Aircraft Squawk List: What It Is, Why It Matters, and How to Manage Defects in Shared Aircraft

Meta description: Learn what an aircraft squawk list is, how to manage maintenance defects under FAA and EASA rules, and why proper tracking matters for airworthiness.

Every shared aircraft develops its quirks. A sticky trim wheel. An intermittent nav light. A door seal that whistles above 120 knots. The question isn’t whether defects will appear—it’s whether they get recorded, communicated, and resolved before they ground the aircraft or compromise safety. If you co-own or operate a GA aircraft with other pilots, a poorly managed aircraft squawk list creates real risk: missed defects, duplicated work, regulatory exposure, and the slow erosion of trust between partners.

Two Meanings of “Squawk” — and Why It Matters

The word “squawk” trips up even experienced pilots because it has two completely different meanings in aviation.

The first meaning is the transponder code assigned by ATC. “Squawk 4521” means dial that code into your transponder. This usage comes from the early days of IFF (Identification Friend or Foe) systems and has nothing to do with maintenance.

The second meaning—the one this article addresses—refers to a reported defect or discrepancy on an aircraft. When a pilot writes up a squawk, they’re documenting something wrong: a malfunction, damage, or abnormal behaviour observed during preflight or flight. This usage likely derives from the idea of the aircraft “complaining” about something.

The confusion matters because when pilots discuss “squawks” without context, they may be talking past each other. In maintenance conversations, an aircraft maintenance squawk is a documented defect requiring evaluation and possible action before the next flight. That’s what belongs on your squawk sheet aviation log—not transponder codes.

Throughout this article, “squawk” means a maintenance defect unless otherwise noted.

What Belongs on a Squawk List

A squawk list is a running record of known defects, discrepancies, and deferred maintenance items for a specific aircraft. It serves three functions: communication between pilots, documentation for maintenance, and evidence of airworthiness decision-making.

Items that belong on a squawk list:

• Malfunctions observed in flight (autopilot disconnect, rough mag, fuel gauge inaccuracy)
• Damage found during preflight (dents, cracks, fluid leaks, tyre wear)
• Inoperative equipment (landing light, intercom, one side of heated pitot)
• Abnormal behaviours (high oil consumption, trim out of rig, unusual vibration)
• Pending maintenance discovered by a shop but not yet completed
• Discrepancies noted during annual or 100-hour inspections that were deferred

Items that don’t belong:

• Routine consumables tracking (oil changes, tyre replacements on schedule)
• Cosmetic preferences (“interior looks dated”)
• ATC-assigned transponder codes
• Modifications you’d like to make but aren’t defects

The purpose of a squawk list is reporting aircraft defects—things that deviate from the aircraft’s type design, approved data, or normal operation. If it’s working as designed, it’s not a squawk.

Classifying Defects by Airworthiness Impact

Not all squawks are equal. A burned-out courtesy light is not the same as a cracked exhaust stack. Effective squawk management requires classification by airworthiness impact—and this is where regulations provide structure.

FAA framework (14 CFR Part 91)

Under Part 91, the pilot in command is responsible for determining whether the aircraft is airworthy before flight. FAA regulations don’t prescribe a formal defect classification system for Part 91 operators, but they do establish clear boundaries:

• Required equipment must be operative (per 91.205, 91.213, and the aircraft’s equipment list)
• Known defects affecting airworthiness must be corrected before flight
• Inoperative equipment may be deferred under 91.213 if it’s not required and is either removed or placarded

Practically, this means you need to evaluate each squawk against the minimum equipment requirements. A Cessna 172 VFR day flight doesn’t require a working autopilot. It does require a working altimeter.

EASA framework (Part-ML for ELA1/ELA2 aircraft)

Part-ML provides more explicit guidance. Under ML.A.301, aircraft must be maintained in a condition of continuing airworthiness. Under ML.A.403, defects must be recorded in the continuing airworthiness records, and the pilot/owner must ensure defects are rectified by appropriately qualified persons.

For aircraft under an AMP (Airworthiness Review Certificate programme), Part-ML.A.305 addresses the handling of defects. While owner-operators of simpler aircraft have some flexibility, the principle remains: known defects must be documented, assessed for airworthiness impact, and either rectified or appropriately deferred before flight.

A practical classification system:

1. Grounding defects — Aircraft cannot fly until rectified (e.g., cracked propeller blade, inoperative pitot heat for IMC flight)
2. Deferrable items — Can be deferred under MEL/CDL or equivalent process (e.g., inoperative dome light)
3. Monitor items — Not yet defective but trending (e.g., increasing oil consumption within limits)

Every squawk should carry a classification. Without it, the next pilot has no basis for a go/no-go decision.

Who Actions Squawks — and When

In a single-owner operation, responsibility is simple: you find it, you own it. In shared aircraft, ambiguity kills.

The pilot who discovers the defect is responsible for:

• Recording it immediately with enough detail for the next pilot and the mechanic to understand
• Making an initial airworthiness assessment (can this aircraft fly legally and safely?)
• Communicating it to co-owners/operators without delay

The owner or operator organisation is responsible for:

• Ensuring the defect is evaluated by someone competent to assess airworthiness impact
• Arranging maintenance action within an appropriate timeframe
• Updating records when the defect is rectified
• Making the entry in the aircraft’s technical log or equivalent

Under FAA Part 91, the PIC has final authority and responsibility for each flight. Under EASA Part-ML, the owner bears continuing airworthiness responsibility but the pilot retains flight-by-flight authority.

The failure mode in most partnerships isn’t hostility—it’s assumption. Pilot A assumes Pilot B saw the note. Pilot B assumes Pilot A is handling it. The defect persists unrectified through multiple flights.

Why Group Chats and Sticky Notes Fail

Most co-ownership groups start with informal systems: a WhatsApp thread, a shared Google Doc, a notepad in the aircraft. These work—until they don’t.

Common failure modes:

• Messages get buried. A squawk reported on Tuesday is invisible under Thursday’s fuel price discussion.
• No audit trail. When did this defect first appear? Who reported it? Was it ever actioned? Group chats don’t answer these questions.
• Ambiguous status. “I mentioned the mag drop to Dave” is not the same as a documented, classified, tracked defect.
• No integration with maintenance records. The squawk list lives in one place; the logbooks live in another. Reconciliation requires manual effort that rarely happens.
• Sticky notes disappear. Rain, wind, curious passengers, and time all destroy paper left in cockpits.

A proper defect tracking system isn’t bureaucracy for its own sake. It’s the difference between “we have a maintenance culture” and “we have a maintenance crisis we don’t know about yet.”

For airworthiness, what matters is demonstrable evidence that defects are identified, assessed, communicated, and resolved. Regulators auditing your records—and insurers investigating claims—won’t accept “we talked about it in the group chat.”

What Happens If a Known Defect Isn’t Actioned

Here’s where informal systems become legal exposure.

Under FAA regulations, operating an aircraft with a known defect that renders it unairworthy violates 14 CFR 91.7: “No person may operate a civil aircraft unless it is in an airworthy condition.” The PIC who flew it bears primary responsibility, but owners can face enforcement action for failing to maintain airworthiness.

Under EASA Part-ML, the registered owner or operator holds continuing airworthiness responsibility. Flying with a known unresolved defect affecting airworthiness can trigger certificate action, and in the event of an incident, both civil liability and potential criminal exposure.

Insurance implications are equally serious. Most hull and liability policies contain airworthiness warranties. If an accident investigation reveals a known, unaddressed defect, underwriters may deny coverage entirely. “We knew about it but didn’t fix it” is among the worst possible findings.

The legal standard isn’t “we planned to fix it.” It’s “was the aircraft airworthy at the time of operation.” A documented squawk that wasn’t actioned is evidence against you.

How Squawkd Helps

Squawkd’s defect tracking feature gives co-owners a single, auditable location for reporting aircraft defects—visible to all operators immediately, with status tracking from report through resolution. Each squawk is timestamped, attributed, and linked to the aircraft’s maintenance records, eliminating the ambiguity that informal systems create.

Frequently Asked Questions

Q: How long can a squawk remain open before it must be fixed?

There’s no universal time limit. The determining factor is airworthiness impact. A grounding defect must be rectified before the next flight. A deferrable item—if properly documented under MEL procedures or equivalent—may remain open for a defined period or number of flights. A monitor item may persist indefinitely with appropriate tracking. What matters is that someone with appropriate authority has made a documented airworthiness determination, and that determination is communicated to all pilots before they fly.

Q: Who is legally responsible if I fly with a known defect: the owner or the pilot?

Both may bear responsibility, but for different things. Under FAA Part 91, the PIC is responsible for determining airworthiness before each flight and cannot delegate that responsibility. Under EASA Part-ML, the registered owner bears continuing airworthiness obligations. In practice, if you’re a co-owner who also flies the aircraft, you may be exposed on both fronts. This is precisely why documented defect tracking matters—it establishes who knew what and when.

Q: Can I just placard something inoperative and keep flying?

Under FAA 91.213, yes—if specific conditions are met. The item must not be required by the aircraft’s type certificate, the regulations (91.205), airworthiness directives, or the aircraft’s minimum equipment list or kinds of operations equipment list. It must then be either removed and the removal documented, or deactivated and placarded “Inoperative.” EASA has similar provisions under Part-ML, though owner-operators should confirm the specific procedures applicable to their aircraft category. Placarding without meeting these conditions does not render the aircraft airworthy.

Tags: squawk list, aircraft defects, GA maintenance, co-ownership, airworthiness, EASA Part-ML, FAA Part 91

Regulatory context: Both

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