What does the isolation valve do on a 737?

With the isolation valve switch in AUTO, the isolation valve will only open when an engine bleed air or pack switch is selected OFF. Air for engine starting, air conditioning packs, wing anti-ice and the hydraulic reservoirs comes from their respective ducts.

Why does the isolation valve switch place in auto during an engine cross bleed start?

The isolation valve separates the left, from the right side of the bleed manifold. When a Pack switch is OFF, the Isolation valve opens to create equal performance of the engines. When a Bleed is selected OFF the Isolation valve opens to allow air from either side of the manifold to be used for the Bleed off side WTAI.

What is aircraft isolation valve?

As a general answer: the purpose of an isolation valve is to separate two (or more) parts of a hydraulic system from each other. The separation is necessary to prevent a failure of one part of the system affecting the rest of the system.

Why do airplanes start with Engine 2?

Engine number 2 is started first because it’s on the opposite side of the air bridge. When starting with external air or power it is normal to start Engine number 1 because it is further away from the carts.

What is a cross bleed start?

Once at least one engine is running, that engine can be used to provide compressed air to the remaining engines, instead of the APU – this is called cross-bleed, to start the remaining engines.

Why do pilots start the left engine first?

Left first – because you can see the prop area is clear from the pilots seat… Right first – because it’s nearer the battery (aircraft specific).

What does the isolation valve do on a bleed?

When a Bleed is selected OFF the Isolation valve opens to allow air from either side of the manifold to be used for the Bleed off side WTAI. Note the isolation valve logic is related to switch position, so a tripped pack or bleed will not open the isolation valve when in AUTO.

How do you open the isolation valve on a Toyota Corolla?

The isolation valve separates the left, from the right side of the bleed manifold. It is powered from AC Transfer Bus 1 but can also be manually opened/closed by a control lever, accessible in the left air condition bay. Because it’s AC power* it will fail in the selected position when power is removed.

Do you turn off the bleed switch during a landing?

There is a procedure for a bleeds-off landing (to get more engine power for a go-around), and there are some QRH instances when you might turn a bleed switch off, but all of that is fairly rare. If the OP is using a flight sim, the simple general answer, always leave the engine bleed switches on, will work fine. Turn off the APU bleed after start.