Ever fly with plane overloaded? Experiences?

From what I understand the 180hp conversion 172N's increase in MToW doesn't have any structural mods in the wings, which leads me to believe that under maneuvering speed your still within design loads otherwise critical AoA is passed (no joke) and the wing stalls
 
Not arguing and it makes sense at face value... just trying to think about the aerodynamic mechanics at play. If I picture a plane flying along and I start adding weight to it the pilot will need to increase AoA to maintain altitude, eventually add too much weight and the wing stalls.. assuming you are below Va.

On the flip side the wing is still carrying more weight so that obv loads structure more... interesting to think about
 
Tantalum said:
Not arguing and it makes sense at face value... just trying to think about the aerodynamic mechanics at play. If I picture a plane flying along and I start adding weight to it the pilot will need to increase AoA to maintain altitude, eventually add too much weight and the wing stalls.. assuming you are below Va.

On the flip side the wing is still carrying more weight so that obv loads structure more... interesting to think about
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To add to your train of thought, a plane's Va goes up as it gets heavier. Well, sort of. The Va is published for gross weight and it decreases with less weight. But, do a little research about how they determined Va in the first place. It isn't what most pilots think it is.

With respect to gross weight you have to include CG in the discussion. In a typical airplane (forget 150s) its hard to overload without the CG being aft. The danger there is maintaining AOA at slow speeds. If you get the CG at the rear limit you may find the elevator less responsive when you slow the plane down, probably to land. Get the CG aft of the limit and at normal landing speeds the tail may not hold the attitude you want. If the tail drops it won't take long for the wing to stall, and believe me, at aft of the envelope CG your tail will drop when you get slowed. Better hope you aren’t very high off the ground when that happens!

https://www.avweb.com/news/features/The-Risks-of-Maneuvering-Speed-Myths-222680-1.html
 
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Mtns2Skies said:
While it's true you have more inertia which would make it harder for you to get knocked around in turbulence, when you do experience G force it's going to be a LOT harder on the airframe. I think normal category aircraft are rated for up to 3.8G at max gross weight. If you exceed this the plane is then only good up to significantly less G force.
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PROPORTIONALLY less G-force.

It's not gonna matter unless you're severely overloaded.

By far the biggest risk is not being able to get out of ground effect, or related poor climbing ability. Especially at high density altitude or in gusty winds.
 
The problem with overgross is that you are now a test pilot. It is like operating the aircraft outside its' certified envelope in aircraft's ceiling, exceeding the Vne, crosswind component, performing aerobatic maneuvers, etc. None of these items absolutely will result in an issue, but they may result in being a factor in an NTSB report..

There is a safety factor in the design of our airplanes, but do you really want to test the edge? There may not be a recovery. Depending on how much overgross, you may or may not be able to climb adequately, you will experience a higher stall speed. Your stall recovery will be affected. Your aircraft will handle more sluggish.

It is best to operate our aircraft within the envelope they were designed.
 
MAKG1 said:
PROPORTIONALLY less G-force.

It's not gonna matter unless you're severely overloaded.
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A 60* bank while maintaining altitude WILL result in 2Gs no matter how you slice it. Maneuvering will be hard on the aircraft.
 
Mtns2Skies said:
A 60* bank while maintaining altitude WILL result in 2Gs no matter how you slice it. Maneuvering will be hard on the aircraft.
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Do the calculation.

To exceed loads at 2Gs, when designed for 3.8, you would need to almost double the max weight.

You will never get off the ground that heavy.
 
frfly172 said:
Who would admit on a public sight ,of flying overweight. It's a personal choice,not recommended,give it a try,let us know how it goes.
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Couple of points. If you actually read the post, I state clearly I am not going to do it. I do the calculations, and stay within boundaries. One of the first flights though we were right at gross. My instructor said he weighed x amount, but if you have may fudge some pounds, I think it is good to know how it actually affects flying.

Also mentioned I picked the lessons learned forum because it allows people to post anonymously if they want.

You are batting a thousand.
 
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Tantalum said:
Not arguing and it makes sense at face value... just trying to think about the aerodynamic mechanics at play. If I picture a plane flying along and I start adding weight to it the pilot will need to increase AoA to maintain altitude, eventually add too much weight and the wing stalls.. assuming you are below Va.

On the flip side the wing is still carrying more weight so that obv loads structure more... interesting to think about
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If we only had some sort of indicator for the AoA...we could fly overgross all day long.



Sent from my iPhone using Tapatalk
 
I would never admit to being "over-loaded"....but I did have an underperforming aircraft that was at or near gross weight one or two times. :D
 
I do wonder often in the commercial aviation world, if you actually weighed planes before T/O how many would be above their max gross. I've been on flights where it looked like just about every pax was a football player or body builder, the average weight must have been around 220 lbs per person.

I read somewhere that the average person drives drunk 7 times before they caught for DUI, wonder if it's something similar with weight... fly 7 times overweight and that 8th time you'll get bitten thanks to DA or something else
 
why yes, I violate the FAA regulations all the time and admit it online . . . . said no one ever. I hope.
 
SkyDog58 said:
As far as your concerns about the CG changing during flight there is a simple solution. When you do your preflight W&B calculation figure it with the fuel you plan on beginning with and again with the amount left when making your planned fuel stop or better yet with empty tanks (worst case scenario). If either one take you outside of the envelope, don't fly without making changes.
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That's a reasonable solution for most GA airplanes, but not all airplanes.
Swept wing airplanes often have a curved fuel line when plotted on a graph, but have a straight edge envelope. You can start and end in CG envelope, but be out during flight.
Plotting the burn on the graph is the sure fire method.
 
Tantalum said:
I do wonder often in the commercial aviation world, if you actually weighed planes before T/O how many would be above their max gross.
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So, here's how I understand the story...

Many years ago, someone from a major airline's management saw this discrepancy between the Fed's "standard" weight and the ever increasing size of the average American. He (or she, or xe, or "it") had someone go out to measure the actual weight of every passenger and luggage loaded on to the airplane. Doing this, he would note the discrepancy between the actual weight and calculated weights of the airplane. Long story short, the data calculated from the actual weight, to this day, has never been released.

That should give you an idea. :D
 
citizen5000 said:
W&B is only part half of the issue. Density Altitude is the other half. You can fly a non fully loaded plane in high density altitude and still not have enough runway or climb power to stay in the air.
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Completely incorrect for all but a handful of aircraft at a handful of airports. Try some numbers. You'll find the statement to be much more wrong than right.

skidoo said:
Weight & Balance.. What's that??? I did most of my lessons in a C-150, including the C-150 aerobat. I got my certificate at 118 lbs :) My instructor was light too. Are students/instructors eating too much these days??

That said, I now carry a few extra lbs, and have moved to a 182...:)
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I know that feeling!
 
Mtns2Skies said:
While it's true you have more inertia which would make it harder for you to get knocked around in turbulence, when you do experience G force it's going to be a LOT harder on the airframe. I think normal category aircraft are rated for up to 3.8G at max gross weight. If you exceed this the plane is then only good up to significantly less G force.
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It depends on where the additional weight is located. If the additional weight is loaded in the fuselage yes you are correct. If you have added tip tanks to the airplane and burn fuel out of the tip tanks last you have actually reduced the fatigue damage accruing in the carrythru and wing structure by balancing out the load. Makes a significant difference on fighter jets with drop tanks and tip tanks when doing high G force maneuvers.
 
Tantalum said:
I do wonder often in the commercial aviation world, if you actually weighed planes before T/O how many would be above their max gross. I've been on flights where it looked like just about every pax was a football player or body builder, the average weight must have been around 220 lbs per person.

I read somewhere that the average person drives drunk 7 times before they caught for DUI, wonder if it's something similar with weight... fly 7 times overweight and that 8th time you'll get bitten thanks to DA or something else
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Not only weight, but balance. Not only do we use standard weights, but we also assume the number of people are spread evenly throughout the cabin.
 
Kritchlow said:
That's a reasonable solution for most GA airplanes, but not all airplanes.
Swept wing airplanes often have a curved fuel line when plotted on a graph, but have a straight edge envelope. You can start and end in CG envelope, but be out during flight.
Plotting the burn on the graph is the sure fire method.
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Agreed. But I was answering the question for the average student or low time GA pilot. Many on here including you surpassed that level awhile back and were not necessarily the primary audience of my statement. Simple solution for simple airplanes.

Of course, many of you have entire departments dedicated to ensuring that the airplane stays within limits. Unless you are deplaning at Frontier. :D
 
Theboys said:
I was told once or twice the way they come up with gross weight is to load a plane until it starts to lose altitude at a set speed with no additional power or trim. Course that could be wrong :)
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I'm pretty sure landing gear failure is the test - engineering takes the gear and tests it to failure at a descent rate designed to cause a bounce -
 
Stewartb said:
To add to your train of thought, a plane's Va goes up as it gets heavier.
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Good point, for my thought exercise I always just assumed I would keep it constant at the POH's max gross for the Va

But overall the wing can only generate so much lift for a given airspeed... and as the plane gets heavier you'll have a harder time maintaining airspeed since you'll need more and more lift and overall the drag will start cancelling out the thrust, so who knows, if heavy enough you might not even get fast enough to hit Va.. isn't it kind of like overloading a boat? You won't punch a whole through the bottom of the boat, eventually instead the boat will just become less and less stable until it either capsizes or sinks

I would never overload a plane, and never have, but my thought exercises have always lead me to believe that the primary reason for the weights was based on performance and overall power, etc. This is why I also believed that you would see different versions of the same plane have different published max weights based on their available power. Like I said, I don't believe the GW increase in the 172 for the 180 conversion comes with any structural mods other than a limit on the flaps
 
Tantalum said:
haha, boats? Or the 172N conversion to 180hp? Serious question actually. Does the 180hp conversion have any structural mods?
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ok...I read what you wrote wrong. I was thinking C-180....vs 180HP. The C-180 is a different aircraft with more HP.

even if you bolted on a 400HP engine to that 172 structure.....it wouldn't get a gross weight increase proportional to the HP increase. You'd reach the structural limitations of a 172 frame....which is why the 182 ain't the same as a 210 as a 172.
 
Tantalum said:
haha, boats? Or the 172N conversion to 180hp? Serious question actually. Does the 180hp conversion have any structural mods?
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No. A related STC limits flap travel to 30 deg. That's what gives you the max gross weight increase. It's related to climb rate on a go-around with the flaps at full.
 
I had the Tiger near gross a few times, but never over. No, I do not like how any plane handles when it is heavy, and the reason I got a 180HP plane was to comfortably be a two person and bags plane, and/or be able to handle high DA situations. Not really to fill the back seats with passengers, although I have done it enough.
 
I have...once, because of me not double checking the graph for high density. My passengers didn't know and I didn't tell them.

Never again.
 
Cpt_Kirk said:
Many years ago, someone from a major airline's management saw this discrepancy between the Fed's "standard" weight and the ever increasing size of the average American. He (or she, or xe, or "it") had someone go out to measure the actual weight of every passenger and luggage loaded on to the airplane. Doing this, he would note the discrepancy between the actual weight and calculated weights of the airplane. Long story short, the data calculated from the actual weight, to this day, has never been released.
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I bet it happens more often than we'd like to think...

Interestingly, some people mentioned density altitude and I was just reading about this last night: http://avherald.com/h?article=4a81da6e&opt=0

"According to preliminary information the aircraft crossed the runway end at about 5 feet above ground instead of 35 feet AGL."
^5 feet crossing the end of the runway is way too close for comfort. I doubt a V1 engine out would have been a good day for these folks
 
We went to Cozumel Mexico to scuba dive in '98.
Chartered flight from a dive company...Seats totally full, most all were scuba divers. No real heavy weight passengers, but the amount of equipment/bags everyone brought was staggering.
Early September, south Florida and hot.
I could feel the plane grunting. Only time I've ever been truly worried we wouldn't get off the ground.
Made it right at the end of the runway.
Coming back hurricane George was moving in. It looked awful outside, but surprisingly uneventful.
The diving was awesome!
 
Timbeck2 said:
I have...once, because of me not double checking the graph for high density. My passengers didn't know and I didn't tell them.

Never again.
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Can you explain? I don't know of any DA performance charts that are based on aircraft weight.

I've seen a number of folks who didn't like the performance of their airplanes up here on a high DA day (we're a lot more used to a 200 ft/min climb after takeoff than most folks, but the aircraft and book are usually pretty close to each other on climb performance), but don't get what you're saying from the typically available performance charts.
 
denverpilot said:
Can you explain? I don't know of any DA performance charts that are based on aircraft weight.

I've seen a number of folks who didn't like the performance of their airplanes up here on a high DA day (we're a lot more used to a 200 ft/min climb after takeoff than most folks, but the aircraft and book are usually pretty close to each other on climb performance), but don't get what you're saying from the typically available performance charts.
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I believe all performance charts (not W&B) are based on DA & weight.

If you go in with PA and temp.... there you have it.

Perhaps I'm not understanding your point.
 
denverpilot said:
Can you explain? I don't know of any DA performance charts that are based on aircraft weight.

I've seen a number of folks who didn't like the performance of their airplanes up here on a high DA day (we're a lot more used to a 200 ft/min climb after takeoff than most folks, but the aircraft and book are usually pretty close to each other on climb performance), but don't get what you're saying from the typically available performance charts.
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When I flew GA aircraft (Cessna charts) I always used standard temp column, but went into the PA column with DA. Comes out the same, but easier IMO.
 
Kritchlow said:
I believe all performance charts (not W&B) are based on DA & weight.

If you go in with PA and temp.... there you have it.

Perhaps I'm not understanding your point.
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Ahhh got it. Brain fart.

Never seen that chart show zero climb until above service ceiling (in DA terms) though. And all have the top line showing max gross.

How freaking hot WAS it, wherever you were, Tim... to put your DA on the ground higher than the service ceiling?!

(Understandably easy to do at Leadville... about 70F takes you off the top of the perf charts there for older aircraft.)
 
Kritchlow said:
When I flew GA aircraft (Cessna charts) I always used standard temp column, but went into the PA column with DA. Comes out the same, but easier IMO.
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That's often what I do, too. Might as well see what the actual performance is going to be... but teaching you gotta follow Cessna's rules and make the poor student do it their way... but later discuss that the same result can be found the other way. :)
 
This may be my cue to chime in with a reminder that in some countries, such as Russia, the "overgross" condition is actually a part of airworthiness certificate. In other words, it has two numbers: one is "gross weight" and another is "overgross weight". The "gross weight" is for airplane to meet a set of "standard" certification requirements, including the stall speed, Vmc, etc. for the certification category. The "overgross" number comes with a different set of restrictions, which may include not only Runway Required numbers, but things like reduced maximum crosswind component. It may also exceed the maximum allowable landing weight, e.g. taking off with "gross" weight allows a guaranteed abort, whereas taking off with "overgross" weight does not. I do not remember precisely how that works, but I presume that scheduled operations with revenue passengers are only permitted with up to "gross" or "standard" takeoff weight. Either way, this should give us an idea that the gross weight can be flexible to an extent, even in the eyes of government bureaucrats.
 
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