Larry Lowenkron
Member
Grant sent me a copy of a letter from the Civil Aeronautics Administration (Yes the CAA!) dated Aug 11, 1954, which states (with conditions) that "A fixed pitch metal propeller may be substituted for fixed pitch wood propeller on aircraft that have been previously approved with fixed pitch wood propellers..."
I have retyped the letter below to the best that I can read it. The copy is not the greatest, but it sure should help anyone trying to install a Sensenich!
C O P Y
DEPARTMENT OF COMMERCE In Reply Address
CIVIL AERONAUTICS ADMINISTRATION Regional Administrator
Civil Aeronautics Administration
Federal Building
New Your International Airport
Jamaica, New York
Attn: NY-245
August 11, 1954
Sensenich Corporation
Lancaster, PA.
Attention: Mr. M. K. Allen
Supervisor of Sales & Services
Gentlemen:
This is in reply to your letter of June 15, in which you request approval for a list of aircraft with Sensenich metal propellers installed, based upon approval granted several different installations of engines and aircraft.
We have several reports approving metal propeller installations and they demonstrate that the metal propellers are more effieient than the corresponding wood propellers and that they produce more cooling air flow to the engine cylinders.
This office now has sufficient data to enable us to approve the installations requested in your letter of June 15, 1954.
A fixed pitch metal propeller may be substituted for fixed pitch wood propeller on aircraft that have been previously approved with fixed pitch wood propellers, if it is rated for the horsepower and maximum r.p.m. of the engine and is approved vibration wise with the engine. The r.p.m. and diameter limits of the wood propeller should be used for the metal propeller unless your company or the installer desires to determine wider limits. This may be done for any model aircraft by checking in flight that the propeller installed does not permit engine overspeeding in full throttle climb at best rate-of-climb speed and does not cause the engine to exceed 110% of its maximum approved speed in power off glide at placard maximum dive speed .
Sincerely yours,
/s/ S.M. Ross
For: E.O. Marsh, Chief
Aircraft Engineering Division
C O P Y
The last name may be E.O. Mersh, but it isn't too clear on my copy....So, guys, you who have been struggling with using a Sensenich on your Cruisairs...have at it!
Larry
I have retyped the letter below to the best that I can read it. The copy is not the greatest, but it sure should help anyone trying to install a Sensenich!
C O P Y
DEPARTMENT OF COMMERCE In Reply Address
CIVIL AERONAUTICS ADMINISTRATION Regional Administrator
Civil Aeronautics Administration
Federal Building
New Your International Airport
Jamaica, New York
Attn: NY-245
August 11, 1954
Sensenich Corporation
Lancaster, PA.
Attention: Mr. M. K. Allen
Supervisor of Sales & Services
Gentlemen:
This is in reply to your letter of June 15, in which you request approval for a list of aircraft with Sensenich metal propellers installed, based upon approval granted several different installations of engines and aircraft.
We have several reports approving metal propeller installations and they demonstrate that the metal propellers are more effieient than the corresponding wood propellers and that they produce more cooling air flow to the engine cylinders.
This office now has sufficient data to enable us to approve the installations requested in your letter of June 15, 1954.
A fixed pitch metal propeller may be substituted for fixed pitch wood propeller on aircraft that have been previously approved with fixed pitch wood propellers, if it is rated for the horsepower and maximum r.p.m. of the engine and is approved vibration wise with the engine. The r.p.m. and diameter limits of the wood propeller should be used for the metal propeller unless your company or the installer desires to determine wider limits. This may be done for any model aircraft by checking in flight that the propeller installed does not permit engine overspeeding in full throttle climb at best rate-of-climb speed and does not cause the engine to exceed 110% of its maximum approved speed in power off glide at placard maximum dive speed .
Sincerely yours,
/s/ S.M. Ross
For: E.O. Marsh, Chief
Aircraft Engineering Division
C O P Y
The last name may be E.O. Mersh, but it isn't too clear on my copy....So, guys, you who have been struggling with using a Sensenich on your Cruisairs...have at it!
Larry
