AD 2011-10-09
SUMMARY: We are superseding an existing airworthiness directive (AD) for Cessna Aircraft Company (Cessna) 150, 152, 170, 172, 175, 177, 180, 182, 185, 188, 190, 195, 206, 207, 210, T303, 336, and 337 series airplanes. That AD currently requires repetitive inspections and replacement of parts, if necessary, of the seat rail and seat rail holes; seat pin engagement; seat rollers, washers, and axle bolts or bushings; wall thickness of roller housing and the tang; and lock pin springs. This new AD requires retaining all of the actions from the previous AD and adding steps to the inspection procedures in the previous AD. This AD was prompted by added steps to the inspection procedures, added revised figures, and clarification of some of the existing steps. We are issuing this AD to prevent seat slippage or the seat roller housing from departing the seat rail, which may consequently cause the pilot/copilot to be unable to reach all the controls. This failure could lead to the pilot/copilot losing control of the airplane.
For More Information:
Please visit the FAA's website to view the entire Airworthiness Directive.
Link to AD 2011-10-09
What to Know BEFORE You Go
Sponsored by AirMart, Inc. –www.AirMart.com
“Cover your Six” with Maintenance, AD Compliance, and Secondary Seat Stops!
I hate it when my seat slides back during takeoff. On two different occasions I’ve had my seat slide all the way back during the takeoff roll. The first time I was an IFR student in a ‘70s-model Cessna 172 with an instructor in the right seat. Right as I rotated for takeoff, the seat just let loose and slid all the way back. Fortunately, even in my state of panicked surprise, I still had enough clarity of thought to let go of the control yoke. The instructor took over control and we averted disaster.
The second time I was in a TU206G and again, it let loose just before the takeoff rotation. However, this time there was a cargo tie-down ring clamped to the seat track. It had been placed there for this very reason, so the seat just moved a short distance. Needless to say, now when I pull my seat forward and let go of the seat release, I do the famous “Cessna butt wiggle” to make sure the seat is securely latched.
Of course, it really doesn’t matter what type of airplane you’re flying—you should always ensure that the seat is securely latched before you start the engine—but it’s the Cessnas that have gotten a reputation for seat slippage. The reality, however, is that properly maintained seats and tracks will not release inadvertently in any make or model.
Anyone who has had an annual done on a pre-90’s single-engine Cessna (and some twins) has seen the line item on the bill: “Seat Track Inspection AD.” In 1987, the FAA issued AD 87-20-03 which required the inspection of the seat tracks, seat rollers, and latching pin. In 2011, the FAA superseded 87-20-03 with AD 2011-10-09. This new AD retains all the inspection criteria from the old AD, but adds a few new items. It also makes a very significant change in the compliance rules. This is a very import change that many pilots and A&Ps haven’t noticed.
87-20-03 required compliance at every annual inspection (for aircraft not used for hire). However, 2011-10-09 has changed that. It reads, “Repetitively thereafter do the actions at intervals not to exceed every 100 hours TIS or every 12 months, whichever occurs first.” If you fly more than 100 hours/year, you will need to comply with the AD’s inspection requirements between annuals.
So, exactly what are the problems that cause the seat to slip? Now keep in mind, we’re only talking about pre-‘90s aircraft. The restart aircraft had a redesigned track system that is far superior.
First, let’s look at the anatomy of the seat. Each of the crew seats has four rollers mounted at the bottom of the four legs. These roll along the top of tracks mounted to the cabin floor (two tracks per seat). In order to keep the rollers on the tracks, each roller is attached to two paws that run down the side of the track and hook under the track. Each seat has a latching pin that drops into holes on the top of the track. If everything is in good working order, the paws that hook under the track keep the roller from lifting. As the seat is moved forward and aft, the latching pin rides along the top surface of the track until it drops into a hole.
So here’s where the problems occur. When the pin drops into the hole on the track, it wears on the top edges of the hole. Eventually, the opening of the hole will “bell mouth” into a larger diameter. It’s not the entire hole that increases in diameter; it’s just the top opening. Also, the paw that hooks under the track will wear. As it gets thinner, it will allow the seat to lift up too far and roller to lift off the top of track. This, in turn, allows the latching pin to partially pull out of the hole. If the pin pulls up to a point where the hole is “bell mouthed,” it will allow the pin to completely slide out of the hole. Now the seat is free to slide to back.
So basically, the AD requires the following inspections:
- Rollers for flat spots and wear
- Roller housing and paws that hook under the track for wear
- Tracks for cracks
- Latching pin engagement depth
- Track holes for “bell mouth” wear
The tricky part is measuring the hole’s wear. The AD allows the opening of the hole to be worn to a diameter of .42″. However that needs to me measured at a depth of .020″ from the top surface. This has always been difficult to measure, but finally, after all these years, McFarlane Aviation came up with a really clever go/no go gauge that works at the .020″ depth. This unique tool was specifically designed for checking seat rail wear limits per FAA AD 87-20-03. It measures the actual radius wear near the seat stop holes. Every Cessna mechanic should have one of these gauges! For more information, visit www.mcfarlaneaviation.com.
You need to make sure your A&P/IA takes these inspections seriously and replaces any worn parts. A few thousandth-inch wear can be the cause of a serious disaster.
Ok, you know how we always like back-up and redundancy systems in aviation? Well, once you have the tracks and seat rollers in good working order; you can get Cessna to pay for the installation of a secondary seat stop on the pilot’s seat!
SEB07-5 Rev 5 provides for the installation of a secondary seat stop under the pilot’s and copilot’s seats. It looks a lot like a seatbelt reel attached to the bottom of the seat. The end of the belt is attached to the cabin floor. The reel has a release mechanism that is activated by the same lever the pilot lifts to release the latching pins.
Cessna really wants everyone to install these, so they keep extending the credit expiration date. At this point, they’ll pay to have the stop installed on the pilot’s seat up to December 31, 2014. I’ve installed a number of these and they work great. I recommend everyone have this installed. It’s well worth having a backup when you consider just how serious it is to have the pilot’s seat slip!
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Seat track AD
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Seat Rail AD 2011-10-09
Yes, you can get the inspection signed off as "unairworthy." Here's what FAR 43.11, paragraph 5 reads:
(5) Except for progressive inspections, if the aircraft is not approved for return to service because of needed maintenance, noncompliance with applicable specifications, airworthiness directives, or other approved data, the following or a similarly worded statement--"I certify that this aircraft has been inspected in accordance with (insert type) inspection and a list of discrepancies and unairworthy items dated (date) has been provided for the aircraft owner or operator."
The next step in getting your airplane back home would be to contact the local Flight Standards District Office (FSDO) and apply for what's called a "ferry permit."
I've attached a pdf that outlines the process for getting a ferry permit.
However, as you can see from note 3 (in red) the IA who said, If it's cracked, replace it" may be a problem.
As you and I read the AD, the track is still airworthy if there are small cracks in certain locations. In fact the AD says, "(
Visually inspect the seat rails for cracks. (i) If there are seat rail cracks that exceed the crack criteria in figure 5, before further flight, replace the seat rail. "As I read the illustration on page 13, it appears to me to say replace the rail when: 1) any portion of the web or lower flange is cracked. 2) if there's a crack in the crown of the rail in any direction other than at right angle to the length of the rail; 3) if there are 5 (exceeds four) or more cracks across the crown of the rail, or any two cracks are closer together than one inch.
I take this to mean there can be cracks only if the crack is perpendicular to the length of the rail unless there are 5 or more cracks across the crown or, if the cracks that are perpendicular are closer together than one inch.
I hope this explanation helps, and the IA is willing to understand the verbiage and picture in the AD.
Let me know how it turns out.
Steve
Track ad seat cessna
Existing gauges still work with the new A.D.!
The gauge is used for inspection of seat rail wear in Cessna aircraft. This gauge is designed to measure the actual radius wear near the seat stop holes. Notice the different sized step the corner. The size applies to the .42 diameter limits referred to by the A.D. The .020 upper surface wear allowance allowed by the A.D. is designed into the gauge.
Note: Earlier versions of the McFarlane seat rail wear gauge feature a .36 and a .42 step. The .36 step was included per an earlier version of the A.D. and is no longer used. Existing gauges may still be used to check wear limits per the new A.D. Future production runs will not include the .36 part of the gauge.
Directions for using the Seat Rail Hole Wear Gauge
FAA Airworthiness Directive 2011-10-09 Cessna Seat Rails
For ordering details, go to part number GAUGE SR1.
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: We are superseding an existing airworthiness directive (AD)
for Cessna Aircraft Company (Cessna) 150, 152, 170, 172, 175, 177, 180,
182, 185, 188, 190, 195, 206, 207, 210, T303, 336, and 337 series
airplanes. That AD currently requires repetitive inspections and
replacement of parts, if necessary, of the seat rail and seat rail holes;
seat pin engagement; seat rollers, washers, and axle bolts or bushings;
wall thickness of roller housing and the tang; and lock pin springs. This
new AD requires retaining all of the actions from the previous AD and
adding steps to the inspection procedures in the previous AD. This AD
was prompted by added steps to the inspection procedures, added revised
figures, and clarification of some of the existing steps. We are issuing this AD
to prevent seat slippage or the seat roller housing from departing the
seat rail, which may consequently cause the pilot/copilot to be unable
to reach all the controls. This failure could lead to the pilot/copilot
losing control of the airplane.
DATES: This AD is effective June 17, 2011.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (phone: 800-647-5527) is Document Management Facility,
U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Gary Park, Aerospace Engineer, ACE-
118W, Wichita Aircraft Certification Office (ACO), 1801 Airport Road,
Room 100, Wichita, Kansas 67209; telephone: (316) 946-4123; fax: (316)
946-4107; e-mail: [email protected]
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to supersede airworthiness directive (AD) 87-20-03 R2,
Amendment 39-6669 (55 FR 36264, September 5, 1990; published as Docket
No. 86-CE-71-AD, Amdt. 39-6669). That AD applies to the specified
products. AD 87-20-03 R2 requires repetitive inspections and
replacement of parts, if necessary, of the seat rail and seat rail
holes; seat pin engagement; seat rollers, washers, and axle bolts or
bushings; wall thickness of roller housing and the tang; and lock pin
springs. The NPRM published in the Federal Register on November 8, 2010
(75 FR 68543). That NPRM proposed to retain all of the actions from the
previous AD and add steps to the inspection procedures in the previous
AD.
The additional steps involve inspections of the tang thickness and
length on the seat roller housing. We also provided improved graphics
for inspecting seat track hole wear and for inspecting proper seat lock
pin engagement depth. We itemized the steps, in sequence, to provide
clearer guidance for the inspector to do the inspections.
Comments
We gave the public the opportunity to participate in developing
this AD. The following presents the comments received on the proposal
and the FAA's response to each comment.
Request Change to Compliance Time
D.A., Ken Anderson, Don Barley, Timothy J. Berg, Joseph Carter,
Gary W. Cleveland, Clifford Coy, Al Dyer, John M. Efinger, Greg Felton,
Berry Gablin, Howard Greenberg, Steve James, Richard Koril, Michael
Minton, Dustin J. Radford, Marc Stancy, Charles L. Trunck, and Walter
Wasowski requested we change the inspection compliance time to annual
inspections. They think that 100-hour time-in-service inspections are
an excessive burden on manpower and an added expense with little
benefit in safety. They also think the frequent inspections would be
difficult to monitor.
We disagree with this comment. The unsafe condition of excessive
wear results from usage, not calendar time. The more an airplane is
used, the more likely wear will develop, causing an unsafe condition.
Parts cost will not be incurred unless the inspection results require
parts replacement. FAA regulations require posting compliance to ADs in
the aircraft logbook. The maintainer should record compliance with this
AD, which includes the 100-hour inspections, in the aircraft logbook.
We have not changed this final rule AD action based on this
comment.
Request Change to Applicability Based on Secondary Seat Stops
Joseph Carter, Greg Felton, Donald L. Griffith, and Richard M.
Warner requested we change the applicability based on the installation
of inertial reel secondary seat stops. They think that if the primary
seat lock fails and the seat slips, the secondary seat stops provide
additional safety.
We partially agree with this comment. We agree that the secondary
seat stop provides additional safety for seat slippage. However, we
disagree that secondary seat stops provide adequate safety for the
unsafe condition associated with this AD action. The secondary seat
stops may be installed only on one side of the airplane, so the pilot
could occupy a seat without a secondary seat stop. Also, secondary seat
stops will not prevent the seat from lifting off the seat track.
We have not changed this final rule AD action based on this
comment.
Request To Remove Models 150, 152, and 188 From Applicability
Mark Stancy requested we remove Cessna Models 150, 152, and 188
from the airplane Applicability. He thinks the seat travel for those
models is too limited to justify this AD even if the locking pin were
to slip.
We disagree with this comment. Even a limited seat travel could
affect short pilots' ability to reach the controls if the seat slips
backwards due to failure of the seat system. This AD action not only
requires inspections to prevent seat slippage but also requires
inspections to prevent the seat from lifting off the seat track.
We have not changed this final rule AD action based on this
comment.
Request Withdrawal of Proposed AD Action
David Abler, Brian A. Andrus, James Barbee, Timothy J. Berg, Al
Dyer, John M. Efinger, Berry Gamblin, Donald L. Giffith, Michael
Minton, Robert J. Pasch, Dustin J. Radford, Charles L. Trunck, and
Walter Wasowski requested we withdraw the proposed AD action because
they think it adds no additional safety than AD 87-20-03 R2.
We disagree with this comment. This AD action provides additional
measurements in the inspections, more clarity in the descriptions of
the required inspections, and provides improved graphics. Inadvertent
seat movement continues to be reported. Also, we received a report of a
seat separating from the seat track due to wear of the seat roller
housing tangs.
We have not changed this final rule AD action based on this
comment.
Request Additional Inspection With Diagrams
One commenter requested we add an inspection of the seat stop with
diagrams showing potential damage because if the integrity of the seat
stop is retained, seat slippage will not occur. The commenter also
requested we not allow repair to the seat roller housing.
We partially agree with this comment. We agree the seat stop should
prevent seat slippage; however, other failure modes can cause seat
slippage even with a functional seat stop. Providing
diagrams of possible damage to the seat stop area will not sufficiently
eliminate the safety issue. Service history has shown that wear and
damage to the seat installation components must be addressed. This AD
action provides clarification to the inspections for those components.
We have not changed this final rule AD action based on this
comment.
Request an Additional Measurement to the Inspection
Dave McFarlane requested we add a maximum allowable incremental
0.07-inch radius dimension to figure 1 at the outside diameter
dimensions for clarification.
We disagree with this comment. The measurement dimensions in figure
1 adequately address the measurements necessary for this AD. Additional
measurements will not provide any additional benefit.
We have not changed this final rule AD action based on this
comment.
Request Changing Compliance Based on Frequency of Seat Movement
Joseph Carter requested we change the compliance time for the
inspection for seats that are moved infrequently because they would not
experience the same amount of wear on the seat components.
We disagree with this comment. Inspectors would not be able to
determine the frequency seat movement.
We have not changed this final rule AD action based on this
comment.
Request Change to the Measurement of the Tangs
Brian A. Andrus, Jim Currie, and Jerry Unruh requested we change
the tang measurement to the outside of the seat roller housing and
change the description of the tang measurement. This change would make
it easier for the inspector to take the measurement and to better
understand what is being measured.
We agree with this comment. We agree that measuring the tang length
inside of the roller housing is difficult because of the presence of
the rollers inside of the roller housing.
We have changed the callouts in figure 4 to measure the tang length
from outside of the roller housing instead of from inside of the roller
housing. We have also changed the description of the tang measurement
in figure 4 to more accurately describe the measurement.
Request Detailed Description of Changes From AD 87-20-03 R2
Robert J. Pasch requested we better describe the changes or added
steps to the inspections from AD 87-20-03 R2 so the owner/operator can
better understand the requirements of this new AD action.
We agree with this comment. We retained all of the actions from the
previous AD and added steps to the inspection. This AD action must be
complied with in its entirety, not just the added steps. This AD action
includes better descriptions and graphics for the mechanic to follow
when complying with this AD. We have added language to the Discussion
section describing in more detail the changes we made in this
superseding AD action.
Request Different Requirements for New Seat Rail Installations
Howard Greenberg requested different requirements for new seat rail
installations.
We disagree with this comment. Documentation positively identifying
that all seat assemblies and associated parts were replaced would be
difficult to obtain. If documentation positively identifying
replacement of the seat assemblies and associated parts can be found,
the FAA will consider any applications we receive for an alternative
method of compliance to extend the compliance time for the initial
inspection.
We have not changed this final rule AD action based on this
comments.
Request Training on Proper Seat Operation Instead of AD
David Abler, Ken Anderson, and Timothy J. Berg requested we provide
a means to educate the pilots on proper operation of the seats rather
than take AD action.
We disagree with this comment. Wear and damage can occur, which may
not be visibly recognizable by the pilot, and may cause the seat to
slip even after proper engagement of the locking pin. In addition, many
sources exist to educate those involved about this unsafe condition,
including Advisory Circular 43-16A, Aviation Maintenance Alerts, found
on the Internet at http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/Frameset?OpenPage; Special Aviation
Information Bulletin, SAIB CE-09-10, Availability of Secondary Seat
Stops for Pilot and Copilot Seats found on the Internet at http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSAIB.nsf/Frameset?OpenPage; Safety Alerts for Operators, SAFO 10016, Missing or
Improper Seat Stops in Cessna Models found on the Internet at http://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/safo/all_safos/; and other related articles in Cessna
Pilots Association Magazine. In spite of the sources of information
regarding the necessity for proper maintenance and proper operations of
the seats, inadvertent seat movement continues to be a safety issue.
We have not changed this final rule AD action based on this
comment.
Request Requiring Reinspection After Repair or Replacement of Parts
An anonymous commenter requested we require verifying the seat stop
pin engagement still meets the 0.150 inch criteria after replacement of
parts as a result of any of the required inspections.
We disagree with this comment. The intent of this inspection is to
detect wear or deformation. Any part used as a replacement part must be
serviceable and not show signs of wear or deformation. Also, this
inspection is a repetitive inspection at intervals not to exceed every
100 hours time-in-service.
We have not changed the final rule AD action based on this comment.
Agreement With AD Action
John M. Conti agrees with this AD action. He states the added
procedures and criteria are good and must be done during annual
inspections so the extra detail is a small price to pay that will
further reduce this risk.
We have not changed this final rule AD action based on this
comment.
Conclusion
We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
the AD with the change described previously to change the tang length
measurement location to outside of the seat roller housing and minor
editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of the AD.
Costs of Compliance
We estimate that this AD will affect 36,000 airplanes in the U.S.
registry.
The estimated total cost on U.S. operators includes the cumulative
costs associated with AD 87-20-03 R2. The required actions of this AD
are the same as in AD 87-20-03 R2 with the exception of some added steps to the
inspection, which do not increase work-hours. The increased estimated
cost of this AD is due to increased labor cost and parts cost from 1987
when AD 87-20-03 R2 was issued.
We estimate the following costs to comply with this AD:
Estimated Costs
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S.operators |
| Inspections of the seat roller housings and seat rail. | 1 work-hour x $85 per hour = $85. | Not applicable | $85 | $3,060,000 |
We estimate the following costs to do any necessary replacements
that would be required based on the results of the inspections. We have
no way of determining the number of aircraft that might need these
replacements:
On-Condition Costs
| Action | Labor cost | Parts cost | Cost per product |
| Replace seat rail | 2 work-hours x $85 per hour = $170 per rail. | $225 per rail | $395 |
| Replace seat roller kit | 2 work-hours per seat (less per leg) x $85 per hour = $170. | $110 | 280 |
| Replace miscellaneous parts, such as seat rollers, washers, bushings, bolts, lock pin springs, etc. | 1 work-hour per seat x $85 per hour = $85. | $15 | 100 |
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
subtitle VII, part A, subpart III, section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by removing airworthiness directive (AD)
87-20-03 R2, Amendment 39-39-6669 (55 FR 36264, September 5, 1990;
published as Docket No. 86-CE-71-AD, Amdt. 39-6669), and adding the
following new AD:
Now discussing:
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- Pm6150l ic
- Raised dog kennel
- Corpus christi weather history
- Mixing store bought slimes
- Bdx performance go kart
- Love horoscope birth chart
- Sonic and shadow
- Delphi diesel injection pump
- Nahum 1 9
- Linux mint workspace switcher
- Bath sheet towels wholesale
Lower your pantyhose and panties and caress yourself while I bring a drink where you have it. In the fridge. She said, pulling down her tights.