From: Lany Visoski To: Je vacation <jeevacation®gmail.com> Subject: G550 update Date: Mon, 04 Sep 2017 13:11:45 +0000 Inline-Images: IMG_2770.JPG; IMG_2771.JPG Jeffrey Gulfstream Tech ops Savanah was perfect with their trouble shooting! Our R/H Low Limit Valve is leaking warm air due to deterioration of the Butterfly valve seal. Right Hand valve is the worst„ the Left is leaking a little,. Ill change them both. To determine if the seal is good, You hold a flashlight at one end of the valve and no light should be seen coming through, see photo below: This is what Gulfstream sent for troubleshooting, which is exactly our issue. From Tech Ops; First, above FL410 the turbine bypass valve opens which is normal. When this occurs the cooling turbine slows down and the pack outlet temp can warm up slightly. Second, you may have two bad low limit valves. what happens is the seals go bad on the butterfly portion of the valves and allow a small amount of warm air to leak by. If you already have a warmer outlet due to the slowing down of the cooling turbine, this can compound the issue. Third, when flying through warmer than expected ISA temps this further compounds the two above issues (We experienced ISA+12 degrees on our flight to Paris) Locating low limit valves at this time, HF coupler arrives in London tonight, will ship all parts from London once they are located. ***Best case scenario, we should have parts in hand Wednesday, Thx, Lany Sent from my i Phone EFTA01034972