Does an Engine upgrade STC still apply if the engine is removed or changed???

[BiffJ]

I know some STC's are one time affairs...you buy the super deluxe engine monitor system and it comes with an STC that lists the serial of the unit. You blow up the unit and the STC isn't valid anymore. You buy a new unit and get a new STC with a new serial.
Other STC's apply as long as the conditions are met. Autogas STC's are good as long as you don't change the model of engine in the STC'd plane. You can swap engines or overhaul with no issues....go to a different horsepower or different make and you need a new STC.
At least this has been my understanding in the years I've been working on planes...
I've come across a Cessna 170 project which had an Avcon STC for the lycoming O-360 180HP conversion. The airplane was groundlooped which damaged the fuselage where the landing gear leg fits. The plane was then disassembled. The engine, prop and cowling were later sold. I don't have the STC paperwork other than the 337 and the owners manual supplement however the supplement has the STC (not the engine) serial number and the aircraft N number on it. There is no engine serial listed other than in the 337. Now the question is, if I choose to rebuild this plane can I put the O-360 in it with no more than a 337 to show the major repair or will I have to buy an STC from someone else to do this? (Avcon is gone). All the mods which the STC required are still there other than the engine and mount....reinforcements on the firewall, larger fuel lines etc....
It may be a moot point but I'd like to know.

Thanks
Frank

 

[Tom-D]

I know some STC's are one time affairs...you buy the super deluxe engine monitor system and it comes with an STC that lists the serial of the unit. You blow up the unit and the STC isn't valid anymore. You buy a new unit and get a new STC with a new serial.

Think Appliances, if you replaced that unit with another of the same design it will still apply, just because you receive a new unit with new paper, doesn't mean the STC no longer applies. they issue a standard off the assembly line package. which includes all the above.

Other STC's apply as long as the conditions are met. Autogas STC's are good as long as you don't change the model of engine in the STC'd plane. You can swap engines or overhaul with no issues....go to a different horsepower or different make and you need a new STC.

Correct so far.

At least this has been my understanding in the years I've been working on planes...
I've come across a Cessna 170 project which had an Avcon STC for the lycoming O-360 180HP conversion. The airplane was groundlooped which damaged the fuselage where the landing gear leg fits. The plane was then disassembled. The engine, prop and cowling were later sold. I don't have the STC paperwork other than the 337 and the owners manual supplement however the supplement has the STC (not the engine) serial number and the aircraft N number on it. There is no engine serial listed other than in the 337. Now the question is, if I choose to rebuild this plane can I put the O-360 in it with no more than a 337 to show the major repair or will I have to buy an STC from someone else to do this? (Avcon is gone). All the mods which the STC required are still there other than the engine and mount....reinforcements on the firewall, larger fuel lines etc....
It may be a moot point but I'd like to know.

Thanks
Frank

The Engine upgrade STC is still good, if you buy and install the same make and model engine, You can if you wish buy any STC and install it. place a 337 in history as to the change.

The gear box is another problem. they are almost impossible to repair with out a fuselage fixture. I have never seen a 170 gear box repair that was done without placing the fuselage in the fixture and setting the gear box straight, they will wear tires and not track straight, and if they don't it could be your demise on a windy day.

And if it had the PeePonk gear mod, the fuselage is toast. when the gear is pulled out with the PeePonk mod installed it virtually pulls the flap handle out thru the bottom of the aircraft.

 

[BiffJ]

I've also heard the P-Ponk mods make damage much worse when it does happen. This one does have damage to the floor, outerskin and the doorpost but its pretty localized. I've seen a couple where the bottom was wrinkled all the way back to the baggage compartment bulkhead. In any case I don't think I'm going to tackle the rebuild but wanted to know if the thing could have a 180 put back in without a new STC...especially since they are very few anymore. I know there is a 170 rebuilder down in Arkansas . I think he's got a fuselage jig....I'll put a post on the 170 association board and see.

Thanks
Frank

 

[BillTIZ]

Our 0-540 235 HP STC upgrade to 250 HP came with two STCs.
One to upgrade the engine and restamp the engine model designation.
The 2nd STC was to mount a 250 HP engine to the airframe.

The first STC stays with the engine, the 2nd STC stays with the airframe.

 

[poadeleted20]

Bottom line is that the STC goes with the airframe, usually by s/n, not the engine. The engine might be removed and installed in a plane for which it was originally intended, and another identical engine installed in the plane with the STC without further STC/337 paperwork. So, while you do need an STC to legally have that engine in that plane, you shouldn't need to buy another one, because the one originally issued remains valid even if you can't find it.

Normally, you'd contact the STC holder and ask for another copy -- they should have that s/n on record as having received one before. However, if the STC holder is defunct, you may have a problem. You might contact the FAA ACO which covers that STC to see if they can help.

 

[Tom-D]

Bottom line is that the STC goes with the airframe, usually by s/n, not the engine. The engine might be removed and installed in a plane for which it was originally intended, and another identical engine installed in the plane with the STC without further STC/337 paperwork. So, while you do need an STC to legally have that engine in that plane, you shouldn't need to buy another one, because the one originally issued remains valid even if you can't find it.

Normally, you'd contact the STC holder and ask for another copy -- they should have that s/n on record as having received one before. However, if the STC holder is defunct, you may have a problem. You might contact the FAA ACO which covers that STC to see if they can help.

To add, when the STC owner no longer supports the STC in any manor, it is known to be in public domain, and the FAA will allow it to be used as appropriate, in any manor you can prove compliance with it.

IOWs, if your buddy has a copy you can use it, if your type club has a sopy you can use it, with out the owners permission.

this was recently approved in guidance given to the ASIs to open the used of old STCs that no one was supporting

 

[BiffJ]

Thanks guys. Anyone know who owns the Avcon STC's now that Avcon is gone...?

Frank

 

[Steve]

Thanks guys. Anyone know who owns the Avcon STC's now that Avcon is gone...?

Frank

Maybe you've already checked this out

http://www.butlernational.com/stc.htm

hard to tell if it's still a live site or not, but it appears Butler National is still in business.

Edit: Nevermind, looks like they mainly do turbine work STC now


If you know the STC number it might make it easier to track down.

 

[N801BH]

I know some STC's are one time affairs...you buy the super deluxe engine monitor system and it comes with an STC that lists the serial of the unit. You blow up the unit and the STC isn't valid anymore. You buy a new unit and get a new STC with a new serial.
Other STC's apply as long as the conditions are met. Autogas STC's are good as long as you don't change the model of engine in the STC'd plane. You can swap engines or overhaul with no issues....go to a different horsepower or different make and you need a new STC.
At least this has been my understanding in the years I've been working on planes...
I've come across a Cessna 170 project which had an Avcon STC for the lycoming O-360 180HP conversion. The airplane was groundlooped which damaged the fuselage where the landing gear leg fits. The plane was then disassembled. The engine, prop and cowling were later sold. I don't have the STC paperwork other than the 337 and the owners manual supplement however the supplement has the STC (not the engine) serial number and the aircraft N number on it. There is no engine serial listed other than in the 337. Now the question is, if I choose to rebuild this plane can I put the O-360 in it with no more than a 337 to show the major repair or will I have to buy an STC from someone else to do this? (Avcon is gone). All the mods which the STC required are still there other than the engine and mount....reinforcements on the firewall, larger fuel lines etc....
It may be a moot point but I'd like to know.

Thanks
Frank

Getting another mount that meets the Avcon STC specs will be problematic for sure. IMHO.

 

[poadeleted20]

If you know the STC number it might make it easier to track down.

That should be in the airframe logbook and the 337 for the alteration. Then go to the FAA web site and check the STC page (just search on STC on the home page).