What's too Much Weight?

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lewy15

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lewy15
There was a thread on hear earlier talking about a student pilot and his large friends trying to takeoff in an Archer and haveing a little issue due to weight so that got me thinking....... How much is to much weight to take off. I learned to fly less than a year ago and have around 55 hours total in an Archer.

Obviously you're not supposed to be over the max gross weigth and have the CG in the envelope but what if your heavy by just a few pounds... Passenger(s) lies about their weight or their baggage.... What is too much weight? What if it's 5 pounds over? 50 pounds? 100 pounds?
 
Re: Whats to Much Weight?

More than 0 pounds over and you're a test pilot and probably uninsured. That's not to say that you'll immediately crash, but come on. Intentionally adding risk onto a flight? Not smart. Look up "hazardous attitudes" sometime. They're on the knowledge exam, so they're good to know. At 55 hours, you should be asking "how much below max gross should I be to be sure I and my friends will be safe?"
 
Re: Whats to Much Weight?

Depends on the conditions and multiple factors. A flight may be safe at 100% over gross, another flight may require you to only carry 20% useful load. It's your job as PIC to determine for every flight what load you can carry safely. Now, when you go above the certified weight, you take on responsibility and liability for a lot more parameters including engineering parameters.
 
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Re: Whats to Much Weight?

I probably should give the typical answer, max gross is max gross and should never be exceeded. But im bored, so the real answer is "it depends". FSDOs will give a waiver of 10% over max gross for virtually any conditions as long as you have a reason to be over gross, and all it takes is a phone call. Typically this is done so planes can carry enough fuel to cross oceans or get to an island.

Real world, you can expect a proportional loss of performance based on percentage over gross for climb rate (if your plane climbs at 600 fpm at gross under current conditions, you add 10% wieght, you lose approx 60-80fpm). Takeoff roll will suffer a little more than that though.

It's done all the time, and i would consider 10% of gross the limit, and only under favorable conditions, and only when there is no chance of getting caught (If an inspector sees four people getting out of a skyhawk, you will be ramp checked).

Ok bring on the flames!:D
 
Re: Whats to Much Weight?

This question comes up every so often.​

These pieces of history are usually included in the response:​


Piper asked Max Conrad to fly one of its new twin engine Apaches over the Atlantic. Conrad jumped at the chance but added that flying nonstop from New York to Paris might be better for publicity. In October 1954, Conrad took off from New York with 369 gallons of fuel on board. The airplane was 1,500 pounds over gross, but because it was a Max Conrad flight, the authorities believed that the long distance champ knew what he was doing.​


In June 1959 Conrad flew a Comanche 250 non-stop from Casablanca, Morocco to Los Angeles, a distance of 7,668 miles (12,268 km). When the aircraft took off from Casablanca, it was loaded 2,000 pounds (909 kg) over its production gross weight limit, demonstrating the ruggedness of the Piper design.

In 1964, Piper brought out a new plane called the Twin Comanche. Conrad quickly loaded one with 800 gallons of fuel and flew it nonstop from Capetown, South Africa, to St. Petersburg, Florida.​



If you're Max Conrad you can put as much as you want in the plane.
 
Re: Whats to Much Weight?

As others have noted, "it depends". Flying an airplane within the weight and CG limits (inside the envelope) gives you a reasonable expectation of how the airplane is going to perform. That's important when you're looking at trees at the far end of the runway.

But flying the airplane outside the envelope isn't a guarantee of death and destruction - it just means that you can't have those expectations anymore, and you're now a test pilot. Sort of like flying a non-deiced airplane into icing conditions - it probably won't fall right out of the sky, but nobody is PROMISING it won't either.

So it comes down to risk. If you fly overweight, you increase risk:
The airplane MAY perform quite differently than you expect.
The FAA WILL (if they find out) take action against you.

So the question is whether that risk is acceptable. As Ron says - if the savages are chasing you and your escape is an airplane, piling your whole family into that 172 with full fuel may be the better alternative to becoming savage stew. Giving fat Uncle Bob a ride is probably not worth it.
 
Re: Whats to Much Weight?

You lowlanders can probably get away with 10% over gross.

Here in the high-country a stock 160HP 172 shouldn't be flow near gross on a hot day. There have been more than a few cases of people loading a plane up (even within limits) and stall/mushing it into the ground off the end of the runway.
 
Re: Whats to Much Weight?

In these discussions, it's also usually said that exceeding gross weight is one thing, but CG limits should definitely be respected.
 
Re: Whats to Much Weight?

The answer is zero, and I can tell you exactly why. A really, really good friend of mine used to fly his Cherokee, basically the same aircraft as the Archer, in an over gross condition all the time. Stuffed it full of passengers and stuff. If it took off, it was good. He figured the same airframe got a larger engine and an increased payload, so he wasn't going to hurt it any. Insurance companies don't deny claims for stupid pilot tricks. They should, but they don't.

Then this good buddy started flying shorter strips with terrain in his travels. Having trees in his windshield made him acutely aware of what the aircraft could and couldn't do, and he doesn't fly over gross any more.

Me, last time I flew to Oshkosh I gave my passenger a weight allotment, and planned 10% under. I left a seat empty for a run to the islands, and while I was sad during the trip I was very happy during the takeoff from a short and very occluded strip. I was very careful to leave the aircraft under gross for our recent trip to Winwood. The high density altitude made that takeoff scary from the ground, and even scarier from the air. And that was under gross.

Plan for zero over gross and you're airplane will always do what the book says it can do. You'll never have any surprises. That's how you want it.
 
Re: Whats to Much Weight?

TMetzinger said:
Sort of like flying a non-deiced airplane into icing conditions - it probably won't fall right out of the sky, but nobody is PROMISING it won't either.
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Of course, nobody is promising a de-iced airplane won't fall out of the sky when exposed to icing conditions, either...

Weight is a funny thing. You can be over gross and still 100% legal with a ferry permit (as is frequently done for ferry flights to and from Hawaii as well as Europe). The legal answer is that any amount over gross without a ferry permit or other legal authorization is too much. However assuming you have a ferry permit, there are a few things to take into account:

1) Structural issues. The airplane needs to be able to structurally handle the extra weight. If you have a hard landing (which is more probable since the airplane's landing characteristics will be different) you may break something

2) Takeoff/climb performance. If you have enough power this probably isn't a big deal, but if you fly most aircraft on a hot day, you'll notice that they are not overpowered in the least when you get up to legal gross and a higher altitude. Max Conrad's takeoffs in the Apache must have been downright frightening.

3) Single engine performance. If you have a single engine plane this is less of an issue, but in a twin it is worth at least consideration. On a hot day at gross if you lose an engine on most piston twins you can end up just as badly off as in a single having lost an engine. Go over gross and the problem is compounded further.

There are more, but those are some of the considerations.

Phil Boyer and his wife flew their Cessna 340 probably 15 or 20 years ago (I'm unsure of the exact date) over to Europe on a personal trip. My friend has the DVD documenting the trip. One of the points they made was that with the extra couple hundred gallons of fuel on board (I forget the exact number) they were something like 800 lbs over gross. Keep in mind that a base 340 with full factory fuel has about enough leftover weight for two adults and their luggage, and they were two adults with enough luggage for traveling all of Europe, plus survival gear, and extra fuel. They had a ferry permit, so they were legal. However they also showed video of taking off out of Greenland in a strip that wasn't particularly long in the first place, and showed the plane basically hovering over the runway when they hit the end of it. They didn't go into the airspeed lost, and I don't think they did any sort of testing whatsoever as to single engine performance. Obviously they made it there and back safely, but they also had no problems. I've done several flights over the Gulf of Mexico heading to and from Cozumel, but one of the reasons that I'm comfortable with that is that the planes I fly have good single engine performance and would be able to get me to my destination if one of the fans quit spinning. If I was going to be flying over gross, I want to do some testing myself to make sure I was comfortable with the single engine performance in that configuration and knew I'd be able to make my destination. Just because I carry a life raft doesn't mean I want to use it.
 
Re: Whats to Much Weight?

And I myself would much rather utilize a life raft in the Gulf of Mexico than the North Atlantic. Talk about a scary trip.
 
Re: Whats to Much Weight?

steingar said:
And I myself would much rather utilize a life raft in the Gulf of Mexico than the North Atlantic. Talk about a scary trip.
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Shark bait vs. freeze to death. I'll take neither, and do my best to fly an aircraft that will take me to safety in the event of an engine failure.
 
Re: Whats to Much Weight?

Ted DuPuis said:
Shark bait vs. freeze to death. I'll take neither, and do my best to fly an aircraft that will take me to safety in the event of an engine failure.
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And I just won't fly over that much water. That way my airplane will take me to safety (or land, at least) in the event of an engine failure.
 
Re: Whats to Much Weight?

Can one obtain a ferry permit to test the overweight performance prior to a flight like the Boyer's ?
 
Re: Whats to Much Weight?

gprellwitz said:
Can one obtain a ferry permit to test the overweight performance prior to a flight like the Boyer's ?
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Maybe since it's not called a "Ferry Permit", rather a "Special Flight Permit" IIRC. The question becomes though can they require you to go into Restricted or Experimental-R&D categories?
 
No matter what my pax tell me (even me!), I always add 5 pounds when doing W&B. As for gear, I have a scale in the hangar for that.
 
Re: Whats to Much Weight?

NotSure said:
I probably should give the typical answer, max gross is max gross and should never be exceeded. But im bored, so the real answer is "it depends". FSDOs will give a waiver of 10% over max gross for virtually any conditions as long as you have a reason to be over gross, and all it takes is a phone call.
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I don't think it's quite as simple as you make it out to be, and when they do approve an over-MGW flight, they normally set restrictions to the operation. So don't get the idea that it's in any way guaranteed safe to operate 10% over MGW.
 
I remember reading about a Learjet that was delivering parts to Detroit.

They took off and the airplane seemed to wallow around a bunch. It was unable to climb to their initial filed cruise altitude. But they did make it to Detroit.

When they finally examined the load they discovered that they didn't have 2000 pounds of parts, but 2000 KILOS!
 
In my youth, I was a charter pilot utilizing a Turbo 206 on straight floats. We flew fishermen into Rivers Inlet Resort.
http://www.riversinletresort.com/
Notice the size of the fish! That was nothing compared to the size of the fishermen, who were all BIG.

Anyway, the deck hands thought it was real funny to slam the float compartments full of these 50-60 pound salmon. One had to watch them like a hawk. It was difficult enough to takeoff at max gross, especially when the big afternoon waves would come in.

Harrowing is more the word! I am sure that there were a couple of times when we were accidentally hundreds of pounds over gross. Hitting those big waves on takeoff pretty much submerged the airplane for a second. Water would hit the prop and a wall of water would hit the windshield.
 
Thanks for all the great posts. I'm planning a flight with some friends in a couple weeks thats about 140nm away. While doing the W&B we were about 25 pounds over weight and it got me wondering what would happen if you took off that heavy, i.e. wings fall off or never leave the ground, etc. Being that I'll be over I've already decided to drain some fuel to be under max gross weight as I won't need all 48 gallons to go 140nm.
 
lewy15 said:
Thanks for all the great posts. I'm planning a flight with some friends in a couple weeks thats about 140nm away. While doing the W&B we were about 25 pounds over weight and it got me wondering what would happen if you took off that heavy, i.e. wings fall off or never leave the ground, etc. Being that I'll be over I've already decided to drain some fuel to be under max gross weight as I won't need all 48 gallons to go 140nm.
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Personally I would probably opt to launch with 4 or 5 gallons less than full and be done with it.
 
lewy15 said:
I've already decided to drain some fuel to be under max gross weight as I won't need all 48 gallons to go 140nm.
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Good plan. And you don't have to drain with an Archer -- just fuel it only to the tabs the time before the flight. 36 gallons should be plenty (about four hours in an Archer), and you'll know just what you have as well as saving the cost of the drained fuel. You can do the same when you refuel at the other end. Line personnel are quite used to "tabs only" fuel requests.
 
lewy15 said:
Thanks for all the great posts. I'm planning a flight with some friends in a couple weeks thats about 140nm away. While doing the W&B we were about 25 pounds over weight and it got me wondering what would happen if you took off that heavy, i.e. wings fall off or never leave the ground, etc. Being that I'll be over I've already decided to drain some fuel to be under max gross weight as I won't need all 48 gallons to go 140nm.
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I wouldn't loose any sleep over 25lbs. There is 2x that much slop in all of the supposed weight measurements that went into your W&B. If you actually weighed your plane you'ld probably find it is nowhere near what is on the W&B form. I don't know what an Archer weighs so lets just say it is 4000lbs max gross; 25lbs is 0.6%! WoopDeeDoo
 
Baron2PG said:
I wouldn't loose any sleep over 25lbs. There is 2x that much slop in all of the supposed weight measurements that went into your W&B. If you actually weighed your plane you'ld probably find it is nowhere near what is on the W&B form. I don't know what an Archer weighs so lets just say it is 4000lbs max gross; 25lbs is 0.6%! WoopDeeDoo
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Wait, so you're saying that since he may already have more weight in the plane than he's accounting for that he should blithely add more?:eek: Sounds, shall we say, unwise!
 
The biggest thing is that it will creep up on you. Twenty-five lbs today, fifty tomorrow. You might get away with it forever. But if it bites, it will bite hard, fast, and permanently.
 
murphey said:
No matter what my pax tell me (even me!), I always add 5 pounds when doing W&B. As for gear, I have a scale in the hangar for that.
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Most pax who lie about their weight lie by a lot more than 5 lbs...
 
Ted DuPuis said:
Most pax who lie about their weight lie by a lot more than 5 lbs...
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Not all. As a student I was doing the W&B and used 135lbs for
the weight of my CFI. She told me she was 127 lbs.

I replied that I was just being conservative and ...

She cut me off and said that she was 127 lbs.

I said but...

She cut me off again and said that she was 127 lbs.

I took the hint.
 
Bob Noel said:
Not all. As a student I was doing the W&B and used 135lbs for
the weight of my CFI. She told me she was 127 lbs.

I replied that I was just being conservative and ...

She cut me off and said that she was 127 lbs.

I said but...

She cut me off again and said that she was 127 lbs.

I took the hint.
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Note I said "most."

If people are going to be ignorant enough to lie, they're probably going to lie by a lot. At least, that's been my experience.
 
Ted DuPuis said:
Note I said "most."

If people are going to be ignorant enough to lie, they're probably going to lie by a lot. At least, that's been my experience.
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Yep. I understand you said "most" and didn't mean to imply otherwise.... I was just saying that some don't lie.
 
gprellwitz said:
Wait, so you're saying that since he may already have more weight in the plane than he's accounting for that he should blithely add more?:eek: Sounds, shall we say, unwise!
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Sounds to me like he thinks it's on the - side of the +/- margin of error. In the recent weeks there have been several changes to my 310, generators replaced with alternators, new different props and a panel redo. When I get back to the plane, I'm going to have it weighed and see how close the calculations since the last weighing managed to get. I like having solid info.

As far as an extra 25 pounds of fuel being wise or unwise, I'd call it situational. In the CONUS it would rarely be wise because fuel is always in a reason distance that you can get most places with an endurance of an hour. If I was somewhere where that 5 gallons I was leaving behind was cutting into my trip reserves, I'd take the overgross any day. If I could potentially ship something, I may try to lose weight that way, but since far more planes fall out of the sky light and exhausted of fuel than over gross but running, the ods say take the extra fuel if you may need it.
 
steingar said:
The biggest thing is that it will creep up on you. Twenty-five lbs today, fifty tomorrow. You might get away with it forever. But if it bites, it will bite hard, fast, and permanently.
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Bingo. You either decide up front to play by the rules, or you take chances that are never certain. How would y'all feel if controllers took the same attitude regarding IFR separations standards? :hairraise:
 
Henning said:
Sounds to me like he thinks it's on the - side of the +/- margin of error. In the recent weeks there have been several changes to my 310, generators replaced with alternators, new different props and a panel redo. When I get back to the plane, I'm going to have it weighed and see how close the calculations since the last weighing managed to get. I like having solid info.
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Curious, what're you getting done to the 310 exactly? Only thing I've done to the one I fly is put the JPI in. We're also planning on adding some oil filters (engines have screens). Otherwise, it's a pretty nice plane as-is, but has also had a lot of work done on it prior to my first flight in it.
 
So how would an airliner compute weight and balance with regards to the weight of the passengers. I've never been asked for my weight when boarding, or do they have a random number say a 275 pound average and hope that the average weight of the passengers is less than that:crazy:.
 
lewy15 said:
So how would an airliner compute weight and balance with regards to the weight of the passengers. I've never been asked for my weight when boarding, or do they have a random number say a 275 pound average and hope that the average weight of the passengers is less than that:crazy:.
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The number isn't random -- it's based on FAA studies of actual passenger weights, and it was kicked up a good bit a few years ago after this accident. Here are the numbers:


TABLE 3-1. STANDARD AVERAGE PASSENGER WEIGHTS Standard Average Passenger Weight​

Weight Per Passenger ​
Summer Weights
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Average adult passenger weight [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]190 lb [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Average adult male passenger weight [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]200 lb [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Average adult female passenger weight [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]179 lb [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Child weight (2 years to less than 13 years of age) [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]82 lb [/FONT][/FONT]​
Winter Weights
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Average adult passenger weight [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]195 lb [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Average adult male passenger weight [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]205 lb [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Average adult female passenger weight [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]184 lb [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]Child weight (2 years to less than 13 years of age) [/FONT][/FONT]​
[FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT][FONT=AJKPBF+TimesNewRomanPSMT,Times New Roman PSMT]87 lb [/FONT][/FONT]​
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Note that these numbers include 16 lb of carry-on baggage. The FAA has determined that for the relatively large numbers of people in an airliner at MGW, the laws of probability provide sufficient safety margin. See AC 120-27D (page 21) for the details for air carrier operations. They also have numbers for them to use for baggage weight -- see that same AC, next page.

OTOH, with two or three people in a 2400 lb airplane, the FAA says the law of averages isn't good enough, and requires us to use actual weights.
 
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FWIW when i was flying Pt. 135 our op specs required us to add 10 lbs to given weight. i've heard of other 135 op specs that required adding 10 lbs under 200 and 20 lbs if given was over 200.
 
tonycondon said:
FWIW when i was flying Pt. 135 our op specs required us to add 10 lbs to given weight. i've heard of other 135 op specs that required adding 10 lbs under 200 and 20 lbs if given was over 200.
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My three years' experience flying light plane 135 suggests that's a good idea.
 
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