diff --git a/flight_quality/model.py b/flight_quality/model.py
new file mode 100644
index 0000000..ffec595
--- /dev/null
+++ b/flight_quality/model.py
@@ -0,0 +1,16 @@
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class Sample:
+    line: int
+    time_ms: int
+    temperature_c: float
+    voltage_v: float
+
+
+@dataclass(frozen=True)
+class Issue:
+    line: int
+    code: str
+    detail: str