Date: 201603
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Light: Night
Aircraft: Regional Jet 900 (CRJ900)
Operating under: Part 121
Flight phase: Parked
Aircraft component: Cockpit Window
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Lead Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Fatigue; Situational Awareness; Time Pressure
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Ground Personnel; Person Maintenance
When detected: In-flight
Contributing factors: Aircraft; Procedure; Human Factors
Primary problem: Human Factors

Narrative: I was asked to go on a road trip to ZZZ at XA:30; did not leave till XD:30. After we were being escorted to the aircraft arrival time approximately XH:30; first thing we did was look at the log book and talk to control to find out exactly where we were with the window change. Around XL:00 we started installing and torqueing bolts; around XL:30 station personnel came and said he had to leave and we could not stay unescorted. We arrived back at the plane around XM:30 finished up the torquing and double checked; I read the manual again to make sure of torques and to make sure we did not forget anything; once done with torques around XN:00 am; I prepared the window for sealing and sealed the window with sealant and forgot to install the weather seals.I believe someone was called out to the aircraft because the sealant I mixed did not cure and it blew out.The aircraft was located in the remote pad; lighting played a big factor also being tired.


Second narrative: We flew out on the XD:30 flight. I and another mechanic went on the road trip. We arrived at the aircraft around XH:00-XH:30 pm. We were told the windshield was in place and we were to finish the install of the LH windshield. At approximately XL:48 our escort from station said we needed to go with him to the office which is off site of the airport. I asked if we could leave in a few minutes because I was in the middle of torquing the bolts on the strap. He said we needed to go. The missing seals were confirmed at the destination airport; the seals were not installed. Once I heard that I knew when the step was missed was when we had to go off site to the office and while we were gone we were discussing with maintenance control about the other mechanics that were going to come back to the aircraft and finish all the checks that needed to be accomplished and finish installing the wiper. Also I notified maintenance control the bolt for the wiper arm was missing. There were a lot of different topics that were discussed in between the time frame.The missed step happened between the time we had to leave the aircraft and go to the offsite office.Between the time we were gone both of us discussed what else needed to be completed when we returned. Once at the office I was in contact with maintenance control. We were already past our duty time. We arrived back to the aircraft 45min. to 1hour and I torqued the bolts from the beginning so I did not miss a bolt. After I completed my co-worker was going to seal the windshield. We finished the windshield and we left the aircraft around XO:00. A mechanic noticed some sealant on the windshield and brought to my attention the sealant had blown out. The aircraft was at its destination and I notified my supervisor about the concern of the seal installation may have been missed. My supervisor notified maintenance and talked to my co-worker on the phone and was determined the seals were not installed. Maintenance installed the seals.


Synopsis: While replacing the Left Hand Windshield on a CRJ-900 the Maintenance crew neglected to install the weather seals.