Aircraft weight - heavy

A

ateamer

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ateamer
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Our new-to-us Cessna 175A is heavy. Way heavy. The basic empty weight as designed is 1338, and from looking around a typical weight is around 1400. Ours is 1538. I was hoping that there had been a math error somewhere along the line, as the W&B was computed, but I just had the airplane weighed and it’s confirmed to be 1538. I don’t have any previous W&B documents, and the logs from 1960-69 were lost in 1969.

It was painted in 2019 with scuff and shoot, but that couldn’t weigh that much. I expect that the extra layer of paint could be 20, maybe. There is soundproofing in the ceiling - black foam panels. Could they add 100 pounds? It has an O-360 and constant speed prop, but it looks like the Lycoming weighs less than the original geared Conti, so with the heavier prop it’s probably a wash (prop wash?).

The avionics are a Garmin GPS 175, Garmin transponder, King KX-155 and -125, a very basic audio panel, two G5s and standard engine gauges, and airspeed, altimeter and electric turn coordinator. The vacuum system was removed.

Suggestions, guesses?
 
200lbs of methamphetamine hidden in the wings before the aircraft was inadvertently sold on the open market, rather than to the specified buyer; a mistake now bitterly regretted by the auctioneer as he finds himself slowly being led toward a wood-chipper?

Just a guess.
 
I thought heavies were 300,000 gross and up. :rolleyes:
 
AvNavCom said:
200lbs of methamphetamine hidden in the wings before the aircraft was inadvertently sold on the open market, rather than to the specified buyer; a mistake now bitterly regretted by the auctioneer as he finds himself slowly being led toward a wood-chipper?

Just a guess.
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By his attorney? (Achtsam Morden = Murder Mindfully)
 
AvNavCom said:
200lbs of methamphetamine hidden in the wings before the aircraft was inadvertently sold on the open market, rather than to the specified buyer; a mistake now bitterly regretted by the auctioneer as he finds himself slowly being led toward a wood-chipper?

Just a guess.
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Well, it is Florida.
 
ateamer said:
Suggestions, guesses?
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Do you have an idea of where your empty CG falls with respect to other 175As with lower empty weights? That might tell you where to start looking.
Also the weight difference between L and R main wheels (lateral CG if you're so inclined) to see if you've got the proverbial vacuum cleaner in a wing tank.

Nauga,
armed
 
ateamer said:
Well, it is Florida.
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True. You should probably check for a gator in the rear fuselage.

More seriously, there are only so many ways to add non-obvious weight to an aircraft. I'm thinking hidden cabling/fittings for previous equipment. The soundproofing is probably a good suspicion. If you can pull a panel and get a weight, you could estimate total weight based on surface area. Extra battery somewhere?

Love the thought of looking at the CG. At least you'd have a sense of roughly where all that additional weight is being carried.
 
Where are you located?
When I brought my plane home It was much heavier than it should have been, so I went looking. I found mud wasps.
By the time I was done, I had taken 90 lbs of mud wasp nests out of the wings, fuselage and tail feathers.
Then I cleaned out 70 plus years of dirt and "stuff" including wiring for lights and an electrical system that was never installed. It totaled another 17 lbs.
And $1.62 cents.
Just some things to look at.
 
Paint will add much more than 20lbs. It was closer to 50lbs on my Sonex and that is a much smaller airplane than yours. Was the airplane in the right condition for weighing? Do your weights include gas or fluids? Was everything removed from the interior (headsets, log books, tie downs etc). Little things can add up quickly to 200lbs. Finally, how was the airplane weighed? Were the scales calibrated and if so when was the last calibration?
 
kmacht said:
Paint will add much more than 20lbs. It was closer to 50lbs on my Sonex and that is a much smaller airplane than yours. Was the airplane in the right condition for weighing? Do your weights include gas or fluids? Was everything removed from the interior (headsets, log books, tie downs etc). Little things can add up quickly to 200lbs. Finally, how was the airplane weighed? Were the scales calibrated and if so when was the last calibration?
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Yep, everything removed, followed the Cessna procedure. Calibrated scales, done by an A&P IA who these days does almost exclusively weight and balance.
 
kmacht said:
Paint will add much more than 20lbs. It was closer to 50lbs on my Sonex and that is a much smaller airplane than yours.
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Hmmm --50 lbs is a lot IMO. The paint on my RV-10 came in at 25 lbs.
 
I'm assuming you've opened everything up and went over the fuselage, engine compartment, and wing interiors with a fine-tooth comb looking for a smoking gun and didn't find anything out of the ordinary (lots of old unused wiring, a really heavy battery, critter homes, heavier than normal fabric/carpet/trim, etc). Sounds like it maybe a death of thousand cuts situation -- IOW a lot of little things that just add up.
 
kmacht said:
Paint will add much more than 20lbs. It was closer to 50lbs on my Sonex and that is a much smaller airplane than yours.
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Paint on my Sonex, including the trim colors, vinyl numbers, & tail art, came to 20 lbs. (I was hoping for less). I bet you get a real shiny paint job for 50 lbs.

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Daleandee said:
Paint on my Sonex, including the trim colors, vinyl numbers, & tail art, came to 20 lbs. (I was hoping for less). I bet you get a real shiny paint job for 50 lbs.
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One coat of epoxy primer, one coat of high build primer, three colors including one with metallics, and two coats of clear all with DuPont 2 stage paint adds up quick. It’s the one thing I splurged on after almost a decade of scratch building. I don’t regret it at all. 11 years later with many of those tied out on the ramp and the airplane still looks as good as the day it came out of the paint booth. I wanted to go polished but couldn’t justify the upkeep needed without having it stored in a hanger which was t an option. My only regret is not going with a single color on the cowel. I wanted to swap out to a Corvair at one point but trying to get a new three color cowel painted to match put the price of the conversion over the top.
 

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I pulled 10lbs of unused wire out of my plane. It was unaccounted for in the w&b docs, too. 10lbs of dirt would not be uncommon. Corrosion x?
 
ateamer said:
It was painted in 2019 with scuff and shoot, but that couldn’t weigh that much. I expect that the extra layer of paint could be 20, maybe
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Was this its only scuff and buff? As mentioned, paint can weigh more than you may think especially on an older aircraft as this. Also I believe 175s have a higher unusable fuel weight than other aircraft that will add to the empty weight numbers. I also think 1400 seems a bit light for a flying aircraft. Perhaps post the work sheet for you're recent actual weight/balance and I can see if anything sticks out. But if you're only chasing an extra 100lbs most of that could easily be in paint and unusable fuel provided it was weighed correctly.
 
We had an aircraft come into our airport once for a pre-buy. The mechanics that were very familiar with the type noticed some unusual inspection covers near the wingtips that didn't belong. They opened them up and found fuel lines there, that shouldn't have been there. Old timer walks by and saw us looking at this stuff and says "Smuggler tanks". Apparently not an uncommon, albeit illegal, "mod" for this particular type of aircraft that could go fast, haul a lot, and with a little extra gas make it non stop from Columbia to the US.
 
kmacht said:
One coat of epoxy primer, one coat of high build primer, three colors including one with metallics, and two coats of clear all with DuPont 2 stage paint adds up quick. It’s the one thing I splurged on after almost a decade of scratch building. I don’t regret it at all. 11 years later with many of those tied out on the ramp and the airplane still looks as good as the day it came out of the paint booth. I wanted to go polished but couldn’t justify the upkeep needed without having it stored in a hanger which was t an option. My only regret is not going with a single color on the cowel. I wanted to swap out to a Corvair at one point but trying to get a new three color cowel painted to match put the price of the conversion over the top.
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Looks good! I owned a polished airplane. Everyone should own a polished airplane once ...
 
A friend had a 175, he put a really nice carpet kit in it. I looked up the carpet because I could use some new in my 180. His carpet kit weighed 13 pounds. A few accessories like that won't take long to add up.
 
Damage history? I’m assuming its not a tailwheel conversion. I know a guy with a’59 175 who said he figured out cessna weight and balance data for the 175 was off a fair bit.
 
Shepherd said:
By the time I was done, I had taken 90 lbs of mud wasp nests out of the wings, fuselage and tail feathers.
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90#, wow. I cleaned an astounding amount of mud wasp nests out of my Parrakeet, especially in the ailerons. I didn't weight it, but probably a couple of pounds at least. I guess that's what happens when you buy an airplane from Texas.
 
Daleandee said:
Looks good! I owned a polished airplane. Everyone should own a polished airplane once ...
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I own 1/3 of a polished airplane. I own the whole airplane, but I've only polished ~1/3 of it. The *only* reasons I'm doing it are (1) I don't have to down the airplane to do it, and (2) I'm not willing to add the weight of paint or vinyl. I hope to get much more of it shining as soon as I'm close to it again.

Nauga,
who knows what it looks like, TYVM. :oops:
 
Bell206 said:
Was this its only scuff and buff? As mentioned, paint can weigh more than you may think especially on an older aircraft as this. Also I believe 175s have a higher unusable fuel weight than other aircraft that will add to the empty weight numbers. I also think 1400 seems a bit light for a flying aircraft. Perhaps post the work sheet for you're recent actual weight/balance and I can see if anything sticks out. But if you're only chasing an extra 100lbs most of that could easily be in paint and unusable fuel provided it was weighed correctly.
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The first repaint, according to the logbook entry in the mid 70s, was a strip and paint. I’m sure the second one, six years ago, was a scuff and shoot.

Cessna says that unusable fuel is 10 gallons. The tanks hold 52, but only 42 is usable in all attitudes. At Vx and above 167 horsepower (92%), that bottom 10 isn’t usable. I’m comfortable planning for those last 10 gallons to be my one hour reserve and briefing no Vx climb or steep descent if we have to divert late in a long flight and take off again without refueling. There are precious few places where we’ll be going that a Vx departure is needed.
 
I should have mentioned; My plane spent 20+ years parked in an open hanger on an island in middle of the Hudson River.
Mud wasps were not the only inhabitants that got driven out of the plane.
 
ateamer said:
The first repaint, according to the logbook entry in the mid 70s, was a strip and paint. I’m sure the second one, six years ago, was a scuff and shoot.

Cessna says that unusable fuel is 10 gallons. The tanks hold 52, but only 42 is usable in all attitudes. At Vx and above 167 horsepower (92%), that bottom 10 isn’t usable. I’m comfortable planning for those last 10 gallons to be my one hour reserve and briefing no Vx climb or steep descent if we have to divert late in a long flight and take off again without refueling. There are precious few places where we’ll be going that a Vx departure is needed.
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What happens when you need to suddenly pitch up in an emergency to go around or avoid something with less than those 10 gallons left? Using them regularly as your reserve isn’t the best of ideas. It only has to not work once.
 
kmacht said:
What happens when you need to suddenly pitch up in an emergency to go around or avoid something with less than those 10 gallons left? Using them regularly as your reserve isn’t the best of ideas. It only has to not work once.
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10 gallons? Why that's two and a half hours . . . :rolleyes:
 
ateamer said:
The first repaint, according to the logbook entry in the mid 70s, was a strip and paint. I’m sure the second one, six years ago, was a scuff and shoot.
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What empty weight do you think you should be at? When they did the last reweigh, did they weigh it with actual unusable fuel or was the aircraft dry and they computed the unusable fuel?

ateamer said:
Cessna says that unusable fuel is 10 gallons.
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FYI: unusable fuel when required to be part of the certified empty weight per the TCDS usually means it wont be available at all regardless of flight attitude or performance.
 
Shepherd said:
I should have mentioned; My plane spent 20+ years parked in an open hanger on an island in middle of the Hudson River.
Mud wasps were not the only inhabitants that got driven out of the plane.
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I also found a considerable amount of mud wasp nest in my plane when I first got it. I call them mud daubers. I was finding them 3 years later the more I worked on the plane. Not 10# worth but I bet 3-4 pounds by the time I got them all out that I could get to.
There's more in there as I can see them with my borescope like in the tail feathers. One fell down from inside the vertical stabilizer and I was able to pick it out.
My plane sat outside a few years next to a river in the low lands and wasn't flown much.
 
Shepherd said:
I should have mentioned; My plane spent 20+ years parked in an open hanger on an island in middle of the Hudson River.
Mud wasps were not the only inhabitants that got driven out of the plane.
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Ok, I'll bite: which island was this? I finally made it out to the Saugerties lighthouse a couple Christmases ago...
 
This was only about half of what I found during a pre buy inspection for me and a first annual inspection I did while it was owned by my friend. The rest got thrown outside at first until there was too much outside.
c5951f6e-f064-49ec-8d74-2544106bbd7f.jpg

Then as the months and years went by I found more.
22fa8b62-bb9e-4709-bb76-7cf41bfc1cb2.heic

And more...
9e4efde9-6358-4b12-95c5-c65f48b69db9.jpg
 
Rene said:
10 gallons? Why that's two and a half hours . . . :rolleyes:
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That 10 gallons is not useable fuel in that particular airplane and won't reach the engine under certain conditions. I don't know about you but when I'm down to reserves I don't want to be worrying about how i can or can't maneuvee to keep the engine running.
 
Gary Ward said:
This was only about half of what I found during a pre buy inspection for me and a first annual inspection I did while it was owned by my friend. The rest got thrown outside at first until there was too much outside.
c5951f6e-f064-49ec-8d74-2544106bbd7f.jpg

Then as the months and years went by I found more.
22fa8b62-bb9e-4709-bb76-7cf41bfc1cb2.heic

And more...
9e4efde9-6358-4b12-95c5-c65f48b69db9.jpg
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But how much did it weigh?
 
I kinda hate to say this, but in addition to the above, Al2O3 and Fe2O3 are heavier than Al and Fe before you add O. No idea how much the corrosion might add, because it's supposed to be just on the surface if it happens, and shouldn't happen to protected metal.
 
tsts4 said:
Hmmm --50 lbs is a lot IMO. The paint on my RV-10 came in at 25 lbs.
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But he did a scuff and paint. Strip and repaint will definitely saved some weight. Fuel bladders add weight. Does it have any mods like winglets, etc?
 
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