Flying Overweight

[MAKG1]

I would agree with this. I have flown far more 172s (from early 60s to post 2000 models) that did not have flight adjustable rudder trim than those that did. In fact, the only ones I have flown that did have adjustable trim were 180 hp models.

OK, I stand corrected.

I have yet to see any 172 that doesn't have it. I've flown M, N, and R models, a total of 10 different tail numbers with four different engines (two of the N's have carb 180s), not counting the RG. Obviously, that's not anywhere near every 172.

By comparison, I have yet to see a 150 or 152 that has anything but the ground-bend tab on the rudder.

 

[docmirror]

I'm with Mase. Find somewhere else to learn, and I see no particular grounds to demand your money back. If nothing else, at least you have five hours of training in your logbook, and you did pay fair value for them.

BTW, if the W&B data show you were 60 lb or so over max gross weight, you are correct that these flights were illegal, and you don't want any further association with the folks who do that. No doubt some will say "it's only 60 lb," "odds are the plane is already that much heavier than the paperwork says," "there's lots of safety margin," etc. That's not how the pros do business, and it's the start of a slippery slope of regulatory misbehavior that has no end short of eventual disaster (legal or otherwise). Good for you for drawing the line as soon as you knew how to draw it, and refusing to step over it knowingly/willingly.

And there's the further questions of what other rules they are willing to violate in the name of expediency...

Jeez. This is gonna hurt. I agree with everything Ron said.

For a new student pilot who doesn't know what he doesn't know - it's a bad start for an FBO/CFI to take him up in a plane knowing right from the start that this plane will not support the weight, and may not be in CG for the flight taken.

It has nothing to do with the cost of the plane, or the hours logged, or the rating sought. Here's an example from my past. I bought a Citabria to learn my TW and acro. It came with chutes. I never knew that chutes had an expiration on the pack times, but of course it makes common sense that it would. Well, my CFI and I went out and did some ground ref work, then we did a few rolls, and went home. My chutes were 26 and 33 days out of date, and he had to apologize for the mistake in breaking an FAR.

Don't start out that way. Do it right, and get safe hours under your belt for a while. Having said that, I've also owned a Bonanza with an extra 40HP that I flew overweight a few times. Things are relative in real life, but start with the basics, like legal W/B data.

 

[Henning]

OK, I stand corrected.

I have yet to see any 172 that doesn't have it. I've flown M, N, and R models, a total of 10 different tail numbers with four different engines (two of the N's have carb 180s), not counting the RG. Obviously, that's not anywhere near every 172.

By comparison, I have yet to see a 150 or 152 that has anything but the ground-bend tab on the rudder.

I have flown one 172 that had an inflight adjustable rudder trim.

 

[Unregistered]

Well, the structural part kinda depends on the plane, gear strength is not calculated to 3.8gs.

Not a true blanket statement...Beechcraft's T-6B gear is limited to 5.5 G's or 700 FPM? Not 100% sure about the FPM number anymore, but the G limit I do remember.

 

[Henning]

Not a true blanket statement...Beechcraft's T-6B gear is limited to 5.5 G's or 700 FPM? Not 100% sure about the FPM number anymore, but the G limit I do remember.

I could believe that, I didn't mean to imply it as a blanket design statement. I do find it hard to fathom that a 700fpm descent would developer a 5.5g hit.

 

[MAKG1]

I had a similar "WTF" moment when I checked out in a 177RG. The useful load on that is pretty high, but it really, really likes forward CG. As part of my prep, I calculated W&B and figured out I needed 90 lb of ballast in rear cargo with me and an instructor, full fuel and nothing else. The instructor showed up as I was loading three 30 lb sandbags into the back. He made the comment that most pilots don't bother (!?!). I can't imagine that nosegear is all that happy about it.

And then I greased the first touchdown -- it's actually a rather docile aircraft, despite it's rep. But it really helps when you balance it correctly...

 

[Unregistered]

I could believe that, I didn't mean to imply it as a blanket design statement. I do find it hard to fathom that a 700fpm descent would developer a 5.5g hit.

The limit we referenced was 5.5 G's, and I never saw anything close to that. Hardest landing I saw was ~3 and I thought the wings were going to come off.

Despite that, the NATOPS referenced both numbers. I'm pretty sure the tires would blow before the airframe limit was reached though.

 

[EdFred]

I could believe that, I didn't mean to imply it as a blanket design statement. I do find it hard to fathom that a 700fpm descent would developer a 5.5g hit.

Depends how fast you go from 700fpm to 0 fpm.

5.5G = approx 176f/s²
700f/m = 11.7f/s

11.7/176 = .066 seconds of deceleration. So yeah, not likely.

 

[airguy]

Depends how fast you go from 700fpm to 0 fpm.

5.5G = approx 176f/s²
700f/m = 11.7f/s

11.7/176 = .066 seconds of deceleration. So yeah, not likely.

.066 seconds of deceleration, with an average speed of 350 fpm (start at 700 and end at 0) yields a deceleration distance of 4.62 inches. That sounds about right to me for a gear-flex scenario under a hard landing, I can buy that.

In reality, the tires are going to absorb at least half of that, if not more, and the gear legs will absorb the rest.

 

[EdFred]

.066 seconds of deceleration, with an average speed of 350 fpm (start at 700 and end at 0) yields a deceleration distance of 4.62 inches. That sounds about right to me for a gear-flex scenario under a hard landing, I can buy that.

In reality, the tires are going to absorb at least half of that, if not more, and the gear legs will absorb the rest.

I think you missed a unit conversion.

d = vt²/2

d = (11.7fps * 0.066²)/2 = .025 feet = 0.305 inches.

There's more than 3/10th of an inch of give in the gear. But let's work backwards and say there's 4" of give in the gear.

4 = (11.7fps * t²)/2

8/11.7 = 0.684 = t²

t = 0.827s of deceleration

v = at

11.7 = a * 0.827

a = 14.15f/s²

14.15f/s²
-------- = .44G added to the 1G you are already experiencing = 1.44G
32.1f/s²


But I haven't had any caffeine yet, so I may have done my math wrong.

 

[PPC1052]

I had a similar "WTF" moment when I checked out in a 177RG. The useful load on that is pretty high, but it really, really likes forward CG. As part of my prep, I calculated W&B and figured out I needed 90 lb of ballast in rear cargo with me and an instructor, full fuel and nothing else. The instructor showed up as I was loading three 30 lb sandbags into the back. He made the comment that most pilots don't bother (!?!). I can't imagine that nosegear is all that happy about it.

And then I greased the first touchdown -- it's actually a rather docile aircraft, despite it's rep. But it really helps when you balance it correctly...

Yep. I keep the extra oil, tie downs, and various other miscelaneous items in the baggage compartment for a little extra ballast to shift the CG back for take off with full fuel in our 177B FG. Fortunately, as the fuel burns off, the CG shifts backwards.

 

[azure]

Yep. I keep the extra oil, tie downs, and various other miscelaneous items in the baggage compartment for a little extra ballast to shift the CG back for take off with full fuel in our 177B FG. Fortunately, as the fuel burns off, the CG shifts backwards.

Unless I'm carrying extra equipment like bicycles in back, I keep a full 60 lbs of ballast in the cargo area. For my IR checkride, I calculated that 50 lbs was pretty much the minimum I'd need to carry myself and the examiner, plus full fuel, and still be within CG limits.

 

[tiger]

It's a long time since I've done any applied math, Ed, so I'm definitely prepared to be wrong, but I got the same result as airguy when I read your earlier post.

If the deceleration is constant, you're going to average 5.85f/s for that 0.066s. Which gives 4.5", give or take. No need to make it more complicated than that, is there?

Assuming your original derivation of 0.066s is correct (which I take on trust, I admit).

I think this is wrong in your subsequent explanation: d = vt²/2
You might mean: d = at²/2

But like I say, it's been a while...

 

[GCA319]

Not that unusual to exceed the manufactures recommended maximum weight in a 150. That's just the way it is.

It's not a "recommended" max weight, it's considered an operating limitation that must be complied with.

 

[EdFred]

It's a long time since I've done any applied math, Ed, so I'm definitely prepared to be wrong, but I got the same result as airguy when I read your earlier post.

If the deceleration is constant, you're going to average 5.85f/s for that 0.066s. Which gives 4.5", give or take. No need to make it more complicated than that, is there?

Assuming your original derivation of 0.066s is correct (which I take on trust, I admit).

I think this is wrong in your subsequent explanation: d = vt²/2
You might mean: d = at²/2

But like I say, it's been a while...

That's what happens when you don't have caffeine and try to do math!! I still think 6/100ths of a second is too fast of a deceleration.

The correct formula is d = vt + 1/2at²

Lemme crunch some numbers... because we don't KNOW what a is for sure.

Yeah, I get that 4.62 number as well. Just seemed like a high G load to me. 6/100ths still seems too fast to me though.

 

[GCA319]

Also, despite what some have advocated, don't be that guy who calls the FAA on people. Aviation is small, word gets around, and you'll be hard pressed to find anybody willing to fly with you.

 

[RotorAndWing]

Also, despite what some have advocated, don't be that guy who calls the FAA on people. Aviation is small, word gets around, and you'll be hard pressed to find anybody willing to fly with you.

The majority of reports received at the FSDO are from other pilots and usually the two know each other.

 

[ClimbnSink]

The majority of reports received at the FSDO are from other pilots and usually the two know each other.

Starts when someone doubts failwheel pilots are super heroes. He's out of the mutual appreciation society. And we're calling the Feds.
All those old, fat, gray dudes hanging around airports are cattier then a sewing circle. Silly girls. Goes to show ya, don't talk to the police or pilots.

 

[FastEddieB]

This is such a tough call and a matter of conscience.

Scroll back to post #64 in this thread.

In the article it describes that the deceased pilot often entertained others with his low level aerobatics.

Maybe, just maybe, if someone had reported him, two people might not have died that day.

I've witnessed lots and lots of questionable behavior in flying. Only once have I ever reported a pilot. I've described the circumstances before, but will again if anyone is interested.

In any case, the conscience thing comes in if you choose not to report patently dangerous behavior and a fatal crash ensues. We are not, individually, "Cops of the World". Yet we still have to be able to sleep at night with the consequences of both our actions and inaction.

Just sayin'.

 

[Henning]

Why should we prevent people crashing and dying? Everybody Dies

 

[ClimbnSink]

Why should we prevent people crashing and dying? Everybody Dies

Call in everybody or nobody. Plenty of regular fly by the rules IFR traveling types denting mountains and killing innocent passengers. We ignore those and get on our high horse about the occasional cowboys that buy the farm.

 

[FastEddieB]

Everybody Dies

Yes.

Eventually.

But a 15 year old? During a Christmas present ride?

Put me down in the camp that would choose to at least try to prevent that.

Unless I'm missing your point, or it was just meant as sarcasm.

Hard to tell

 

[danhagan]

Negative. We flew with full tanks, and according to the W & B that was done later after the flights by the instructor, it showed that we were overweight if we had more than 13 gallons.

That's the situation in 152's. I'm 180 and my instructor wasn't much bigger, but I recall 15-16 being the "magic" fuel on board. Get a CFI that will have you flight plan correctly before each flight - mine was a stickler and I had to arrive an hour early for weather, W&B, Nav-Log if not in the pattern and pre-flight (which he did with me initially, but expected me to complete without him shortly after).

The 152 is a great trainer and cheaper than the 172 for training.

 

[Palmpilot]

I trained in a 172 because of this issue.

 

[Dead Stick]

Many of these discussions lead me to conclude that some think that maximum weight limitations are primarily performance limitations.

There are many reasons for max gross weight restriction and they aren't all performance or structural related. Some one related to the arbitrary limitations in the FARs. For example the 12,500 lbs limitation on light aircraft. The military routinely operates bone stock King Air 200s well above that weight and there is an STC that increases the max weight of the KA-200 to well over 12,500 lbs but the pilots are required to get a type rating to fly the airplane. US Customs also used to operate Cheyenne IIIs at weights up to 14,000 lbs if I remember correctly. Back when the Cessna 340 was in production the airplane originally had a 5,975 pound max gross weight limitation. This placed it conveniently just below an IRS imposed Federal Excise Tax category at 6,000 lbs. Once the tax consideration went away you started to see STCs increasing the 340's max gross weight by several hundred pounds.

Does this give us license to fly our aircraft over weight? I've heard many guys try to rationalize it by saying that "In Alaska they..." and "they put ferry tanks in them all of the time and fly them way overweight..." This is all great info for the next time you play Trivial Pursuit - Light Airplane Edition, but the bottom line is if you fly at a weight or CG location outside of the legal envelope for the airplane you happen to be flying you are exposing yourself to several things, none of which are particularly pleasant.

 

[denverpilot]

Catching up late to the thread. Nobody pointed out the very likely obvious reason for the behavior... the school probably needs new students badly and has at least one instructor who will play the game of renting out the cheapest airplane in the fleet until they know they've set the hook, and then whip out the "Oh, you weigh HOW much?" line.

There's always one or two schools around here at 6000' MSL that have 150s or 152s on the line. They're ridiculously marginal up here. My first instructor put up with me choosing the cheap 150 to start and I even soloed in one up here, but it never had more than half tanks full ever, and was way too marginal in the summertime. And we were both skinny people back then.

As soon as Spring came around, we switched to a 172. He was kind to save me a few bucks early on, and a 150 really does have a better in-flight feel than a 172, but we both knew when to quit playing chicken with the performance up here and move on.

 

[Alexb2000]

What concerns me more is pilots who use a W&B paper (B.S. or true) as an excuse to fly without listening to the aircraft. There are many things besides weight that will determine how an aircraft performs and those things in combinations produce a lot of variables. If you're heavy raise the nose and see if the airplane wants to fly, if it doesn't, put it back down. Don't just rip it off the ground. If you find your controls out of harmony with a load, perhaps you have a CG issue, etc.

Flying has to have a level of art IMO and that's hard to put on paper.