. (Can't rember model) that had apparently run out of fuel and had to glide to land. The nose gear had collapsed. Apparently, their was a miscalculation in fuel load due to a multitude of factors. I will never forget that day.
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Maybe that's the way you remember it...but it didn't happen that way 'cause the 767 landed on a runway that had already been converted to a drag strip. In other words, the drag strip was blocked, not a runway.
 
I seem to recall it landed on the runway since the pilots saw the motocross activity on the other former parallel runway. The other runway was packed that day with go carts, people etc. but memories do fade. Nonethe less it was certainly an interesting site, especially if I recall YGM was a non towered airport.
 
zaitcev said:
However, I'm surprised anyone would fly around with passenger with such small reserves that missing a timer by 20 minutes would unport a tank. I never landed with passengers and less than 10 gallons remaining.
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After reading through this thread, it seems there is a broad spectrum of fuel management practices. The anon seems to think its reasonable to run tanks almost dry, while the above poster wants 20 minutes of fuel in each tank. I'm familiar with some planes where that would leave over 1.5 hours of fuel untouched, and split between 5 tanks. The anon risks small errors causing BIG problems.

Maybe we need a new thread, but I'm curious to hear a discussion of fuel management, particularly in planes that don't have the "both" option.
 
Unregistered said:
who's run a tank dry on a super nervous passenger? Here's the setup:

<snip>

Let's hear your version...
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My wife and I were returning to Atlanta from Texas. Don't remember if we were coming from Houston, Dallas, College Station, San Antonio or what, but due to distance and winds, we were fairly tight on fuel, so I was intentionally planning to run one tank dry so all of the remaining fuel would be in one place.

I fuel plan using my watch and know that a tank takes ~2:20 to empty at typical cruise settings. Either the engine was burning a little more fuel than expected, I miscalculated by a few minutes, or we got a half gallon less gas in the fuel tank than I expected, but the tank ran dry and the engine sagged about two minutes before I planned on briefing her. Oops.

She strongly suggested that I warn her beforehand next time. ;-)
 
Ianovic said:
After reading through this thread, it seems there is a broad spectrum of fuel management practices. The anon seems to think its reasonable to run tanks almost dry, while the above poster wants 20 minutes of fuel in each tank. I'm familiar with some planes where that would leave over 1.5 hours of fuel untouched, and split between 5 tanks. The anon risks small errors causing BIG problems.

Maybe we need a new thread, but I'm curious to hear a discussion of fuel management, particularly in planes that don't have the "both" option.
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I'm a believer in not having the last bits of remaining fuel split between tanks. If you have multiple tanks (say 4 to make it interesting), with a little fuel in each, do you really have a good idea of when you're gonna run a tank dry? My opinion is no and that a best practice (if you're trying to maximize range) is to know that the fuel on board will last "X" hours, and plan on having all of your fuel in one tank as you get to X-1 hours or whatever.

The problem in having a little fuel in each tank is that if you know you have 12 gallons in the airplane, but that's split between 4 tanks, can you really be sure which tank(s) have more or less than 3 gallons? Guess wrong and you might select the tank that runs dry on base to final or when you have to go-around because of a botched approach.
 
Ianovic said:
After reading through this thread, it seems there is a broad spectrum of fuel management practices. The anon seems to think its reasonable to run tanks almost dry, while the above poster wants 20 minutes of fuel in each tank. I'm familiar with some planes where that would leave over 1.5 hours of fuel untouched, and split between 5 tanks. The anon risks small errors causing BIG problems.

Maybe we need a new thread, but I'm curious to hear a discussion of fuel management, particularly in planes that don't have the "both" option.
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still don't get this fascination with spreading around small amounts of fuel among various tanks. I want to land with an hours worth of fuel but I want it in one place. In order to accomplish that I run the other tanks dry.
 
JHW said:
still don't get this fascination with spreading around small amounts of fuel among various tanks. I want to land with an hours worth of fuel but I want it in one place. In order to accomplish that I run the other tanks dry.
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That's a problem as far as I'm concerned as well. Fortunately, we seldom have to dip into our reserves, but when you do, it's nice to have all of your reserves in one tank. I've flown some singles that had 4 tanks. Having to switch tanks every 15 minutes to get at your 60 minute reserve doesn't seem like the best idea. Usually then that happens you tend to be up to your eyebrows in weather or airplane stuff. Fortunately just about every fuel injected airplane I've ever flown gave you plenty of notice that it was time to switch tanks.
 
JHW said:
still don't get this fascination with spreading around small amounts of fuel among various tanks. I want to land with an hours worth of fuel but I want it in one place. In order to accomplish that I run the other tanks dry.
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Right On
 
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