inverted Schweizer towhook

On Wednesday, July 29, 2020 at 8:07:01 AM UTC-7, Dan Marotta wrote:
When I suffered an engine failure at around 200' while still over the
runway and while towing my wife (she was pre-solo), she was pulling her
release while I was pulling my release.Â* She returned safely to the
runway and after rolling to a stop, her instructor asked, "Did you do
that?"Â* She replied in the affirmative.

On 7/29/2020 6:48 AM, wrote:
On Wednesday, July 29, 2020 at 12:55:38 AM UTC-4, 2G wrote:
On Tuesday, July 28, 2020 at 9:28:02 PM UTC-7, wrote:
On Tuesday, July 28, 2020 at 9:53:55 PM UTC-4, wrote:
On Tuesday, July 28, 2020 at 6:22:48 PM UTC-7, Charles Longley wrote:
By the way why would you install a Schweizer hook when that Tost hook is a better, safer product?
Charles, my club has two pawnees, each with (non inverted) Schweizer towhooks. The proposal being considered is that we invert these existing hooks, since that cost seems much lower than buying two Tost hooks (listed at at about $2,500 each). If cost was no issue, I would prefer to instal two Tost hooks personally. The reason for inverting the Schweizer hooks is to hopefully eliminate the possibility that these hooks fail to release in a kiting incident.
The inversion of the Schweizer hook is the least that should be done but I agree with Mr Longley, the Tost hook is a better safer product. While you are at it why not insure that the release handle is available to the tow pilot while in the upright, seated position? I can tell you from experience that when you are in a sudden kiting situation, reaching for the handle down on the floor isn't easy. Towing is dangerous as we all know, everything that can be done SHOULD be done to give the tow pilot a fighting chance to stay alive.

What I find most telling is that the last two kiting incidents resulting in the death of the tow pilot had INSTRUCTORS at the controls of the glider. INSTRUCTORS!!! How can you expect a 15 year old kid with her head up her ass to respond correctly when INSTRUCTORS can't seem to do so?

Invert the hook or better yet, spend the money for the Tost system and bring the release handle up where the tow pilot will have a fighting chance when incompetence and lack of attention raises its ugly head. ANYTHING less and you are not serious about safety.

Walt Connelly
Former Tow PIlot
Now Happy Helicopter Pilot
The last fatal accident proved conclusively that even if you have the ideal release system (in that case a guillotine that severed the rope) you cannot guarantee that the tow pilot will be saved. You need a KGARS.

Tom
Very true. Flying tow is dangerous but the fact remains, if instructors can't be trusted to fly the airplane, to not properly secure the canopy before take off, to not reach for the canopy when it opens low on tow, to not take their eyes off the tow plane even for a moment, to not release IMMEDIATELY on losing sight of the tow plane, how can young students be expected to perform flawlessly? Often our instinctive reactions are the wrong reactions. I am appalled that today there are still tow planes with Schweizer hooks conventionally installed. Nothing in aviation is 100 percent safe, never has been, never will be but to ignore the most evident of dangerous conditions is folly.

Walt Connelly

--
Dan, 5J

I'm glad that she didn't release YOU!

Tom

Tow....@gmail,

I see that I did not address this portion of your question, my apologies....

"To make it clear, I'm asking about a Pawnee that already has a Schweizer hook installed.....what paperwork will it take to invert it?"

If this were me wanting to invert the hitch I would persue a field approval to do so.
I would use the 43.13 data that guides the installation for the hitch and present to the FAA that an inverted hitch is obviously considered to operate correctly on an aircraft because 43.13 clearly accepts its inverted use for tricycle gear aircraft.
Show them how your inverted installation will be completed and how it meets all the other clearance and strength requirements contained in 43.13. State the improved safety reasons as why you want to make this change.

Charles attached the ac 43-210a guidance on persuing a field approval in a previous post above, it is good.


If you do this for your aircraft the paperwork is clean and all controversy for this installation is removed.
If you do invert it by simply stating 43.13 as the reference, you will always be opened to opposing views.

If its inverted, a towing accident happens and my name is documented as having put it inverted on a Pawnee....I personally want as little controversially documentation as possible.

If I was asked to invert a Schweizer hook I would try and talk whoever wanted it into a Tost hook. If I couldn’t I believe I could use AC 43.13-2B, Chapter 8, paragraph 804 (a), the manufacturers data and other parts of Chapter 8 as appropriate. Field Approvals are kind of hit or miss in my area. In block 8 of the 337 I would start out, “For safety .....�.

On Saturday, August 1, 2020 at 8:28:30 AM UTC-7, Charles Longley wrote:
If I was asked to invert a Schweizer hook I would try and talk whoever wanted it into a Tost hook. If I couldn’t I believe I could use AC 43..13-2B, Chapter 8, paragraph 804 (a), the manufacturers data and other parts of Chapter 8 as appropriate. Field Approvals are kind of hit or miss in my area. In block 8 of the 337 I would start out, “For safety .....�.



Thank you, to all who offered their advice on this. It is appreciated.

Definitions provided in 14 CFR Part 1.1 state, “Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications—

(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or

(2) That is not done according to accepted practices or cannot be done by elementary operations.�

Note that Advisory Circular 43.13-1b/2b, which is by definition acceptable data, covers basic tow hook installation. Flipping the hook-- arguably a removable, already installed appliance that effectively changes nothing on the airframe itself-- isn't a major mod. Since Schweizer isn't around anymore to adjudicate, just do it if you're convinced it's safer. Or better yet, buy the Tost.

Larry Ruggiero A&P/IA, tow pilot

My gliding club still has not got FAA approval to invert the current Schweitzer towhooks on their two Pawnees. The reasons are too complex to describe, but I feel it would help if we had photos of FAA approved inverted Schweitzer towhooks installed on Pawnees, showing exactly how it was done. Can anyone send me such photos? The more the better. Thanks in advance. Send any photos to raxyloid then gmail then com.

On Sunday, August 23, 2020 at 3:16:29 PM UTC-7, NEW YEARS RESOLUTION 2010 MOCIUNPICTURES wrote:
My gliding club still has not got FAA approval to invert the current Schweitzer towhooks on their two Pawnees. The reasons are too complex to describe, but I feel it would help if we had photos of FAA approved inverted Schweitzer towhooks installed on Pawnees, showing exactly how it was done. Can anyone send me such photos? The more the better. Thanks in advance. Send any photos to raxyloid then gmail then com.

You’re probably going to spend more money trying to get the Schweitzer hook inverted than just buying the Tost hooks.

On Sunday, August 23, 2020 at 3:16:29 PM UTC-7, NEW YEARS RESOLUTION 2010 MOCIUNPICTURES wrote:
My gliding club still has not got FAA approval to invert the current Schweitzer towhooks on their two Pawnees. The reasons are too complex to describe, but I feel it would help if we had photos of FAA approved inverted Schweitzer towhooks installed on Pawnees, showing exactly how it was done. Can anyone send me such photos? The more the better. Thanks in advance. Send any photos to raxyloid then gmail then com.

I'm still trying to find a copy of the 337 for inverting a Schweizer towhook on a Pawnee. It seems I need a N number for the FAA to track down a copy of the 337. The 1996 article attached says a 337 was granted by the FAA, and I suspect this was for the Pawnees operating at Turf. Does anyone know the N numbers of the Pawnees operating in the 90s at Turf?

https://www.dropbox.com/s/bsp9r0oj2n...hooks.doc?dl=0

Rick Brown at the Pleasant Valley Airport in Peoria, Arizona knows. I don't know if he will help you tho.....

Boggs