Supplemental Type Certificate ST00757DE Issued By FAA

An FAA supplemental type certificate (STC) issued to Trolltune Corporation promises to help operators of Gulfstream IIB and GIII (G-1159B & G-1159A) airplanes fly within strict noise limits at the Van Nuys Airport (KVNY) in Southern California. The STC isn’t a Stage 3 hush kit, explained Trolltune president Tom Storli, but cuts takeoff noise by three decibels – from 82.8 to 79.8 dBA by limiting maximum takeoff weight to 64,000 pounds. This is enough to meet the new Van Nuys limit of less than 80 dBA. That limit is a City of Los Angeles ordinance that took effect on January 1 this year.

Stage 2 airplanes have not been able to take off at Van Nuys between 10 p.m. and 7 a.m. for many years, but they can land at any time. However, as of Jan. 1, 2016, no Stage 2 operations are allowed in the lower 48 U.S. states, so the Trolltune STC provides two years of operating relief at Van Nuys for GIIB/GIII operators.

While the STC is simple to accomplish with a placard and some paperwork, Storli spent two years researching and flight-testing the mod. The Trolltune STC costs $37,000, just a fraction of what a Stage 3 “hush kit” would cost. Because older Gulfstream values are so low, he explained, operators may be balking at the cost of hush kits. “Others want to defer that decision, and this STC allows them another two years to decide in the case of Van Nuys.”

Operationally, the 8% reduction in MGTOW has little impact to the airplanes’ performance. Only takeoffs using 10 degree flap settings (most normal takeoffs use 20 deg) require simple new procedures. Since superior initial climb and cruise altitudes are achieved, only a minimal range impact is encountered.

FMI: www.gulfstream-stc.com