EMB145 first officer reports a power interruption during APU start with a ground power unit. After t...

Narrative:

Before pushback the APU was started with the gpu. The gpu did not have enough power to start the APU and power the airplane. Power to the airplane was interrupted. We notified maintenance and they come out and looked at it. We're not sure if it's related to the event that occurred but might be useful. After takeoff the airplane would not pressurize in the automatic mode. We leveled the airplane at 10;000 and went to the QRH. The airplane would pressurize in manual mode. We contacted maintenance to see what if they had any input; and they requested we return. We attempted to burn as much fuel as we could prior to landing but still needed to land overweight. We used the manual mode to depressurize the airplane during the descent. The captain made the landing and touched down at 96 feet/minute; well below what was required for an overweight landing. Threats included the pressurization controller and the possibility in not catching it after takeoff. We noticed it soon enough that oxygen or passenger oxygen was not needed. Other threats included the overweight landing. There were QRH recommendations that were helpful. The situation was handled with the correct amount of urgency. We worked well together to resolve the cabin pressurization issue and the overweight landing. This was a situation where we did not need to rush and make a mistake and therefore we didn't.

Original NASA ASRS Text

Title: EMB145 First Officer reports a power interruption during APU start with a Ground Power Unit. After takeoff the aircraft will not pressurize in the automatic mode and Maintenance Control requests that the flight return.

Narrative: Before pushback the APU was started with the GPU. The GPU did not have enough power to start the APU and power the airplane. Power to the airplane was interrupted. We notified Maintenance and they come out and looked at it. We're not sure if it's related to the event that occurred but might be useful. After takeoff the airplane would not pressurize in the automatic mode. We leveled the airplane at 10;000 and went to the QRH. The airplane would pressurize in manual mode. We contacted Maintenance to see what if they had any input; and they requested we return. We attempted to burn as much fuel as we could prior to landing but still needed to land overweight. We used the manual mode to depressurize the airplane during the descent. The Captain made the landing and touched down at 96 feet/minute; well below what was required for an overweight landing. Threats included the pressurization controller and the possibility in not catching it after takeoff. We noticed it soon enough that oxygen or passenger oxygen was not needed. Other threats included the overweight landing. There were QRH recommendations that were helpful. The situation was handled with the correct amount of urgency. We worked well together to resolve the cabin pressurization issue and the overweight landing. This was a situation where we did not need to rush and make a mistake and therefore we didn't.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1114825
Time
Date	201309
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	EMB ERJ 145 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Pressurization Control System
Person 1
Function	Pilot Not Flying First Officer
Events
Anomaly	Aircraft Equipment Problem Less Severe

EMB145 first officer reports a power interruption during APU start with a ground power unit. After takeoff the aircraft will not pressurize in the automatic mode and maintenance control requests that the flight return.