Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Distraction; Confusion; Communication Breakdown; Workload
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Object
Aircraft Aircraft Damaged; Flight Crew Became Reoriented; General Flight Cancelled / Delayed; General Maintenance Action
Procedure; Weather
We were loaded up and waiting push back at departure time. The Lead Ramper had gone in search of a broom in hopes of brushing off the snow on the aircraft due to 2 plus inches of snow on the aircraft and the fact that they were running low on deicing fluid. When he returned we began our push shortly after sunrise local time based on my estimation of a 20 minute delay and the times recorded by the ACARS. We requested a push clearance to deice. I informed the driver over the intercom that the brakes were off and we were cleared to push. He responded with brakes off cleared to start (engines). As we pushed back I started the #1 engine first and ran the first flight fuel pump checks. I then proceeded to start the #2 Engine. It stabilized just prior to the driver advising push back complete set brakes. I set the brakes and responded brakes set cleared to disconnect. I began my pre-taxi flow with first/flight checks. Maybe 15/20 seconds since setting the brakes I got to the 14th stage ISOL valve check. It did not open. I advanced the thrust levers just out of idle. The thrust levers weren't open for a more than 1 second and when the 14th stage ISOL valve opened; I closed the thrust levers. The thrust levers from idle to cracked to idle was less than 2 seconds. I can't speak to the exact N1 or N2 as I was not watching the gages although the power added was very little. Just as the thrust levers reached idle the aircraft; for lack of a better description; hopped slightly then stopped. There was no detectable motion other than the vertical movement. Moments later the push back driver stated that we were sitting on top of the tow bar. The First Officer and I both verified that the parking break was set. I then decided to shut down both engines; ran a shutdown check; informed the Flight Attendant as to the situation and asked her to open the main cabin door; made  a quick announcement to the passengers and went outside to investigate. I first ascertained if any one was injured. Fortunately no one was injured. I then looked at the situation and the aircraft nose gear had jumped over/up the C portion of the tow bar and climbed up the main square tubing of the tow bar until the bottom of the strut had encountered a bolt protruding from the top of the tow bar were it stopped. The tow bar was still attached to the tug so the C portion of the tow bar was resting almost on the ground. On first glance it appeared that the aircraft had traveled about a foot before it encountered the tow bar then an additional 2 feet over the tow bar total distance approximately 3 feet. The tire tracks in the snow from the main gear as well as the nosed gear supported that estimate. The nose wheel tires were approximately 2 inches off the ground and the weight of the aircraft was resting on the tow bar. One of the ramp personnel wanted to pull the aircraft back to the gate with the aircraft resting on the tow bar. I declined and said the first thing to do was to pin the landing gear to prevent further damage and or injury to the passengers. I then asked a Ramp Agent to chock the main landing gear. I noticed that the chocks were sitting on the back of the tug. I then took several pictures for my own records. As we were completing this the Airport Manager and Fire Chief arrived and we discussed the safest way to deplane the passengers. We decided to sweep the ramp and sand the path back to the terminal. I then went back aboard informed the Flight Attendant and the passengers as to the deplaning. I then tried to call Dispatch and Maintenance Control but I had no cell service. I tried repeatedly to contact Operations to have them call but throughout the entire incident I could not raise them. In all fairness there was a Customer Service Agent there almost immediately and she was very helpful but it didn't help me with company communication. The First Officer sent an ACARS to Maintenance Control to inform them. After the passengers were deplaned I left the aircraft in control of the First Officer. I then went back in the terminal to contact Maintenance Control and Dispatch. Maintenance Control confirmed that the aircraft should not be moved. I returned to the aircraft and we shut it down.  Just prior to returning to the terminal; I was reexamining the aircraft snow etc. and it occurred to me that the aircraft had not been chocked after push back. The snow would have been pushed back over the tire tracks in the snow. I confirmed this with the Airport Manager and Fire Chief on the pictures I had taken.The root cause of this event was a contaminated ramp with traction conditions that were unreported by the ATIS or ground crew that were far worse that I perceived them to be; compounded by my unintentional failure to comply with the new (as of last June) abnormal operations procedure in the SOP for contaminated ramp pushback. I vaguely remember it coming out and reading it; after it was brought to my attention; after the fact. In 12 years of operating CRJ-200s; I've had significant contaminated ramp as well as runway experience. I never got down onto the ramp that morning and physically judged the 1 plus inch of snow on the ramp.  Had I done so; I would have delayed the engine start. Since the jet bridge was hooked up I judged the snow from the flight deck to be of average consistency. It didn't occur to me that since the ramp had previously been dry and relatively warm (above 0) that there might be slush under the snow. The runway was reporting 1 inch contamination 100% coverage in snow/slush. I didn't make the connection as it looked like average light snow on the ramp having started 10 hours earlier. Since it was the first flight of the morning off that gate and the tug was already attached and it was snowing; there weren't any obvious signs of wet snow or slush. Also in that abnormal push back procedure it states that prior to commencing pushback: (2) The pushback crew must make the Captain aware of ramp conditions. This never happened. Although I'm not sure when the AC started to move; cracking the thrust levers aggravated if not initiated the aircraft movement. A Contributing factor was that I was rushing due to a 20 plus minute delay caused by the Ramp Lead who went in search of a broom at scheduled departure time (we were ready to go) and returned 20 plus minutes later. The airport was running out of Type Four deicing fluid and they were trying to conserve it apparently. Didn't make sense to me because you don't deice with Type Four; you use Type One. Normally 20 minutes would [not] be that big of a concern except that the Flight Attendant and I both had a deadhead to catch to return to domicile. We both had the same show time for the same trip early the next morning. Another contributing factor was the condition of the main tires. All four main gear tires although they were legal; had very little tread left. Post incident inspection of the three feet of slide marks behind the main gear showed the failure of the tires to break through the slush/snow that was formed as the tire passed over it. I have several suggestions: 1. First and foremost; had I used the contaminated ramp procedure the event may have been avoided. Although the conditions on the ramp may have allowed the aircraft to move anyway; I may have been able to stop the aircraft prior to it catching up to the tug and ground crew. However in my experience; if the aircraft had started to move with the parking brake on; the only way to stop it would be to shut down the engines as thrust reversers do not help in this situation. The procedure was developed for just this scenario to avoid injury and damage to equipment. I didn't follow it; my mistake; my responsibility.  2. In the future; if the SOP doesn't specify to crack the thrust levers; don't. 3. Being aware of actual conditions would have delayed the engine start. I could have gone out and checked myself. The First Officer could have brought it to my attention.The ramp agents could have brought it to our attention. It could have been reported by the Tower on the ATIS. I don't recall any traction reports either for the ramp or the runway in use.  4. I shouldn't allow myself to be rushed for any reason. 5. Had the aircraft been chocked it might have prevented the aircraft from moving or at least stopped it at the tow bar. 6. Had the tires had more tread they may have performed better.
[Report narrative contains no additional information.]
A CRJ-200 pushed back and started engines on an ice and snow covered ramp. When the 14Th Stage ISOL Valve Check light illuminated; the Captain momentarily advanced the thrust lever causing the aircraft skidded forward onto the tow bar; even with the brakes set.