B737Theory - APU backpressure. Here a question out of the field of operation related to APU bleed use in flight. Flying with some colleagues, we were studying (y) a couple scenarios relating
![model aircraft: AIRFLOW CONTROL - A hydraulically operated bleed valve and inlet guide vane airflow control system. model aircraft: AIRFLOW CONTROL - A hydraulically operated bleed valve and inlet guide vane airflow control system.](http://4.bp.blogspot.com/-sAU5IQ2jdtw/Tv8PY6Ka_cI/AAAAAAAABZU/fbC38VIOQNc/s1600/18.jpg)
model aircraft: AIRFLOW CONTROL - A hydraulically operated bleed valve and inlet guide vane airflow control system.
![RR 250-C20W Bleed Valve - Aerodynamics, Mechanics, or other... - Vertical Reference Helicopter Forums RR 250-C20W Bleed Valve - Aerodynamics, Mechanics, or other... - Vertical Reference Helicopter Forums](https://i.imgur.com/fqESr7W.jpg)
RR 250-C20W Bleed Valve - Aerodynamics, Mechanics, or other... - Vertical Reference Helicopter Forums
![model aircraft: AIRFLOW CONTROL - A hydraulically operated bleed valve and inlet guide vane airflow control system. model aircraft: AIRFLOW CONTROL - A hydraulically operated bleed valve and inlet guide vane airflow control system.](http://1.bp.blogspot.com/-mEbstzMxENE/Tv8PeJXArgI/AAAAAAAABZc/Ilt9I_EyX9E/s1600/19.jpg)