170 axles

n4517c · Post by **n4517c** » Mon Jan 05, 2004 12:07 pm

During the course of a project, I discovered an interesting detail concerning 170 solid axles; they are not all the same. Both hollow and solid aluminum axles (0541124 and 0541124-1) were machined from 2024-T4 bar until 1959. From 1959 until 1995 0541124-1 was machined from a 2014-T6 forging. Beginning in 1995 0541124-1 was machined from a 7175-T14 forging. This sequence represents an effort by Cessna to strengthen the part. I know of no way to identify the various axles except by alloy analysis. The hollow steel axle ( 1441003-1 ) machined from a 4340 forging is by far the strongest of all, and is STD'd for the 170A and 170B.

jrenwick · Post by **jrenwick** » Tue Sep 14, 2004 1:23 pm

n4517c wrote:During the course of a project, I discovered an interesting detail concerning 170 solid axles; they are not all the same. Both hollow and solid aluminum axles (0541124 and 0541124-1) were machined from 2024-T4 bar until 1959. From 1959 until 1995 0541124-1 was machined from a 2014-T6 forging. Beginning in 1995 0541124-1 was machined from a 7175-T14 forging. This sequence represents an effort by Cessna to strengthen the part. I know of no way to identify the various axles except by alloy analysis. The hollow steel axle ( 1441003-1 ) machined from a 4340 forging is by far the strongest of all, and is STD'd for the 170A and 170B.

Thanks for this information! Do you know who holds the STC for the hollow steel axles? (I didn't see it in the STC list in the 170 book.)

John

n4517c · Post by **n4517c** » Sat Sep 18, 2004 1:02 pm

Some more information for those contemplating installing 1441003-1 hollow steel axles on 170B aircraft. The 1441003-1 axle was designed for use on the Cessna Model 336 airplane and since that time has been used on some versions of the following Cessna Models: 180, 182,185,205,206,210,337, and military O-2. The axle is machined from a 4340 steel forging and is heat treated to 124/145 ksi ftu. All sharp corners are broken to .030 after machining, it is shot peened, the surface finish of all barrel diameters is 125 micro, the surface finish of all inside diameters is 175 micro, it undergoes magnetic particle inspection per CES1018 and is plated. It is secured to the landing gear by NAS145 and NAS146 bolts. The hollow aluminum axle weighs ~0.6 pounds, the solid aluminum axle weighs ~1.2 pounds and the hollow steel axle weighs ~2.2 pounds. In this part of the country, no one with any experience, would consider flying a bushplane with a solid aluminum axle. Too many have learned to hard way with broken axles AND BOLTS. That is why Cessna went to NAS bolts for the heavy duty axles and that is why I went to the trouble to get the STC>

ak2711c · Post by **ak2711c** » Sat Sep 18, 2004 7:20 pm

N4517C that is great info. Who would I contact about this STC? This STC will make my job much easier. I would just like some more basic info. Price of STC, does it specify only Cessna axles or only Airframes INC. axles, does the STC come with axles and bolts, does it cover all 170's, ect...? Thanks
Shawn

n4517c · Post by **n4517c** » Sat Sep 18, 2004 8:59 pm

Shawn,
Let me answer all of your questions except price since that would be selling, using the forum. STCSA00189BO covers the 170-B and the 170-A ( serial 19219 and higher) The STC references Cessna 180 landing gear axles ( P/N 1441003-1). Check with your FSDO, but according to the theory of PMA approval, any company that holds PMA authority to produce part 1441003-1 may sell that part as a direct substitute for the original Cessna part. If Airframes uses a different number, all bets are off. Aero, LLC does not sell axles or bolts. Aero, LLC's number is 207 924 5905.
Jake

The International Cessna 170 Association

170 axles

170 axles

Re: 170 axles