Jump to content

Solutions for a rocket with low useful load?


Schllc

Recommended Posts

Found a rocket with a useful load of 721#

i havn’t seen something that low since the very first mooney I ever looked at which was a converted Porsche model that had a useful load in the high 600’s. The broker told me the last time anyone who asks about useful load in a mooney is when you buy it. 
Five years and four mooney’s Later, I understand why he said that, even though I still believe it was an irresponsible statement. 
I understand why that one was low, but I don’t get why this K model is so low. 

Can this be all old avionics and accumulation of unnecessary additions, or is this typical for rockets/missile conversions?  Or is this more similar to what the encore conversions require?

Link to comment
Share on other sites

38 minutes ago, Schllc said:

Found a rocket with a useful load of 721#

i have seen something that low since the very first mooney I ever looked at which was a converted Porsche model that had a useful load in the high 600’s. The broker told me the last time anyone who asks about useful load in a mooney is when you buy it. 
Five years and four mooney’s Later, I understand why he said that, even though I still believe it was an irresponsible statement. 
I understand why that one was low, but I don’t get why this K model is so low. 

Can this be all old avionics and accumulation of unnecessary additions, or is this typical for rockets/missile conversions?  Or is this more similar to what the encore conversions require?

No.  My Missile is 1111 useful load.  NOT common at ALL for a Missile.

Link to comment
Share on other sites

Ok, so an update, ironically right after I posted this I received an email explaining that someone who calculated the W&B at some point added the additional weight of the engine to the calc, didn’t add the increased gross useful load that comes alone. 
The correct UL is actually 904#, which makes more sense....

still love to know if it’s possible to get the 3200 gross weight for this airframe?

Link to comment
Share on other sites

Time to find all the paperwork to make sure you aren‘t getting A FrankenPlane...

It shouldn’t be too hard to search the records...

The logs are one source, the FAA is another source... Rocket engineering is the third source...

When a sales guy hands you a line....  That you have proven complete crap...

Do you tell anyone? Or do you use it to your advantage while negotiating the price?
 

holey cow, this plane has no UL... nobody is going to pay real money for thatttt....

I don’t even think I can take it off your hands fer... a few AMUs less than thought before...

Then deploy the other bits you noticed just because...  :)

 

If the sales guy is really artful... you may not catch the crap... 

Be on the look out for the Franken Plane...  they are built by people with a fair amount of knowledge...

 

If it were an honest franken plane... it’s history will be handed to you with all the explanation expected...

 

There isn’t an airplane bought or sold without consideration for UL... this isn’t a Mooney specific issue.

Of course, if you are single and only weigh 175#s yourself... this stuff never crosses your mind...  :)

Boats, cars and trucks, and planes all have their gross limits... 
 

When would you like to find out this limitation... before or after you take the vehicle home...

For your car’s weight limitation, it is written in the driver’s door frame... look for a shiny name plate that also records the air pressure requirements...
 

PPIs were invented to keep from accidentally buying a Franken Plane when you want a whole Mooney...

You still don’t want to get a PPI to tell you what you can determine for yourself...  this would be money not well spent...

PP thoughts only, not secrets of life...

Best regards,

-a-

Link to comment
Share on other sites

54 minutes ago, PJClark said:

Yes, all rockets should be 3200 lb gross weight

I've heard the same. That said, I looked at a different Rocket recently, and the original STC papers showed the gross weight was changed from 2900 pounds to 3017 pounds (takeoff only -- landing stayed at 2900). The subsequent W&B performed by mechanics used the 3017 pound weight. Nothing in the paperwork for the plane mentioned 3200.

Maybe 3200 applied to Rockets based on later M20Ks? The one I looked at was pretty early in the production run.

Link to comment
Share on other sites

2 minutes ago, adverseyaw said:

I've heard the same. That said, I looked at a different Rocket recently, and the original STC papers showed the gross weight was changed from 2900 pounds to 3017 pounds (takeoff only -- landing stayed at 2900). The subsequent W&B performed by mechanics used the 3017 pound weight. Nothing in the paperwork for the plane mentioned 3200.

Maybe 3200 applied to Rockets based on later M20Ks? The one I looked at was pretty early in the production run.

My rocket is based on 1981 m20k and I have the 3200.

i bet that’s it And I bet this plane has an extra 300 to give you.

Link to comment
Share on other sites

Just now, aviatoreb said:

My rocket is based on 1981 m20k and I have the 3200.

i bet that’s it And I bet this plane has an extra 300 to give you.

Does your STC paperwork say 3200 or 3017? I have to assume that the STC is what determines the truth, since that's the only that updates the type data. If more weight can be had, it would come in the form of an updated STC.

Link to comment
Share on other sites

Mid body Mooneys have different MGTWs depending on the S/Ns... there was a change to the tube structure to allow for this...  the FAA approved the change by serial numbers...

The fun comes in when Rocket applied for their STC... and included a new GW based on the work they had proved out... the FAA approved it... it isn’t accidental...  
 

The magic comes from the fact that the Rocket engineering data applies to all STC updated M20Ks and Js for the Missile...

There are a few changes to the tube structure over the years... and they don’t get mentioned all the time...

Some are more obvious than the others...  Somewhere along the way the center tube got swapped out for a stainless steel piece that is non magnetic, and a few MMs wider in dia....

It wouldn’t be too unrealistic to swap in some new tubes if that is all it takes... expect a new STC to support the work..?

MS has a few STC writers...

So... if you have an older M20K and want to raise its MGTW...consider getting the Rocket Engineering STC...  
 

hmmmmm... that ship may have sailed already.... Rocket engineering still supports all the rockets and missiles... but doesn’t make any new ones... it was incredibly expensive at the time...  like buying a new Mooney, only using your old Mooney as a down payment...   :)

PP thoughts only, not a mechanic...

Best regards,

-a-

Link to comment
Share on other sites

Here we go, figured it out -- it's two different STCs. Found these copies online.

SA5691NM is the original Rocket STC that installs the TSIO-520. It increases takeoff weight to 3017 pounds.

sa5691nm.thumb.jpg.c14013e8dcb75bf703dc2bdf54ff9744.jpg

SA00243SE is an additional STC by Rocket that appears to increase the gross weight. I've omitted the first page but it requires SE5691NM to already be on the airplane.

sa00243se.thumb.jpg.476921cc861d542489a8406fe19ac003.jpg

It's not clear to me if SA00243SE involves changes to the airplane (besides limited nosewheel tires). Does anyone know?

Link to comment
Share on other sites

  • 2 weeks later...

I'm buying the plane the OP, @Schllc , originally questioned - we close this week. As suspected above, a records scrub revealed the 721 UL was an issue with the second STC not being applied in the W+B or logbook. Both STCs were present in the logbook, but the Max Gross was still showing 3017. She's not as "big boned" as originally thought, she just had on tight pants. With the adjustment to 3200, the UL is 904. Both the W+B and logbook have been corrected with entries by the A&P and IA and the plane is almost ready to come to her new home. She's going on a weight-loss program and we're expecting 1k UL in the near future. 

  • Like 3
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.