Narrative:

Frosty wings. A sunny, clear, yet cold morning for departure from ZZZ. A special qualification city in mountainous terrain. No special reason for concern about the condition of the aircraft or my first officer, with whom I have enjoyed a good month of trouble-free flying. Normal sequence of events in preparation for start, taxi, etc, until a cabin call came to the cockpit. A fellow deadheading company pilot, riding in main cabin reported through one of our flight attendants that there was frost prevalent on the top surfaces of both wings. I decided immediately to return to the ramp for deicing. ATC, station personnel, and passenger were advised of the circumstances and our intentions as we returned for deicing. A ZZZ ramp agent and a deicer guided us to a ramp-side deicing pad for deicing with type I fluid. Once complete, we restarted engines, and resumed taxi out and a subsequent normal, uneventful takeoff into a beautiful rocky mountain morning. The first officer is a diligent professional. I'm confident in his ability and performance. This morning, however, the coffee just wasn't doing the trick, and he admittedly failed to adequately confirm that the wings were clean. Temperature was several degrees below freezing, although the air was relatively dry. No evidence of frost was present on the undersides of the wings, so he concluded the tops must also be frost-free, without actually having examined the upper wing surfaces. If a glance back from the rear of the aircraft had been made during the walkaround, the frost would have been spotted, and deicing would have been called for prior to taxi out. Besides the opportunity for frost detection during the normal exterior walkaround sequence, a good practice to alleviate the risk of such an embarrassing and possibly critical oversight as this may be to make a habit of checking wing surfaces from within the cabin in the case of preflight in such freezing conditions. I, too, should simply make it a habit to maintain a degree of skepticism about the possibility of ice or frost on the aircraft whenever an aircraft has been overnight at sub-freezing temperatures. I'll ask rather than assume. My query during cockpit preparations may have prompted one more check which would have revealed the contaminated wings. Many thanks to non-revenuing captain for his intervention. His input spared us from making a takeoff with contaminated wings.

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Original NASA ASRS Text

Title: A B757-200 DEADHEADING COMPANY CAPT POINTED OUT THAT THE ACFT WINGS WERE CONTAMINATED WITH FROST. THIS OCCURRED ON TAXI TO THE RWY.

Narrative: FROSTY WINGS. A SUNNY, CLR, YET COLD MORNING FOR DEP FROM ZZZ. A SPECIAL QUALIFICATION CITY IN MOUNTAINOUS TERRAIN. NO SPECIAL REASON FOR CONCERN ABOUT THE CONDITION OF THE ACFT OR MY FO, WITH WHOM I HAVE ENJOYED A GOOD MONTH OF TROUBLE-FREE FLYING. NORMAL SEQUENCE OF EVENTS IN PREPARATION FOR START, TAXI, ETC, UNTIL A CABIN CALL CAME TO THE COCKPIT. A FELLOW DEADHEADING COMPANY PLT, RIDING IN MAIN CABIN RPTED THROUGH ONE OF OUR FLT ATTENDANTS THAT THERE WAS FROST PREVALENT ON THE TOP SURFACES OF BOTH WINGS. I DECIDED IMMEDIATELY TO RETURN TO THE RAMP FOR DEICING. ATC, STATION PERSONNEL, AND PAX WERE ADVISED OF THE CIRCUMSTANCES AND OUR INTENTIONS AS WE RETURNED FOR DEICING. A ZZZ RAMP AGENT AND A DEICER GUIDED US TO A RAMP-SIDE DEICING PAD FOR DEICING WITH TYPE I FLUID. ONCE COMPLETE, WE RESTARTED ENGS, AND RESUMED TAXI OUT AND A SUBSEQUENT NORMAL, UNEVENTFUL TKOF INTO A BEAUTIFUL ROCKY MOUNTAIN MORNING. THE FO IS A DILIGENT PROFESSIONAL. I'M CONFIDENT IN HIS ABILITY AND PERFORMANCE. THIS MORNING, HOWEVER, THE COFFEE JUST WASN'T DOING THE TRICK, AND HE ADMITTEDLY FAILED TO ADEQUATELY CONFIRM THAT THE WINGS WERE CLEAN. TEMP WAS SEVERAL DEGS BELOW FREEZING, ALTHOUGH THE AIR WAS RELATIVELY DRY. NO EVIDENCE OF FROST WAS PRESENT ON THE UNDERSIDES OF THE WINGS, SO HE CONCLUDED THE TOPS MUST ALSO BE FROST-FREE, WITHOUT ACTUALLY HAVING EXAMINED THE UPPER WING SURFACES. IF A GLANCE BACK FROM THE REAR OF THE ACFT HAD BEEN MADE DURING THE WALKAROUND, THE FROST WOULD HAVE BEEN SPOTTED, AND DEICING WOULD HAVE BEEN CALLED FOR PRIOR TO TAXI OUT. BESIDES THE OPPORTUNITY FOR FROST DETECTION DURING THE NORMAL EXTERIOR WALKAROUND SEQUENCE, A GOOD PRACTICE TO ALLEVIATE THE RISK OF SUCH AN EMBARRASSING AND POSSIBLY CRITICAL OVERSIGHT AS THIS MAY BE TO MAKE A HABIT OF CHKING WING SURFACES FROM WITHIN THE CABIN IN THE CASE OF PREFLT IN SUCH FREEZING CONDITIONS. I, TOO, SHOULD SIMPLY MAKE IT A HABIT TO MAINTAIN A DEGREE OF SKEPTICISM ABOUT THE POSSIBILITY OF ICE OR FROST ON THE ACFT WHENEVER AN ACFT HAS BEEN OVERNIGHT AT SUB-FREEZING TEMPS. I'LL ASK RATHER THAN ASSUME. MY QUERY DURING COCKPIT PREPARATIONS MAY HAVE PROMPTED ONE MORE CHK WHICH WOULD HAVE REVEALED THE CONTAMINATED WINGS. MANY THANKS TO NON-REVENUING CAPT FOR HIS INTERVENTION. HIS INPUT SPARED US FROM MAKING A TKOF WITH CONTAMINATED WINGS.

Data retrieved from NASA's ASRS site as of July 2007 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.