From: jeffrey E. <[email protected]> Sent: Saturday, January 14, 2017 4:20 PM To: Larry Subject: Re: update question would be why is it like glass on descent On Sat, Jan 14, =017 at 12:12 PM, Larry c > wrote: Jeffrey interesting findings: 1-left engine is oscillating air pressure into the cabin while APU bleed ai= and engine bleed air are ON, while advancing the throttles, there is a ch=ck valve that prevents air from engine to back feed the air duct from APU =nto cabin,. Suspect faulty check valve,. Inspecting and removing check val=e for possible fault. 2-during low power setting idle engine, the conditioned air that comes out =y your feet along lower cabin side wall is not working properly when selec=ing auto full cold., when you advance the power on engines, the air blows =arm to hot air, even when full auto cold is selected,. In Manuel operation=, it works Normal,. This could be our issue during your last flight from P=ris to NY when you stated you couldn't control cabin temp properly., Mechanics are in constant communication with Tech ops for proper trouble sh=oting techniques for this item. Support in Brunswick has been great. Both could be contributing factors to our Vib issue i think? •• **just pulled plane into hanger to start sheet metal repair,. The trouble=shooting of Cabin temp and check value will continue, since electrical wir=ng and Cabin temp probe checks can be done in hanger with aircraft power.c=r> 3- precooler and pylon area, Fan Air modulation controller appear be to be =orking normal, during their functional checks. Will keep you updated,. Thx Larry Sent from my iPad > On Jan 14, 2017, at 8:05 AM, jeffrey E. <[email protected] <mailto:[email protected]» wrote: > Would be nice to have expert on test flight and play with cabin temp c=ntrol etc =AO please note EFTA_R1_01916112 EFTA02665589