Ever fly with plane overloaded? Experiences?

MAKG1 said:
Umm, that's obvious.

Zeppelins would not work if helium gasbags didn't make them lighter.

Quite different from the bird question.
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Yes, a Zeppelin is different, unless it is a lead one....

So, you are thinking the plane would be lighter..,??
 
Skyrys62 said:
They then placed a model helicopter inside the box and had it hover above the ground, but this method also failed to produce any results.
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I like that, the helicopter really helps visualize what is happening... so no overall net weight change

Skyrys62 said:
But the effect is very short-lived – and worse, immediately afterwards, the avian cargo might actually be up to twice as heavy as the combined weight of the birds.
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I suppose that's like jumping up in an elevator...
 
Two Irish hunters from Chicago hired a pilot to fly them to Canada to hunt moose.

They bagged six. As they started loading the plane for the return trip home, the pilot tells them the plane can take only three moose.

The two Irishmen objected strongly, stating; "Last year we shot six moose and the pilot let us put them all on board and he had the same plane as yours."

Reluctantly, the pilot gave in and all six moose were loaded. Unfortunately, even on full power, the little plane couldn't handle the load and went down a few minutes after takeoff.

Climbing out of the wreck, Ian asked Seamus, "Any idea where we are?"

Seamus replied, "I think we're pretty close to where we crashed last year."
 
Skyrys62 said:
Below are a couple sources for contemplation:

#1 MythBusters Episode 77: Birds in a Truck
Premier Date: April 18, 2007

A truck carrying birds will be lighter if the birds fly around than if the birds sit/stand.
busted

Adam and Jamie constructed a large box and placed it on top of scale and then filled it with captured pigeons. Then, the MythBusters activated a special contraption that would force the pigeons to fly into the air, but they could not detect any discernible difference in the weight of the box. They then placed a model helicopter inside the box and had it hover above the ground, but this method also failed to produce any results. The MythBusters theorized that the air being displaced by the birds’ wings and the helicopter rotors was pressing down the box, which is why there was no change in the overall weight.

#2
It’s an urban myth that had US TV show Mythbusters weighing a truck full of pigeons on a scale and getting them to fly. Now it seems there’s some truth to the idea that a truck driver carrying a cargo of birds can lighten the load by making the birds fly.

But the effect is very short-lived – and worse, immediately afterwards, the avian cargo might actually be up to twice as heavy as the combined weight of the birds.

So says David Lentink, a mechanical engineer at Stanford University whose team has designed a system for measuring the aerodynamic forces generated by an untethered bird in flight.
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The REAL answer of course is he lets them out on the near side of the bridge, drives over and birdseed in hand, set them in the truck again.
 
To answer the original question, I did it. I planned a flight with my wife and her parents. the plan was to get the plane at the small untoward airport with 20 gallons of fuel and burn a couple gallons flying to a larger airport to pick up the in-laws. that would put us right at gross weight leaving the big airport. well, I got to the plane, and it had 28 gallons (I called the day before to have them not fuel it at the end of the day but high winds cancelled the last few flights) . the airport manager said they can't drain fuel but that I will be fine to fly with the extra fuel and to not worry about it. the big airport had 11000 feet. so I launched. it took a little longer to get off the ground, and climb was a bit anemic, but other than that, I saw no adverse effects. I actually had probably my best landing when we got to the destination- only about 45 minutes away, so we were still right at or maybe a little over gross.


All that being said, yes, I made a mistake. a combination of the in-laws already waiting at the other airport, the manager saying I'd be fine, and not wanting to cancel the flight on an otherwise perfect day all lead to making the wrong decision. I understand that, and Im posting this for the benefit of the OP who wanted to know about flying over gross.
 
tubby said:
To answer the original question, I did it. I planned a flight with my wife and her parents. the plan was to get the plane at the small untoward airport with 20 gallons of fuel and burn a couple gallons flying to a larger airport to pick up the in-laws. that would put us right at gross weight leaving the big airport. well, I got to the plane, and it had 28 gallons (I called the day before to have them not fuel it at the end of the day but high winds cancelled the last few flights) . the airport manager said they can't drain fuel but that I will be fine to fly with the extra fuel and to not worry about it. the big airport had 11000 feet. so I launched. it took a little longer to get off the ground, and climb was a bit anemic, but other than that, I saw no adverse effects. I actually had probably my best landing when we got to the destination- only about 45 minutes away, so we were still right at or maybe a little over gross.


All that being said, yes, I made a mistake. a combination of the in-laws already waiting at the other airport, the manager saying I'd be fine, and not wanting to cancel the flight on an otherwise perfect day all lead to making the wrong decision. I understand that, and Im posting this for the benefit of the OP who wanted to know about flying over gross.
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Interesting. Even with my limited flying experience, the plane I was originally learning in had to also have less than full tanks with just me and my CFI in it. Like you say, some cancelled flights and all the plans go out the window because the tanks are too full. I guess even though technically doable, it wouldn't be allowed to transfer AVGAS say from one plane to another (instead of dumping) ?

Leads to a theoretical (maybe dumb) question also...say you didn't have a LOT of excess in that same situation you had. IF you wanted to burn off the most amount of fuel the quickest without fouling the plugs, what would you do? Climb and descent, or just extra power flying around level?
It's just a for fun question.
 
LongRoadBob said:
Leads to a theoretical (maybe dumb) question also...say you didn't have a LOT of excess in that same situation you had. IF you wanted to burn off the most amount of fuel the quickest without fouling the plugs, what would you do? Climb and descent, or just extra power flying around level?
It's just a for fun question.
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There's a small Aircraft manufacturer out there that is trying to get into LSA that is claiming that most LSA (presumably in EU) are flying over-gross weight. I don't know that to be true in the US, though I have heard some stories of folks flying from 10 to 100 pounds over gross weight. It's conceivable given the 1,320 limit of LSA, though I wouldn't want to do that...especially on a high density altitude day.

Theoretically, if I had the extra weight in terms of fuel on board, and had to burn it off, I would climb and descend as much as I could without overheating the engine. If I had the time (so not the quickest fuel burn), I'd go sight seeing at a fast cruise.
 
LongRoadBob said:
Interesting. Even with my limited flying experience, the plane I was originally learning in had to also have less than full tanks with just me and my CFI in it. Like you say, some cancelled flights and all the plans go out the window because the tanks are too full. I guess even though technically doable, it wouldn't be allowed to transfer AVGAS say from one plane to another (instead of dumping) ?

Leads to a theoretical (maybe dumb) question also...say you didn't have a LOT of excess in that same situation you had. IF you wanted to burn off the most amount of fuel the quickest without fouling the plugs, what would you do? Climb and descent, or just extra power flying around level?
It's just a for fun question.
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If you must burn off fuel rapidly, fly in circles at high speed, a LITTLE rich. Climbing burns fuel, but also builds heat due to lower airspeed, and burns far less on the way down.

Power necessary to maintain airspeed goes as its cube.
 
I can vividly remember two flights where W&B missteps provided much entertainment: One was in a Beech E-18 out of SFO runway 10L, laden with 2 pilots, fuel for San Diego plus reserves and enough U.S. mail to (we later speculated) put us some 1,500lbs. over gross. A 10,000lb Twin Beech is a precarious machine anyhow, but loaded such as it was, at max takeoff power and the gear retracted I think we were climbing less than 250fpm. Good thing there was nothing around but the San Francisco bay, because I was never so happy to fly over water. We climbed straight out for awhile then made a shallow left turn back to the 19s, not daring to extend the gear til the runway was made. Threw out over a thousand lbs of freight and left 30 mins later. A few years later, I was the Captain on a Metro III on a very full flight from SJC-RDD and, after takeoff - but before the gear was in the wells, I was at the elevator trim full nose-down stop and having to hold 35lbs of forward pressure on the yoke, because the airplane was so far out of CG. In the Metro, the CG moves aft with fuel burnoff, so I continued the hour and twenty minute flight to Redding. I insisted they weigh every last bag in the baggage compartment. We found some 400lbs more than listed on the manifest. I made quite a fuss about that, and I think the airline provided some much needed counseling to our ramp personnel.
 
j1b3h0 said:
but before the gear was in the wells, I was at the elevator trim full nose-down stop and having to hold 35lbs of forward pressure on the yoke, because the airplane was so far out of CG. In the Metro, the CG moves aft with fuel burnoff, so I continued the hour and twenty minute flight to Redding.
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Huh?

You already had to hold forward pressure (meaning CG was way too far aft) and the CG moves even farther aft with fuel burnoff, so... You continued?!? Am I missing something?
 
Anyone who is willingly flying over gross is a test pilot, and you can tell me how that goes...
 
Jim Case said:
Anyone who is willingly flying over gross is a test pilot, and you can tell me how that goes...
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Done it often. It goes well.

Look up 91.323. Are these guys test pilots?

I have also flown planes with an increase in factory max takeoff weight due to adding vortex generators. All flights went well.

I think I understand what you meant. Yes, taking off in a C-172 that is 200 pounds over max gross weight could have problems taking off here in the high desert where the density altitude is 9500 today at 2:35p.
 
Zeldman said:
Done it often. It goes well.

Look up 91.323. Are these guys test pilots?

I have also flown planes with an increase in factory max takeoff weight due to adding vortex generators. All flights went well.

I think I understand what you meant. Yes, taking off in a C-172 that is 200 pounds over max gross weight could have problems taking off here in the high desert where the density altitude is 9500 today at 2:35p.
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You can do whatever you what. I'm simply stating they are listed in the poh for a reason. I'm glad it's worked out for you, just be careful.
 
Stewartb said:
Controls are heavy and response is sluggish. Acceleration is sluggish. In a taildragger the tail is hard to lift. To maintain normal control on final the landing speed is a little higher. With faster speed and a heavier plane the brakes are less effective. The only way the be heavy and out of the CG envelope is to be aft. That makes the control feel even heavier and the landing speed even higher. Some planes fly very well at or slightly over gross. A Supercub is an example. You can feel the weight in the controls but the plane still performs well. Get a Skywagon over gross and you know it as soon as you leave ground effect. And that's a point to consider. You can get the plane off the ground in ground effect but once you do you're committed. Getting it down safely may not be as easy as you think.
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Yes....and the DHC2/3 may or may not handle very well at weights far in excess of gross. Or so I've heard.
 
Acting as test pilot of an experimental, I needed to test flying characteristics near the limits to the weight and balance envelope. Since we had horses, bags of horse feed were a readily available ballast that could be secured fairly easily in the aircraft. My big mistake was trusting that 50 lb bags of feed actually weighed 50lb which was really stupid. In any event I loaded up the plane to what I thought was close to full gross and near the aft CG of the envelope. Takeoff was scary as the airplane pitched up with the stall horn blaring. I held the nose down, picked up speed and climbed to altitude with the nose down trim cranked in. I was not comfortable trying to land in it that way so I pulled a couple of the bags forward off the rear seats to the floor which made it handle much better and landed uneventfully. Turned out on average those 50# bags averaged 60# so I was about 90# over gross weight, but more importantly, with a significant aft CG. The airplane was controllable and climbed ok, but I think the combination of being used to flying it light with the CG near the forward limit of the envelope, and being slightly overloaded with an aft CG took me by surprise and scared the heck out of me. It turned me into a W+B nerd with a scale in the baggage compartment to weigh anything and anybody that goes into my plane. I also kept buying the feed from the same place because they remained consistently over weight :).
 
flyingcheesehead said:
Huh?

You already had to hold forward pressure (meaning CG was way too far aft) and the CG moves even farther aft with fuel burnoff, so... You continued?!? Am I missing something?
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In what plane does the CG move aft when fuel is burned? Fuel moves the CG aft. Removing or consuming fuel moves the CG forward, at least in the planes I've owned and flown.
 
Stewartb said:
In what plane does the CG move aft when fuel is burned? Fuel moves the CG aft. Removing or consuming fuel moves the CG forward, at least in the planes I've owned and flown.
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If the CG of your fuel tanks is infront of the aircraft's current CG, then it will indeed move the CG aft when the fuel is burned. I'm sure it happens.
 
What plane was the question. I've never flown a plane that had fuel tanks forward of datum.
 
Stewartb said:
In what plane does the CG move aft when fuel is burned?
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Might be grasping at straws here, but the Concorde had pumps to move the fuel aft, and hence the CG aft, as fuel burned and they passed the sound barrier to compensate for the shift in center of pressure

A little more related to your question and GA though, I am pretty sure I recall reading that the GLASAIR II cg moves aft as fuel is burned

FOUND IT, sorta
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http://glasairaviation.com/wp-content/uploads/2016/07/GSB114.pdf
 
I don't like that weight and balance get lumped together.

Being overweight, the plane will be slower and less responsive, use more runway and climb slower. Ferry flights, for example, do it regularly without too much drama.

But balance is a much bigger deal... If you're out of balance, especially to the rear, the plane will turn on you quickly.
 
jbarrass said:
Being overweight, the plane will be slower and less responsive, use more runway and climb slower.
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That can be a pretty big deal in the west. Potentially more so than being out of balance. Not every plane is operating off of mile-long plus paved runways at sea level.
 
I done a bad thing in my Cherokee. I wanted to take cousin Debbie and her husband Mike on a short flight. It was supposed to be just Mike, but Debbie stepped in at the last minute. I couldn't say no. Debbie was of course in shape. Round is a shape.

We flew to a nearby airport that had the cheapest gas anywhere, I was near empty and wanted to fuel up. The fuel was on an honor system and a very interesting hand pump. I wanted to just fill her up to the tabs, but we wound up filling the airplane up full. The takeoff was, er, interesting. Had it been hotter we would have wound up in the trees. After that I made the habit of weighing everything that went in that airplane and even going one gram over gross.
 
Stewartb said:
Do tell?
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Do you really want him to tell? He does have “young engineer syndrome” which is expected in engineers with only a few years experience.

Obviously with fuel tanks in the wings the centroid of the fuel tank is going to be (very) near the aft limit. On the other hand aircraft with tanks forward of the wing will be more likely to exhibit the CG moving aft as fuel is burned. The Spirit of Saint Louis had this problem as one of the tanks was emptied. Not a real common aircraft though...
 
Stewartb said:
Do tell?
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As you burn fuel... the CG moves backwards. The seesaw should be level for the "center" of gravity, but for the demo, it works. Basically as the seesaw tilts back more (burning fuel), the CG is moving aft.
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Clark1961 said:
Do you really want him to tell? He does have “young engineer syndrome” which is expected in engineers with only a few years experience.
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My experience really has very little to do with basic physics.
 
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Mtns2Skies said:
As you burn fuel... the CG moves backwards. The seesaw should be level for the "center" of gravity, but for the demo, it works. Basically as the seesaw tilts back more, the CG is moving aft.
View attachment 61840


My experience really has very little to do with basic physics.
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But your experience does have a lot to with practicality. Your explanation here is a perfect example. It is entirely correct but not useful in describing the CG problem of most general aviation aircraft.
 
Stewartb said:
In what plane does the CG move aft when fuel is burned? Fuel moves the CG aft. Removing or consuming fuel moves the CG forward, at least in the planes I've owned and flown.
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In my RV-6 and most of the RV series, the cg moves aft with fuel burn. I understand Bonanzas are the same.
 
Mtns2Skies said:
As you burn fuel... the CG moves backwards. The seesaw should be level for the "center" of gravity, but for the demo, it works. Basically as the seesaw tilts back more (burning fuel), the CG is moving aft.
View attachment 61840
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The CG is represented as inches aft of datum. How you get there is the sum of all added weight at various stations. Fuel is one component. As fuel is consumed that component is reduced and the CG moves forward. You need to borrow a Cub or similar light taildragger with empty tanks. Lift the tail. Add 5 a side and lift the tail. It's heavier. Add more, the tail gets heavier. Whether the plane is loaded or empty adding fuel adds weight to the tail. Conversely, removing the fuel makes the tail lighter.
 
Stewartb said:
The CG is represented as inches aft of datum. How you get there is the sum of all added weight at various stations. Fuel is one component. As fuel is consumed that component is reduced and the CG moves forward. You need to borrow a Cub or similar light taildragger with empty tanks. Lift the tail. Add 5 a side and lift the tail. It's heavier. Add more, the tail gets heavier. Whether the plane is loaded or empty adding fuel adds weight to the tail. Conversely, removing the fuel makes the tail lighter.
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I'll make this as simple as possible and maybe @Clark1961 can make this more "practical". It's an average. If you lose stuff infront of the average, the average moves back. The plane isn't lifting from the tail so that doesn't work that way.
 
Mtns2Skies said:
I'll make this as simple as possible and maybe @Clark1961 can make this more "practical". It's an average. If you lose stuff infront of the average, the average moves back. The plane isn't lifting from the tail so that doesn't work that way.
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Yer on yer own now. :):D I already tried to discourage Stewart from getting into this one.
 
Go fly your Skywagon with minimum fuel. Then do it with full fuel. Tell me how it feels to lift the tail on the takeoff run. For grins add some ballast in back before you do it. You'll find the tail is still harder to lift with more fuel. That's about as simple a demo as there is. Actually running a few sample W&Bs is even easier.
 
Stewartb said:
Go fly your Skywagon with minimum fuel. Then do it with full fuel. Tell me how it feels to lift the tail on the takeoff run. For grins add some ballast in back before you do it. You'll find the tail is still harder to lift with more fuel. That's about as simple a demo as there is. Actually running a few sample W&Bs is even easier.
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That's not how it works. The plane is supported by very far forward wheels on the ground and by the wings in the air. But I give up. If someone else wants to explain student pilot level CG go ahead.
 
I hope this is some kind of troll thread. @Mtns2Skies has it right. The seesaw is the best way to visualize this. Adding weight behind the main gear of a taildragger will obviously make the tail heavier. That doesn't prove that burning fuel off in every single airplane moves the CG forward. I even posted the GLASAIR which has the CG move aft as fuel is burned, and the Concorde example above is actually a great illustration of how they moved fuel around the plane to keep the CG at an optimum point by the center of pressure
 
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