STC Gross weight increase for 252

[Mark89114]

I am looking for a 252 occasionally depending on balance of my checkbook and weighing plus's and minus's of each.  One of the concerns is useful load.  I questioned one broker/mechanic on it and he said their is an STC that gives a 150 lb weight increase for about $3K and some paperwork diddling and new speeds on the ASI.  The only one I have come across is the Encore increase which is 230lbs and costs from $5k to $15K depending on who is answering on the forums.  I think he is full of nonsense and just wants to sell an airplane or does this really exist? 

 

Thanks,

[Parker_Woodruff]

The 160 lb increase applies to certain serial numbers of the Mooney M20J which were made around the time the 252 was in production.  Cost for this is less than $1,000, if I remember correctly.

 

The Encore conversion will give you an increase of 230 lbs and $15,000 is closer to the actual cost.

 

 

I gave the weight increase to my 1990 M20J and did the Encore conversion to my 1987 252.  So consider me a reliable source. :)

[John Pleisse]

The paper work + 150lbs GWI is for the 201's (1989 and up), not he 252. The only GWI for the 252, that I know of, is the Encore conversion. One gentleman who frequents this board did it a few years back and I am sure he'll join this thread. Or use the search tools and you will find a chronicle of his conversion.

 

Edit...well there you go...his post preceded mine.

[231LV]

The Encore for another 230 pounds is the upgrade as others have remarked....I did the research (back about 5 years ago) on converting a 231 to the 262 (252 Encore) and only serial numbered planes 25-1000 through 25-1230 are doable at a "then" cost of approximately $36,000

[byrdflyr]

My M20k 231K has the 262 conversion, but it is SN 25-0867, and retained the 2900 lb MGW limitation.  My understanding is that to get the 230 lbs MGW increase, requires two modifications - the RPM redline must change from 2700 to 2800 (thus an increase in max rated power from 210 to 220); and the gear is updated to a beefier version  - with 2-cyl brake caliper, rather than a single cylinder.  The beefier gear adds weight, so you don't get a 230 lbs increase in useful load; it would be more like an increase of about 200lbs.  This is from memory, so if I'm wrong about this, let me know.  

[gsxrpilot]

8 minutes ago, byrdflyr said:

This is from memory, so if I'm wrong about this, let me know.  

Not completely wrong, but not completely correct either. This thread is 6 years old and there have been numerous threads since then with a lot of accurate detail.

[kortopates]

1 hour ago, byrdflyr said:

My M20k 231K has the 262 conversion, but it is SN 25-0867, and retained the 2900 lb MGW limitation.  My understanding is that to get the 230 lbs MGW increase, requires two modifications - the RPM redline must change from 2700 to 2800 (thus an increase in max rated power from 210 to 220); and the gear is updated to a beefier version  - with 2-cyl brake caliper, rather than a single cylinder.  The beefier gear adds weight, so you don't get a 230 lbs increase in useful load; it would be more like an increase of about 200lbs.  This is from memory, so if I'm wrong about this, let me know.  

Unfortunately a 262 conversion is not eligible, because of minimum airframe is 252 starting with 1000 serial number.

But you do effectively get most of the full 230 lbs since the "beefier" gear is not what you think but merely a beefier attachment welding  on the otherwise same spindles to support the 3 bolts to attach the double puck brakes versus the singe puck calipers which required only 2 bolts to attach. The additional weight for the  larger calipers and thicker rotors added some weight but very little. 

The increased power did not come from higher RPM, its actually reduced to a redline of 2600 rpm, but higher boost.

Many threads on this elsewhere.

The brake upgrade is really expensive, since its mostly all Mooney parts with new gear doors etc. But if your heart is really set on this, I'd recommend consulting with a DAR, preferably one that already has some knowledge of the issue since he alone could possibly work up a one time STC to get you the gross weight increase. But it would probably be cheaper to just sell and buy a 252.

 

[shawnd]

I feel like we should create a new thread and make it a sticky for this sub-forum and link the other threads from there. Then we will have one place to point people to for it.