Date: 201510
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Citation X (C750)
Operator: Fractional
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Cockpit Window
Component problem: Failed
Reporter organization: Fractional
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Diverted; Flight Crew Landed As Precaution
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: The event of a cracked; co-pilot #2 side window occurred during climb out phase of flight around 21;000 feet. We were roughly around 20-25 miles northwest ZZZ. As we were climbing to 24;000 feet the entire side window cracked all over and made a loud popping noise. There was a shockwave feeling on my chest and I felt my ears pop as well. The best way to describe this is like going to a fireworks display show and feeling the shockwave and hearing a loud bang from the big 'boomer' type fireworks. The pilot sitting next to me in the left seat heard the noise as well and visually saw the windshield but didn't feel the pressure on his chest or ears like I did. The event nonetheless caused us to react accordingly. I donned my O2 mask and we [advised ATC] and began an expedited descent to land as soon as possible at the nearest airport; which in our case was ZZZ. Once we were at a safe altitude to sustain life without supplemental oxygen I removed my O2 mask. We safely landed in ZZZ without injury to crew or passengers; which there were 3 of them. I couldn't say what caused the window to crack like that but it's the first time I've seen anything like that happen in flight. It should be noted that cabin pressure was nominal and was climbing and descending on schedule as it normally would during the climb and descent phase of flight. No cabin pressure change occurred when the window cracked in flight. Another aircraft was flown in to ZZZ to recover the passengers and continue them on their journey.Since it appeared to be a freak accident in flight to the window I couldn't say a suggestion to avoid recurrence of this event. Neither the Captain nor I had any CAS message or indication in flight that would prelude to the window cracking like it did. It was a learning experience however and did build more confidence to reacting to inflight abnormalities that one can't really train for and that it's important to keep flying the airplane number one; and number two safely and efficiently react and get the aircraft on the ground as soon as practical; which the 'cracked/shattered windshield' QRH says to do.


Second narrative: The flight was with 3 passengers. The aircraft had an existing MEL for Baggage Door Open CAS message. This message did illuminate prior to engine start. The FO was pilot flying for this flight. After takeoff; we felt a pressurization bump in our ears climbing through 1500 feet. A Baggage Door Seal Amber message followed. We decided to climb a little higher to see if the message would cycle. At 6000 feet; the Baggage Altitude Amber message posted. Cabin pressure was on the normal schedule and at normal rates. We climbed to 13;000 feet and requested a holding pattern to troubleshoot the problem. We decided to isolate the baggage compartment and continue the flight since the cabin pressure was normal. We exited the hold and were instructed to climb to FL240 and proceed on course. Climbing through 20;000 feet; there was a very loud sound and I noticed the right hand forward side windshield had completely shattered. [The First Officer] was slightly disoriented from this but immediately donned his oxygen mask. He stopped the climb and leveled the aircraft. I [advised ATC] on the radio and requested a descent to 10;000 feet. The cabin did not depressurize; although the explosive sound of the window shattering had us expecting a rapid decompression. We chose to land at the closest large airfield; ZZZ. I ran the radios while setting up the FMS and frequencies for the visual approach. We did not have time to run the Abnormal Checklist for shattered windshield as we were more focused with landing the aircraft safely and were not continuing the flight. I did run the Normal Checklist as usual. I quickly yelled back to the passengers and told them our situation. We landed without incident and taxied to the FBO. After speaking with maintenance about this event; it appears the problem with the baggage seal and the windshield shattering are most likely unrelated. I was told the outer pane of the window is not capable of cracking from a pressurization problem; especially with cabin pressure normal and the baggage compartment isolated. The most probable cause was a windshield heat malfunction. Maintenance said there have been; on occasion; windows shattered for a heater failure without a CAS message at all. In our case; we were not sure if the two events were related; and could not verify if the inner structural pane of the side windshield was intact due to the plastic cover blocking our access. We made the conservative decision to land at ZZZ to have it inspected.


Synopsis: CE-750 flight crew reported the First Officer's windshield shattered in flight; so the flight diverted to the nearest suitable airport.