Mid atlantic weather

gne in prog said:
sweet shots. what was wrong with the pressurization?
Click to expand...

The original issue was the PRSOV (pressure regulating and shut off valve). After the bleed air comes off the engines, it goes through the mixing valve. The mixing valve will pull LP air off the engines in normal conditions, but will introduce HP air when the pressure drops below 18-22 psi. After the mixing valve, the air goes through the PRSOV to regulate it as to not cause any drastic pressure changes in the cabin. We were getting severe pressure bumps on takeoff and the cabin controller was overly sensitive (it is already ultra sensitive under normal circumstances) We ran some tests up at FL390 so that the system was under a full "load", and we were able to determine the PRSOV was the culprit.

On the way out of maintenance, we got a #2 (right) Main Air Valve disagree light when we selected them on after takeoff (have to take off with them off in the mighty Hawker). We recycled it, and it functioned correctly, but again, we tested it at higher altitude under a load. It should take about 45 seconds to open when turned on, but it was taking nearly a minute and a half. We returned to the shop and had them change the valve.
 
TFaudree_ERAU said:
The original issue was the PRSOV (pressure regulating and shut off valve). After the bleed air comes off the engines, it goes through the mixing valve. The mixing valve will pull LP air off the engines in normal conditions, but will introduce HP air when the pressure drops below 18-22 psi. After the mixing valve, the air goes through the PRSOV to regulate it as to not cause any drastic pressure changes in the cabin. We were getting severe pressure bumps on takeoff and the cabin controller was overly sensitive (it is already ultra sensitive under normal circumstances) We ran some tests up at FL390 so that the system was under a full "load", and we were able to determine the PRSOV was the culprit.

On the way out of maintenance, we got a #2 (right) Main Air Valve disagree light when we selected them on after takeoff (have to take off with them off in the mighty Hawker). We recycled it, and it functioned correctly, but again, we tested it at higher altitude under a load. It should take about 45 seconds to open when turned on, but it was taking nearly a minute and a half. We returned to the shop and had them change the valve.
Click to expand...

we had the same issue in our hawker.
 
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