Overloading Max Gross

[Alexb2000]

They do. The issue is how the planes are flown. The FAA trusts those professionals to stay within the reduced limits for such operations. They do not trust others the same.

The exact same individual "professional" is untrusted to fly over gross in Arizona, then he gets a transfer to Alaska, now he's trusted!

Come on man, even you have to chuckle at that one.

Have a drink, relax, if we can't laugh at some of this we'll all go crazy.

 

[Apache123]

Reasons for published max gross weight:

1) Structural issues
2) Desired performance numbers
3) Certification/marketing concerns

If you're going to exceed gross weight, it would help to know what the reason is. It seems that most wings fall off of airplanes when people are performing maneuvers that they aren't supposed to, though...

Not my fault if the passenger presses Z or R twice.

 

[bbchien]

Quite the contrary, perhaps I am being unclear. Why don't the laws of physics, mechanical engineering, and materials science apply equally to pilots flying for the department of the interior in Alaska as they do for pilots flying for the department of the interior in say Arizona? It really shouldn't be a hard question to answer if there is any technical basis for the difference in the FAR's.

If I've got it right, the wiaver is granted pretty much only to known commercial operators....it is pretty much at the FSDOs discretion.

On this point I could be incorrrect.
But one thing for sure, when you operate at military gross, the # of inspections and book life of many many parts is reduced.

 

[flyingcheesehead]

My own pponk 182 will happily carry 200lb over max gross without blinking. I learned these things over time.

How long have you been flying? And how long have you been flying that 182? Neither is what I'd call "over time"... You're a relative newbie. And just because the p-ponk 182 has LOTS of performance to spare doesn't mean it's OK to load 200 pounds over gross.

Not saying there isn't a physical change to an airplane, but find a make and model of airplane where you can't increase MGW. Sometimes it is very simple, sometimes its more complicated.

Well, if someone knows the engineering details behind the STC, maybe they can fly safely without it. Otherwise...

 

[bqmassey]

Even if it could be done safely, should I put my ticket on the line to save face for someone who lied to me? Uh. Nope.

Your mistake, perhaps, was in not expressing the seriousness of the matter when you asked for people's weights, and insisting that they be accurate numbers, not approximations. One thing I learned from the military is that peer pressure (mass punishment) is quite the motivator.

Implying that the trip might have to be called off at the last minute if someone is not honest or accurate and the plane ends up overloaded might be more effective than the safety approach.

If this happened on a flight I was making: Sorry guy, you lied, so we no longer have have room for two fatties on this airplane. I'm the pilot, so I'm the one that gets to go.

 

[bbchien]

Oh geez. Fuel density also changes with temps so hey, why don't we monitor that too so we can all pat ourselves on the back?

Fundamental confusion here. The absolute mass of the fuel remains the same. The space it takes up, changes. But it sounds like it's news to you, the MASS does not change.

Know your plane and how it functions. Then you won't need to worry so much. My answer to all this is "if its a new plane to me, I am more conservative until I learn its behavior and characteristics". My flying clubs 172 I won't load even to max gross cause it becomes sluggish heavy. My own pponk 182 will happily carry 200lb over max gross without blinking. I learned these things over time.

Uh, okay. I'll remember to never purchase a pponk 182 that used to live in Cal....I'm also sure that when you finally sell it, you'll advertise, "chronically flown 200 overgross..."...not.

Your argument boils down to, "I've never gotten hurt before, so it must be okay." We've already discounted that one. Keep it up. Pretty soon the mechanical fatigue will become apparent. I only buy runouts; the way my mech says it, "I can't tell you why this is just one worn out bird, but I'd advise against buying it...."

 

[docmirror]

I would, in my plane, but you shouldn't in any plane.

Here's my defense, weak though it may be:

1 The current engine installed puts out 21% more power than the engine installed from the factory.

2 The prop installed provides about 20% greater thrust at take off than the original prop installed from the factory.

3 The same airframe is given a 200lbs increase in gross weight the following year model.

4 The original specs for the airframe are designed to utility category up to max gross weight.

5 The gross weight is increased by 200lbs by adding tip tanks(yes, I know this is a wing loading analysis, but it's still 200lbs).

6 I've personally measured the performance at gross weight in the conditions given by the OP and found it to be not just acceptable, but outstanding with over 1100FPM with 10deg of flaps and full power. But, visibility over the nose is yuck.

Don't try this at home, your mileage may vary, objects in the mirror are larger than they appear, contents of box may have settled.

I realize and accept that the increased load of 50lbs for 50 flight minutes will shorten the life span of my spar due to the increased stresses on it(and related structure) so that now it will have a life span reduced from ~100,000 hours to something less, like ~80,000 hours of service(currently at 4200 hours).

 

[bbchien]

What type?

 

[docmirror]

Old Bonanza.

 

[wabower]

The point about GW being governed by paperwork limitations vs structural limitations is valid for many airplanes. In many cases it's simply driven by competition and marketing. "Oh, their new offering has 200# higher gross weight than ours? Stand by, I'll get the engineers on it today and will have an answer next week."

I would, in my plane, but you shouldn't in any plane.

Here's my defense, weak though it may be:

1 The current engine installed puts out 21% more power than the engine installed from the factory.

2 The prop installed provides about 20% greater thrust at take off than the original prop installed from the factory.

3 The same airframe is given a 200lbs increase in gross weight the following year model.

4 The original specs for the airframe are designed to utility category up to max gross weight.

5 The gross weight is increased by 200lbs by adding tip tanks(yes, I know this is a wing loading analysis, but it's still 200lbs).

6 I've personally measured the performance at gross weight in the conditions given by the OP and found it to be not just acceptable, but outstanding with over 1100FPM with 10deg of flaps and full power. But, visibility over the nose is yuck.

Don't try this at home, your mileage may vary, objects in the mirror are larger than they appear, contents of box may have settled.

I realize and accept that the increased load of 50lbs for 50 flight minutes will shorten the life span of my spar due to the increased stresses on it(and related structure) so that now it will have a life span reduced from ~100,000 hours to something less, like ~80,000 hours of service(currently at 4200 hours).

 

[bnt83]

The point about GW being governed by paperwork limitations vs structural limitations is valid for many airplanes. In many cases it's simply driven by competition and marketing. "Oh, their new offering has 200# higher gross weight than ours? Stand by, I'll get the engineers on it today and will have an answer next week."

I imagine the Cirus CAPS makes that a big more of a challenge.

 

[bbchien]

Old Bonanza.

Like a J model ?

 

[j1b3h0]

I have lived to regret taking off in a waay overloaded airplane - A twin Beech with probably 1000lbs too much mail - thanks US Post Office, I wont ever forget it. Ditto with out of CG. Took off in a heavy Metro 3 and was at the full down stop on the elevator trim before the gear was in the wells. Yikes! So, unless there's some really compelling reason to abandon the book numbers, uh, no.