AIRSPEED SAFETY SWITCH AVAILABILITY

[EricJ]

2 hours ago, N201MKTurbo said:

At the last maintenance symposium (I hope there are more someday) I attended a session with the FAA person who approves PMA parts and another session about field approvals. The PMA lady spoke a bit about owner produced parts. In both cases they said that the FAA will not approve an OPP or field approval just because you want to save money. If the part is available, or the STC is available, you have to use it. Which begs the question about McFarlane cables. Most people buy them to save money, not because the factory cable is not available. 

The saving grace on most of this stuff is the FAA doesn't check anything anymore. They don't even read 337s unless it requires an FAA signoff, most don't.

I figure that until McFarlane cables start causing problems, the FAA has better things to do.

AC 23-27 just says that substitution via OPP can apply "where the parts or materials are either difficult or impossible to obtain".    My understanding from the old salt instructors at A&P school was that OPP was originally developed for the airlines so that they could fab their own parts when possible rather than suffer down time due to long lead times or other part inventory issues.    So even if a part is "available", OPP can apply if it is diffcult to obtain.    AC 23-27 also says this helps owners obtain "newer and usually better parts". 

I think most people were going to McFarlane (et al) for cables because there weren't other practical sources.    You could order one from an MSC with a TBD delivery that might be measured in years.   A reasonable person might conclude that constitutes "difficult to obtain".     I don't think they were necessarily cheaper from McFarlane, either.   I ordered two from McFarlane under OPP and one with a Mooney part number once they started accepting that, and the prices weren't any different, and as far as I could tell not much different than what the MSCs would charge when they had them.

 

[DCarlton]

After starting this thread back in 2021, I'm once again in annual and now chasing down an airspeed safety switch.  This will be the fourth one to be installed in my '67F in its life span.  Looks like they're lasting about 10 years roughly.   I noticed Lasar has them advertised at a price less than the original manufacturer.  Trying to chase that lead while chatting with Lasar's bots.  World Magnetics (OEM) has a three week lead time at a higher price.  

https://lasar.com/switches/880013-505-v21614-safety-switch

Any other leads appreciated.  Thanks.  

[EricJ]

11 minutes ago, DCarlton said:

After starting this thread back in 2021, I'm once again in annual and now chasing down an airspeed safety switch.  This will be the fourth one to be installed in my '67F in its life span.  Looks like they're lasting about 10 years roughly.   I noticed Lasar has them advertised at a price less than the original manufacturer.  Trying to chase that lead while chatting with Lasar's bots.  World Magnetics (OEM) has a three week lead time at a higher price.  

https://lasar.com/switches/880013-505-v21614-safety-switch

Any other leads appreciated.  Thanks.  

Does it not work at all or just not switch at a reasonable airspeed?    There've been notes here in the past where people have adjusted and/or repaired them.   

[DCarlton]

5 minutes ago, EricJ said:

Does it not work at all or just not switch at a reasonable airspeed?    There've been notes here in the past where people have adjusted and/or repaired them.   

Doesn't work.  We repaired this one in 2021.  New shop is not comfortable repairing.  Since it's failed twice in two years, I'm inclined to agree to replace.  Might try the other microswitch though.  

[PT20J]

Did you try calling Dan at LASAR? He works out of his home and he’s answered the phone the last few times I’ve called. 

[DCarlton]

Just now, PT20J said:

Did you try calling Dan at LASAR? He works out of his home and he’s answered the phone the last few times I’ve called. 

Tried twice then sent the chat thing.  Phone wouldn't transfer to any of the menu choices.  Will try again next week I guess.