Flying overweight

Don’t be a test pilot. You aren’t trained for it.

do people fly airplanes overweight? No, not really. There may be a few scofflaws who ignore it, but the max weight is not just a rule, it’s a safety margin. There aren’t a lot of crash videos out there of people who tried. They frequently end with a fire consuming the video evidence.

reduce your fuel. Go on a diet. Get a different airplane.

no, people don’t fly overweight.
 
Ferry pilots fly overweight all the time, but they are more experienced, usually taking off from long runways at sea level and are smart enough to takeoff in the morning when it’s cooler.
 
There is no standard endurance for aircraft. One plane's "full fuel" might be 7 or 8 hours, another's might only be 3 or 4.

When comparing missions, it's worth comparing planes with a similar "runtime", so 2-3 hours' cruise for instance. It's philosophy of aircraft design to decide whether it makes more sense to allow a pilot to take partial fuel + full seats v fill tanks + seats. I've heard arguments for either. If I'm solo, I would prefer the option to take additional fuel.

Plane performance drops rapidly as you exceed max weight, and in unpredictable ways. You can also get strange and unsafe flight control behaviors. I crashed a plane early in my flying career due to flying about 10% over gross weight on a hot/high day. It flew like garbage, the nose wouldn't naturally stay on trim, and it had no more tendency to nose down when removing power. After departing, we could not get above 1500 AGL and that was at a 50-100fpm cimb rate. This was in a 4 seat aircraft. Any inattention to pitch would have earned me a stall/spin. Instead I caught a downdraft that I had no ability to outclimb and we put the thing in a field.

Not recommended. :)
 
You'd be surprised how many pilots don't even check. I looked at a cherokee six that had no current w&b... the owners said they never worried about it. If it fit inside they flew it. You can get away with that right up until you don't.

On a cold day you can get away with a lot, which is why 135 operators in Alaska can legally get a 15% increase in mgw. The problem is how to know where the line is. Remember that extra 100 lbs can become 300 real fast in turbulence or an unusual attitude. At some point metal starts to fail, which is why the manufacturer drew the line where they did.

I'm not familiar with the mooney, but on some planes the long range tanks are there for a mgw increase moreso than to actually fill. My plane holds 6 hours of fuel, but I never fly more than 3 nonstop; the excess capacity is useful for tankering fuel when I can buy it cheap.

The last time my plane was weighed was 1976. I suspect if I put it on scales it would gain 50 lbs, as do most old airplanes. I fly at mgw a few times a year. There's a digital scale in my hangar and I'm very careful about w&b, but if you made me roll across scales on the way to the runway, I might be over my mgw due to that old airplane weight gain. Legal by the official w&b. Safe? My home base has an 8000' runway and no obstructions for miles, so I don't lose any sleep over that 50 lbs.... I burn that much fuel in the climbout. On a hot day or a shorter runway... better not fill the tanks.

I'll add... flying at mgw isn't fun. The climb is slow and at least in the planes I've flown it "feels" heavy & sluggish. 200 lbs overweight in your example PROBABLY won't kill you, but it will still suck.
 
Last edited:
Flying over gross won’t kill you, until it does. People do it every day and get away with it. We talk about some of the others here when the accident reports come out. Seriously though, it all depends on the situation. Some planes have a lot of wiggle room, others not so much. Are you qualified to know the difference?
 
Ernesto Castro said:
I'm a fairly new private pilot.

During training, and my flying afterwards I've always made my W&B and have always flown inside weight and cg limits.

How is that there are airplanes that can barely take a person when full of fuel? I'm looking at a Mooney M20k, with extended fuel tanks, that with full fuel it is just 170lb under MTOW.

Then in this 170lb you need to fit backpack, pilots clothes and pilots own weight.

I'm sure that an airplane like this most likely was never flown full of fuel or it has exceeded it's MTOW.

So, my silly question is: what's the deal with fyling heavier than MTOW? Apart from the fact that is ilegal...

As long as a CG is within limits, flying a 2900 lb airplane with a 200lb overweight, is that risky? Does people sometimes take off above max to weight?
Click to expand...
There is a formula that the FAA uses in granting approval for some overweight conditions. Now the plane itself doesn’t know what State it’s in or who the pilot works for, so the formula might be looked at as a limit that stays within a safe boundary. Comments above Pilot experience not withstanding.


§91.323 Increased maximum certificated weights for certain airplanes operated in Alaska.
(a) Notwithstanding any other provision of the Federal Aviation Regulations, the Administrator will approve, as provided in this section, an increase in the maximum certificated weight of an airplane type certificated under Aeronautics Bulletin No. 7-A of the U.S. Department of Commerce dated January 1, 1931, as amended, or under the normal category of part 4a of the former Civil Air Regulations (14 CFR part 4a, 1964 ed.) if that airplane is operated in the State of Alaska by—

(1) A certificate holder conducting operations under part 121 or part 135 of this chapter; or

(2) The U.S. Department of Interior in conducting its game and fish law enforcement activities or its management, fire detection, and fire suppression activities concerning public lands.

(b) The maximum certificated weight approved under this section may not exceed—

(1) 12,500 pounds;

(2) 115 percent of the maximum weight listed in the FAA aircraft specifications;

(3) The weight at which the airplane meets the positive maneuvering load factor n, where n=2.1+(24,000/(W+10,000)) and W=design maximum takeoff weight, except that n need not be more than 3.8; or

(4) The weight at which the airplane meets the climb performance requirements under which it was type certificated.

(c) In determining the maximum certificated weight, the Administrator considers the structural soundness of the airplane and the terrain to be traversed.

(d) The maximum certificated weight determined under this section is added to the airplane's operation limitations and is identified as the maximum weight authorized for operations within the State of Alaska.
 
I'd be willing to bet the extended range tanks are mostly useless. People put them on because more is better right? Ok great you can haul around more fuel. Whats the standard fuel capacity 78 gallons? Long range tanks bump it to 108gallons ( heard one guy had his first fill to 117), 650 lbs of fuel. With a 12gph burn, Does anyone really want to sit in a Mooney (or any GA plane) for nearly 10 hours? Are Mooney drivers that masochistic? Can your bladder take it? I want to stretch after 4 hours.
 
Except there's far more than just being in Alaska. The operator has to show that all the stuff in (b) is met before the FAA will approve it. It's not just the case that you get an automatic 15% bump in gross weight if operating in the great white north.
 
Don’t fly overweight. I’ve investigated two accidents in the last year that were overweight. One was 1000Lbs+ which was a multiple fatal.
 
Note that ferry pilots get a waiver from the FAA to do it, which includes additional restrictions, and 135 pilots in Alaska should have additional training that mitigates the reduced safety factor.
 
It happens.
But, you are eating into one or more safety margins.
You may or may not get away with it.
 
I don’t recommend flying over gross, has it happened safely a lot if times, of course it has. BUT, max gross takeoff weight is there for safety! As you fly more, you’ll figure out that you almost never need full tanks. 5-6 hours of fuel is generally double the range of most bladders! It’s good to plan a fuel stop along the way, get out to stretch and pee!
 
ARFlyer said:
Don’t fly overweight. I’ve investigated two accidents in the last year that were overweight. One was 1000Lbs+ which was a multiple fatal.
Click to expand...
Jesus! Who in their right mind can load up that much over and not even think it might not be too much?
 
Ernesto Castro said:
what's the deal with fyling heavier than MTOW? Apart from the fact that is ilegal...
Click to expand...
In general terms, an aircraft certified maximum gross weight is determined based certain physical limitations (structural, performance, control, etc) depending on the specific aircraft. So any aircraft operated above max weight will be operating outside one of those physical limitations. And one of the first things looked at when an aircraft has an incident/accident is whether it was within its certified weight/balance/CG limits. In some cases an aircraft may have several maximum weight limits depending on operation. For example, some helicopters are limited to X max weight static on the landing gear (structural limit) but that max wt increases by 1000lbs when you add the weight to the cargo hook while the aircraft is flying. Same for some large aircraft that have a max takeoff weight and a lesser max landing weight. It's all how the weight affects the aircraft. So operating above the certified max weight can have a number of consequences none of them positive. Most questions on aircraft weight procedures/process can be found here: https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/faa-h-8083-1.pdf

FYI: the reference in 91.323 is not applicable to private GA ops and only applies to a very limited group of aircraft that was needed many years ago.
 
Bell206 said:
FYI: the reference in 91.323…only applies to a very limited group of aircraft…
Click to expand...
Good point…I could do the stress analysis required by Aeronautical Bulletin 7-A in my garage, and offhand I can’t think of an airplane certificated under the normal category of 4a.
 
Last edited:
but...if you do it enough you become an expert. lol :cool:
Salty said:
Flying over gross won’t kill you, until it does. People do it every day and get away with it. We talk about some of the others here when the accident reports come out. Seriously though, it all depends on the situation. Some planes have a lot of wiggle room, others not so much. Are you qualified to know the difference?
Click to expand...
 
Most non trainer aircraft you can carry gas or folks, but not both. The long body Mooneys are a good example, they carry a LOT of gas, I think you can fly to Iceland and still have IFR reserves. But carry all that gas you can’t carry much else. You want to fill the seats, you leave some gas behind. Real pity, on half tanks you can only made it to Florida.
 
A certified plane is safe in that it was tested to almost all conceivable conditions within the certified envelope. You give up that guarantee of safety when you go outside the CG or weight. The test pilots that helped get the plane certified may know where those limits are, and why, but that will not be published in the POH. So you are on your own and are a poorly qualified test pilot. There have been 2 recent fatals in my area with prominent people that affect my life in so many ways that were over gross, and ran out of performance. In addition to putting a big black eye on general aviation, for those of us that fly "those dangerous little planes" reinforced when good people end up charbroiled in an aluminum oven. Just don't do it. It is a slippery slope that insidiously poisons the mind. 50 lbs today, 75 lbs tomorrow, what is an extra 100 lbs, until you hit that wake turbulence and accidentally and unexpectedly explore the performance envelope of the airplane. 200 lbs over, and lose a magneto or compression on one cylinder, what may have been flyable at GW is now a brick 200 over gross.
 
flyingron said:
Except there's far more than just being in Alaska. The operator has to show that all the stuff in (b) is met before the FAA will approve it. It's not just the case that you get an automatic 15% bump in gross weight if operating in the great white north.
Click to expand...
Yeah. Got that. Thought it was interesting the formulas they use to set the limits. They could be applied to any plane. Just the number crunching. The FAR makes it clear it doesn’t constitute approval and that there are other factors.
 
Last edited:
Rockymountain said:
A certified plane is safe in that it was tested to almost all conceivable conditions within the certified envelope.
Click to expand...
But the certified envelope involves a fairly limited set of conditions, so “almost all conceivable conditions within the certified envelope” is still fairly limited.
 
Racerx said:
Jesus! Who in their right mind can load up that much over and not even think it might not be too much?
Click to expand...
I have met many stupid pilots. One did a roll in a Cessna shortly after takeoff, at a scary low altitude. And he owned a flight school / FBO!
 
Some of you have come close, but no one has pointed out another factor: MGTOW in some aircraft has nothing whatsoever to do with the airplane and everything to do with bureaucracy.
There are a number of air frames out there that have different weight limits based on nothing more than how you register it and in what country you register it. Kitfox is a good example, So are many home built planes.
You can build the same kit as a part 103, light sport or even heavier.
The Jabirus were originally designed with 4 seats, take out 2 seats and it's a light sport. Will you die if you put 1420 lbs in it? Probably not.
Just don't get caught.
 
Ernesto Castro said:
What is not very clear is if a plane that at MTOW can do 1000 ft/min climb, it won't do even 500 ft/min if 10% overweight. As you all said, finding out that would be being a test pilot, as it would be operating outside the peformance charts.
Click to expand...
Or do the math.
 
I think of it as flexibility. If your normal mission involves taking passengers and baggage, then only fill it up with so many gallons of fuel. This will be your normal profile. But you have the ability to trade payload for range. Maybe you don't need that...maybe you will. All up to you. No one's telling you to just fill it up. So, to me, it's a good thing.
 
Flying UNDER weight can be scary sometimes...fly 100 lbs under on a hot hot day, for example.
 
Ernesto Castro said:
I'm a fairly new private pilot.

During training, and my flying afterwards I've always made my W&B and have always flown inside weight and cg limits.

How is that there are airplanes that can barely take a person when full of fuel? I'm looking at a Mooney M20k, with extended fuel tanks, that with full fuel it is just 170lb under MTOW.

Then in this 170lb you need to fit backpack, pilots clothes and pilots own weight.

I'm sure that an airplane like this most likely was never flown full of fuel or it has exceeded it's MTOW.

So, my silly question is: what's the deal with fyling heavier than MTOW? Apart from the fact that is ilegal...

As long as a CG is within limits, flying a 2900 lb airplane with a 200lb overweight, is that risky? Does people sometimes take off above max to weight?
Click to expand...

Think of the number of seats and tank size as flexibility rather than absolute capability. Just because you have the space in the tank, doesn't mean you should fill it up. Similarly, just because you have four seats doesn't mean you should carry four people. The mooney can't carry four people with full fuel, even without the extended range tanks.

You might be able to fly it over gross, but don't get used to it. This is the first link in the accident chain. Combine it with a hot summer day and a short runway, the outcome won't be good.
 
Ernesto Castro said:
Yeah, I understand the flexibility... what I don't understand is how useful is a plane that not even the pilot will fit! I mean, if it were an RC plane ok... but we are not in that buisness.

Again, we are talking about a plane that only has 170lb spare after full of fuel. Most average americans won't fit there. I am on the skinny side and weight 165lb... if I add my headset, ipad, kneeboard and my clothes I'm already over 170lb...
Click to expand...
How useful is a plane that can fly 10 straight hours and not have an occupant need a bathroom break?
 
Ernesto Castro said:
we are talking about a plane that only has 170lb spare after full of fuel.
Click to expand...
Is the 170 using aircraft original actual empty wt & balance figures or has the EWB been computed a number of times?
 
BTW, while most gross weight for most aircraft is a real value. For LSAs the gross weight is typically 1320lbs (due to LSA regulations) and the real design MTOW is much higher. Flying at gross or slightly
over 1320 in a LSA is a lot different then flight at gross in a 172 or 150.


Flying 100lbs over gross in a 172 = Illegal and Dangerous
Flying 100lbs over gross in a 162 = Illegal

This is easily seen with the Jabiru LSA which is a 4 seat aircraft in Australia and a 2 seat aircraft here with 2 seats removed.
 
Last edited:
Sometimes GW is based on other than climb and flight performance. For example, my Super D has MGW of 1800 lb. At GW it climbs like a frightened monkey. I cross the far end of my 4000' grass runway at 500' AGL or greater.

The max GW is based on drop tests and potential for prop strike on a hard landing. New stiffer gear upgrade ups MGW to 1950 lb.
 
Last edited:
Shepherd said:
Some of you have come close, but no one has pointed out another factor: MGTOW in some aircraft has nothing whatsoever to do with the airplane and everything to do with bureaucracy.
There are a number of air frames out there that have different weight limits based on nothing more than how you register it and in what country you register it. Kitfox is a good example, So are many home built planes.
You can build the same kit as a part 103, light sport or even heavier.
The Jabirus were originally designed with 4 seats, take out 2 seats and it's a light sport. Will you die if you put 1420 lbs in it? Probably not.
Just don't get caught.
Click to expand...
Yeah. I’ve been lookin around about the Jabiru J230D with just that in mind.
 
Racerx said:
How useful is a plane that can fly 10 straight hours and not have an occupant need a bathroom break?
Click to expand...

Some of us aren’t fat and can handle longer trips. I know for a fact I can currently do 4 hours without using the Gatorade bottle, and could probably do 8-10 with it if I planned my food the day before correctly. Would I use ALL of that gas frequently? No, but it makes the airplane more flexible. Leave out 7 gallons from the extended tanks and I’d have 50 pounds for baggage.
 
Ernesto Castro said:
Calculated using the most current W&B
Click to expand...
Perhaps this way may make more sense. Is this "most current" empty weight figure from an actual weighing of the aircraft? Or, are these "most current" figures the result of mathematical calculations of the empty weight after equipment changes? The reason is that aircraft have a tendency to gain weight when the empty weight is calculated vs actual weighing the aircraft. While it doesn't work in all cases, performing an actual empty weight and balance of the aircraft can regain that "lost" usable weight and possibly change your 170lb to 210lbs available.
 
Bell206 said:
Perhaps this way may make more sense. Is this "most current" empty weight figure from an actual weighing of the aircraft? Or, are these "most current" figures the result of mathematical calculations of the empty weight after equipment changes? The reason is that aircraft have a tendency to gain weight when the empty weight is calculated vs actual weighing the aircraft. While it doesn't work in all cases, performing an actual empty weight and balance of the aircraft can regain that "lost" usable weight and possibly change your 170lb to 210lbs available.
Click to expand...

This, totally this. You might or might not be shocked at how many 2-place taildraggers I’ve looked at before purchase that the owner acted like I was an idiot for asking for the current empty weight and even had more than two tell me to look it up on the TCDS. Seriously.
 
N747JB said:
I don’t recommend flying over gross, has it happened safely a lot if times, of course it has. BUT, max gross takeoff weight is there for safety! As you fly more, you’ll figure out that you almost never need full tanks. 5-6 hours of fuel is generally double the range of most bladders! It’s good to plan a fuel stop along the way, get out to stretch and pee!
Click to expand...
Yeah. Sometimes though, it might be nice to stop, take a whiz and grab a bite to eat without having to gas up.
 
You must log in or register to reply here.
Back
Top