Date: 201502
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Weather elements / visibility: Icing; Windshear; Snow
Light: Night
Aircraft: Regional Jet 700 ER/LR (CRJ700)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
ATC / advisory: Ground ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Training / Qualification; Communication Breakdown
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: Flight Crew Took Evasive Action; General Release Refused / Aircraft Not Accepted
Contributing factors: Company Policy; Weather; Procedure; Human Factors
Primary problem: Procedure

Narrative: The Captain and First Officer (FO) operated flight from Airport ZZZ. This flight was scheduled to depart at XA06 local time and we originally blocked out a few minutes early. On our way to the deice pad we discovered the wind had shifted towards a tailwind and during deicing we calculated that we needed the wind to shift further away from the tail or to die down below 2 knots of tailwind component before we would be able to depart.The deice crew were told to deice the aircraft with type one fluid only as there was no precipitation at that time; however; the aircraft had sat on the ground for approximately 6 hours during various snow showers. Estimated ?? inch of snow covered the entire aircraft. Additionally; the flight crew had flown the aircraft into ZZZ earlier that day and some ice accumulation was on the aircraft; therefore; the flaps were in the approach flap setting. After parked in the deice pad; the deice crew began and finished type one fluid application. Next; the deice crew informed us they would be starting type four application; which we stopped them from doing. We again advised that only type one fluid was required.Some confusion arose that was apparent over the radio because the person speaking to the crew hesitated at first; but then came back and said 'Your aircraft is clean.' The FO asked if the deice crew had completed a post-deice check and she affirmed; 'Yes we did; your aircraft is clean.'They began fluid application at XA:06 local and finished at XA:16 according the deicer. At this point; we were ready for departure; but the wind was still a steady 4 or 5 knot tailwind. The Captain coordinated with dispatch once again to move fuel in an effort to lower our minimum takeoff fuel to facilitate waiting a few more minutes for the wind to shift or decrease.It was approximately XA:45 when the crew decided that the wind was not going to shift or decrease enough to facilitate a departure and we decided to return to the gate. Upon return to the gate we informed the station that we needed to reduce payload and plan for a 5 knot tailwind. This in itself seemed to perplex the station because they continued to ask the flight crew how many people we wanted to remove.Regardless; the FO performed a walk-around after the passengers had deplaned. He discovered snow and ice covering the aircraft. There was ice on the nose and fuselage; as well as snow on the wings and trailing edge of the flaps; and we do not know what the top of the tail looked like.Pictures have already been forwarded to the appropriate parties so the condition of the aircraft should be apparent; but let me reiterate: there was completely untouched snow and ice on the left wing. The right wing also contained snow but not as much as the left wing.The FO contacted the deice crew following the post-flight to ascertain why the crew failed to completely clean the aircraft. Speaking with the deice crewmember that was in the deice bucket (spraying the aircraft) he was asked: 'Did you see the snow on the wings?' He responded; 'Yes; but the things were up and I couldn't reach that part of the wing.' When asked 'Why did you tell us the aircraft was clean if you knew there was still snow on the wings?' No response.The flaps were set for deice at the approach setting of 45 degrees. Usually when the flaps require deicing; the deice crew will use a hose and walk up to the wing and spray from under the wing and along the leading edge and trailing edge; then use the bucket to spray the top of the wing. It seems apparent that this technique was not used. Regardless; if snow was seen on the aircraft and the crew was unable to reach it; that information should have been relayed to the flight crew.Under no circumstances should a deicer inform a flight crew that 'your aircraft is clean' while snow or ice remains on the aircraft.  I suggest better deice training. The deicer had no idea that leaving snow on the wings was dangerous or cause for concern.




Synopsis: A de-ice crew reported a CRJ-700 clean of ice and snow but when the First Officer completed a walk around after returning to the gate to reduce takeoff weight; ice and snow were discovered on the wings and flaps.