Complex sentence: On 21 July 2013, a Russian Sukhoi Superjet 100 airliner, prototype aircraft 95005, crashed upon landing at the Keflavík International Airport near Reykjavík, Iceland, when the automatic landing system neglected to deploy the landing gear.
Split into simpler sentences: On 21 July 2013, a Russian Sukhoi Superjet 100 airliner, prototype aircraft 95005, crashed upon landing at the Keflavík International Airport near Reykjavík, Iceland. When the automatic landing system neglected to deploy the landing gear.