Had them stickers on my 3 bladed custom painted yellow MT prop (homebuilt), peeled them off as soon as I could 
I would say no. Here is what the FAA regulations say:
45.11 Marking of products.
(c) Propellers and propeller blades and hubs. Each person who produces a propeller, propeller blade, or propeller hub under a type certificate or production certificate must mark each product or part. Except for a fixed-pitch wooden propeller, the marking must be accomplished using an approved fireproof method. The marking must –
(1) Be placed on a non-critical surface;
(2) Contain the information specified in § 45.13;
(3) Not likely be defaced or removed during normal service; and
(4) Not likely be lost or destroyed in an accident.
Appendix B to Part 43 – Recording of Major Repairs and Major Alterations specifies what should be recorded for overhauls:
(a) Except as provided in paragraphs (b), (c), and (d) of this appendix, each person performing a major repair or major alteration shall –
(1) Execute FAA Form 337 at least in duplicate;
(2) Give a signed copy of that form to the aircraft owner; and
(3) Forward a copy of that form to the FAA Aircraft Registration Branch in Oklahoma City, Oklahoma, within 48 hours after the aircraft, airframe, aircraft engine, propeller, or appliance is approved for return to service.
(b) For major repairs made in accordance with a manual or specifications acceptable to the Administrator, a certificated repair station may, in place of the requirements of paragraph (a) –
(1) Use the customer’s work order upon which the repair is recorded;
(2) Give the aircraft owner a signed copy of the work order and retain a duplicate copy for at least two years from the date of approval for return to service of the aircraft, airframe, aircraft engine, propeller, or appliance;
(3) Give the aircraft owner a maintenance release signed by an authorized representative of the repair station and incorporating the following information:
(i) Identity of the aircraft, airframe, aircraft engine, propeller or appliance.
(ii) If an aircraft, the make, model, serial number, nationality and registration marks, and location of the repaired area.
(iii) If an airframe, aircraft engine, propeller, or appliance, give the manufacturer’s name, name of the part, model, and serial numbers (if any)
skydriller wrote:
I m possibly being daft, but is said sticker in exactly the same place on each blade? If only one blade or in different places, is the balance not affected at 2500rpm, even though stickers don’t weigh much??
MT usually puts one Ad-sticker on the propeller and – beware they balanced the prop with it so you can’t remove it ;-).
I m possibly being daft, but is said sticker in exactly the same place on each blade? If only one blade or in different places, is the balance not affected at 2500rpm, even though stickers don’t weigh much??
boscomantico wrote:
Question: is this a legally required placard by FAA rules following an overhaul?
Answer IMHO: No, it is one of these infamous marketing and advertisement thingies.
This is not an identifying data plate, does not provide information about the manufacturer nor any explicit information on the manufacturer’s part number or FAA type certification. It is just a sticker placed on the part by an overhaul shop, without description of its content except for (via ‘S/No’) a restatement of the manufacturer’s serial number.
Hartzell, the propeller manufacturer and TC holder specifies that their part number and serial number data is properly determined by reference to stamped numbers elsewhere on the propeller, not by reference to an overhaul shop’s sticker. MT acting as an FAA repair station has no authority to supersede required manufacturer’s identifying data. That is probably why the MT sticker does not identify what its numbers signify – to ensure that it is not mistaken for an Identification Plate.
If you have a vivid imagination and know MT does overhauls, you might be able to guess that it was overhauled (OHC) by MT in November 2022. Otherwise I think it’s just inconsequential commercial practice, in comparison to either stamped manufacturer’s identifying data or the official overhaul logbook entries entered by MT as an FAA repair station. I do not believe removing such a sticker has any airworthiness impact at all.
If the aircraft were Canadian, the following excerpt from the regulations would apply:
Information Relating to Aircraft Engines and Propellers
201.08 The identification information that shall be placed on an aircraft engine, aircraft engine module, fixed pitch propeller, propeller blade and propeller hub is
(a) the name of the manufacturer and, if the manufacturer is an entity, its legal name; (b) the manufacturer’s model designation as described in the type certificate or equivalent document; (c) the type certificate number or equivalent designation; (d) the aeronautical product serial number; and (e) in the case of an aircraft engine, the power rating established for the engine by the manufacturer.QuoteAnd,
201.12 (1) No person shall remove or replace an identification plate attached to an aeronautical product that is not an aircraft or alter the identification information that is required by section 201.06, 201.07, 201.09, 201.10 or 201.11 to be on an aeronautical product that is not an aircraft unless a written application is submitted to the Minister, including evidence that establishes the identity of the aeronautical product, and a written authorization is issued by the Minister pursuant to subsection (4). QuoteRemoval and Replacement of Identification Plates and Alteration of Identification Information on Aeronautical Products Other Than Aircraft
I don’t know the FAA regulations well, but they’re usually really similar to Transport Canada regulations.
When I changed the flight authority basis for my airplane, which requires a change to the data plates for the airplane, engine, and propeller, I sought, and received authorization from Transport Canada to make the change. Removing the data plate was not an option.
To sort of answer my own question, I guess that while of course one does have to have a placard on the prop which shows the prop model designation and the S/N, but I guess it does not have to „branded“ by an overhaul shop.
All the parts were impression stamped at manufacture by Hartzell, there is no need for a sticker from the overhaul shop (or anybody else) to reference the assembly or component serial numbers to the overhaul records in the propeller logbook. Maintenance logbook records are what is relevant for US registered aircraft if (hypothetically) operation outside of Part 91 requires something other than propeller maintenance on condition.
Perhaps it can be put on the rear of the blade near the root where it is largely hidden by the cowling?
