Safe Flight Speed Control

[GAHorn]

Karl, that paragraph does not say permission from the party that got approval from the CAA in most cases, is required.

...

Nor does STC paperwork. But we all know it is (required.) You must contact the supplemental type certificate holder to seek written permission.
Because it's listed on the TCDS does not grant permission for installation... it only means it does have a basis of approval.

[Bruce Fenstermacher]

Karl, that paragraph does not say permission from the party that got approval from the CAA in most cases, is required.

...

Nor does STC paperwork. But we all know it is (required.) You must contact the supplemental type certificate holder to seek written permission.
Because it's listed on the TCDS does not grant permission for installation... it only means it does have a basis of approval.

George, you are wrong. All STC paperwork now has the following statement. This is from one of our own Association STCs:

No written permission for an STC today, you can't use it. Items on the TCDS are not STC'd. They are approved items on the TCDS. That is why permission is not required.

I understand that STC paperwork did not always include this statement. I'm afraid many just copied paper and filled out a 337 and did not have permission required. Some STC owners have issued a blanket statement or letter giving anyone permission to use their STC on any aircraft that is on the eligibility list. STC's for dacron fabric covering and the glue and paint process for Poly Fiber and Ceconite, are two of these that come to mind. Today as I said all STCs have the statement and you must submit the permission that written permission when filling the 337. Before this paperwork went direct to Oak City, you wouldn't get it past most FSDO inspectors missing the permission.

[GAHorn]

The point is being missed, or I am not being effective in describing it....
Unless a basis of approval is provided then an alternative basis must be found for any installation of items listed with an asterisk. The Cessna 170 TCDS listing is only that, ... a listing of products which have gained approval for installation. Each owner must obtain written permission or find another basis to install the equipment. The OLD TCDS system did not automatically provide permission, but only listed certain products which could be approved. I will try to get the legal statement from FAA on this, but the old CAA documents differed in this particular (according to my local FSDO in DFW area.) FAA revised the method and no longer list products on each TCDS.
I would be thrilled if we could simply grab parts and install them because they're mentioned on the TCDS, but I ran into this several years ago when I provided a complete set of installation blueprints to a Member who ran into blockades after he tried to get his system inspected. He ultimately gave up.

[bagarre]

The point is being missed, or I am not being effective in describing it....
Unless a basis of approval is provided then an alternative basis must be found for any installation of items listed with an asterisk. The Cessna 170 TCDS listing is only that, ... a listing of products which have gained approval for installation. Each owner must obtain written permission or find another basis to install the equipment. The OLD TCDS system did not automatically provide permission, but only listed certain products which could be approved. I will try to get the legal statement from FAA on this, but the old CAA documents differed in this particular (according to my local FSDO in DFW area.) FAA revised the method and no longer list products on each TCDS.
I would be thrilled if we could simply grab parts and install them because they're mentioned on the TCDS, but I ran into this several years ago when I provided a complete set of installation blueprints to a Member who ran into blockades after he tried to get his system inspected. He ultimately gave up.

From the TCDS
Approval for the installation of all items of equipment listed herein has been obtained by the aircraft
manufacturer except those items preceded by an asterisk (*). The asterisk denotes that approval has been
obtained by someone other than the aircraft manufacturer. An item marked with an asterisk may not have
been manufactured under a FAA monitored or approved quality control system, and therefore conformity
must be determined if the item is not identified by a Form ACA-186, PMA, or other evidence of FAA
production approval.


That's interesting 'cuz there are a few asterisk'd items that are taken for granted as approved. (like a 35 amp generator or a Scott 3200 tailwheel)
but other items make complete sense that they'd need approval (like javelin tanks)

[GAHorn]

Not to mention the Franklin engine and Sensenich DR props.
I believe the 35A gen was obtained by DelcoRemy for the 172. This was brought up at Continental last summer at the factory tour when "specification numbers" was discussed when ordering engines. TCM (now Continental Engines) no longer rebuilds the O300 so the spec is considered obsolete. For repair purposes, the gen and reg must have PMA/8130-3 (and of course they do).

The old method of TCDS raises lots of questions, but the subject is specifically avoided/overlooked by many owners/inspectors. I don't mean my comments above to be taken as "absolute", ... but only posted them because of past discussions in which I've participated that raised the matter. Those discussions were unsettling because I too would prefer all the TCDS stuff to be "OK" and it became questionable when I heard "expert" opinions on it.
I've searched the archives for Bill O'Brien's opinion on it but haven't found anything, and I'm leery of asking OKC.

[lowNslow]

What was that about saying things twice

[Bruce Fenstermacher]

It depends on what "experts" are in the crowd offering their opinion as to what you might hear.

Prior to the STC format all approved mods regardless of who got the approval where added to the TCDS and they were approved with no further permission required. Still are. However, as was the case even back then, the mods have to be done exactly per the instructions. Quite often today it is impossible to acquire the instructions and that becomes the fly in the ointment when talking legality. This problem is the same regardless whether Cessna, Scott, Continental, Safe Flight, Goodyear, or anyone else got the approval.

The STC program has been in place so long that airplanes produced and certified after the program started don't have any approved mods other than that offered by the manufacturer. Compare the 170 TCDS to a 172 TCDS. You will see the difference.

So it depends on the circles you travel what opinions you will hear. I travel in a circle who fly and maintain golden age aircraft. Their original Jenny being the oldest. My other airplane is a Clipped Wing Piper Cub and of course I follow that circle. These folks are well versed in this subject. While the Jenny doesn't even have a TCDS the Cub TCDS has 625 items on it, most not approved by Piper. The last item #625 is for the Reed Clipped Wing Conversion which my aircraft has. There is no permission, no further approval. But I have the original modification instructions used and my aircraft meets those instructions. (Univair also sells the instructions today).

If you want to clip a Cub today you buy the instructions from Univair. Per the instructions take your saw to the wood spars, a torch and ball peen hammer to the strut fuselage strut attach points, a hack saw and torch to the struts. You fill out a 337 with the approval being the #625 on the TCDS and a log entry in the log books. No permission from Reed required. Reed BTW is dead. And even if he wasn't I just read that after running a business converting many Cubs he decided the conversion destroyed the Cub and was against it being done. So I doubt permission would be forth coming from him.

[Avee8or]

Safe Flight is now producing an Angle of Attack system which is an updated version of the "Speed Control". A vane as in the photos below is mounted on the right wing and connected to an indicator in the cabin--a series of lights indicating basically fast/slow/on target or in reality angle of attack relative to the desired. I have just installed it in 11A and have only a few hours of experience with it. Will post again after having adequate experience to judge if it is as useful as it should be. BTW, I looked at installing the Garmin AoA but we could not figure out how to properly mount it on the 170.