Seat belt wear limits

[riggerrob 561]

Hi folks,

I knew this is wandering away from TSO C23B ... but does anyone have PUBLISHED wear limits on seat belts?

Yes, I know that aircraft seat-belts are manufactured under FAA TSO C22g.

Specificly: how much fraying is allowed on a selvage edge, before the seat-belt must be replaced?

[Scrumpot 1]

Safety Belt Maintenance & Inspection Requirements, as found by searching the FAA database:

Quote

SAFETY BELTS
The FARs require that when safety belts are to be replaced in aircraft
manufactured after July 1, 1951, such belts must conform to standards established by the
FAA. These standards are contained in Technical Standard Order TSO-C22. Safety belts
eligible for installation in aircraft may be identified by the marking TSO-C22 on the belt
or by a military designation number since military belts comply with the strength
requirements of the TSO. Each safety belt must be equipped with an approved metal to
metal latching device. Airworthy type-certificated safety belts currently in aircraft may be
removed for cleaning and reinstalled. However, when a type certificated safety belt is
found unairworthy, replacement with a TSO-C22 or a new belt is preferred.
a. The webbing of safety belts, even when mildew-proofed, is subject to deterioration due
to constant use, cleaning, and the effects of aging. Fraying of belts is an indication of
wear, and such belt are likely to be unairworthy because they can no longer hold the
minimum required tensile load. Difference of opinion as to the airworthiness of a belt can
be settled by testing a questionable belt to demonstrate that it will support the required
load. Airworthy one person type-certificated belts should be able to withstand a tensile
load of 525 pounds, and TSO belts withstand the rated tensile load indicated on the belt
label. Most one person TSO belts are rated for 1,500 pounds. For two person belts,
double the loads. Since type-certificated belts will not afford the crash protection
provided by a TSO or military belt, such type-certificated belts are not to be repaired nor
should their buckles or end fittings be reused on safety belts. If replacement of webbing
or hardware of TSO or military belt is attempted, use parts of identical design and
material. Make the stitch pattern identical to the original and the number of stitches per
inch equal to the number used in the original belt. There is no objection to having a
greater total length of stitching, provided one line of stitches is not placed over another
line. Space lines of stitching at least 3/16 inch apart. Keep a record, preferably in the
logbook, stating the extent to which the belt was repaired and the date. Retain the original
identification marking on the belt, conforming either to that required by TSO-C22 to a
deviation from this marking, or to the military designation. Operators of a fleet of
airplanes should follow the above suggestions, but keeping a record of renovations in a
logbook is impractical, since the belts are never associated with any one particular
aircraft for any length of time. Therefore, in addition to retaining the original
identification label and attaching it to the renovated belt, use some additional simple
marking to indicate that the belt has been renovated and show the date of renovation. The
use of letter "R" followed by the date would be acceptable. This marking could be in the
form of an indelible ink stamping or cloth label stitched to the webbing.

Several references throughout were also made with regards to belt inspection, applicability & maintenance, to: 14 CFR part 23, § 23.561 & § 23.785, but absolutely nothing I could find, spoke to or addressed VISUAL wear indication / standards.

Seems absolutely everything wants to reference to load & strength TESTING as being "the standard". I've highlighted the section that seems most pertinent to your question, and how the FAA anyway, seems to want to address it - vis-a-vis observed / noticed visible wear.

Does any of this happen to help you any?

coitus non circum - Moab Stone

[riggerrob 561]

Thanks,

I also found Society of Automotive Engineers standard SAE J800c.
SAE J800c seems o be mostly about seat belts for (ground-bound) motor vehicles and mainly about design and testing standards for new seat-belts.

My next step is to look up FMVSS 209/302.

... but right now I have to meet a colleague who just returned from a winter of "tandeming" in New Zealand. ... and I have to meet him in a pub! Dang!
May I have some sympathy???
Hah!
Hah!