GROB-WERKE GMBH & CO KG Model G102 ASTIR CS Sailplanes

This comment was submitted in response to a solicitation for comments regarding a contemplated standardized MCAI AD procedure. These comments would also apply to this NPRM: Comment on foreign MCAI AD Procedure The generic aircraft parts industry exists under the aegis of 14 CFR § 21.303 (frequently referred to as PMA for Parts Manufacturer Authority) and is reasonably well developed in this country. Other countries are gradually adopting programs similar to those of the US, but have not developed their procedures to the level of that of the US FAA. Therefore, the adoption of certain manufacturer authored service information, particularly when it originates outside of the United States, may contain requirements that pose problems for US operators and support firms. A frequently appearing problem is a manufacturer identifying a certain part numbered part as defective and then requiring the installation of a different part numbered part to correct the deficiency. This action can have the following unintended consequences: (1) The defective part identified in the manufacturer service bulletin as defective may have existing generic alternatives (PMA) that suffer the same defects. Moreover, it is likely in such instances that the equally defective PMA part may carry a different part number and so escape the sweep of the corrective action. The FAA should be sensitive to this condition and modify in the AD the language of the service document to also include generics that contain the same defect. (2) Specifying a certain part numbered part to be installed contains the possibility of a conflict with FAR 21.303 which permits the installation of approved generic parts. This conflict can be in two forms: a. If a PMA part exists that does not contain the same defects as the part required to be removed then the AD has the effect of nullifying the PMA granted on that part. If there is no discernible safety involved basis for such nullification then the prohibition becomes one of economic rather than safety effect. Because AD's by statute may involve only safety issues the nullification of a PMA granted on a non-defective part may become a basis for an action to void the entire AD. (Generally, if a material portion of a document is found to be unenforceable then the entire document is equally unenforceable.) EXAMPLE: Suppose an OEM switch box has a plastic cover P/N 12345 and this switch box is used in a high heat area where the plastic cover melts. The aircraft manufacturer becomes aware of this problem and develops a metal cover, P/N 12345-1, and issues a mandatory service bulletin to replace P/N 12345 with P/N 12345-1. Now further suppose that a PMA firm has developed a plastic cover, P/N 98765, and a metal version P/N 98765-1. An AD that specifies only the OEM P/N 12345 will not capture the defective PMA P/N 98765 allowing the defect to escape the regulatory safety action. Specifying installation of only the OEM P/N 12345-1 effectively voids the PMA on P/N 98765-1 for no good safety reason. The PMA manufacturer then has a cause of action against the FAA for economic damage resulting from issuing an AD that contains prohibitions not based on safety. b. Implicit in the existence of 21.303 is the opportunity to develop and market new FAA approved parts. When an AD mandates the installation of a certain part numbered part to the exclusion on all other parts the abilities contemplated under 21.303 no longer exist with respect to that part. This also becomes an economic rather than a safety issue and exposes the AD to legal challenge. EXAMPLE: Extending the above example if the AD is issued without modification of the requirement to install only OEM P/N 12345-1 the entire sweep of 21.303 with respect to this part is void. While a manufacturer would be granted a PMA on a newly designed metal switch cover, the AD would prohibit its installation and use. While this effect is an unintended consequence, its impact is none the less real…