McCauley 1A90 and 1B90 props...

[paulnuss]

I thought I had read on this forum that the McCauley 1B90 was an "approveable" prop for a Taylorcraft BC12-D with Continental A-65-8 engine installed. The basis for approval was: the McCauley 1A90 was shown as an approved prop on the type certificate; and the 1B90 was shown by the manufacturer as an approved/approveable substitute/replacement for the 1A90. By the way, it is a CM7445. I searched the forums and didn't find any direct info to that effect. Anyone know if it is so? And if so, how does one find the supporting paperwork?

[dedrekon]

Re: McCauley 1A90 and 1B90 props...

I have an 1B90 7445 on mine. If you can't find what you need, I'll send you a copy of the 337. It's a great prop....I get a good solid 98mph cruise on just 65 little ponies.

Vincent

[Mark Julicher]

Re: McCauley 1A90 and 1B90 props...

I have the 1B90 also. Works well, lasts a long time...

I called McCauley directly and a tech rep sent me a letter on letter head saying that McCauley regards the 1A90 and 1B90 as totally interchangeable including both thrust and vibration characteristics. I used that letter to get a 337.

[paulnuss]

Re: McCauley 1A90 and 1B90 props...

I just talked to a Tech Rep at McCauley, he was unwilling or unable to send me a letter such as described, to use with obtaining a Form 337. He did say the only difference between the 1A90 and the 1B90 was the tip shape. Instead he referred me to an FAA Type Certificate data sheet #P-842, referencing note 6. I have been all over the FAA website, and so far, no joy in finding the reference. Any chance of a copy of that letter you received, Mark? And the 337 used? Or perhaps help in finding the FAA data? I guess I'll have to be prepared with data for the FSDO in order to get a 337 or field approval or whatever it may take to install this prop.

[Mark Julicher]

Re: McCauley 1A90 and 1B90 props...

Let me go dig the letter out of my records and make it available.
I just have to recall where I put it...I use to know, but I slept since then

[Garry Crookham]

Re: McCauley 1A90 and 1B90 props...

Paul:

Note 6 of TCDS P-842 states:

NOTE 6. Interchangeable blades. Models 1A90 series and 1B90-CM, or 1 C90-ALM and 1C90-CLM are sufficiently similar aerodynamically and
vibrationwise to permit interchangeability in the same diameter and
static r.p.m. without a flight test.

If you need the complete type certificate data sheet let me know and I'll send it to you.

Garry Crookham
Tulsa

[paulnuss]

Re: McCauley 1A90 and 1B90 props...

Hi Garry! I sure would appreciate it if you could send me a copy of the type certificate data sheet you mentioned, for the McCauley 1A90 and/or 1B90 propellor. If by mail: Paul Nuss, 22 Chandelle Drive, Martinsburg, PA 16662 or via fax 814-940-8096 or via e-mail: [email protected] I must leave tonight to go to Seattle Washington area, will return home late Tuesday next week. I may not have internet service available while away. Thank you oh so much!

[NY86]

Re: McCauley 1A90 and 1B90 props...

Any type certificate you could possibly want:
can be found here

[paulnuss]

Re: McCauley 1A90 and 1B90 props...

Thanks NY 86 and all the others who responded. The link NY 86 sent was perfect, it took me directly to the data shhets I needed for the installation via field approval. It is great to have so many knowledgeable and helpful people on the web-site here!

[Mark Julicher]

Re: McCauley 1A90 and 1B90 props...

Paul,
Found it. I will mail you the letter I got from McCauley. It references the TDCS as have the other tribesmen here.

Last sentence in the letter states, "The propeller type certificate data sheet does not give you the approval to install te 1B90/CM on your airplane, but it should definitely help you get the approval through a 337."

[paulnuss]

Re: McCauley 1A90 and 1B90 props...

Thanks to Mark Julicher and garry Crookham, who each mailed to me (from Mark) a copy of a letter to him from McCauley, and (from Garry) a copy of the Type Certificate Data Sheets for the prop. A shining example of the extreme helpfulness and pleasantness of members of this forum, and I am truly appreciative. Now, the quest is on, to get the paperwork all squared away! Again, Thank you!

[cpirrmann]

Re: McCauley 1A90 and 1B90 props...

Remember the FAA's motto: We're not happy til you're not happy.