[Federal Register Volume 63, Number 192 (Monday, October 5, 1998)] [Rules and Regulations] [Pages 53278-53279] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-26603] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Parts 23, 25 and 33 [Docket No. 28652; Amendment Nos. 23-53, 25-95, and 33-19] RIN 2120-AF75 Airworthiness Standards; Rain and Hail Ingestion Standards; Correction AGENCY: Federal Aviation Administration, DOT. ACTION: Final rule; correction. ----------------------------------------------------------------------- SUMMARY: This document corrects a final rule that was published in the Federal Register on March 26, 1998 (63 FR 14794). The final rule addressed engine power loss and instability phenomena attributed to operation in extreme rain or hail. Also, the final rule generally harmonized the Federal Aviation Administration and Joint Aviation Authorities rain and hail ingestion standards. DATES: Effective October 5, 1998. FOR FURTHER INFORMATION CONTACT: John Fisher, Burlington, Massachusetts 01803-5229; telephone (781) 238-7149; fax (781) 238-7199. SUPPLEMENTARY INFORMATION: The Airworthiness Standards final rule on Rain and Hail Ingestion Standards, Docket No. 28652 was published in the Federal Register on March 26, 1998 (63 FR 14794). Under ``Discussion of Comments,'' there is an incorrect phrase, and under Sec. 33.77 of the rule, the foreign object ingestion conditions table provides either misplaced or incorrect phrases. 1. On page 14795, under ``Discussion of Comments,'' third column, third paragraph, nine lines down, the phrase ``Some amount of sustained power or thrust loss is permitted following an ice ingestion test'' should be replaced with ``Some amount of sustained power or thrust loss is permitted following testing to the new rain and hail ingestion standards, but no power or thrust loss is permitted following an ice ingestion test.'' 2. On page 14798, third column, under Sec. 33.77(e), the ingestion conditions table is corrected to read as follows: -------------------------------------------------------------------------------------------------------------------------------------------------------- Foreign object Test quantity Speed of foreign object Engine operation Ingestion -------------------------------------------------------------------------------------------------------------------------------------------------------- BIRDS: 3-ounce size.................... One for each 50 square Liftoff speed of typical Takeoff.................... In rapid sequence to inches of inlet area, or aircraft. simulate flock encounter in fraction thereof, up to and aimed at selected a maximum of 16 birds. critical areas. Three-ounce bird will pass the inlet guide vanes into the rotor blades. 1\1/2\-pound size............... One for the first 300 Initial climb speed of Takeoff.................... In rapid sequence to square inches of inlet typical aircraft. simulate a flock encounter area, if it can enter the and aimed at selected inlet, plus one for each critical areas. additional 600 square inches of inlet area, or fraction, thereof up to a maximum of 8 birds. 4-pound size.................... One, if it can enter the Maximum climb speed of Maximum cruise............. Aimed at critical area. inlet.. typical aircraft, if the engine has inlet guide vanes. Liftoff speed typical Takeoff.................... Aimed at critical area. aircraft, if the engine does not have inlet guide vanes. ICE................................. Maximum accumulation on a Sucked in.................. Maximum cruise............. To simulate a continuous typical inlet cowl and maximum icing encounter at engine face resulting from 25 deg.F. a 2-minute delay in actuating anti-icing system, or a slab of ice which is comparable in weight or thickness for that size engine. -------------------------------------------------------------------------------------------------------------------------------------------------------- Note: The term ``inlet area'' as used in this section means the engine inlet projected area at the front face of the engine. It includes the projected area of any spinner bullet nose that is provided. [[Page 53279]] Issued in Washington, DC on September 30, 1998. Donald P. Byrne, Assistant Chief Counsel. [FR Doc. 98-26603 Filed 10-2-98; 8:45 am] BILLING CODE 4910-13-M