Quote Originally Posted by HighWing View Post
3. REQUIREMENTS. New models of 406 MHz ELTs identified and manufactured on or after the effective date of this TSO must meet the MPS qualification and documentation requirements in RTCA Inc. document, RTCA/DO-204A, Minimum Operational Performance Standards (MOPS) for 406 MHz Emergency Locator Transmitters (ELTs), dated December 6, 2007, sections 2.2 and 2.4. The 406 MHz ELT must include a 121.5 MHz homing beacon. We also require that you obtain a Cospas-Sarsat type approval certificate before applying for this TSO. Additionally, the use of hook and loop fasteners is not an acceptable means of attachment in complying with the Crash Safety requirements of section 2.2.5 of RTCA/DO-204A for automatic fixed (AF) and automatic portable (AP) ELTs.

g. Deviations. We have provisions for using alternate or equivalent means of compliance to the criteria in the MPS of this TSO. If you invoke these provisions, you must show that your equipment maintains an equivalent level of safety. Apply for a deviation under the provision of 14 CFR § 21.618.

This brings up the story a friend - former Model IV owner - told me two days ago. A year or so ago, he sold a pristine 1950-ish C-150 to a guy. Recently, due for an annual, the new owner takes it to an AI for the inspection. The AI checks every log book entry from day 1 and discovers that in 1955 it had a nose gear collapse repair that was documented in the log book, but never officially signed off. Now, this new AI is insisting that the nose gear repair be redone so the correct entry can be placed in the log book - $12,000. A law-suit was filed against my friend to cover the cost of this inspection (repair). This airplane has had regular Annual Inspections for 60 years and a professional nit-picker is insisting that every one of those inspections was defective and "HE" needs to make it right.
Of course you left off the immediately preceeding paragraph which states:

"2. APPLICABILITY. This TSO affects new applications submitted after its effective date.

a. All prior revisions to this TSO are no longer effective. Generally, we will not accept applications for the previous revision after the effective date of this TSO. We may do so, however, up to six months after it, if we know that you were working against the prior MPS before the new change became effective.

b. 406 MHz ELTs approved under a previous TSOA may still be manufactured under the provisions of its original approval."

The 1st sentence says "affects new applications submitted" and Sub paragraph b says they can continue to make the old ones. No "deviation" required.

Your analogy (story) would be make sense, if I were to simply replace an elt because it had hook and loop mounting. But if I'm going to spend $500 to 900 anyway to get 406 - I might as well do it for the $500 and meet the current requirements whether "required" or not.