Although their B737 was free of contamination during preflight by the time the flight crew taxied ou...

Narrative:

It was a cold 20 degree C early morning. Upon arrival at the aircraft; I took a quick glance at the aircraft surfaces and didn't notice any frost. After my first officer completed his walk around; I asked if he saw any frost and he said 'no'. During cockpit preparations we were distracted by items like the flight attendants requesting more ice; then later they asked for a new credit card battery replacement; then the ground power failed; and finally we noticed the mode control panel (MCP) had no power. Maintenance took about 30 minutes; delaying the flight past scheduled departure. We taxied out and after notifying the flight attendants that we were ready for takeoff; the flight attendants informed us a company commuting pilot told them there was frost on the wings. We returned to the ramp for deice. I believe the one hour time that elapsed from the preflight walk around to the takeoff; frost must have formed; and my first officer and I failed to double-check before takeoff. We almost performed a takeoff with frost on the wings; but with help from our commuting pilot; we averted the dangerous event.

Original NASA ASRS Text

Title: Although their B737 was free of contamination during preflight by the time the flight crew taxied out; following servicing and maintenance delays; they were advised by a deadheading pilot via a Flight Attendant that there was frost on the wings. They returned for de-icing.

Narrative: It was a cold 20 degree C early morning. Upon arrival at the aircraft; I took a quick glance at the aircraft surfaces and didn't notice any frost. After my First Officer completed his walk around; I asked if he saw any frost and he said 'No'. During cockpit preparations we were distracted by items like the Flight Attendants requesting more ice; then later they asked for a new credit card battery replacement; then the ground power failed; and finally we noticed the Mode Control Panel (MCP) had no power. Maintenance took about 30 minutes; delaying the flight past scheduled departure. We taxied out and after notifying the flight attendants that we were ready for takeoff; the flight attendants informed us a company commuting Pilot told them there was frost on the wings. We returned to the ramp for deice. I believe the one hour time that elapsed from the preflight walk around to the takeoff; frost must have formed; and my First Officer and I failed to double-check before takeoff. We almost performed a takeoff with frost on the wings; but with help from our commuting Pilot; we averted the dangerous event.

Data retrieved from NASA's ASRS site 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	1228804
Time
Date	201412
Local Time Of Day	0601-1200
Place
Locale Reference	MDW.Airport
State Reference	IL
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 235 Flight Crew Type 10000
Person 2
Function	First Officer
Experience	Flight Crew Last 90 Days 148
Events
Anomaly	Deviation - Procedural Published Material / Policy Ground Event / Encounter Other / Unknown

Although their B737 was free of contamination during preflight by the time the flight crew taxied out; following servicing and maintenance delays; they were advised by a deadheading pilot via a flight attendant that there was frost on the wings. They returned for de-icing.