No

A cyber attack is a cyber operation, whether offensive or defensive, that is reasonably expected to cause injury or death to persons or damage or destruction to objects.

Michael Schmitt et al; Tallinn Manual 1.0, pp 92

✅ Cyber Operation?
❌ Expected to cause death or injury to people or damage to objects?

A Russian DDoS of US Airport Websites does not match this definition. Here's a list of actual cyberattacks and and why this matters.

Was A Russian DDoS of US Airport Websites A Cyber Attack? No
Was A Skiddie DDoS of North Korea A Cyber Attack? No
Was Russian Defacement of Several Ukrainian Websites A Cyber Attack? No
Was A Web Skimmer on The Principality of Sealand’s Online Store A Cyber Attack? No
Was Asymmetrical cyber operations conducted by Israel and Iran A Cyber Attack? No
Was Beer taps shut down at Barcelona's Damm brewery A Cyber Attack? No
Was Chinese-linked Actors Probing The New York MTA's PulseSecure VPN A Cyber Attack? No
Was Russian-linked Actors Use of USAID's Constant Contact API Keys For Malware Distribution A Cyber Attack? No
Was Chinese Military Linked Cyber Espionage Operation on Japanese Defense Industrial Base A Cyber Attack? No
Was Irish Healthcare Ransomware Incident A Cyber Attack? No
Was Suspected Pakistan-linked Campaign Using Catfishing For Espionage On Indian Defense Sector A Cyber Attack? No
Was This Tweet A Cyber Attack? No
Was The Colonial Pipeline Ransomware Incident A Cyber Attack? No
Was The Ghostwriter Influence Operation in Poland A Cyber Attack? No
Was GRU-linked Groups Intrusion Into Swedish Sports Confederation A Cyber Attack? No
Was GRU-linked Groups Spearphishing Ukranian Officials A Cyber Attack? No
Was MSS-linked Espionage Operations Targeting Defense Industrial Base Companies Using PulseSecure, F5 and Citrix Vulnerabilities A Cyber Attack? No
Was PLA-linked-Naikon’s Espionage Operations Across South East Asia A Cyber Attack? No
Was MSS-linked Espionage Operation Targeting Vietnamese Government Officials and Political Parties A Cyber Attack? No
Was Palestinian Intelligence Services Espionage Campaign on 800 Reports, Activists and Dissidents A Cyber Attack? No
Was Radixx Airline Reservation Malware Incident A Cyber Attack? No
Was Lazarus “Recruiting” on LinkedIn A Cyber Attack? No
Was The Russian SVR Supply Chain Compromise of SolarWinds Orion A Cyber Attack? No
Was Russian Operations to “Prepare the Battlefield” for Potential Future Operations Against the US Power Grid, If Necessary A Cyber Attack? No
Was US Operation to Disrupt Iranian Missile Launch Control A Cyber Attack? Yes
Was US Operations to “Prepare the Battlefield” for Potential Future Operations Against the Russian Power Grid, If Necessary A Cyber Attack? No
Was GCHQ Operations to Support Lethal Fires Against ISIS A Cyber Attack? Yes
Was Russian Supply Chain Operations in the United Kingdom A Cyber Attack? No
Was City of Atlanta Ransomware Incident A Cyber Attack? No
Was Operation Glowing Symphony A Cyber Attack? Yes
Was Russian Intrusion of Yahoo A Cyber Attack? No
Was Shadow Brokers Espionage and Tool Dump Operation A Cyber Attack? No
Was Russian Espionage and Leak of DNC Emails A Cyber Attack? No
Was The German Steel Mill Incident A Cyber Attack? Yes
Was North Korean Disruptive Activity Against Sony Pictures A Cyber Attack? No
Was Operation Outside the Box A Cyber Attack? Yes
Was Russian Malign Cyber Activity In Estonia Disrupting Government Services A Cyber Attack? No
Was Chinese Espionage Operation Gathering F-35 Designs A Cyber Attack? No
Was Chinese Espionage Operation Gathering Space Shuttle Designs A Cyber Attack? No
Was Titan Rain A Cyber Attack? No