During ground stop at ord MD80 has APU fail with both engines shut down.

Attributes
ACN	704119
Time
Date	200607
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	agl single value : 0
Environment
Weather Elements	Rain
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : holding
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	704119
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

After being notified of a destination ground stop; we shut down both engines with the APU running while parked in the taxiway B penalty box at ord. 10 mins later the APU had an intermittent fault causing it to intermittently shut down. We attempted to start the left engine while it was doing this intermittent shutdown cycling; but the control valve was closed allowing no air flow for the start. After several cycles the captain shut down the APU resulting in the aircraft reverting to emergency battery power only. He attempted to restart the APU but it would hang up at 55%. We called ord maintenance to either bring a tug to tow us in or bring an aircraft to start one of the engines. They had to coordination with the airport authority/authorized to get an escort for equipment and personnel. After waiting on an aircraft for 1 hour with no ventilation; the party arrived after which we started the left engine and taxied back to the gate. The flight was subsequently canceled. Observations: had no prior indication APU would fail. It is common practice to have both engines off with APU running during extended ground stops. A tow back to the gate would have been quicker and used less ground personnel versus rounding up an air cart and gpu along with maintenance personnel.

Original NASA ASRS Text

Title: DURING GND STOP AT ORD MD80 HAS APU FAIL WITH BOTH ENGS SHUT DOWN.

Narrative: AFTER BEING NOTIFIED OF A DEST GND STOP; WE SHUT DOWN BOTH ENGS WITH THE APU RUNNING WHILE PARKED IN THE TXWY B PENALTY BOX AT ORD. 10 MINS LATER THE APU HAD AN INTERMITTENT FAULT CAUSING IT TO INTERMITTENTLY SHUT DOWN. WE ATTEMPTED TO START THE L ENG WHILE IT WAS DOING THIS INTERMITTENT SHUTDOWN CYCLING; BUT THE CTL VALVE WAS CLOSED ALLOWING NO AIR FLOW FOR THE START. AFTER SEVERAL CYCLES THE CAPT SHUT DOWN THE APU RESULTING IN THE ACFT REVERTING TO EMER BATTERY PWR ONLY. HE ATTEMPTED TO RESTART THE APU BUT IT WOULD HANG UP AT 55%. WE CALLED ORD MAINT TO EITHER BRING A TUG TO TOW US IN OR BRING AN ACFT TO START ONE OF THE ENGS. THEY HAD TO COORD WITH THE ARPT AUTH TO GET AN ESCORT FOR EQUIP AND PERSONNEL. AFTER WAITING ON AN ACFT FOR 1 HR WITH NO VENTILATION; THE PARTY ARRIVED AFTER WHICH WE STARTED THE L ENG AND TAXIED BACK TO THE GATE. THE FLT WAS SUBSEQUENTLY CANCELED. OBSERVATIONS: HAD NO PRIOR INDICATION APU WOULD FAIL. IT IS COMMON PRACTICE TO HAVE BOTH ENGS OFF WITH APU RUNNING DURING EXTENDED GND STOPS. A TOW BACK TO THE GATE WOULD HAVE BEEN QUICKER AND USED LESS GND PERSONNEL VERSUS ROUNDING UP AN AIR CART AND GPU ALONG WITH MAINT PERSONNEL.

Data retrieved from NASA's ASRS site as of January 2009 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.