How do you determine what a "safe" overweight condition is?

Hocky said:
So I've been looking at these CG envelopes. They always seem to be bounded by straight lines. Always. Are there any examples that are not? Any with curved lines (non linear)? So... then it would appear that assuming that the envelope continues linearly beyond the level of gross weight would be an excellent assumption.
Click to expand...

You'd better sit down and think some on that. Those charts are graphing weight and moment. If a CG stays the same as weight increases, the moment will also increase and you get a straight line. The boundaries of the box are to allow for the CG range.

Basic math, that.

Making assumptions is a good way to get killed. Excellent assumptions provide excellent ways to get killed. While flying over gross might be legal with certain permissions, and maybe even a bit safe under some conditions, it's not for low-time pilots. There are far too many other factors that come into play, as many other people here have pointed out. Furthermore, making a habit of violating such things often leads to violating other rules, and sooner or later it's going to cost you big time. I've known of too many guys who took chances and paid with their lives, and some managed to kill their friends as well.

It's all about attitude. Aviation is terribly unforgiving of a bad attitude.


Dan
 
Well said, Dan.

Of course the most sensible solution to figuring out how to carry more than the useful load of an aircraft is to

1. Reduce the load

Or

2. Elect to fly an aircraft with a larger useful load

No sensible pilot chooses

3. To fly illegally and possibly unsafely over MGW.

"Safe" and "is possible" are not necessarily synonymous. I have plenty of personal experience flying at or near legal MGW and was glad I had margin to cope with unexpected turbulence, wind shift, or downdraft on takeoff.

When I trained, my instructor had his students go up on a few occasions to fly at MGW so we could appreciate what that means. It's easy to do in a 2 seater, but requires an extra passenger in most 4 seaters. 2 extra pax are usually over MGW. Your instructor won't allow that.

It's not what you don't know that will kill you...it's what you know that ain't so...

Cheers.
 
Dan Thomas said:
It's all about attitude. Aviation is terribly unforgiving of a bad attitude.


Dan
Click to expand...

9437357014_17fcef4778.jpg
 
We won't be going over weight or out of balance to KOSH or anywhere. :nonod:

Everything will be weighed the best we can, and a weight and balance done on mine.

Smartphone apps are the way to go for having specific info about your plane and it's weight C/G condition at your fingertips imo. :redface:
 
Hocky said:
So I've been looking at these CG envelopes. They always seem to be bounded by straight lines. Always. Are there any examples that are not? Any with curved lines (non linear)? So... then it would appear that assuming that the envelope continues linearly beyond the level of gross weight would be an excellent assumption.
Click to expand...

You haven't looked at many envelopes then, besides a straight line can still be at an angle. Plenty of examples where the allowable CG shifts toward center with increasing weight.
 
Y'all should just admit that you're keeping this thread going just to see what the troll is going to say next. There's not much more enlightenment going on now than there was on page one. C'mon, 'fess up. This troll is pretty entertaining. Am I right?
 
tomf188 said:
Y'all should just admit that you're keeping this thread going just to see what the troll is going to say next. There's not much more enlightenment going on now than there was on page one. C'mon, 'fess up. This troll is pretty entertaining. Am I right?
Click to expand...

I'll admit it. If it wasn't for "trolls" then we'd be talking about sock change intervals and identifying turf grass.
 
tomf188 said:
Y'all should just admit that you're keeping this thread going just to see what the troll is going to say next. There's not much more enlightenment going on now than there was on page one. C'mon, 'fess up. This troll is pretty entertaining. Am I right?
Click to expand...

Gotta keep Jay amused.
 
N747JB said:
I won't say most people have flown 50 lbs over gross, but a lot of people have, whether they did it intentionally or not. :rolleyes2: Not every weight and balance is accurate, fuel gauges are notoriously inaccurate and almost every woman over the age of 12 will lie about her age and weight, most guys will just lie about their weight. :D
Pretty easy in a 182 to have 5 more gallons than you think, and the two extra quarts of oil and the step stool in the baggage area, add the 125 lb lady that is actually 135-140 a 10 lb flight bag that no one ever seems to account for in W&B and suddenly you are 100 lbs heavier than you thought. May put you over gross, it may not, but it has happened thousands of times with no negative consequences. BUT, it's still not a good practice and I personally verify that I am under gross on every flight!:D
I know you can weigh everyone and everything that goes into the airplane and that's a noble idea, just not a practice I see very often. :dunno:
Click to expand...

This is probably the most practical statement I have ever read on weight and balance. Truly real world. I commend you sir !
 
Hocky said:
So I've been looking at these CG envelopes. They always seem to be bounded by straight lines. Always. Are there any examples that are not? Any with curved lines (non linear)? So... then it would appear that assuming that the envelope continues linearly beyond the level of gross weight would be an excellent assumption.
Click to expand...

I haven't seen any with actual curved lines, but there are plenty that have multiple straight lines. for various weights. And I do mean more than the standard 5-line envelope.
 
Ref to Henning's post #311
I would like to suggest a slight correction:

Smoking rivets does not equal scrap airframe in one or two years. They do indicate areas that need attention and stress is one of the causes, but not the only cause.

Q: are there some rivets that are life limited? Simply remove the rivet, inspect the area, re-rivet and go?
 
Jaybird180 said:
Ref to Henning's post #311
I would like to suggest a slight correction:

Smoking rivets does not equal scrap airframe in one or two years. They do indicate areas that need attention and stress is one of the causes, but not the only cause.

Q: are there some rivets that are life limited? Simply remove the rivet, inspect the area, re-rivet and go?
Click to expand...

True, They are not the cause, but rather a symptom of an airframe that will likely need more repair than the value of the airframe will allow, hence making it scrap.

Smoking rivets from over stress typically have oblong holes. If they go beyond published oversized allowances, then a DER needs to get involved.
 
MAKG1 said:
There appear to be some real limitations related to turbochargers. I suspect the fully closed waste gate above the limit may result in undesigned operation.

A naturally aspirated 182 does not have this limitation. The service ceiling is performance related.

The bottom line is, read your POH.
Click to expand...

Often these limitations on altitude for turbo powered a/c are related to the possibility of flutter occurring due to the large change in Reynolds number reflected by the large difference between true and indicated a/s. It sometimes won't rear it's ugly head until it's put into thin air moving fast. Don't know about the Turbo Arrow but I've seen it applied that way for a cessna before. I think the 210 T/P or something of the like.
 
frcabot said:
What's the point? The fire was caused by riding the brakes (who ever thought that was a good idea) during an extended taxi at high power settings, not by being 60 lbs overweight.
Click to expand...

Very true, but the point you're looking for is that one problem (overweight) led to another because someone attempted to fix the first problem with a poor choice of technique.

Most accidents aren't attributable to a single failure. The Swiss-cheese concept explains it best:

pre-flight7.gif


Dan
 
Dan Thomas said:
Very true, but the point you're looking for is that one problem (overweight) led to another because someone attempted to fix the first problem with a poor choice of technique.

Most accidents aren't attributable to a single failure. The Swiss-cheese concept explains it best:

pre-flight7.gif


Dan
Click to expand...
If they had ridden the brakes 200 lbs or more underweight the same thing would have happened. The 60 lbs overweight was not a "problem" in the sense that the safety of the aircraft was jeopardized.
 
This is a good example of a case where if the pilot had just accepted being a small amount over in weight this accident would not have happened.
 
Hawka said:
This is a good example of a case where if the pilot had just accepted being a small amount over in weight this accident would not have happened.
Click to expand...
Especially since 60 lbs is about half a percent of the useful load of a Short 360.
 
Hawka said:
+1

You're reasonably safe up to 10% over in a pinch.
Click to expand...

Damn. I hope the OP doesn't read that or we will never hear the end of it. Fifty answers he didn't like he rejected. One person cautiously agreed with him and he said that was proof he was right.
 
JOhnH said:
Damn. I hope the OP doesn't read that or we will never hear the end of it. Fifty answers he didn't like he rejected. One person cautiously agreed with him and he said that was proof he was right.
Click to expand...

Oh no worries about that. He is gone. Left the building and locked out. :D
 
Hawka said:
+1

You're reasonably safe up to 10% over in a pinch.
Click to expand...


:rofl::rofl::rofl: Another sock puppet is born, welcome back.


I agree, in that case the 60lbs was not the problem, it was however indicative of the real problem, and that is the pilot was dumbass. 60lbs over, no worries, drag the brakes, no worries.

GW comes down to this: A team of engineers got together and figured in all the limiting factors, added in load factor variables, and set a weight that if used will minimize the chance you break the plane in a normal flight regime to very slim and you will be able to brief your T/O performance from the numbers generated in the testing. There are hundreds of individual factors to take into account to get this figure and a fairly large sum of money is spent in proving the number for certification.

If you want to violate those numbers, you are free to. You now become the engineer and test pilot who determines the new structural and performance limitations. This isn't overwhelmingly difficult for someone with a fabrication and aircraft maint & repair background as well as some time in the plane to know what kind of performance to expect, and can land the plane smoothly all the time.

Where you run into trouble with going over gross is when you kill someone and you survive, because that is where the insurance will look to hang you to dry. Insurance never worries about paying for damaged property, it's cheap. They don't like the million dollar payouts, and if you only have $100k per person coverage, you're ****ed anyway. You see, you're open to punitive damages, you are grossly negligent because you already proved by multiple examinations that you can accurately determine W&B, and the only reasons that you would leave over gross boil down to, "Knew better, Didn't Care," and that leaves you in a world of hurt.

So when we look at the 'safe' gross weight, we first have to determine all the hazards, physical and tort.
 
Henning said:
If you want to violate those numbers, you are free to. You now become the engineer and test pilot who determines the new structural and performance limitations.
Click to expand...

Not exactly true. When flying overweight you need to make sure you don't go anywhere the limits whereas a test pilot will be deliberately going near the limits.

The trick here is to evaluate the risks then make sure you operate the aircraft in a manner where you are still working with a reasonable margin with respect to the limits.
 
Hawka said:
Not exactly true. When flying overweight you need to make sure you don't go anywhere the limits whereas a test pilot will be deliberately going near the limits.

The trick here is to evaluate the risks then make sure you operate the aircraft in a manner where you are still working with a reasonable margin with respect to the limits.
Click to expand...

Well, you need to determine what all the limits are before you can make sure you don't go anywhere near them. Once you exceed the factory numbers, you have to develop your own. In order for them to be accurate, the factory breaks some planes, how would the typical operator determine theirs?

Remember this about people running over gross on ferry permits, they are only allowed required flight crew. This means the FAA doesn't think it's a good idea, but if you really want to, go ahead, they don't really care if you just kill yourself and maybe another pilot.
 
Henning said:
:rofl::rofl::rofl: Another sock puppet is born, welcome back.


I agree, in that case the 60lbs was not the problem, it was however indicative of the real problem, and that is the pilot was dumbass. 60lbs over, no worries, drag the brakes, no worries.

GW comes down to this: A team of engineers got together and figured in all the limiting factors, added in load factor variables, and set a weight that if used will minimize the chance you break the plane in a normal flight regime to very slim and you will be able to brief your T/O performance from the numbers generated in the testing. There are hundreds of individual factors to take into account to get this figure and a fairly large sum of money is spent in proving the number for certification.

If you want to violate those numbers, you are free to. You now become the engineer and test pilot who determines the new structural and performance limitations. This isn't overwhelmingly difficult for someone with a fabrication and aircraft maint & repair background as well as some time in the plane to know what kind of performance to expect, and can land the plane smoothly all the time.

Where you run into trouble with going over gross is when you kill someone and you survive, because that is where the insurance will look to hang you to dry. Insurance never worries about paying for damaged property, it's cheap. They don't like the million dollar payouts, and if you only have $100k per person coverage, you're ****ed anyway. You see, you're open to punitive damages, you are grossly negligent because you already proved by multiple examinations that you can accurately determine W&B, and the only reasons that you would leave over gross boil down to, "Knew better, Didn't Care," and that leaves you in a world of hurt.

So when we look at the 'safe' gross weight, we first have to determine all the hazards, physical and tort.
Click to expand...
Negligence is not enough for punitive damages (at least in most cases). It requires willful, malicious, etc. action in most cases (i.e., the actor intended the harm to befall the victim). Again, this varies state by state but the test in California, for example, is that there must be clear and convincing evidence that the defendant is guilty of fraud, oppression, or malice.

Negligence is required in the first place to find someone liable at all, except in specialized cases such as products liability which are sometimes subject to strict liability depending on the state (don't need to prove negligence). For example, if a patient died during surgery but the doctor did everything he was supposed to do and exercised ordinary care, he is typically not liable. Likewise, if a driver gets in an accident due to an act of god or the car had an unknowable defect or something, the driver is not liable. Similarly, if a pilot crashes a plane but the pilot wasn't negligent, did everything right, maintenance was up to date, etc. then the pilot isn't liable. These are all issues of proof, and the jury typically decides whether someone is or isn't negligent. It's certainly possible that a jury could say "you were negligent because you flew 60 lbs overweight), but there also has to be a causal connection between the accident and the alleged negligence. If the plane would have crashed regardless of the 60 lbs overweight, then I as a juror would probably conclude that the pilot was not negligent such that he should be liable for an accident. In any event, I think it would be unconscionable for an insurance policy to say that it wouldn't pay out if the pilot was negligent. I mean, the pilot is only liable in the first place if s/he is negligent...

Now, let's say the pilot neglects to perform W&B, takes off overweight on a hot summer day at 6000 ft DA altitude and isn't able to clear the tops of the trees, crashes and kills a couple young children or high earners who are passengers (or crashed into a bedroom window or something)?

Probably not enough for punitive damages but the pilot would certainly have been negligent, maybe even reckless. Compensatory damages in that case could well exceed $1m (figure the lifetime earnings of the person, loss of life, wrongful death, etc.). In that case the insurance will pay out the policy limits and the pilot is responsible for the rest. The remainder can usually be discharged in bankruptcy, but that means liquidation of any non-exempt assets, etc. This is all assuming the pilot survives in the first place. Otherwise, the estate will have to deal with it.
 
Last edited:
Darsh said:
He's just trying to ask questions that we all had as students. Only difference is that I was smart enough to ask someone who wouldn't call me an idiot for simple curiosity.
Click to expand...

Yeah, but with all the ultra polished egos here, how could any other answers result?
 
frcabot said:
Negligence is not enough for punitive damages (at least in most cases). It requires willful, malicious, etc. action in most cases (i.e., the actor intended the harm to befall the victim). Again, this varies state by state but the test in California, for example, is that there must be clear and convincing evidence that the defendant is guilty of fraud, oppression, or malice.
Click to expand...

We'll be sure to call you as an expert witness for the defence if we're ever dragged into court this way.

But even then, a defendant might win his case but be left with huge legal bills. Isn't that about the same thing as losing everything anyway?


Dan
 
Dan Thomas said:
We'll be sure to call you as an expert witness for the defence if we're ever dragged into court this way.

But even then, a defendant might win his case but be left with huge legal bills. Isn't that about the same thing as losing everything anyway?


Dan
Click to expand...
Insurance will pay legal bills. Insurance companies have a duty to defend. But it'll count against your limits. Your best bet is usually to settle regardless of fault. But if you have insurance you shouldn't worry too much. Insurers also have a duty to settle and if they refuse to settle for an amount at or within policy limits, and the judgment ends up being more, they will typically have to pay the whole thing including over limits as it would be a bad faith refusal to settle.

I'd be more worried about being dead if I'm ever in the situation where I'd have to defend a suit involving someone else's death where I'm the pilot.


The important thing is really making sure you're properly insured up to the amount of your net worth. If judgment comes in for more than that, declare bankruptcy. If less, insurance will cover. If you're a multi-millionaire, you should have a multi-million dollar liability policy or an umbrella policy that covers aviation activities (frankly I'm not sure if this even exists). Plaintiffs will not go after someone who is judgment proof.
 
Last edited:
Here is one to consider. A Cessna 172S stall-spin accident in Florida in 2008 killing all 4 on board. With a useful load of 862 lbs, the plane was carrying 808 lbs. not including fuel. That left 54 lbs for fuel (9 gallons), and with 56 gallons of fuel capacity, the aircraft was almost certainly overweight. Apparently it took off and flew just fine...

until it got low and slow. And then it didn't.

The stall warning horn was inoperative, so maybe the 3,000 hour pilot was focused on the airspeed indicator, making sure to keep it above stall speed. Of course the stall speed that he would have been relying on was based on an aircraft operating within its approved weight and balance envelope, which this one was not.

http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20080321X00349&key=1
 
flytime said:
Here is one to consider. A Cessna 172S stall-spin accident in Florida in 2008 killing all 4 on board. With a useful load of 862 lbs, the plane was carrying 808 lbs. not including fuel. That left 54 lbs for fuel (9 gallons), and with 56 gallons of fuel capacity, the aircraft was almost certainly overweight. Apparently it took off and flew just fine...

until it got low and slow. And then it didn't.

The stall warning horn was inoperative, so maybe the 3,000 hour pilot was focused on the airspeed indicator, making sure to keep it above stall speed. Of course the stall speed that he would have been relying on was based on an aircraft operating within its approved weight and balance envelope, which this one was not.

http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20080321X00349&key=1
Click to expand...

And how much does lets say a 5% increase in GW increase the stall speed?
Less than the width of the ASI needle, I'd say?
 
mtuomi said:
And how much does lets say a 5% increase in GW increase the stall speed?
Less than the width of the ASI needle, I'd say?
Click to expand...

Maybe. But being overweight could affect performance in unexpected ways. A power on turning stall can be a handful even when flying light.
 
Maybe the small overweight didn't cause the crash. But, as I said before, the attitude that leads a guy to deliberately fly overweight is the same attitude that will lead him to flout other regulations, and eventually he gets bitten.

Flying like that can't be called pilot error, either. Errors are innocent, inadvertent things that can cause accidents. Flying over gross isn't an error. Buzzing friends isn't an error. VFR into IMC isn't an error. Those are all deliberate. And the ensuing crashes aren't "accidents;" they are predictable payoffs for deliberate violations.

Dan
 
You must log in or register to reply here.
Back
Top