Embraer 170 air carrier crew reported a flight deck window malfunction during cruise flight. The crew diverted to an alternate airport and landed.
Synopsis
Embraer 170 air carrier crew reported a flight deck window malfunction during cruise flight. The crew diverted to an alternate airport and landed.
Narrative
Enroute to ZZZ at FL310 approximately 50NM Southwest of ZZZ1. EICAS message Windshield 1 HTR Fail" was received. At that time; we noticed a crack beginning to form on the lower section of the Captains windshield… shortly after (1-3) seconds; the windshield cracked severely across the entire panel within approximately 1 second; accompanied by a loud "thud" sound. We immediately put on our O2 masks in the event an unexpected decompression took place; and advised ATC of the issue; requesting an immediate descent; which was immediately cleared by ATC. We descended rapidly to 14;500 ft and then reduced speed to 250 knots for the rest of our descent to avoid excess wind pressure on the windscreen. During the descent; the Captain ran the appropriate QRH (Quick Reference Handbook) procedure in accordance with his duties; as he was the pilot monitoring. Once reaching a safe altitude we removed our oxygen masks and re-established communication via headset. ATC [requested priority handling] on our behalf during the descent in an abundance of caution. The Captain and I were still communicating a plan of action at that point. Shortly after reaching a safe altitude and reducing speed; we agreed that given the seemingly un-airworthy condition of the windscreen; the best course of action would be to divert to the nearest suitable airfield; which was ZZZ1. We advised the flight attendants of the condition and plan of action at that time; asking them to prepare the cabin for landing and take their seats. We advised dispatch of this decision via ACARS; and took a turn direct to ZZZ1; set up for landing; and landed without further event. ARFF (Airport Rescue and Fire Fighting) was standing by for us; and I made contact with them via radio as soon as receiving taxi instructions to the gate. Upon landing dispatch had already coordinated a gate and we proceeded to that gate. After reviewing the situation upon returning home yesterday evening; I realized that there was an additional QRH procedure that should have been executed during the decent… "Windshield - Cracked or Impaired". Neither of us realized during the series of decisions that were being made to look for a checklist other than "Windshield 1 HTR Fail" which was displayed on EICAS. Fortunately; the decisions that we made and executed were in accordance with the missed QRH procedure; except for depressurizing the cabin upon reaching 10;000 ft.Cause: I would summarize the cause of missing a QRH procedure to be two things:1. A lack of immediate knowledge of the existence of the "Windshield - Cracked or Impaired" QRH procedure.2. Not searching for an additional QRH procedure after executing the "Windshield 1 HTR Fail" due to a rapid series of decisions that were made to get the aircraft on the ground at the nearest suitable airfield due to our concern of the structural integrity of the cracked windshield. Suggestions: I am now aware of the particular QRH procedure that was missed. Also; in the future during a similar situation; I will remember the lesson learned during this [priority handling]… slow down and make sure all available information provided to us through checklists and QRH procedure is complied with… that includes searching the QRH for a procedure; even when it is not annunciated by the EICAS."
Second reporter narrative
Flying from ZZZ2 to ZZZ we were flying over the gulf. I was pilot monitoring and my FO was flying. Beginning the arrival into ZZZ we were at FL310 direct to the fix ZZZZZ from what I can remember. Suddenly we get an EICAS message that read WINDSHIELD 1 HEAT FAIL. I noticed a crack on my windshield followed by a loud thumb sound. At that moment the entire windshield cracked. I requested an immediate descent and ATC initially instructed us to descend to 15000 ft. As we were descending I followed the QRH (Quick Reference Handbook) procedure. We decided to divert to ZZZ1. Later on in the day I realized there was a QRH procedure for a cracked windshield. I was unaware of this procedure. Due to the severity and time sensitive nature of a cracked windshield; my priority was the safety of my passengers and crew. I was hyper focused on landing the aircraft safely in ZZZ1. I used my best judgment at the time. I failed to realize there was a procedure in the QRH for the windshield. Tracing back my steps the FO and I complied with the QRH procedure. Our precautions as a crew met the QRH standards. Cause: It is possible that the rapid cooling of the windshield caused the cracks. As for the QRH procedure; I believe the urgency of the situation did not allow time for us to think about a cracked windshield procedure. Suggestions: Have the windshield cracked item as an immediate action item on QRH.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.