Narrative:

A H60 was level at 7;000 ft eastbound and requested to return to nzy. The aircraft was vectored for traffic and climbed to 8;000 ft. The H60 was issued a reverse routing to nzy airport. Company traffic was initially approximately 15 miles in trail of the H60 at 7;000 ft and requested to join up with company as the H60 approached his position opposite direction at 8;000 ft. The company traffic was instructed to maintain 7;000 ft and his request was relayed to the H60 who was issued merging target procedures and instructed to report marsa. The company traffic was issued merging target procedures. The company traffic changed course at 7;000 ft which put him two to three miles in trail of the H60; and began to climb to join company. The company traffic was once again instructed to maintain 7;000 ft. The H60 was once again instructed to report marsa in order to allow company to join up. The H60 advised that he was going to execute a 360 degree turn in order to join up with company. The H60 was instructed to remain on course and advised to report marsa with company in order to join up. The H60 'rogered' the instruction and advised that he was descending. The H60 was instructed to maintain 8;000 ft and report marsa with the company traffic. The H60 reported marsa with the company traffic. The company traffic was issued a climb to 8;000 ft and issued an airport clearance to nzy. Recommendation; the pilot called in to give his statement; the pilot misheard my instruction to report marsa as an instruction to report marshalling; which he read back but was missed by me. I thought I heard marsa. This was an issue because of similar sounding terms with different meanings. Also the pilot was not familiar with the term marsa and I was not familiar with the term marshalling. I would recommend a fam flight.

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Original NASA ASRS Text

Title: ZLA Controller described a confused join up event between two military aircraft when the term MARSA was unfamiliar to one of the pilots involved.

Narrative: A H60 was level at 7;000 FT eastbound and requested to return to NZY. The aircraft was vectored for traffic and climbed to 8;000 FT. The H60 was issued a reverse routing to NZY airport. Company traffic was initially approximately 15 miles in trail of the H60 at 7;000 FT and requested to join up with company as the H60 approached his position opposite direction at 8;000 FT. The company traffic was instructed to maintain 7;000 FT and his request was relayed to the H60 who was issued merging target procedures and instructed to report MARSA. The company traffic was issued merging target procedures. The company traffic changed course at 7;000 FT which put him two to three miles in trail of the H60; and began to climb to join company. The company traffic was once again instructed to maintain 7;000 FT. The H60 was once again instructed to report MARSA in order to allow company to join up. The H60 advised that he was going to execute a 360 degree turn in order to join up with company. The H60 was instructed to remain on course and advised to report MARSA with company in order to join up. The H60 'rogered' the instruction and advised that he was descending. The H60 was instructed to maintain 8;000 FT and report MARSA with the company traffic. The H60 reported MARSA with the company traffic. The company traffic was issued a climb to 8;000 FT and issued an airport clearance to NZY. Recommendation; the pilot called in to give his statement; the pilot misheard my instruction to report MARSA as an instruction to report MARSHALLING; which he read back but was missed by me. I thought I heard MARSA. This was an issue because of similar sounding terms with different meanings. Also the pilot was not familiar with the term MARSA and I was not familiar with the term MARSHALLING. I would recommend a FAM FLIGHT.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.