Aeromatic propeller

I have one on my criuseair and love it. much easier to slow down than with an fixed pitch prop.....
 
There are a few who disagree, however, I believe the Aeromatic propeller, properly setup, is the best all around prop for the 150/165 Franklin powered Cruisair. There is no "rocket science" involved with a proper setup. You need to follow the available manuals. Do not accept an as received propeller as being "good enough." Beg, borrow, or steal a digital tach checker to verify the on board tach. Those old mechanical tachs can be 100 RPM off. Dan
 
Dan is right, start with good grounds before doing anything, had 150 rpm mistake on mine checked with digital r.p.m. tool.
:shock:

Gone for overhaul at Keystone Instruments.
I whish I could get aeromatic. Need the fine pitch for take off with this machine and 150 or 165, this is not the most powerful engine when full of gas, warm and humid weather and passenger content. Once in the air, fine pitch over rev the engine because it is a slippery bird. So now you need coarser... I feel aeromatic is the best formula without adding much weight like a CS of some kind.

Alain.
 
Thanks for the feedback. Mine came with an Aeromatic but had rot. I think I will plan to save up some money and make the plunge for the new Aeromatic. My A and P is not a fan because of the lag screws which keep the blades from going their own separate ways. But it seems they have a pretty good record of remaining with the plane. It wil probably be a few months before I send my money away.
 
There are a few serviceable Aeromatics still out there. Unused on shelves, garages and hangars. If in doubt about it's airworthiness, send it to Kent Tarver for inspection and or repair. I think all adjustable pitch wood blade propellers, Aeromatic, Sensenich Skyblade, Beech, Beech Roby, Erco, Hartzell, and many more used lag screws to attach the blade to the metal shank. As a general rule, these have not been a problem. Make sure the used prop you buy is applicable to the 14-13 series as Aeromatics were used on many airframe/engine combinations. Dan
 
i have a 46 cruisair 14-13-2 (N86728) with 165 franklin that has right carb, zone and manifolds.

it had a sensenich fixed metal prop on it when i bought it in 1991. i had it repitched about 10 years ago to its maximum flat pitch to give me the best climb possible. the 165 at 2700 rpm on a long flight at 3500 to 5500 altitude would give me a true air of around 140mph. climb out was good enough - ok.

i bought a new kent tarver aeromatic and installed it about two years ago. my field elev in upstate SC is 780 msl.

the aeromatic turns up more static and gives me maybe 200 rpm more on take off and an additional 200 fpm climb out. i can only cruise it at 2450 rpm max, so my cruise speed came down to around 125 mph with the aeromatic vs. the fixed sensenich metal prop.

spoke to kent numerous times and played with the aeromatic setup half a dozen times. kent sent me an old data sheet that compared fixed prop performance with the aeromatic performance on a stinson (the aeromatic greatly improved the performance over the fixed). i concluded that that old data was comparing a fixed wood prop with the aeromatic.

my final thoughts > i really wanted to put an aeromatic on the cruisair, i did so and it looks beautiful. i get a little better climb performance which is important to me. the cruise speed came down but i am running at a lower rpm which must mean something, and i hope it is something good. i think that fixed metal props are much more efficient than fixed wood props.

re: the lag screws > take a look at kent's discussion about the screws and the tests he did and the forces that they are designed to resist. i had an old aeromatic that i 'disassembled' and i pulled a few of the screws out . . . those babies are really in there. as long as the prop doesn't sit around outside in the weather i think they will be just fine.

jeff warren
 
What kind of climb numbers can you get with your aeromatic? I also have a '46 with a 165 , cruise at about 130 mph throttled back to 2400 rpm can see 140 wide open . I find the cruise acceptable but climb is pretty slow, 500 fpm about the best, 300 more common. Would like to change prop to get better climb but hate to lose speed.The aeromatic sounds good, but have heard some not so good reports also, sounds like you were getting pretty good results from your fix
ed pitch steel prop,mabee thats the way to go. Prop I'm using now is wood Sensenich 74RR66
Thanks, Richard
 
Guys............you are not hearing me!!!! You are comparing apples and oranges. Read my old posts! You are not checking your Tach and not getting the propeller set up correctly. Jeff, do you really think you are going to get equal cruise performance at 2450 rpm with the Aeromatic as you did at 2700 with a fixed prop. Properly adjusted, your Aeromatic should turn 2800 rpm, the rated rpm for the 165, flat out over those South Carolina badlands at 3000' MSL. Now, back off to 2550-2600rpm and you should see at least 140mph TAS. If your prop is correct...........It should also turn 2800rpm as you break ground during takeoff. There are several manuals for setting up the Aeromatic propeller. The one I like is called "Field Service Instructions for the Model F-200 Aeromatic Propeller," published by Univair Aircraft Corporation. If you will read, understand and follow the instructions in these manuals, you will have far more knowledge than 99.9% of all the A&P mechanics out there. As an A&P, I wouldn't let another mechanic near any of my Aeromatics, unless he/she demonstrated knowledge of it's workings. Those of you with the Franklin 150.......everything applies to you, except that the rated RPM is 2600. Nuff said! Dan
 
Dan,

I read, reread, and think that I understood and followed the instructions in the 'field service instructions F-200' and the much more specific "Installation Procedure and Operating Limitations No. 84" for the F-200 mounted on the Franklin 165 for a 14-13-2; and at least six conversations with Kent Tarver. The field service manual does not get as specific as the No. 84 Instruction re RPM targets and limits.

Both the No. 84 Instruction and the DOT FAA Aircraft Specification No. A-773 (Type Certificate) dated October 1, 1973 for the 14-13-2 specify that the Koppers F-200 mounted on the 165 Franklin shall be red-lined at 2650 RPM. The type cert does list the 165 engine limits as 2800 RPM; but the F-200 RPM limit is clearly shown as 2650. Instruction 84 states that ". . best performance and economy may be obtained [at] cruise 2450 RPM . . .".

When I set it up I used a digital tach and kept pretty good data records of all my test flights.

Kent Tarver told me that he has heard that some folks will run the aeromatic at 2800RPM but he did not recommend it based on Instructions No. 84 and the Type Certificate.

Kent told me that there were at least two adjustments that could be made to the Aeromatic that might increase my cruise without affecting the climb performance but that those adjustments needed to be done by a prop shop or by him. That means crating, insuring, shipping, - or leave it as is and fly the plane.

If there is another setup instruction that says something different, let me know what it is and so I can take a look at it.

I did not state nor did I ever believe that I would get the same performance with an Aeromatic at 2450 as i did with the metal prop at 2700; I was just stating what I experienced. I believe it is possible to set the Aeromatic to turn 2800 RPM but that is not certified in any instructions or manuals I know about.

jeff
 
I will state that the final authority on the the operation of this propeller is Kent Tarver. He is the TC holder and manufacturer. I know him personally and respect his input and knowledge. I have seen that 2650rpm limitation many times. However, if you restrict yourself to that, you do not have a 165HP Franklin........maybe 154hp. Call Kent. Don"t call me, Jeff. Your hand on the throttle is the limiting factor. If that prop won't turn 2800 on Takeoff and turn 2800 rpm in level flight at 3000msl......you don't have a 165 Franklin. Dan
 
Yes, i have realized that that is what those limitations mean. My conclusion is then that there must be a risk that the aeromatic may be damaged or come apart over 2650rpm. I'll call Kent again and ask if he knows of any F-200 that is permitted to run up to 2800 on any other airframe/engine combo. That might shed another light on those restrictions.

Maybe the F-200 was originally designed to accommodate a 150hp and never upgraded or certificated for the 165, except at the lower rpm.

jeff
 
I don't know about the after the fact 165 Franklin installations, especially in the Stinson -2 and -3 models. If you abided by the published limitations, you should have very acceptable performance. Dan
 
Dan, I have been going through all of my paper stuff about the aeromatic and came across an Installation Procedure No. 110 (may be "11C") for the Aeromatic for the Stinson 108-2, 108-3 and (also noted in the title) the Bellanca 14-13-2/3. It included a note at the end that the copies of the other instructions I have did not include (all the others did end right at a page bottom, so it may have been on a next page that wasn't included in the copies).

Here it is:
===============
"NOTE:
An extensive vibration survey has been made with our [Koppers] propeller Model F200/00-76B installed on the Franklin engine Model 6A4-165-B3. The propeller was found to be in resonance at 2700 - 2800 RPM. This may eventually result in either propeller or crankshaft failure.

In order to reduce exposure to this condition, a never exceed 2650 RPM placard is to be installed in all Aeromatic equipped Stinson Model 108-2 and 108-3 airplanes; and the tachometer is also to be red-lined at 2650 RPM.

With full throttle regulated at 2650 RPM, the net propulsive thrust is not reduced, as the blade efficiency is increased by a reduction in the tip speed loss. The airplane performance should, therefore, not be changed. A recommended cruising engine speed is 2400 - 2500 RPM."
================

The note does not specify this being applicable to the 14-13's but I'm going to believe it must be for the 165 whatever it might be hung on to. The last paragraph of the note sounds like it might have been authored by a marketing department with a highly active imagination; an aeronautical engineer with a specialty in blade airfoils would likely have interesting comments (pro or con).

jeff
 
Dan,
I called Univair Aircraft Corp. to see if I could get a copy of "Field Service Instructions for the Aeromatic Propeller", but was told that they aven't had that publication for many years. They sold their Aeromatic certificate to Kent Tarver, so I placed a call to him to see if he has the manual available but haven't heard back yet. If I can't locate one, what would be your second choice for the best resource? :?:
Gary Brink
 
I put one on my Cruiseair and love it. As nead as I can tell, I gained about 300fpm on takeoff and about 7 mph in cruise over the metal fixed pitch I had. I'm getting a shorter takeoff roll, too because the engine turns 2550 from the instant I advance the throttle.

Bill
 
You must log in or register to reply here.
Back
Top