After an avionics upgrade, a King Air goes back into service only after ground checks, the tests the regulations require for the systems that were touched, a flight test when the work could affect how the aircraft flies, and the paperwork that approves it. At 305 SKY's Fort Lauderdale (FLL) location, that sequence is planned before the first panel comes out, so the aircraft isn't sitting finished and waiting on a test or a signature.
This applies whether you fly a King Air C90GTx, a B200 or a 350i, and whether the upgrade is a new autopilot, an integrated flight deck such as the Garmin G1000 NXi, or a transponder and ADS-B change.
The test plan comes from the installation data
Most King Air avionics upgrades are installed under a Supplemental Type Certificate (STC). The STC's installation manual and instructions for continued airworthiness say which ground tests and flight tests are required and what results count as a pass. That document, not a generic checklist, is the test plan. Ask your shop to show you the test section before the aircraft is down, so you know how long testing takes and whether your pilot is needed.
Ground checks before the aircraft flies
- Installation inspection. Mounting, connector seating, wire routing and clamping, clearance from controls and hot surfaces, and labeling, all checked against the installation drawings.
- Power and grounds. Bus voltage at each unit, bonding and ground paths, and circuit breaker sizing and labeling as the installation data specifies.
- Functional tests. Each unit powers up, passes its built-in tests and talks to the systems it is wired to: displays, air data, AHRS, radios, the autopilot and its servos, and the transponder.
- Configuration. Software and configuration settings match the approved data for that serial number, and the database is current.
Tests the regulations require after certain work
Two tests come up on almost every King Air panel upgrade:
- Altimeter and static system. If the static system was opened (other than the drain and alternate static valves), it has to be tested before the aircraft is flown IFR (14 CFR 91.411, to Part 43 Appendix E). New air data computers and integrated flight decks usually mean it was opened.
- Transponder. After a transponder is installed or worked on in a way that could introduce an altitude-reporting error, the integrated system has to be tested (14 CFR 91.413, to Part 43 Appendix F).
If the upgrade includes ADS-B Out, request the FAA's free Public ADS-B Performance Report after a flight. It shows whether the installation is transmitting correctly.
When a flight test is required
Not every avionics change needs a flight test. Under 14 CFR 91.407, if the work may have appreciably changed the aircraft's flight characteristics or substantially affected its operation in flight, no passengers can be carried until an appropriately rated pilot has flown it, made an operational check and logged the flight in the aircraft records. Autopilot and flight director installations, and integrated flight decks that drive the autopilot, are the usual cases, and their STCs normally list specific flight test steps.
A typical King Air acceptance flight follows the STC's test procedure and the AFM supplement, and covers:
- Display and air data agreement with the standby instruments through climb, cruise and descent
- Autopilot and yaw damper engagement, each mode the installation adds, and disconnect, within the limits in the AFM supplement
- Navigation and approach guidance, including a coupled approach if the upgrade adds that capability
- Radios, transponder and, for ADS-B, a flight long enough for the performance report
Any discrepancy ends that test point. It is written up, fixed on the ground and retested before the aircraft is released.
Return to service and the paperwork
A major alteration, which most panel upgrades are under Part 43 Appendix A, needs approved data (usually the STC) and an FAA Form 337. It is approved for return to service by an Inspection Authorization (IA) holder or a repair station. 305 SKY has an IA on staff. Before the first trip, make sure you have:
- The maintenance record entry for the work (14 CFR 43.9) and the Form 337
- The AFM supplement for the new equipment, inserted in the flight manual, and the pilots briefed on it
- Updated weight and balance and equipment list
- The 91.411 and 91.413 test entries, if those tests were required
- The flight test logged, if 91.407 required one
- The instructions for continued airworthiness added to your maintenance program or tracking
If you operate under Part 135, the work and the return to service also follow your maintenance program and manual (14 CFR 135.411).
Keeping the King Air down once
Testing is where avionics projects slip, usually because a required test, a pilot or a signature wasn't scheduled. Plan the upgrade alongside the King Air's next phase inspection, book the static and transponder tests and the test flight with the installation, and confirm who will fly the operational check. For costs, see what drives avionics upgrade cost.
Planning a King Air avionics upgrade at FLL? Call 305 SKY at (305) 326-3498. Our Fort Lauderdale location is at 240 SW 34th St, Fort Lauderdale, FL 33315.
Frequently asked questions
Does every King Air avionics upgrade need a flight test?
No. Under 14 CFR 91.407, a flight test (an operational check flown by an appropriately rated pilot and logged) is required before carrying passengers only when the work may have appreciably changed flight characteristics or substantially affected operation in flight. Autopilot and integrated flight deck installations usually qualify, and the STC normally lists the flight test steps. 305 SKY plans this with you before work starts at FLL.
What tests are required after replacing a King Air's altimeter, air data or transponder?
If the static system was opened, the altimeter and static system must be tested before IFR flight (14 CFR 91.411). If the transponder or its altitude reporting was installed or worked on, the integrated system must be tested (14 CFR 91.413). Most King Air flight deck upgrades trigger both, so 305 SKY schedules them with the installation.
Who signs off a King Air avionics upgrade?
Most panel upgrades are major alterations. They need approved data, usually an STC, and an FAA Form 337, and are approved for return to service by an Inspection Authorization (IA) holder or a repair station. 305 SKY has an IA on staff at its South Florida locations, including Fort Lauderdale (FLL).
What paperwork should I have after the upgrade?
The maintenance record entry and Form 337, the AFM supplement for the new equipment, updated weight and balance and equipment list, entries for any 91.411 and 91.413 tests, the logged flight test if one was required, and the instructions for continued airworthiness added to your tracking. Call 305 SKY at (305) 326-3498 with questions.