EMB135 departed without deicing while light freezing rain was being reported on ATIS.

Attributes
ACN	765422
Time
Date	200712
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : stl.airport
State Reference	MO
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Weather Elements	Rain Ice
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 135 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 150 flight time type : 200
ASRS Report	765422
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 200 flight time type : 3000
ASRS Report	765420
Events
Anomaly	non adherence : far non adherence : company policies
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Weather Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

I was acting as first officer on a scheduled part 121 operated flight from stl airport. While the captain was tending to his preflight duties; I tended to getting ATIS; clearance; and calculating the weight and balance. Afterwards we completed a briefing of current conditions at departure and proposed arrival airports. After doors had been closed and the necessary checklists had been completed; I called for push and taxi from their respective frequencys. While taxiing out of the non movement area; ground-metering advised us to pick up the most recent ATIS. While listening; the captain and I neglected to hear the light freezing rain existence on the field due to frequency congestion and continued toward the departure runway as usual. After departing the terminal area; the captain turned on ATIS again questioning what had been previously noted; and realized the freezing rain and our situation of not being deiced and anti-iced as per our general operations manual. Prior to our departure; our separate duties to check the aircraft control surfaces and verify the proper settings for engine and airframe anti-ice selectors; which were both on due to current airport conditions as observed from the cockpit had been completed. I do realize why the situation escalated into what it did; this flight was my second flight ever experiencing temperatures below freezing before takeoff. All my flight training was conducted in temperatures above freezing. The previous day was my first day experiencing freezing conditions. At the time I had read all the company memos; however; had not had any experience; so it did not register. I have then since read over the memos again and with my experience have understood them better. The captain and I discussed the situation and I fully understand the severity of the situation and can assure that this mistake will never recur. The takeoff and flight were completed with no further occurrences; however; we realized the situation and learned from our mistakes and fully intend to pay better attention in the future.

Original NASA ASRS Text

Title: EMB135 DEPARTED WITHOUT DEICING WHILE LIGHT FREEZING RAIN WAS BEING REPORTED ON ATIS.

Narrative: I WAS ACTING AS FO ON A SCHEDULED PART 121 OPERATED FLT FROM STL ARPT. WHILE THE CAPT WAS TENDING TO HIS PREFLT DUTIES; I TENDED TO GETTING ATIS; CLRNC; AND CALCULATING THE WT AND BAL. AFTERWARDS WE COMPLETED A BRIEFING OF CURRENT CONDITIONS AT DEP AND PROPOSED ARR ARPTS. AFTER DOORS HAD BEEN CLOSED AND THE NECESSARY CHKLISTS HAD BEEN COMPLETED; I CALLED FOR PUSH AND TAXI FROM THEIR RESPECTIVE FREQS. WHILE TAXIING OUT OF THE NON MOVEMENT AREA; GND-METERING ADVISED US TO PICK UP THE MOST RECENT ATIS. WHILE LISTENING; THE CAPT AND I NEGLECTED TO HEAR THE LIGHT FREEZING RAIN EXISTENCE ON THE FIELD DUE TO FREQ CONGESTION AND CONTINUED TOWARD THE DEP RWY AS USUAL. AFTER DEPARTING THE TERMINAL AREA; THE CAPT TURNED ON ATIS AGAIN QUESTIONING WHAT HAD BEEN PREVIOUSLY NOTED; AND REALIZED THE FREEZING RAIN AND OUR SITUATION OF NOT BEING DEICED AND ANTI-ICED AS PER OUR GENERAL OPS MANUAL. PRIOR TO OUR DEP; OUR SEPARATE DUTIES TO CHK THE ACFT CTL SURFACES AND VERIFY THE PROPER SETTINGS FOR ENG AND AIRFRAME ANTI-ICE SELECTORS; WHICH WERE BOTH ON DUE TO CURRENT ARPT CONDITIONS AS OBSERVED FROM THE COCKPIT HAD BEEN COMPLETED. I DO REALIZE WHY THE SITUATION ESCALATED INTO WHAT IT DID; THIS FLT WAS MY SECOND FLT EVER EXPERIENCING TEMPS BELOW FREEZING BEFORE TKOF. ALL MY FLT TRAINING WAS CONDUCTED IN TEMPS ABOVE FREEZING. THE PREVIOUS DAY WAS MY FIRST DAY EXPERIENCING FREEZING CONDITIONS. AT THE TIME I HAD READ ALL THE COMPANY MEMOS; HOWEVER; HAD NOT HAD ANY EXPERIENCE; SO IT DID NOT REGISTER. I HAVE THEN SINCE READ OVER THE MEMOS AGAIN AND WITH MY EXPERIENCE HAVE UNDERSTOOD THEM BETTER. THE CAPT AND I DISCUSSED THE SITUATION AND I FULLY UNDERSTAND THE SEVERITY OF THE SITUATION AND CAN ASSURE THAT THIS MISTAKE WILL NEVER RECUR. THE TKOF AND FLT WERE COMPLETED WITH NO FURTHER OCCURRENCES; HOWEVER; WE REALIZED THE SITUATION AND LEARNED FROM OUR MISTAKES AND FULLY INTEND TO PAY BETTER ATTN IN THE FUTURE.

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.