Flying Over Gross

[bbchien]

I have been thinking about this gross weight stuff alot. I have a Pitts S-2c. Empty is real close to 1300 and gross is 1700. That leaves 400 useful. You get a 200 pound pilot and 24 gallons that leaves you just over 50 pounds for the front passenger and 2 parachutes. It burns close to 20 Gph so you don't go with a half tank. Now how do you stay under gross? No possible way. There are numerous guys that do aerobatic and spin training in these airplanes everyday. How?

The S2C is not inetended to be a trainer. It only is, if you weigh 130. I agree that extra seat is like the fourth seat in a Cessna 172. That said, not all of us weigh 200.

But for basic training you use a Citabria.
Then you graduate to the S2c and work the rest out on your own.

 

[pigpenracing]

Ha!
If you train in a Citabria and jump in a S-2C you will probably kill yourself. The S-2C is a trainer. I had 50 hours in my decathlon and if I would have not had a instructor on my first biplane trip I probably would not have made it without wrecking. First the extra power was a big deal on the runway and second being blind is a bigger deal.
Have you flown a Pitts Bruce?
I think alot of airline guys do their spin checkout in the Pitts. I bet its overweight also....

 

[flyingcheesehead]

what happens when you fly over gross weight?

Depends on the airplane. There are a number of factors that go into determining MGW on certified aircraft - Structural, performance, etc. etc.

Assuming you don't break the airplane, here's a few things that will change:

1) You need to stay within CG limits, and those are shrinking at higher weights - Extending the lines straight is a start, but some planes will require even more restrictive limits above max gross - And you don't know what those are.

2) Many of your airspeeds - Vs0, Vs1, Vg, and maybe Vx and Vy, will increase by the square root of the ratio of the actual weight to the max gross weight, just like how they go down when you're flying at less than max gross.

3) Some of the high-end speeds such as Vno and Vne should be reduced.

4) Climb rate will be drastically reduced. There's a formula you can use to determine how much, but I don't have it handy right at the moment.

So, there you have it - An actual answer to the question. There are a lot of other things to know if you want to attempt it safely, though, most important of which is why the max gross weight was set where it was in the first place - What's the limiting factor? Since you're unlikely to get that information from Cessna, Piper, etc. you're on your own. Tread carefully.

 

[bbchien]

Ha!
If you train in a Citabria and jump in a S-2C you will probably kill yourself. The S-2C is a trainer. I had 50 hours in my decathlon and if I would have not had a instructor on my first biplane trip I probably would not have made it without wrecking. First the extra power was a big deal on the runway and second being blind is a bigger deal.
Have you flown a Pitts Bruce?
I think alot of airline guys do their spin checkout in the Pitts. I bet its overweight also....

Power is not a problem. I solo'd in a D17 in 1969. I had about 12 hours in my logbook. It was all I could afford to fly, they were all considered JUNK back then.

Someone just has to tell you, and you have to listen up. If you don't listen up, and you end up in the weeds, well it's your fault. And if you can't listen up, that IS a problem.

And, Well, that's exactly how I did it.

YOU'RE trying to make the point that overgross is okay. Well, routine busting of the engineering limits is not so okay. In the P3 we flew at mil gross pretty frequently- but the chiefs had a different inspection schedule, a different IRAN schedule, and we got good instruction. And if you demonstrated that you couldn't listen and carry out, you got removed.

If you fly consistently overgross saying "everyone does it" I certainly don't want to go anywhere near your bird, and CERTAINLY not below it. Ever seen a Citab that's been consistently snaprolled AT gross (It's certified for that)? Not a pretty tail inspection, for sure. So how is the Pitts any different?

 

[pigpenracing]

I am not at all saying it is ok and go do it. What I am saying is I own a S-2C and useful load is 400. I am also saying Pitts instructors train dual everyday. I am asking how they can do it?
A D17 is a bit difference than flying a Pitts. Why you think the main people who crash Pitts are airline pilots. They think just because they fly a jet and have 10,000 hours a little Pitts is nothing. LOL!
Go to the biplane forum and post you just bought a Pitts and plan to fly with no dual. See what they say. I had a guy a month ago that I helped buy a S-1. He was going to hop in and fly. I told him you better get some dual and he listened.
He called after flying a S-2B with and instructor and thanked me. He said he would have never made it off the ground. The next day he flew the S-1 solo and said after he took off he thought he would never get it back on the ground alive.
You should go fly a S-2C dual. It is a eye opener if you have not done it.

 

[Dave Krall CFII]

Not really. I really want to come out there and fly. Can I bring my dad out and take him on a couple day to couple week trip in the Highlander?

Yes Really. It's true what you say about kinetic energy and engine out landings, just how often are you forced into those?

PM me status on your SES PIC hours, accident/incident history, medical class, and the two weights.

 

[NineThreeKilo]

It happens, real world.


Now for flight training, it's a no, no.

Ask the ferry guys, or some of the folks up north or over in Africa

Personally I avoid it, especially in welfare states like CA, too many state workers with ticket books and nothing else to do.

Also not the greatest thing to do to your airframe, I've never flown my own plane more then 70 or 80% of its max gross.

If you do go over, keep the CG out of the tail, I'd rather be over gross then have a bad CG. Also if you're heavy have a go/no go point at the field, the 50%/70% rule works

At the halfway point of the runway (pick something to identify this point), if you arn't at 70% of rotation speed, abort.

 

[Dr. O]

In the freight running days of my wasted youth we were never much concerned about weight - as long as we felt the runway was long enough to take off. If the doors would close, we were good.
We were more careful about CG however. Being out of balance for 4 or 5 hours in the clouds and turbulence was something you only did once - at least voluntarily.

However if something can go wrong it will. Steve (not me thank goodness) let the ramp monkeys load the Aztec late one night and did not check how it was strapped down. He was way over gross of course (SOP) and the old girl eased her way off the ground without a lot of runway left over - hot July night.
On rotation there was turbulence and suddenly the ship pointed at the sky. Steve has been around awhile so he stuffed the yoke hard forward and kept throttle and props hard against the stops. Gradually the nose came down and he called the tower and announced he was going around.
He said he had to keep the yoke right against the panel and full takeoff power the whole way around in order to keep the nose down. He did not put on flaps (pitch up) and did not pull the throttles until the wheels touched. When the tires contacted the runway, it wasn't a chirp but a prolonged scream of smoking rubber as the tires tried frantically to catch up with the concrete whizzing past. He used up the whole runway at Detroit City getting stopped and both the tires and the brakes were smoking.
Anyway, the ramp monkeys had put the heaviest box on top of the load instead of on the floor. The turbulence had snapped the one lousy little strap they put over it and the box slid back sending the nose of the ship to the moon. He nonchalantly made them reload the boxes the proper way and took off again.
Later in the week the boss (Steve's dad) was grumbling about having to put new tires on the old girl - "I thought we just changed these tires a few months back when we did the brake pads?"
Steve just shrugged and said "Must be a bad batch of rubber."
He never told dad about not checking the load before taking off.

 

[Fearless Tower]

However if something can go wrong it will. Steve (not me thank goodness) let the ramp monkeys load the Aztec late one night and did not check how it was strapped down. He was way over gross of course (SOP) and the old girl eased her way off the ground without a lot of runway left over - hot July night.
On rotation there was turbulence and suddenly the ship pointed at the sky. Steve has been around awhile so he stuffed the yoke hard forward and kept throttle and props hard against the stops. Gradually the nose came down and he called the tower and announced he was going around.
He said he had to keep the yoke right against the panel and full takeoff power the whole way around in order to keep the nose down. He did not put on flaps (pitch up) and did not pull the throttles until the wheels touched. When the tires contacted the runway, it wasn't a chirp but a prolonged scream of smoking rubber as the tires tried frantically to catch up with the concrete whizzing past. He used up the whole runway at Detroit City getting stopped and both the tires and the brakes were smoking.
Anyway, the ramp monkeys had put the heaviest box on top of the load instead of on the floor. The turbulence had snapped the one lousy little strap they put over it and the box slid back sending the nose of the ship to the moon. He nonchalantly made them reload the boxes the proper way and took off again.
Later in the week the boss (Steve's dad) was grumbling about having to put new tires on the old girl - "I thought we just changed these tires a few months back when we did the brake pads?"
Steve just shrugged and said "Must be a bad batch of rubber."
He never told dad about not checking the load before taking off.

Sounds like he got lucky.

Sometimes the 'get 'er done' attitude gets folks killed in the freight hauling world.

If you do some searching, you'll see a video of a carrier C-2 launch where the load shifted. Airplane shot up to the sky and then stalled and spun in - all killed.

Background story is the first Aircraft Commander saw the load and refused to fly it. Another pilot comes along and says - 'we can do this'. Got himself and his crew killed.

 

[HerrGruyere]

That sweet story about the incorrectly loaded plane was a good example of how vastly the CG can affect flight characteristics.

Depends on the airplane. There are a number of factors that go into determining MGW on certified aircraft - Structural, performance, etc. etc.

Assuming you don't break the airplane, here's a few things that will change:

1) You need to stay within CG limits, and those are shrinking at higher weights - Extending the lines straight is a start, but some planes will require even more restrictive limits above max gross - And you don't know what those are.

2) Many of your airspeeds - Vs0, Vs1, Vg, and maybe Vx and Vy, will increase by the square root of the ratio of the actual weight to the max gross weight, just like how they go down when you're flying at less than max gross.

3) Some of the high-end speeds such as Vno and Vne should be reduced.

4) Climb rate will be drastically reduced. There's a formula you can use to determine how much, but I don't have it handy right at the moment.

So, there you have it - An actual answer to the question. There are a lot of other things to know if you want to attempt it safely, though, most important of which is why the max gross weight was set where it was in the first place - What's the limiting factor? Since you're unlikely to get that information from Cessna, Piper, etc. you're on your own. Tread carefully.

Thanks! That was informative. Made me realize that I will likely never risk my or my friends' lives to give a ride in a plane. I don't want to be a test pilot.

 

[Henning]

Ha!
If you train in a Citabria and jump in a S-2C you will probably kill yourself. The S-2C is a trainer. I had 50 hours in my decathlon and if I would have not had a instructor on my first biplane trip I probably would not have made it without wrecking. First the extra power was a big deal on the runway and second being blind is a bigger deal.
Have you flown a Pitts Bruce?
I think alot of airline guys do their spin checkout in the Pitts. I bet its overweight also....

Having AgCat and other biplane time, I just don't get the attraction. All the visibility disadvantages of a high and a low wing...

As I said before, I'd be more concerned about CG than a few extra pounds, however make sure you land with your 'A' game on, that extra weight ain't gonna working in stabilities favor, she could try to buck you for the overload if you're not nice, and extra weight on a ground loop will add to the chances and severity of damage. It will also lead to a violation quite likely.

 

[Jaybird180]

In the freight running days of my wasted youth we were never much concerned about weight - as long as we felt the runway was long enough to take off. If the doors would close, we were good.
We were more careful about CG however. Being out of balance for 4 or 5 hours in the clouds and turbulence was something you only did once - at least voluntarily.

However if something can go wrong it will. Steve (not me thank goodness) let the ramp monkeys load the Aztec late one night and did not check how it was strapped down. He was way over gross of course (SOP) and the old girl eased her way off the ground without a lot of runway left over - hot July night.
On rotation there was turbulence and suddenly the ship pointed at the sky. Steve has been around awhile so he stuffed the yoke hard forward and kept throttle and props hard against the stops. Gradually the nose came down and he called the tower and announced he was going around.
He said he had to keep the yoke right against the panel and full takeoff power the whole way around in order to keep the nose down. He did not put on flaps (pitch up) and did not pull the throttles until the wheels touched. When the tires contacted the runway, it wasn't a chirp but a prolonged scream of smoking rubber as the tires tried frantically to catch up with the concrete whizzing past. He used up the whole runway at Detroit City getting stopped and both the tires and the brakes were smoking.
Anyway, the ramp monkeys had put the heaviest box on top of the load instead of on the floor. The turbulence had snapped the one lousy little strap they put over it and the box slid back sending the nose of the ship to the moon. He nonchalantly made them reload the boxes the proper way and took off again.
Later in the week the boss (Steve's dad) was grumbling about having to put new tires on the old girl - "I thought we just changed these tires a few months back when we did the brake pads?"
Steve just shrugged and said "Must be a bad batch of rubber."
He never told dad about not checking the load before taking off.

Unless you used Mark-1 IBall, you can't check CG without knowing weight of the load. If you went that far, may as well know weight and at least you know what % over you are.

 

[flyingcheesehead]

If you do some searching, you'll see a video of a carrier C-2 launch where the load shifted. Airplane shot up to the sky and then stalled and spun in - all killed.

Background story is the first Aircraft Commander saw the load and refused to fly it. Another pilot comes along and says - 'we can do this'. Got himself and his crew killed.

This one?

 

[flyingcheesehead]

Also if you're heavy have a go/no go point at the field, the 50%/70% rule works

At the halfway point of the runway (pick something to identify this point), if you arn't at 70% of rotation speed, abort.

Better go with 75% of speed - You need 70.71% if you started EXACTLY on the very edge of the pavement at the beginning of the runway and you're going to reach takeoff speed just in time to lift off from the very edge of the pavement at the other end of the runway.

Better yet, also know how much runway it's going to take to abort, and if you're not off by then, abort.

DA and weight will both have a large effect on takeoff acceleration and climb performance.

BTW, one example of extreme overgross operation: Max Conrad flew a Comanche 250 loaded to around DOUBLE its certified max gross weight with fuel, and flew nonstop from Casablanca (Morocco, NW Africa) to Los Angeles. IIRC, it took him most of 8,000 feet to get airborne.

 

[Fearless Tower]

Unless you used Mark-1 IBall, you can't check CG without knowing weight of the load. If you went that far, may as well know weight and at least you know what % over you are.

I think that is what he is saying. They didn't care how much over gross they were as long as they were within CG.

 

[Henning]

In the freight running days of my wasted youth we were never much concerned about weight - as long as we felt the runway was long enough to take off. If the doors would close, we were good.
We were more careful about CG however. Being out of balance for 4 or 5 hours in the clouds and turbulence was something you only did once - at least voluntarily.

However if something can go wrong it will. Steve (not me thank goodness) let the ramp monkeys load the Aztec late one night and did not check how it was strapped down. He was way over gross of course (SOP) and the old girl eased her way off the ground without a lot of runway left over - hot July night.
On rotation there was turbulence and suddenly the ship pointed at the sky. Steve has been around awhile so he stuffed the yoke hard forward and kept throttle and props hard against the stops. Gradually the nose came down and he called the tower and announced he was going around.
He said he had to keep the yoke right against the panel and full takeoff power the whole way around in order to keep the nose down. He did not put on flaps (pitch up) and did not pull the throttles until the wheels touched. When the tires contacted the runway, it wasn't a chirp but a prolonged scream of smoking rubber as the tires tried frantically to catch up with the concrete whizzing past. He used up the whole runway at Detroit City getting stopped and both the tires and the brakes were smoking.
Anyway, the ramp monkeys had put the heaviest box on top of the load instead of on the floor. The turbulence had snapped the one lousy little strap they put over it and the box slid back sending the nose of the ship to the moon. He nonchalantly made them reload the boxes the proper way and took off again.
Later in the week the boss (Steve's dad) was grumbling about having to put new tires on the old girl - "I thought we just changed these tires a few months back when we did the brake pads?"
Steve just shrugged and said "Must be a bad batch of rubber."
He never told dad about not checking the load before taking off.

I had that once in my buddies 185 I took to go down to the Gulf to get some shrimp. The shrimp and ice shifted on take off in some turbulence and I had to get my left knee involved as I told the girl that was with me to start shoveling it forward as fast as she could. She did and we got back in trim and up to St Louis with the 4th's picnic shrimp. He said that plane stank all the way to winter. luckily it had a jump door and interior.

 

[Fearless Tower]

I had that once in my buddies 185 I took to go down to the Gulf to get some shrimp. The shrimp and ice shifted on take off in some turbulence and I had to get my left knee involved as I told the girl that was with me to start shoveling it forward as fast as she could. She did and we got back in trim and up to St Louis with the 4th's picnic shrimp. He said that plane stank all the way to winter. luckily it had a jump door and interior.

Ernie Gann had a similar story of a load shift taking off in a DC-3 during the war. Fortunately for them, the crew chief was in the back hauling the steal beams forward while both pilots pushed forward on the controls with all their might.

 

[wabower]

Some friends did it to themselves without moving anything. One guy came up with the weight of a box of shotgun shells, the other guy did the W&B arithmetic. His only mistake was that he forgot that a case of shells includes more than one box. They were all stuffed in the very back of an extended bag compartment.

They made it around the pattern without bending anything but neither was happy after they landed.

 

[poadeleted20]

It was covered in my course
And I think it's in the Jepp course too....

Perhaps so, but to my thinking, it's superfluous, and I'm pretty sure it's not in either the written test question bank or any Area/Task of the PP PTS. Since you're not allowed to use standard average weights without special FAA approval, there's just no point to it.

But if you want to learn more about this, see AC 120-27E.

 

[alaskaflyer]

I'm not sure of the regs, and not going to look it up but I think I recall that if you fly in AK you get an automatic bump in gross. Maybe 10% or something? So if you're gross in the lower 48 were 2600#, you could legally take off at 2860 in AK.

Also, one more in the strange file for the early Bonanza. The first ones came out of the factory with 185 or 196HP. They were also certified to max gross at utility category. The factory allowed, and even encouraged early plane owners to upgrade the engine to 225HP, a nice boost of 40HP or about 13-20%. If a Bonanza owner can tolerate the lower level of certification to normal category when overgross it would be a minimal issue to operate over gross. Sadly, when Beech authorized the increased power, they didn't go the extra distance and cost to up the gross weight. As for the loading, it's a simple matter of jacking the loading graph 260#, the curves remain the same.

That Alaska-specific regulation is very narrowly tailored for certain commercial operations requiring specific items in the company's opspec, which I would guess are roughly analogous to military procedures under higher GWL's.

Back to the OP, I am by no means well informed on aircraft certification but I know that for Cessna one parameter for establishing gross weight is balked landing performance at different landing configurations. This is an area that could potentially bite the pilot flying over gross intentionally or carelessly. Like most violations of the regulations everything will be fine while toodling along well inside normal flight envelopes...until it isn't and you are forced to replicate the manufacturer's testing results on a go around, or slow flight, or steeper crosswind components, or a bank angle that SHOULD be ok or...or...

Then it bites you.

In my airplane, at gross, on a warm day or at altitude, with flaps forty, a go around initiated from near VSO is...illuminating. I don't want to imagine what it is like with a stock engine and prop.

 

[Alexb2000]

Short of carrying a precision scale everywhere you go and offending every woman that flies with you...

How about just learning your bird like it was a part of your body?

IMO you should be able to feel CG and weight in a small aircraft to a degree accurate enough to judge basic safety. I know instantly if my CG is off just by the feel of the elevator or how the nose wheel taxis. Weight is apparent almost instantly on the roll. If it feels too heavy and doesn't want to fly, put it back down. If I do fly heavy, I fly in a way that is as easy on the airframe as possible. Basicially, if it doesn't feel right don't push it, use common sense.

I'm not advocating flying by the seat of your pants as a primary means of determining CG and load, but any pilot should be able to use it as a double check when these things are nearing the limit (personal, published, or paid for).

 

[poadeleted20]

Short of carrying a precision scale everywhere you go and offending every woman that flies with you...

If you fly 135, you may not have any other choice. And one can, if resourceful and imaginative, find polite ways to do this without offending one's passengers.

 

[N801BH]

What happens is you become a test pilot. Legallity aside, this time of year, given suffuicient runway and low DA, you probably would have been able to takeoff and land safely....although landing overgross could overstress the airframe. Most folks who get FAA paperwork to exceed gross for overseas ferry operations land well under gross due to fuel burn enroute.

Bottom line is that your performance will be degraded, but how much? You'll get to find out since you are playing the test pilot.

All you guys with certified aircraft have the luxury of a thoroughly tested airframe with documented specs for weight and balance and most all other "quirks" that will happen......

Us experimental guys get to do the whole kit and kabootle... On my Zenith, the factory gives us a "suggested" CG to shoot for.. Then some idiot comes along and more then doubles the HP and installs a powerplant within 3 lbs of the recommended firewall forward weight. I literally wore out several sand bags and spent 30 hours investigating the total envelope of my particular airframe.. I now know the max forward and aft CG range and I think I know the max loading I can carry.

Pushing the ragged edge of the envelope will cause gray hairs to sprout out of your head, REAL fast.. As scary as some of the tests went, I am a better pilot because of it... and.......... I have a whole new respect for test pilots.... That job can get deadly in about 0.3 seconds.

 

[wabower]

I've flown 135 off-and-on since the 90's and have never needed to weigh pax or bags. Weights are handled as part of the opspec. Count the heads, multiply by the constant, kick the tires and light the fires.

If you fly 135, you may not have any other choice. And one can, if resourceful and imaginative, find polite ways to do this without offending one's passengers.

 

[denverpilot]

Some friends did it to themselves without moving anything. One guy came up with the weight of a box of shotgun shells, the other guy did the W&B arithmetic. His only mistake was that he forgot that a case of shells includes more than one box. They were all stuffed in the very back of an extended bag compartment.

They made it around the pattern without bending anything but neither was happy after they landed.

There's something to be said for checking any arithmetic against "does that seem right?"

Neither thought 5 lbs was weird for something they had to grunt to lift?

 

[HighFlyingA380]

I'll be honest, I didn't read the whole thread, but here's my take on it:

Even at the 170lbs, assuming you had a few thousand ft. of runway and didn't do any yankin' and bankin', you'd never have known the difference. Sure, a bit longer t/o roll and a bit less performance, but not anything drastic.

Unfortunately, I've experienced this first-hand, flying a 172P more than 200lbs over MTOW in a high-altitude/high-DA/mountainous terrain scenario. (No, I wasn't PIC.)

DON'T MISUNDERSTAND ME, I'M NOT ADVOCATING DOING IT, AND I WOULD NEVER DO IT AGAIN. Just pointing out that as long as you're within balance, a little extra weight generally won't be the difference between life and death.

 

[wabower]

Most of my friends (along with me) were in the half of the class that made the top half possible.

There's something to be said for checking any arithmetic against "does that seem right?"

Neither thought 5 lbs was weird for something they had to grunt to lift?

 

[Dave Krall CFII]

All you guys with certified aircraft have the luxury of a thoroughly tested airframe with documented specs for weight and balance and most all other "quirks" that will happen......

Us experimental guys get to do the whole kit and kabootle... On my Zenith, the factory gives us a "suggested" CG to shoot for.. Then some idiot comes along and more then doubles the HP and installs a powerplant within 3 lbs of the recommended firewall forward weight. I literally wore out several sand bags and spent 30 hours investigating the total envelope of my particular airframe.. I now know the max forward and aft CG range and I think I know the max loading I can carry.

Pushing the ragged edge of the envelope will cause gray hairs to sprout out of your head, REAL fast.. As scary as some of the tests went, I am a better pilot because of it... and.......... I have a whole new respect for test pilots.... That job can get deadly in about 0.3 seconds.

What is the recommended FWF wt?

 

[flyingcheesehead]

How about just learning your bird like it was a part of your body?

IMO you should be able to feel CG and weight in a small aircraft to a degree accurate enough to judge basic safety. I know instantly if my CG is off just by the feel of the elevator or how the nose wheel taxis. Weight is apparent almost instantly on the roll. If it feels too heavy and doesn't want to fly, put it back down. If I do fly heavy, I fly in a way that is as easy on the airframe as possible. Basicially, if it doesn't feel right don't push it, use common sense.

That sort of intuition can only come from experience - The first couple dozen hours in a new airframe, at least, will have to be done accurately on paper. Once a pilot has a decent amount of experience with the airplane and has flown it with several different weights and CG's, then they can start to develop a feel for the airplane like you're describing.

One thing I like to do is calculate scenarios for all the corners of the CG envelope. For example, I know that in the 182 there is *NO WAY* I can load it out of CG - With me in the front, if I load the baggage compartment to limits I'm still inside the aft limits, and I can put me plus a 350-pound buddy in the front seats with nothing in the back or baggage and still be (just) inside the front limits. I spent an hour or two calculating various loading scenarios to see what it would take, and that was my result. However, I also know that the Diamond may be out the forward limit if I have another above-FAA-average person in the right seat, but will be back within if I put either any person in the back seat, or 15 lbs in the aft baggage.

Long story, uh, long, those calculations will help develop the pilot's sense of what will and won't work, and experience with the airframe will give them the extra feel for the plane that'll give them another alert that things aren't normal.

 

[denverpilot]

Most of my friends (along with me) were in the half of the class that made the top half possible.

LOL!

I have met far too many "academic geniuses" who can't figure out how to design things that work in the real world, in computers...

So them being at the top of the bell curve as measured by 'education' isn't always all it's cracked up to be, either.

 

[denverpilot]

For example, I know that in the 182 there is *NO WAY* I can load it out of CG - With me in the front, if I load the baggage compartment to limits I'm still inside the aft limits, and I can put me plus a 350-pound buddy in the front seats with nothing in the back or baggage and still be (just) inside the front limits.

Smaller folk than you or I can do it with the right front seat empty and a pair of rather large lovebirds and full baggage aft. If the lovebirds fit.

In my 182, I'd have to lose 20 lbs myself, put two 300 lb folk in the back seats, 200 more lbs in the rear, and I'd only have 13 gal of fuel on board. VFR reserves means, it'd be a 1/2 hour flight. That's as far aft as I can get it.

That's right at the rear CG limit, and honestly I've never gotten it there, not even by design for practice.

Not to mention... the tail would probably be sitting on the ground before I got in, unless I put weights in my seat until everyone and everything was loaded.

With the LR tanks, I can get it over the top of the slope in the forward CG trapezoid with a 224 lb pax and full fuel (80 gallons) with nothing aft. I do have to watch that.

5 lbs at Baggage 2 will get me 9 lbs more of right front pax. 45 lbs of stuff at Baggage 2 gets me completely under the "knuckle" in the trapezoid and can do a 300 lb pax plus me, plus full fuel then.

I can't load it forward enough to get to the hard forward CG at all, ever. It's limited by fuel on board only.

 

[N801BH]

What is the recommended FWF wt?

440 lbs....

My set up is 437.......

A comparable 350+ HP aircraft engine, complete and ready to run would be almost 700 lbs.

 

[poadeleted20]

I've flown 135 off-and-on since the 90's and have never needed to weigh pax or bags. Weights are handled as part of the opspec. Count the heads, multiply by the constant, kick the tires and light the fires.

Whether or not you can get approval for that in your ops specs depends on how many seats/pax you have. The outfit I flew for had mostly 5 passenger seats, and the GADO (that ought to date it) wouldn't buy off on standard weights for that. The AC I cited indicates the same is true today.

 

[Velocity173]

If you fly 135, you may not have any other choice. And one can, if resourceful and imaginative, find polite ways to do this without offending one's passengers.

Can't speak for other operators but for EMS we are required to get a patient weight. While it can be an approximate we still need it for W&B calculations. The multiengine guys have a PDA/IPAD for calculations and required to do a load manifest as well.

I agree that the Vietnam guys balled up a lot of aircraft. Probably because of that we have such stringent requirements in the military today for W&B. While I was too young to serve in "The Nam" I've never over grossed a Black Hawk and never met anyone who did. No reason to either if you know your aircraft and the proper way to load it. We already know how much we weigh at a hover. If you're above your go/no go TRQ you're not going. If we're over grossed you can't just remove weight and continue on your mission either. You have to shutdown and write up the over gross in the logs. Maintainence now has to inspect the aircraft because we exceeded an operational limit. This might seem like unecessary red tape to some, even in a combat zone, but better to bring the bullets and MREs in one piece than to lose an entire aircraft and crew over it. We always delivered when called anyway.

I think the biggest problem when it comes to weight is far too often someone exceeds gross on a day that allows it. They think well that's not so bad the aircraft performed fine. Then they try it again with a higher DA and crash. I trained at gross all the time flying a C-150. It was all during the winter though. After getting my license I did a flight in the summer at gross and barely cleared the trees at the end of the runway. The book said I'd have no problem but somehow I don't think it takes into account the effects of a 30 yr old aircraft flown by a non test pilot.

 

[Fearless Tower]

I agree that the Vietnam guys balled up a lot of aircraft. Probably because of that we have such stringent requirements in the military today for W&B. While I was too young to serve in "The Nam" I've never over grossed a Black Hawk and never met anyone who did. No reason to either if you know your aircraft and the proper way to load it. We already know how much we weigh at a hover. If you're above your go/no go TRQ you're not going. If we're over grossed you can't just remove weight and continue on your mission either. You have to shutdown and write up the over gross in the logs. Maintainence now has to inspect the aircraft because we exceeded an operational limit. This might seem like unecessary red tape to some, even in a combat zone, but better to bring the bullets and MREs in one piece than to lose an entire aircraft and crew over it. We always delivered when called anyway.

Unfortunately, it still happens today (just not as much as Vietnam). HM-15 lost an MH-53E 5 months ago in Oman because they miscalulated the load on a HOT summer day. 2 crewmembers killed....all in an attempt to recover an another crashed helo.

 

[Alexb2000]

That sort of intuition can only come from experience - The first couple dozen hours in a new airframe, at least, will have to be done accurately on paper. Once a pilot has a decent amount of experience with the airplane and has flown it with several different weights and CG's, then they can start to develop a feel for the airplane like you're describing.

One thing I like to do is calculate scenarios for all the corners of the CG envelope. For example, I know that in the 182 there is *NO WAY* I can load it out of CG - With me in the front, if I load the baggage compartment to limits I'm still inside the aft limits, and I can put me plus a 350-pound buddy in the front seats with nothing in the back or baggage and still be (just) inside the front limits. I spent an hour or two calculating various loading scenarios to see what it would take, and that was my result. However, I also know that the Diamond may be out the forward limit if I have another above-FAA-average person in the right seat, but will be back within if I put either any person in the back seat, or 15 lbs in the aft baggage.

Long story, uh, long, those calculations will help develop the pilot's sense of what will and won't work, and experience with the airframe will give them the extra feel for the plane that'll give them another alert that things aren't normal.

I completely agree the calculations are the place to start.

I'd say the experience will take quite a bit of time and energy. Flying with all different W&B's in high DA, short fields, high temperatures, etc, etc. for the typical small GA pilot will take some effort.

For example say someone comes to the mountains for the first time in their bird. Why not take a morning or two and go out to the field without the pressure of a trip, use some ballast, and fly at different weights and temps? Then they'll find the limits without scaring the passengers into a ride on Southwest or worse.

No substitute for time experience in type.

 

[DutchessFlier]

This thread has proven to be more valuable than first proposed, if nothing than for the need to not have this issue bite ones butt (to put it nicely) by becoming complacent or sloppy about considering W&B and gross weight no matter what. For me, when I do most of my flying it's just me, maybe another pilot/passenger in the front seat and full fuel. Very hard to get at gross or out of CG under those conditions. It's when ya load the bird up and/or have those high DA days that you gotta be careful not to assume she's gonna fly....well.

 

[X3 Skier]

LOL!

I have met far too many "academic geniuses" who can't figure out how to design things that work in the real world, in computers...

So them being at the top of the bell curve as measured by 'education' isn't always all it's cracked up to be, either.

Just remember, the lowest ranking member of a Med School Class is still called Doctor.

Cheers

 

[HerrGruyere]

I'll be honest, I didn't read the whole thread, but here's my take on it:

Even at the 170lbs, assuming you had a few thousand ft. of runway and didn't do any yankin' and bankin', you'd never have known the difference. Sure, a bit longer t/o roll and a bit less performance, but not anything drastic.

Unfortunately, I've experienced this first-hand, flying a 172P more than 200lbs over MTOW in a high-altitude/high-DA/mountainous terrain scenario. (No, I wasn't PIC.)

DON'T MISUNDERSTAND ME, I'M NOT ADVOCATING DOING IT, AND I WOULD NEVER DO IT AGAIN. Just pointing out that as long as you're within balance, a little extra weight generally won't be the difference between life and death.

I reckon I would have gotten away with about 40 pounds overweight. But, I always err on the side of safety. I'm not in a position to take risks!

 

[Velocity173]

Unfortunately, it still happens today (just not as much as Vietnam). HM-15 lost an MH-53E 5 months ago in Oman because they miscalulated the load on a HOT summer day. 2 crewmembers killed....all in an attempt to recover an another crashed helo.

That's brings up a whole seperate issue. That is an allowable gross weight based upon DA. I was simply referring to a structural limit in the flight manual. I believe that it was the original poster was referring to. Most of us have brushed up against an environmental limit that fly combat aircraft at one time or another. I've done resupplies in the mountains of Afghanistan during the summer where my structural limit is always 22,000 lbs but by max allowable gross weight for the day (OGE) was around 18,000 lbs. Now if I exceed the 18,000 lbs it's not an "over gross" as far as a book definition of a write up. Just like if I exceed the max TRQ available published for that altitude. Both are far below the structural limits published in the limits section of the flight manual. I've still drooped the rotor operating just less than my environmental limits. All it takes is a gust of wind when your max performing it like that and she'll droop. Generally though the engines and transmission on a UH-60 can easily handle the structural gross weight published in the manual. Still, with the flight planning technology and simple hover checks that we do, there's no excuse for exceeding a limit in a helicopter.