Date: 201811
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Rain; Turbulence; 2
Light: Daylight
Aircraft: Gulfstream G280
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Pitot-Static System
Component problem: Improperly Operated
Reporter organization: Corporate
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Situational Awareness; Workload
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Took Evasive Action; Flight Crew Landed in Emergency Condition; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Takeoff from ZZZ Airport was normal until 400 feet AGL. Received WINDSHEAR caution message; initiated full power climb; per windshear escape procedure. Received immediate approach to stall indication. Approximately 1;000 feet. AGL; autothrottles began to retard due to erratic airspeed indications. Disconnected autothrottles and did not engage autopilot. Continued climbing to cleared 2;500 feet MSL while assessing the problem. Determined that airspeed and altitude indications were inaccurate. ADC1; ADC2 and standby instruments were all unreliable. [Advised] Approach [of our situation] and requested vectors for ILS XXR at ZZZ. During the flight; we experienced both low airspeed and over speed warnings in rapid succession. In addition; Approach was delivering occasional low altitude alerts. Used standard power settings and Angle of Attack indications to maintain safe airspeed. Flew the ILS XXR; breaking out of clouds just prior to minimums for the approach. Position was right of the runway; so missed approach was initiated. Following climb out; requested vectors for second approach. Successfully completed the approach and accomplished uneventful landing on XXR. Cleared runway and terminated [our situation with ATC].Post-flight revealed small pieces of black electrical tape covering all static ports on the aircraft. This tape had been to prevent water entering the pitot/static system during aircraft washing at our hangar. The tape was missed for removal after aircraft wash. Due to the size and color of the tape; it was missed during aircraft preflight by both Maintenance and the pilots. Lack of static air information led to the erratic indications for all instruments.As corrective/preventative action following this incident; our flight department implemented changes to our aircraft washing procedures as well as exterior inspection procedures. Tape will no longer be used to cover static ports. The manufacturer's large; red overnight covers will be installed on the static ports prior to aircraft washing. A training session was completed for all department pilots and mechanics; wherein; a thorough exterior preflight inspection of the aircraft was completed with reference to the manufacturer's checklist. It was emphasized that Maintenance and flight crews closely inspect the static port 'holes;' in addition to assessing the general condition of the static port areas. Pilots were instructed to use the manufacturer checklist for the next five preflight; then once per month thereafter.




Synopsis: G280 Captain reported diverting due to inaccurate airspeed after departure.  Post-flight inspection revealed pieces of electrical tape covering the pitot static system.