ALERT: Failed Landing Gear Spring Strut (ACS)

How to keep the Cessna 170 flying and airworthy.

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mod cessna
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Post by mod cessna »

A couple oddities cropped up when I was looking at these...
1. The 120/140 manual lists a "right" leg for later serials, but no Left?
The early models had straight gear. The later gear was swept forward to eliminate the often installed "gear extenders" on the straight gear. The swept gear was either a right or a left. I never tried to swap my straight legs side to side.
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GAHorn
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Post by GAHorn »

Just want to emphasize that a "dash number" is a legitimate portion of the part number. A part without a "dash number" is not the same as one with a "dash number", regardless of any similarity in the basic number.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
doug8082a
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Post by doug8082a »

gahorn wrote:Just want to emphasize that a "dash number" is a legitimate portion of the part number. A part without a "dash number" is not the same as one with a "dash number", regardless of any similarity in the basic number.
Exactly. that's what I was getting at but did not convey very well. the 170 IPC states the gear leg p/n is 0441138. The 170A IPC states the gear leg p/n is 0441138-3 s/n 18003 - 19219 (note the s/n range from the 170A IPC includes all production 170s up to s/n 19219, but gives a different p/n than the 170 IPC).
Doug
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GAHorn
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Post by GAHorn »

I have today received response from Mr. Gary Park, FAA Aero Engineer who first communicated the Landing Gear Spring alert that resulted in this message thread.

I communicated to him the opinion of TIC170A as I have already posted, and their response is an Aviation Maintenance Alert, for December 2007, which alerts all operators/owners of Cessna's with flat spring landing gears to Cessna's official response: Temporary Revision No. 5 dated July 1, 2007 to the Service Manuals for the associated airplanes (which includes our 170's and all other Cessna's with this type gear.)

This Service Manual Temporary Revision is exactly the same as that which is already posted in the MX Library: http://www.cessna170.org/phpBB2/viewtopic.php?t=4973

The bad news is that Cessna (and the FAA-ACA) is recommending the inspection be accomplished at 1400 hours and every 100 hours/annual inspection thereafter.

The good news is that no AD is contemplated.


The actual wording of the document from FAA:

"Cessna: 120—337 (see list); Main Landing Gear Fatigue; ATA 3213
(The following alert originates from the Wichita Aircraft Certification Office. It affects the following Cessna model aircraft: 120, 140, 150, 152, 170, 172, 175, 177, 180, 182, 185, 188, 190, 195, 205, 206, 207, 208, 210, 336, and 337. Contact information is found at the article’s end.)
“The Wichita ACO (Aircraft Certification Office) conducted statistical analyses on SDR’s (Service Difficulty Reports) and accident data from the NTSB (National Transportation and Safety Board). The analyses indicate wearout (fatigue failure) of the landing gear spring struts. The spring struts, axles, and associated hardware on the above aircraft need to be visually inspected at or before 1400 flight hours, and at 100-hour or during annual inspections, thereafter. The ACO further recommends the spring struts be inspected using magnetic particle or florescent dye-penetrant at or before 1400 flight hours, and at 100-hour or during annual inspections, thereafter. These inspections target corrosion, pitting, and cracking on gear springs—particularly on those airplanes having had skis installed and/or having been operated on rough, unimproved runways."

Again, the actual inspection can be found in the MX Library:
http://www.cessna170.org/phpBB2/viewtopic.php?t=4973
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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thammer
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Re:

Post by thammer »

doug8082a wrote:
3958v wrote: 1. The 120/140 manual lists a "right" leg for later serials, but no Left?
It's there. Better late then never :) The left side spring is listed up higher in the figure 26 parts list, last item 26-14 for the later serial numbers. 0441149, the -1 is the right side. Took me a couple minutes of looking at the list to find it.

tye
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blueldr
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Re: ALERT: Failed Landing Gear Spring Strut (ACS)

Post by blueldr »

Where did the odd comment go?
BL
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GAHorn
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Re: ALERT: Failed Landing Gear Spring Strut (ACS)

Post by GAHorn »

blueldr wrote:Above comment ----- ????????????? Is it just me?
It's what happens when someone posts a response to a question asked a full-year earlier. (You're still OK, bluElder....we ain't gonna commit you to the facility just-yet.) :lol:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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