Vintage Mooney Cowling Mod

[DXB]

6 minutes ago, Sabremech said:

on my first test flight the cylinder temps are down about 30 degrees Fahrenheit.

If this holds up in the following weeks, it will officially be a Christmas miracle for C owners everywhere!  

[Raptor05121]

Maybe Christmas 2016.

But I am really really excited by this.

[mike_elliott]

9 hours ago, Sabremech said:

Hi francisg,

on my first test flight the cylinder temps are down about 30 degrees Fahrenheit. I'm  sealing up my baffling and replacing one of my baffle seals to close an air gap. My new carb airbox almost works too well in that when the carb heat is pulled to full on, the engine stumbles briefly. I need to limit the travel of the carb heat to keep it from stumbling as the temp increase is more than sufficient in less than full on position. I'm also adjusting the cowl flaps in different positions to see what impact that has on cylinder temp. It will be about a week and a half before I take it back up on another test flight. I'll do a couple more general test flights to work cowl flap data then do the performance flights to see what gain in performance I achieved. 

Thanks,

David

Hi David, bear in mind what Bob Kromer said about cowl flap positioning in his presentation at the Mooney Summit. Granted, your cowl design changes all the rules, but the gist was to make sure you evacuate the air that is induced for less drag along with cooling.

[Mooneymite]

2 hours ago, mike_elliott said:

....... but the gist was to make sure you evacuate the air that is induced for less drag along with cooling.

Which makes me wonder how the new cowling will work for those doghouse C's that have fixed cowl flaps.

Maybe better?

[Sabremech]

Hi Mike,

 I'm following Bob K's advise. For the first test flight I had the cowl flaps open an inch plus when in the closed position. On my upcoming flight, I'm putting them back to the book spec to see what difference there is. I'll also be trying them in different positions when I do my performance flights.

 Thanks,

 David

[jamesm]

Hi David,

How is the testing of the new cowling going? 

Cooler CHT than expected ?

Do you have prove to the FAA for carb Icing conditions?

 

Thanks,

[Sabremech]

Hi Jamesm, 

I'm tightening up the baffling right now and adjusting the carb heat. My CHT's are down about 30 degrees Fahrenheit right now. I'm hoping to get them down a little more. 

I will have to provide data to the FAA during the STC process that my carb heat works as well as or better than the original carb airbox. 

Thanks,

David

[DaV8or]

Just curious David, technically your plane is now an Experimental in the R&D category now. Did you have to get a new certificate, or paperwork from the FAA? Is your plane now required to have the "EXPERIMENTAL" placarding on it?

[bradp]

Just now, DaV8or said:

Just curious David, technically your plane is now an Experimental in the R&D category now. Did you have to get a new certificate, or paperwork from the FAA? Is your plane now required to have the "EXPERIMENTAL" placarding on it?

And is each test flight required to have a special permission from the FAA (like a ferry permit) ?

[Sabremech]

 I was able to get the modification done on my airplane as a field approval (FAA form 337) so no experimental category or restrictions on the flights I'm doing.

 Thanks,

 David

[Hank]

Love your new avatar, David! One day . . . .

[N601RX]

7 hours ago, Sabremech said:

 I was able to get the modification done on my airplane as a field approval (FAA form 337) so no experimental category or restrictions on the flights I'm doing.

 Thanks,

 David

Were you able to get the FSDO to do the approval or was it done by a DER? Did they require any fly offs before completing the approval?

[Sabremech]

I was able to get the approval through the FSDO (no DER yet) and no fly offs before signing it off. I did submit a 337 with my data for pre approval before starting my project as I didn't want my airplane potentially unable to fly while waiting on the STC process.

Thanks,

David

[DaV8or]

9 hours ago, Sabremech said:

 I was able to get the modification done on my airplane as a field approval (FAA form 337) so no experimental category or restrictions on the flights I'm doing.

 Thanks,

 David

Wow. That is amazing. I've been told nothing but horror stories about the FSDOs and how they are pretty much denying everything. Stuff like putting the factory stock 201 cowl on a vintage Mooney. Clearly not all FSDOs are created equal. It seems so inconsistent. Why not skip the STC, sell the kits as is and tell everybody to go down to the FSDO, get approval and file a 337 like you did? 

The FAA and the FARs have become sort of nonsensical at times too me. Just let us all certify our planes as Experimental / Factory Built, have the same privileges as somebody buying a used kit plane and be done with it!

[Shadrach]

Dave,

That would never work. Years ago I was part of an HID landing light group buy on the Mooney Mailing List. I think we had north of 20 purchasers in the group. The first guy to get it approved sent everyone the 337 he used to attain his "Field Approval".  We all used the same 337 with the exact same wording...initially. The ensuing $hitshow of bureaucratic inconsistency and subjectivity jaded me quite a bit. There were FSDOs that refused to even consider "Field Approval" stating that installation was illegal, there were FSDOs that stated no "Field Approval" was needed as the HID was a drop in replacement, and there was just about everything in between. As far as I know, very few were able to use the original 337 wording. Almost every FSDO had to send it back once to have the wording tweaked to theirsatisfaction.

[Hank]

Nothing quite like consistent application of the rules! Gotta love the multiple mini-bureaucracies spun off by FAA HQ in DC . . .

[Sabremech]

Shadrach and Hank summed it up well. The only way for me to guarantee that my kit can be installed following the rules is to get an STC. 

Thanks,

David

[DaV8or]

38 minutes ago, Shadrach said:

Dave,

That would never work. Years ago I was part of an HID landing light group buy on the Mooney Mailing List. I think we had north of 20 purchasers in the group. The first guy to get it approved sent everyone the 337 he used to attain his "Field Approval".  We all used the same 337 with the exact same wording...initially. The ensuing $hitshow of bureaucratic inconsistency and subjectivity jaded me quite a bit. There were FSDOs that refused to even consider "Field Approval" stating that installation was illegal, there were FSDOs that stated no "Field Approval" was needed as the HID was a drop in replacement, and there was just about everything in between. As far as I know, very few were able to use the original 337 wording. Almost every FSDO had to send it back once to have the wording tweaked to there satisfaction.

I know, that's the kind of crap I was talking about. Field approvals are very, very spotty and individual dependent. I had read on the AOPA forums years ago by some that work with the FAA that the FAA was working to become more uniform nation wide and the easiest way to do that was just to say "no" everywhere. All second hand internet talk, so I'm not so sure how factual it is.

That's why I'm surprised in this case. Some guy invents his own cowling and baffling system that hasn't been tested yet, puts it on the plane and the FSDO says- "Yeah, alright. Good enough for me. Your plane is still a factory certified airplane."   Another guy some where else puts an LED light in his wing tip, and the plane is grounded.

I don't get it.

[Marauder]

There is an FAA function that specifically manages the small plane programs. I have seen letters issued by this office. Has anyone contacted the manager for this program? I think they were the ones that issued the electronic attitude indicator as a replacement to a vacuum one decision.

It might be good to find out what that office can offer in terms of alignment.

Sent from my iPad using Tapatalk

[mike20papa]

Yes,
A FIELD APPROVAL!!??  Wow, David!  Right on! 

All comments aside..it is the issue I wish AOPA would pick up after this medical thing.  The whole 337 enchilada, with or with out onions, TEX MEX, or just what comes out of the oven at your local FSDO from one day to the next.  It's a freekin' joke!

[Sabremech]

Hi Dave,

The FAA approved my mod by a field approval as I supplied them the data they needed to satisfy any concerns they had. The components I used were being used on a very similar performing aircraft (Vans RV's) with the same engine and propeller combinations that are on my Mooney. It wasn't extremely difficult to get it approved, but it wasn't easy either. 

Thanks,

David

[DaV8or]

1 hour ago, Sabremech said:

Hi Dave,

The FAA approved my mod by a field approval as I supplied them the data they needed to satisfy any concerns they had. The components I used were being used on a very similar performing aircraft (Vans RV's) with the same engine and propeller combinations that are on my Mooney. It wasn't extremely difficult to get it approved, but it wasn't easy either. 

Thanks,

David

That's great. I'm glad it all worked out for you. I just can't understand the inconsistencies and twisted logic that is our federal bureaucracy. 

[Sabremech]

Hi Dave, 

I think the FAA could improve on the field approval process if they would make themselves like a repair station in that the inspectors could approve a mod using an FAA cert number instead of being like individual AP/IA's each being held personally accountable for the return to service. 

Just a thought.

David

[DaV8or]

23 minutes ago, Sabremech said:

Hi Dave, 

I think the FAA could improve on the field approval process if they would make themselves like a repair station in that the inspectors could approve a mod using an FAA cert number instead of being like individual AP/IA's each being held personally accountable for the return to service. 

Just a thought.

David

I guess, but how would they get this "FAA cert number"?

[Sabremech]

Hi Dave,

 The folks in Washington can make it up and issue it to all the inspectors. Sounds simple, but would take 20 years of discussion to come up with a 1000 page regulation.