Grulfstream MEMORANDUM OUNERAL DYNAMICS COMPANY Check Boxes as Appropriate Action K Date: May 2, 2008 Information Only Reply Requested K To: Jeff Schuh cc: Andy Slater, Tom Rothermel, Knute Pedersen, Beckey Elliott, John Maxon, Joe Salamone. Randy Grovenstien, Andrew Malluck John Louis, Michael Brinley From: Charles Roberts, II Job #AC-08-45 FS-A/V-08-45 Subject: Cabin Noise Survey Results on G550, Serial Number 5176 Attachments: Detailed Cabin Noise Results Introduction A cabin noise survey was conducted on 19 March 2008 on G550 s/n 5176 by GAC's Acoustics & Vibration group. This aircraft is owned by Cristen Limited EACE and was outfitted at GAC's completion center in Appleton. WI. Test Item The test item is a completed 6550 with a custom interior that includes a forward galley and an enhanced acoustics package. The aircraft has an aft and a forward lavatory. The passenger cabin has 18 seats, including club seating with a forward divan for six at Windows 3 and 4. standard club seating for four at Windows 5 and 6, and private double aft divans at Window 7 and aft. A standard pocket door is separating the vestibule and passenger cabin. A second pocket door was located between Windows 6 and 7 separating the forward and aft passenger cabins. An ultraleather material was used for the headliner, and PSU's. A leather material was used for the cabin seats, and a decorative fabric was used to cover the dado panels and window panels. The divan was covered is a cloth finish. Cabin Noise Metrics SIL's are the speech interference levels measured in decibels. defined as the arithmetic average of the un-weighted 1000 Hz, 2000 Hz, and 4000 Hz octave band sound pressure levels. The dB(A) levels are the summation of sound pressure over all frequencies after the W weighting is applied. The reference level is 20 pPa. Engine/Aircraft Settings The aircraft was operated in normal, level flight at 45,000 feet, 0.80 Mach. An doors and gaspers wer