B737 flight crew was informed by maintenance that the aircraft was free of ice; and the flight depar...

Narrative:

It was a cold clear morning with frost on the ground and all surfaces. I asked first officer to look for ice or frost on all surfaces of the jet. First officer reported that wings were frost covered and would require a deice. I contacted line maintenance 25 mins prior to scheduled push time to arrange for deice. Maintenance responded they would be ready. At push time I radioed maintenance deice for the deice. Line maintenance responded that they had inspected the aircraft and verified that it was free of ice and did not need a deice. It had been 45 mins since the exterior preflight and the sun was out so I took maintenance on their word. We taxied and took off normally with no problems. At the completion of the flight; a captain who sat in an exit row reported that the wings; including the ailerons; were frost covered at the time of the push. He took a picture of the frost covered wing with his cell phone. If maintenance tells me that my jet is airworthy then they should be the authority/authorized and I should be able to accept their evaluate. In retrospect I now know that this is not the case and I should have set the brakes and had my first officer inspect the wings from the cabin or a ladder. I believe this to be a very serious safety violation and significant threat to safe operation of this airline. I am told after reporting this event that this has happened before and continues to be a problem. I do not think that this was a simple communication failure between maintenance and me. I was very clear to maintenance and our conversation was concise; accurate and clear. I cannot over emphasize the seriousness of this threat or the profound need for investigation and immediate action. Maintenance has got to be truthful and accurate to the capts. In the near term we pilots must take the time to verify to the best of our ability the airworthiness of the jet. There is no substitute for the integrity and expertise of a mechanic and a pilot. This cannot continue to happen.

Original NASA ASRS Text

Title: B737 FLT CREW WAS INFORMED BY MAINT THAT THE ACFT WAS FREE OF ICE; AND THE FLT DEPARTED. IT WAS LATER DISCOVERED THAT THE WINGS HAD BEEN COVERED WITH FROST.

Narrative: IT WAS A COLD CLR MORNING WITH FROST ON THE GND AND ALL SURFACES. I ASKED FO TO LOOK FOR ICE OR FROST ON ALL SURFACES OF THE JET. FO RPTED THAT WINGS WERE FROST COVERED AND WOULD REQUIRE A DEICE. I CONTACTED LINE MAINT 25 MINS PRIOR TO SCHEDULED PUSH TIME TO ARRANGE FOR DEICE. MAINT RESPONDED THEY WOULD BE READY. AT PUSH TIME I RADIOED MAINT DEICE FOR THE DEICE. LINE MAINT RESPONDED THAT THEY HAD INSPECTED THE ACFT AND VERIFIED THAT IT WAS FREE OF ICE AND DID NOT NEED A DEICE. IT HAD BEEN 45 MINS SINCE THE EXTERIOR PREFLT AND THE SUN WAS OUT SO I TOOK MAINT ON THEIR WORD. WE TAXIED AND TOOK OFF NORMALLY WITH NO PROBS. AT THE COMPLETION OF THE FLT; A CAPT WHO SAT IN AN EXIT ROW RPTED THAT THE WINGS; INCLUDING THE AILERONS; WERE FROST COVERED AT THE TIME OF THE PUSH. HE TOOK A PICTURE OF THE FROST COVERED WING WITH HIS CELL PHONE. IF MAINT TELLS ME THAT MY JET IS AIRWORTHY THEN THEY SHOULD BE THE AUTH AND I SHOULD BE ABLE TO ACCEPT THEIR EVAL. IN RETROSPECT I NOW KNOW THAT THIS IS NOT THE CASE AND I SHOULD HAVE SET THE BRAKES AND HAD MY FO INSPECT THE WINGS FROM THE CABIN OR A LADDER. I BELIEVE THIS TO BE A VERY SERIOUS SAFETY VIOLATION AND SIGNIFICANT THREAT TO SAFE OP OF THIS AIRLINE. I AM TOLD AFTER RPTING THIS EVENT THAT THIS HAS HAPPENED BEFORE AND CONTINUES TO BE A PROB. I DO NOT THINK THAT THIS WAS A SIMPLE COM FAILURE BTWN MAINT AND ME. I WAS VERY CLR TO MAINT AND OUR CONVERSATION WAS CONCISE; ACCURATE AND CLR. I CANNOT OVER EMPHASIZE THE SERIOUSNESS OF THIS THREAT OR THE PROFOUND NEED FOR INVESTIGATION AND IMMEDIATE ACTION. MAINT HAS GOT TO BE TRUTHFUL AND ACCURATE TO THE CAPTS. IN THE NEAR TERM WE PLTS MUST TAKE THE TIME TO VERIFY TO THE BEST OF OUR ABILITY THE AIRWORTHINESS OF THE JET. THERE IS NO SUBSTITUTE FOR THE INTEGRITY AND EXPERTISE OF A MECH AND A PLT. THIS CANNOT CONTINUE TO HAPPEN.

Data retrieved from NASA's ASRS site as of May 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.

Attributes
ACN	771006
Time
Date	200801
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 60 flight time type : 10000
ASRS Report	771006
Person 2
Function	observation : passenger other personnel other
Events
Anomaly	non adherence : published procedure non adherence : far non adherence : company policies
Independent Detector	other other : 2
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Maintenance Human Performance Flight Crew Human Performance
Primary Problem	Maintenance Human Performance

B737 flight crew was informed by maintenance that the aircraft was free of ice; and the flight departed. It was later discovered that the wings had been covered with frost.