What is the useful load of your J?

[0TreeLemur]

Interested to see what the range of UL for M20Js is.  Please fill out the poll you own an M20J, or even if you used to own one.

[ArtVandelay]

Wow, you must think Js are pigs if top is 939? I’d expect most were shipped from the factory close to 1000lbs, except for maybe the years 82-86 when they were getting heavier and before the increase of MGW to 2900lbs

[ttflyer]

1988 J (205) = 1055.1 lbs (Note has GW mod to 2900 lbs).

[dzeleski]

Yeah the numbers don’t go high enough IMO. My 1977 J is 1009lb UL. I believe it’s empty weight is like ~1731lbs. My J is way to early for the GW increase as well.

[ArtVandelay]

Yeah the numbers don’t go high enough IMO. My 1977 J is 1009lb UL. I believe it’s empty weight is like ~1650lbs. My J is way to early for the GW increase as well.

Check your math, your EW should be around 1730.

[dzeleski]

13 minutes ago, ArtVandelay said:

Check your math, your EW should be around 1730.

Yep thats what happens when I try and do things a few minutes after waking up. Its 1731 EW. Thanks, ill update my post above.

[0TreeLemur]

16 hours ago, ArtVandelay said:

Wow, you must think Js are pigs if top is 939? I’d expect most were shipped from the factory close to 1000lbs, except for maybe the years 82-86 when they were getting heavier and before the increase of MGW to 2900lbs

Not at all.  The top category is >939 lb, which lets you fly with full 64 gallon tanks plus at least 556 lb of other stuff.

I'm more interested in the low end of the distribution.   Note in my profile that I have an '83J, before the MGW increase.  I'm trying to get a sense for how heavy my bird is.   I hope that explains why the poll is set up the way it is.  

Thanks to everyone who replies.

Edited August 24, 2023 by 0TreeLemur
detail

[PT20J]

1994. Weighed after panel upgrade. 1895 lb. empty; 1005 lb. useful load.

[haymak3r]

1979 Weighed after panel upgrade. 1791.88 Empty - 948.12 UL.

[katzhome]

 My 1977 J is 988 lb UL.  Empty weight is like ~1752 lbs.

[ArtVandelay]

My 78 came from the factory at 996lbs, was 938 when I bought it, and after a number of upgrades it sits at 1012.
I have a number of 205 upgrades like wing tips, wing landing lights, speed brakes, etc, otherwise it would be over 1040, probably 1050 is the theoretical limit for earlier Js.

[201Steve]

With the early J’s getting near 1050 on 2740, conceivably with some jiggering you could get one to 1300 useful on a 2900 eligible ship.  On 9gph. That’s a lot of options!!!

[0TreeLemur]

3 hours ago, 201Steve said:

With the early J’s getting near 1050 on 2740, conceivably with some jiggering you could get one to 1300 useful on a 2900 eligible ship.  On 9gph. That’s a lot of options!!!

Curious- what makes one "2900 eligible"?   I recall reading that the UL increase required redesign of the steel cage with some beefed up members.   That sound muy expensivo as a retrofit.

[EricJ]

19 minutes ago, 0TreeLemur said:

Curious- what makes one "2900 eligible"?   I recall reading that the UL increase required redesign of the steel cage with some beefed up members.   That sound muy expensivo as a retrofit.

Starting at a certain serial number all J's are eligible (mine, sadly, is not).   A new rudder balance weight is required.    Other than that it is a paperwork mod, iirc.

There is no approved method to convert an ineligible airplane, so the earlier serial numbers are out of luck.

[ArtVandelay]

With the early J’s getting near 1050 on 2740, conceivably with some jiggering you could get one to 1300 useful on a 2900 eligible ship.  On 9gph. That’s a lot of options!!!

Unlikely, I’ve never seen a 2900 J with a UL above 1100. Obviously the changes made to fuselage to allow the heavier weight also added weight can’t be removed. The fancier seats, 205 upgrades, etc really can’t be removed as there is an expectation that certain years have certain options.

[RoundTwo]

5 hours ago, 0TreeLemur said:

Curious- what makes one "2900 eligible"?   I recall reading that the UL increase required redesign of the steel cage with some beefed up members.   That sound muy expensivo as a retrofit.

Here’s the Mooney Special Letter SL 92-1 describing how to upgrade the eligible SN’s.

SL92-1_SN24_3057-3078 AFMS 1233(B).pdf

[A64Pilot]

My 81 according to W&B isn’t but 900ish lbs.

I think it interesting that so many get so concerned by gross weight / useful load. AK FSDO use to and I assume still does issue waivers for 10% overload and CAR3 allows a 31% overload for “special purpose aircraft” IE crop dusters. Just if you do end up heavy be aware of how it affects performance (that’s how it usually gets someone) and as we all probably fly as gently as we can anyway there isn’t much else to be concerned about.

Except for not making the takeoff and or climb above obstacles I don’t think I’ve read about an accident from being overgross.

Not saying to get stupid with it, but a few lbs over at takeoff especially if planned fuel burn has you landing at less than gross shouldn’t be a big deal.

Vast majority of people don’t compute that didn’t become common until apps like Fore Flight became common and made it easy.

Yes I know we shouldn’t be abdicating breaking the rules, I’m just bringing up if it’s between barely having enough legal fuel and being a few lbs over, I’m not pushing fuel is all.

[Fly Boomer]

2 hours ago, RoundTwo said:

Here’s the Mooney Special Letter SL 92-1 describing how to upgrade the eligible SN’s.

SL92-1_SN24_3057-3078 AFMS 1233(B).pdf 9.49 MB · 0 downloads

Interestingly (to me at least) this Special Letter incorporates new AFM/POH pages and, in SECTION VI WEIGHT AND BALANCE Equipment List (PDF page 139), it specifies "Type III" tires for both main and nose tires.  As far as I can tell, this has nothing to do with any particular brand or grade (specifically not Goodyear Flight Custom III).  Rather it specifies something about the profile.  According to Bridgestone, Type III specifies that:

"The section width of these tires is large in relation to the bead diameter, so that improved cushioning and floatation are obtained at low pressure."

Compared to (for example) Type VII which specifies that:

"This type of tire is used on the jet and turboprop aircraft of today. It is characterized by its conventional sectional shape and by its high load capabilities."

https://www.bridgestone.com/products/aircraft/products/basicstructure/

This may be common knowledge to you all, but it's the first time I have encountered the specification.

[A64Pilot]

The type 3 tires are likely required to pass the drop test at the higher weight, the size, type and even pressure in the tires make a large difference on the drop test, tires can absorb a huge amount of the energy.

Now that’s me speculating of course, but I’ve done instrumented drop tests and seen what just pressure does. In our case having tires under inflated did not absorb more energy like you would think, tires at the higher end of the allowable range did better, which I didn’t expect. Higher ply ratings did better too, we ended up with 10 ply tires, which as they were 29” tires I don’t think we needed to carry the weight.

[0TreeLemur]

10 hours ago, RoundTwo said:

Here’s the Mooney Special Letter SL 92-1 describing how to upgrade the eligible SN’s.

SL92-1_SN24_3057-3078 AFMS 1233(B).pdf 9.49 MB · 4 downloads

Thanks for posting.   I'm ineligible by S/N.

 

[Bolter]

Another 1983 reference point from 24-1412.  The last W&B calc from my former J was:

• Empty Weight: 1826.7
• Gross: 2740 (wrong serial number for considering 2900 upgrade)
• Useful: 913.3

[INA201]

1978J

Serial number 24-0578

calculated and not weighed. 990.80 lbs useful. I have a newer glass panel and no vacuum pump etc. we cleaned a lot of wires and old junk out a few years ago. I’m curious to how close folks calculations vs weighed are. 
 

40 gallons of fuel with my wife and I leaves 450 lbs.  40 gallons of fuel is a solid 450 miles with 10 gallons left. Whoops! I’m preaching to the choir. 

[0TreeLemur]

On 8/28/2023 at 4:27 PM, Bolter said:

Another 1983 reference point from 24-1412.  The last W&B calc from my former J was:

• Empty Weight: 1826.7
• Gross: 2740 (wrong serial number for considering 2900 upgrade)
• Useful: 913.3

Thanks for the data point.  My J is 24-1402, and my UL is 880 according to the most recent W&B calcs.  Looking at the low end of the distribution that my poll was designed to analyze, there is such a difference.  Equipment?   They are probably similarly equipped- mine has a KFC150 AP.  The manual says that when they painted my J in 2019 they stripped it before painting, so that's not it.   I've read that a paint job weighs at least 30 lb so if not stripped it goes on all the rides and eats UL. 

In an upgrade in March we installed a JPI EDM900 and removed all the legacy gauges and the ADF.   It has a single Aspen PDF so it has vacuum pump, and legacy flight instruments required as backups but they don't weigh 10 lbs all together.

When I bought it Jimmy G. told me that "in the early 80's J's started getting heavy".   I didn't ask him for clarification as in "what changed"?  Anybody know?

Despite advice I give others, I'm starting to think about tempting fate and weighing it...  Somebody STOP ME!

[Bolter]

1 hour ago, 0TreeLemur said:

Thanks for the data point.  My J is 24-1402, and my UL is 880 according to the most recent W&B calcs.  Looking at the low end of the distribution that my poll was designed to analyze, there is such a difference.  Equipment?   They are probably similarly equipped- mine has a KFC150 AP.  The manual says that when they painted my J in 2019 they stripped it before painting, so that's not it.   I've read that a paint job weighs at least 30 lb so if not stripped it goes on all the rides and eats UL. 

In an upgrade in March we installed a JPI EDM900 and removed all the legacy gauges and the ADF.   It has a single Aspen PDF so it has vacuum pump, and legacy flight instruments required as backups but they don't weigh 10 lbs all together.

When I bought it Jimmy G. told me that "in the early 80's J's started getting heavy".   I didn't ask him for clarification as in "what changed"?  Anybody know?

Despite advice I give others, I'm starting to think about tempting fate and weighing it...  Somebody STOP ME!

The skytec versus legacy starter is a fair bit.  8.5 pound difference.  I had the KAP150, but probably the same weight.  Garmin 430 and one King radio  for NAv/Com, removing a King radio and Loran.  1 G5 in place of the complete King HSI.  That G5 was a big weight savings over the King, but I do not have the record of it in my notes.  

[A64Pilot]

Aircraft gain weight a little bit at a time, over time. A lot of it is the factory of course receives reports that this or that piece part is cracking as they age so they increase the thickness of the material in that part, some of it is increasing skin thickness because thicker skins are easier to work, less likely to wrinkle. I fought to keep the skin thickness from being increased in the flap bay area of the aircraft we manufactured because of wrinkling, turned out the material we were buying came off of a roll of metal, not flat sheets, purchasing saved a few bucks, flat sheets cost a little more. To be clear the metal we received all came as flat sheets, just some of it was cut from metal that was rolled but cut into sheets by the supplier.

Then aircraft gain weight over time as they age from repairs, just plain dirt and especially from luxury interiors, that high grade of leather weighs a lot, more than you might think. I know it’s nice.

Mine is heavy I suspect from equipment, it has every bell and whistle available back then, with of course DME, ADF etc removed but a 430 installed, but the Radar altimeter and Stormscope isn’t light to say nothing of the Century 41 autopilot, but she has her original interior.

Best way in my opinion to lose weight is probably the starter, CG gets better, you get a better starter and price per pound is probably the least of any thing else. Ever picked up a vacuum pump? those things don’t weigh much at all, sure it’s weight but surprisingly not much.

Maybe a three blade metal prop isn’t the best thing, the one on my Maule which is bigger than a Mooney prop, but it weighed 12 lbs more than the two blade it replaced and if anything I lost performance. It did look cool though with its Scimitar blades etc. so there is that I guess.

You can spend a huge amount of money in the search of light weight.

Weight wise for pretty much all aircraft the older ones with their original interiors, one without all the IFR gear and two blade prop even with the old heavy starter and generators are the lightest, put in a modern alternator, seemingly plane powers are among the lightest and starter and you have a very light aircraft.

It’s the C-182’s that the difference is Huge, the old square tailed girls are stellar STOL airplanes, the newer ones with IO-540’s three blade props and 92 gls of fuel are I believe honestly more than 100 lbs heavier, actually fully fueled I think it’s hundreds of lbs but haven’t looked.

OK I just looked at a quick glance it seems over the years the 182 has gained about 600 lbs empty weight and while the gross weight has been increased tremendously, it still has about the same useful load it always had, about 1100 ish lbs.

That’s just a quick glance and could be wrong of course, but Damn 600 lbs? Surely that can’t be right?

From this article https://www.planeandpilotmag.com/article/used-cessna-182-skylanes/#:~:text=Cessna specified an empty weight,only went up 300 pounds.

Cessna specified an empty weight on the 1956 model at 1,560 pounds against a 2,550-pound gross, and the same parameter on the newer 182T was 1,860 pounds from a gross of 3,100 pounds. In other words, gross weight increased by 550 pounds, but useful load only went up 300 pounds.