Date: 202101
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 50
Light: Daylight
Aircraft: Small Transport; Low Wing; 2 Turboprop Eng
Operator: Corporate
Operating under: Part 91
Flight plan: None
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Corporate
Reporter function: Flight Engineer / Second Officer; Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Situational Awareness
Second reporter function: Pilot Flying; Captain; Instructor; Single Pilot
Anomaly: Airspace Violation All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Airspace Structure; Environment - Non Weather Related; Staffing; Human Factors
Primary problem: Environment - Non Weather Related

Narrative: We had departed ZZZ1 to the south; when Tower was shut down due to COVID-19; VFR to pick up IFR clearance over ZZZ2. After passing under the [ZZZ] Class B to clear it; we contacted ATC. After giving us the clearance; the Controller gave the Captain a phone number to call (which he did later after landing); and advised of a report; that we had strayed into [ZZZ] Class B airspace.


Second narrative: ZZZ airport Tower was closed for to Coronavirus. [ZZZ is] a busy airport with mixed high speed and low speed aircraft.I departed VFR to pick up IFR clearance over ZZZ2 for arrival into ZZZ3.ATC; as always was very busy in that congested area and it took several attempts to make contact with ZZZ Approach.Very busy in cockpit looking for traffic; etc. May have clipped Class B airspace.ZZZ Approach advised; I may have entered Class B airspace and to copy phone a phone number.I replied: thank you; what altitude and heading would you like? The Controlled replied: 'continue; there is no traffic and then handed us off to ZZZ Center.I followed up with a phone call and thanked them for the wonderful service and protection they provide.I have been flying there for years. I have thousands of hours in general aviation and XX years flying airliners.The controllers do an unbelievable job working with an airspace system that does not work. The way it is designed doesn't work for the controllers or the pilots. At times the controllers are at max effort to keep up with the congested radio traffic.I am sure just they have their distractions with the maximum workload and have their own mistakes to sort out.That airspace configuration needs a good look at for something that works better for high speed aircraft. Get them out up and out of the way as fast as possible.It's a poor system to have jet aircraft level off at 1600 feet right after takeoff for normal operation under IFR conditions. In the cockpit of a jet aircraft you are very busy during this time.There needs to be change even if it slows down the current operations.


Synopsis: Flight crew reported a Class Bravo airspace violation due to the Tower being closed for COVID-19 issues.