Narrative:

This time of year; it is necessary to put covers of some sort over the potential points of entry into the tail rotor gearbox fairing in order to prevent birds from building nests in the tail rotor gearbox fairing or tail rotor drive shaft tunnel. After washing the aircraft; I placed a rag in the little hole on top of the tail rotor gearbox fairing and another on the right side where the drive shaft and linkage come out of the tail rotor gearbox. We received a dispatch from communications for a hospital transfer flight. During my walkaround; I failed to notice the rags in the tail rotor gearbox fairing. I started the aircraft and while at idle; realized I had not removed the rags. I immediately shut down the aircraft. After the rotors stopped; I proceeded to the tail rotor area and saw that the rags were still where they had been placed. I then removed them and inspected for damage. There was none; so I proceeded with the mission without further incident.I highly recommend that the company purchase safety orange tail rotor gearbox covers with a 'remove before flight' streamer attached for all rotary wing aircraft. Birds attempting to nest in the tail rotor gearbox is a constant problem during the spring through mid summer. To not cover the tail rotor gearbox makes nesting birds a certainty. They make remarkable progress in a very short period of time; necessitating having the mechanic remove the tail rotor gearbox cover to remove FOD producing material. This causes that could be avoided if we were equipped with proper covers.

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Original NASA ASRS Text

Title: AS-350 pilot reported advising his company of the need for covers for tail rotor components that birds often nest in.

Narrative: This time of year; it is necessary to put covers of some sort over the potential points of entry into the tail rotor gearbox fairing in order to prevent birds from building nests in the tail rotor gearbox fairing or tail rotor drive shaft tunnel. After washing the aircraft; I placed a rag in the little hole on top of the tail rotor gearbox fairing and another on the right side where the drive shaft and linkage come out of the tail rotor gearbox. We received a dispatch from communications for a hospital transfer flight. During my walkaround; I failed to notice the rags in the tail rotor gearbox fairing. I started the aircraft and while at idle; realized I had not removed the rags. I immediately shut down the aircraft. After the rotors stopped; I proceeded to the tail rotor area and saw that the rags were still where they had been placed. I then removed them and inspected for damage. There was none; so I proceeded with the mission without further incident.I highly recommend that the company purchase safety orange tail rotor gearbox covers with a 'Remove before flight' streamer attached for all rotary wing aircraft. Birds attempting to nest in the tail rotor gearbox is a constant problem during the spring through mid summer. To not cover the tail rotor gearbox makes nesting birds a certainty. They make remarkable progress in a very short period of time; necessitating having the mechanic remove the tail rotor gearbox cover to remove FOD producing material. This causes that could be avoided if we were equipped with proper covers.

Data retrieved from NASA's ASRS site 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.