diff --git a/DECISIONS.md b/DECISIONS.md
index 29eb2bf..2a3825f 100644
--- a/DECISIONS.md
+++ b/DECISIONS.md
@@ -1620,3 +1620,10 @@ Implementation decisions not spelled out in `memory-bank/implementation-plan.md`
 
 - **Numbering:** received as "CR-018 — Only Show Jobs the Fleet Can Complete" for "Phase 18"; stored as **CR-019**, built as **Phase 19** (its 18.n = 19.n). Its decisions CR-018.D1–D4 are **0.5.114–0.5.117**. Its references: CR-005 → CR-007 (steps 10E.n → 10G.n), CR-006 → CR-009, CR-009 → CR-012, CR-011 → CR-014, CR-014 → CR-015; CR-002, CR-004 and plan steps 3.9, 3.11, 9.4 are unchanged.
 - **It replaces this repo's CR-006 board rules**, which its numbering doesn't know about: the open and preview slots of decision 0.5.52 and the weight warning of 0.5.53.
+
+## Step 19.1
+
+- **One rule set, two uses**: `permanentFailure` checks the same things in the same order as `validateDispatch`, but it treats the tank as fillable where the origin sells fuel, because fuel on board is temporary there. `validateDispatch` keeps its "now" checks (idle, shop, rest, assignment, expiry, fuel on board) in front of and behind the permanent ones. The dispatch sheet still shows `validateDispatch`'s reason per pair, which is a superset.
+- **"No pair here" also covers ships with no pilot**: the whole-fleet fallback applies whenever no ship-and-pilot pair qualifies, not only when no ship is there. A pilotless ship can't take a job, so a board built for it alone would be empty.
+- **Whole-fleet pairs** are each ship with its assigned pilot and with every unassigned pilot, wherever they are, the most generous reading of "every owned ship and pilot pair".
+- **"Arrives before the period ends" is strict** (`arrivalAt < periodEndsAt`).
diff --git a/memory-bank/progress.md b/memory-bank/progress.md
index 9eb6bd3..c7b3158 100644
--- a/memory-bank/progress.md
+++ b/memory-bank/progress.md
@@ -440,7 +440,7 @@ Spec: `memory-bank/change-requests/CR-018-fuel-tuning.md` (received as "CR-017 
 
 Spec: `memory-bank/change-requests/CR-019-completable-boards.md` (received as "CR-018 … Phase 18"). New decisions recorded as plan §0.5.114–0.5.117.
 
-- [ ] Step 19.1 — Sim: completability check
+- [x] **Step 19.1 — Sim: completability check.** `packages/sim/src/completable.ts`: `permanentFailure(contract, member, discoveredIds, content)` gives a pair's first failing permanent check: over-capacity, cannot-land, out-of-range, would-strand, too-slow, cargo-skill-too-low, long-haul-too-low. It uses the same rules and order as `validateDispatch`, with the tank counted full where the origin sells fuel and the fuel on board where it doesn't. `completability` returns whether any pair passes plus each pair's failure; `isCompletable` is the shorthand. `qualifyingFleet` builds the pairs for a location (ships there or landing before the period ends, with their pilot or any unassigned pilot there if the player has a bay there; else the whole fleet). `FleetMember` (now with `fuelFu`) moved here from `board.ts`. Tests (`packages/sim/test/completable.test.ts`): one per permanent check (landing and stranding via content with a hardened Earth and a dry Mars); a dry origin counts only the fuel on board; Cargo Bay upgrades count; any one pair passing makes a job completable, with per-pair failures; rest, the shop and an empty tank block dispatch but not completability; the qualifying fleet's local pairs, ships landing before and after the period ends, spare pilots only with a bay, the whole-fleet fallback, and upgrades and fuel carried into the snapshot.
 - [ ] Step 19.2 — Sim: generation keeps only completable jobs
 - [ ] Step 19.3 — Engine: boards, filtering, and migration
 - [ ] Step 19.4 — Client: cards and empty state
diff --git a/packages/sim/src/board.ts b/packages/sim/src/board.ts
index d1ff3e7..c728d5d 100644
--- a/packages/sim/src/board.ts
+++ b/packages/sim/src/board.ts
@@ -15,7 +15,7 @@ import { checkRoute } from "./eligibility";
 import { LONG_HAUL_SKILL_ID, skillLevel, type SkillLevels } from "./pilot";
 import { createRng, deriveSeed, type Rng, type Seed } from "./rng";
 import { travelTimeGameHours } from "./travel";
-import { effectiveStats, type UpgradeLevels } from "./upgrades";
+import { effectiveStats } from "./upgrades";
 
 /** The static data the sim needs. The `content` bundle satisfies this. */
 export interface SimContent {
@@ -49,13 +49,8 @@ export function standardCargo(content: SimContent): CargoType {
   return standard;
 }
 
-/** One of the player's ships, with its pilot's skills (none without a pilot). */
-export interface FleetMember {
-  modelId: string;
-  skills: SkillLevels;
-  /** Installed upgrades: boards fit the ship's effective capacity (CR-009). */
-  upgrades?: UpgradeLevels;
-}
+export type { FleetMember } from "./completable";
+import type { FleetMember } from "./completable";
 
 export interface BoardInput {
   /** The location whose freight market this is; every contract starts here (CR-002). */
diff --git a/packages/sim/src/completable.ts b/packages/sim/src/completable.ts
new file mode 100644
index 0000000..889cda6
--- /dev/null
+++ b/packages/sim/src/completable.ts
@@ -0,0 +1,187 @@
+import type { SimContent } from "./board";
+import type { RealTime } from "./clock";
+import type { Contract } from "./contract";
+import {
+  contractTripGameHours,
+  findLocation,
+  findShipModel,
+  tripFuel,
+  wouldStrand,
+  type DispatchFailure,
+} from "./dispatch";
+import { checkRoute } from "./eligibility";
+import { checkPilotEligibility, type SkillLevels } from "./pilot";
+import { effectiveStats, type UpgradeLevels } from "./upgrades";
+
+/**
+ * One ship-and-pilot pair's lasting capabilities (decision 0.5.115): the ship's
+ * model and upgrades, its pilot's skills, and the fuel on board (which counts
+ * only where the job's origin sells no fuel).
+ */
+export interface FleetMember {
+  modelId: string;
+  skills: SkillLevels;
+  /** Installed upgrades: effective stats count (CR-009). */
+  upgrades?: UpgradeLevels;
+  /** Fuel on board; absent means a full tank. */
+  fuelFu?: number;
+}
+
+/** The permanent checks, in order (decision 0.5.116): the dispatch reasons that can't be waited out. */
+export const PERMANENT_FAILURES = [
+  "over-capacity",
+  "cannot-land",
+  "out-of-range",
+  "would-strand",
+  "too-slow",
+  "cargo-skill-too-low",
+  "long-haul-too-low",
+] as const satisfies readonly DispatchFailure[];
+export type PermanentFailure = (typeof PERMANENT_FAILURES)[number];
+
+/**
+ * The first permanent check a pair fails for a contract, or null when it could
+ * fly it once rested, out of the shop and refuelled (decision 0.5.116). Same
+ * rules and order as `validateDispatch`, but the tank counts as full wherever
+ * the origin sells fuel.
+ */
+export function permanentFailure(
+  contract: Contract,
+  member: FleetMember,
+  discoveredIds: ReadonlySet<string> | undefined,
+  content: SimContent,
+): PermanentFailure | null {
+  const model = effectiveStats(
+    findShipModel(member.modelId, content),
+    member.upgrades ?? {},
+    content,
+  );
+  const origin = findLocation(contract.originId, content);
+  const destination = findLocation(contract.destinationId, content);
+
+  if (contract.massTonnes > model.cargoCapacityTonnes) return "over-capacity";
+  const route = checkRoute(model, origin, destination, content.config);
+  if (!route.ok) return route.reason;
+  // Where the origin sells fuel the tank can be filled first; elsewhere only what's aboard.
+  const available = origin.sellsFuel
+    ? model.tankCapacityFu
+    : Math.min(member.fuelFu ?? model.tankCapacityFu, model.tankCapacityFu);
+  const leg = tripFuel(model, origin, destination, content.config);
+  if (leg > available) return "out-of-range";
+  if (wouldStrand(model, destination, available - leg, discoveredIds, content)) {
+    return "would-strand";
+  }
+  if (
+    contract.priority &&
+    contract.deliveryWindowGameHours !== null &&
+    contractTripGameHours(model, contract, content) > contract.deliveryWindowGameHours
+  ) {
+    return "too-slow";
+  }
+  const pilot = checkPilotEligibility(member.skills, contract);
+  return pilot.ok ? null : pilot.reason;
+}
+
+export interface Completability {
+  /** At least one pair passes every permanent check (decision 0.5.114). */
+  completable: boolean;
+  /** Per pair, in order: the first failing permanent check, or null. */
+  failures: (PermanentFailure | null)[];
+}
+
+/** Whether any pair in `fleet` could complete `contract` (decisions 0.5.114, 0.5.116). */
+export function completability(
+  contract: Contract,
+  fleet: readonly FleetMember[],
+  discoveredIds: ReadonlySet<string> | undefined,
+  content: SimContent,
+): Completability {
+  const failures = fleet.map((m) => permanentFailure(contract, m, discoveredIds, content));
+  return { completable: failures.some((f) => f === null), failures };
+}
+
+/** Shorthand: true when some pair could complete the contract. */
+export function isCompletable(
+  contract: Contract,
+  fleet: readonly FleetMember[],
+  discoveredIds: ReadonlySet<string> | undefined,
+  content: SimContent,
+): boolean {
+  return fleet.some((m) => permanentFailure(contract, m, discoveredIds, content) === null);
+}
+
+/** An owned ship as the qualifying-fleet rule sees it. */
+export interface FleetShip {
+  id: string;
+  modelId: string;
+  upgrades?: UpgradeLevels;
+  fuelFu?: number;
+  /** Where it is; null in flight. */
+  locationId: string | null;
+  /** In flight: where to, and when it lands. */
+  destinationId?: string | null;
+  arrivalAt?: RealTime | null;
+}
+
+/** A pilot as the qualifying-fleet rule sees it. */
+export interface FleetPilot {
+  id: string;
+  skills: SkillLevels;
+  assignedShipId: string | null;
+  /** Where an unassigned pilot is; null otherwise. */
+  locationId: string | null;
+}
+
+export interface QualifyingFleetInput {
+  locationId: string;
+  /** In a stable order: the snapshot (and so the board) follows it. */
+  ships: readonly FleetShip[];
+  pilots: readonly FleetPilot[];
+  /** Locations with a player bay: unassigned pilots there can be assigned. */
+  bayLocationIds: ReadonlySet<string>;
+  /** The end of the board period: ships landing before then count. */
+  periodEndsAt: RealTime;
+}
+
+export interface QualifyingFleet {
+  members: FleetMember[];
+  /** No pair qualified at the location, so this is the whole fleet. */
+  wholeFleet: boolean;
+}
+
+const member = (ship: FleetShip, pilot: FleetPilot): FleetMember => ({
+  modelId: ship.modelId,
+  skills: pilot.skills,
+  ...(ship.upgrades ? { upgrades: ship.upgrades } : {}),
+  ...(ship.fuelFu !== undefined ? { fuelFu: ship.fuelFu } : {}),
+});
+
+/**
+ * The pairs a location's board is made for (decision 0.5.115): ships there, or
+ * landing there before the period ends, each with its assigned pilot, or with
+ * any unassigned pilot there when the player has a bay there. With no such
+ * pair, every ship with its pilot, or with any unassigned pilot, anywhere.
+ */
+export function qualifyingFleet(input: QualifyingFleetInput): QualifyingFleet {
+  const { locationId, ships, pilots } = input;
+  const unassigned = pilots.filter((p) => p.assignedShipId === null);
+  const pairsFor = (ship: FleetShip, spare: readonly FleetPilot[]) => [
+    ...pilots.filter((p) => p.assignedShipId === ship.id).map((p) => member(ship, p)),
+    ...spare.map((p) => member(ship, p)),
+  ];
+
+  const here = ships.filter(
+    (s) =>
+      s.locationId === locationId ||
+      (s.locationId === null &&
+        s.destinationId === locationId &&
+        s.arrivalAt != null &&
+        s.arrivalAt < input.periodEndsAt),
+  );
+  const spareHere = input.bayLocationIds.has(locationId)
+    ? unassigned.filter((p) => p.locationId === locationId)
+    : [];
+  const local = here.flatMap((s) => pairsFor(s, spareHere));
+  if (local.length > 0) return { members: local, wholeFleet: false };
+  return { members: ships.flatMap((s) => pairsFor(s, unassigned)), wholeFleet: true };
+}
diff --git a/packages/sim/src/index.ts b/packages/sim/src/index.ts
index 2f9125b..b05dc78 100644
--- a/packages/sim/src/index.ts
+++ b/packages/sim/src/index.ts
@@ -26,6 +26,22 @@ export {
 } from "./fuel";
 
 export { canLandAt, checkRoute, rangeFrom } from "./eligibility";
+
+export {
+  completability,
+  isCompletable,
+  PERMANENT_FAILURES,
+  permanentFailure,
+  qualifyingFleet,
+} from "./completable";
+export type {
+  Completability,
+  FleetPilot,
+  FleetShip,
+  PermanentFailure,
+  QualifyingFleet,
+  QualifyingFleetInput,
+} from "./completable";
 export type { RouteCheck } from "./eligibility";
 
 export { contractPayout } from "./contract";
diff --git a/packages/sim/test/completable.test.ts b/packages/sim/test/completable.test.ts
new file mode 100644
index 0000000..932c98c
--- /dev/null
+++ b/packages/sim/test/completable.test.ts
@@ -0,0 +1,262 @@
+import { content } from "@deadhead/content";
+import { describe, expect, it } from "vitest";
+import {
+  completability,
+  isCompletable,
+  permanentFailure,
+  qualifyingFleet,
+  validateDispatch,
+  type Contract,
+  type FleetMember,
+  type FleetPilot,
+  type FleetShip,
+  type SimContent,
+} from "../src/index";
+
+const job = (over: Partial<Contract> = {}): Contract => ({
+  id: "j",
+  originId: "earth",
+  destinationId: "moon",
+  cargoTypeId: "standard",
+  goodId: "consumer-goods",
+  shipper: "Pacific Orbital Logistics",
+  priority: false,
+  deliveryWindowGameHours: null,
+  tier: 0,
+  massTonnes: 10,
+  payout: 1000,
+  requiredSkill: null,
+  requiredLongHaulLevel: 0,
+  offeredAt: 0,
+  expiresAt: 600_000,
+  firstContact: false,
+  ...over,
+});
+const courier: FleetMember = { modelId: "courier", skills: {} };
+const clipper: FleetMember = { modelId: "clipper", skills: {} };
+
+/** Content with one location changed (no ship lands vacuum-only, and every place sells fuel). */
+function withLocation(id: string, change: object): SimContent {
+  return {
+    ...content,
+    locations: content.locations.map((l) => (l.id === id ? { ...l, ...change } : l)),
+  };
+}
+
+describe("completability check (Step 19.1, decisions 0.5.114, 0.5.116)", () => {
+  it("passes a pair that can fly the job", () => {
+    expect(permanentFailure(job(), courier, undefined, content)).toBeNull();
+  });
+
+  it("fails on cargo that doesn't fit the ship's effective capacity", () => {
+    expect(permanentFailure(job({ massTonnes: 25 }), courier, undefined, content)).toBe(
+      "over-capacity",
+    );
+  });
+
+  it("fails where the ship can't land", () => {
+    // Earth demanding a hardened landing: nothing in the fleet can land there.
+    const hardEarth = withLocation("earth", { landingRequirement: "hardened" });
+    const toEarth = job({ originId: "moon", destinationId: "earth" });
+    expect(permanentFailure(toEarth, courier, undefined, hardEarth)).toBe("cannot-land");
+  });
+
+  it("fails out of full-tank range", () => {
+    expect(permanentFailure(job({ destinationId: "mars" }), courier, undefined, content)).toBe(
+      "out-of-range",
+    );
+  });
+
+  it("uses only the fuel on board where the origin sells none", () => {
+    const dryEarth = withLocation("earth", { sellsFuel: false });
+    expect(permanentFailure(job(), { ...courier, fuelFu: 1 }, undefined, dryEarth)).toBe(
+      "out-of-range",
+    );
+    expect(permanentFailure(job(), { ...courier, fuelFu: 40 }, undefined, dryEarth)).toBeNull();
+  });
+
+  it("fails when the ship would be stranded at the destination", () => {
+    // Mars selling no fuel: a Clipper lands there with too little to leave.
+    const dryMars = withLocation("mars", { sellsFuel: false });
+    expect(permanentFailure(job({ destinationId: "mars" }), clipper, undefined, dryMars)).toBe(
+      "would-strand",
+    );
+  });
+
+  it("fails a Priority window the ship can't make", () => {
+    const rushed = job({ priority: true, deliveryWindowGameHours: 0.01 });
+    expect(permanentFailure(rushed, courier, undefined, content)).toBe("too-slow");
+  });
+
+  it("fails a cargo tier above the pilot's skill", () => {
+    const heavy = job({
+      cargoTypeId: "heavy",
+      tier: 2,
+      requiredSkill: { skillId: "heavy-cargo", level: 2 },
+    });
+    expect(
+      permanentFailure(heavy, { ...courier, skills: { "heavy-cargo": 1 } }, undefined, content),
+    ).toBe("cargo-skill-too-low");
+    expect(
+      permanentFailure(heavy, { ...courier, skills: { "heavy-cargo": 2 } }, undefined, content),
+    ).toBeNull();
+  });
+
+  it("fails a Long Haul requirement above the pilot's level", () => {
+    expect(permanentFailure(job({ requiredLongHaulLevel: 1 }), courier, undefined, content)).toBe(
+      "long-haul-too-low",
+    );
+  });
+
+  it("counts upgrades: Cargo Bay makes a heavier lot fit", () => {
+    const bay = content.upgrades.find((u) => u.stat === "cargoCapacityTonnes")!;
+    const upgraded = { ...courier, upgrades: { [bay.id]: 3 } };
+    expect(permanentFailure(job({ massTonnes: 22 }), upgraded, undefined, content)).toBeNull();
+  });
+
+  it("is completable when any one pair passes, and reports each pair's first failure", () => {
+    const heavyLot = job({ massTonnes: 25 });
+    expect(completability(heavyLot, [courier, clipper], undefined, content)).toEqual({
+      completable: true,
+      failures: ["over-capacity", null],
+    });
+    expect(completability(heavyLot, [courier], undefined, content).completable).toBe(false);
+    expect(isCompletable(heavyLot, [], undefined, content)).toBe(false);
+  });
+
+  it("ignores rest, the shop, fuel on board and credits (decision 0.5.116)", () => {
+    const now = 1_000;
+    // The dispatch check refuses all of these for now; none of them is permanent.
+    const ship = {
+      id: "s",
+      modelId: "courier",
+      locationId: "earth",
+      inFlight: false,
+      tank: { fuelFu: 0, avgPrice: 8 },
+    };
+    const pilot = {
+      id: "p",
+      isAvatar: true,
+      assignedShipId: "s",
+      inFlight: false,
+      skills: {},
+      restEndsAt: null,
+    };
+    const contract = job();
+    const check = (over: { ship?: object; pilot?: object }) =>
+      validateDispatch(
+        {
+          ship: { ...ship, ...over.ship },
+          pilot: { ...pilot, ...over.pilot },
+          contract,
+          tutorial: false,
+          now,
+        },
+        content,
+      );
+    expect(check({})).toEqual({ ok: false, reason: "not-enough-fuel" });
+    expect(check({ pilot: { restEndsAt: now + 1 } })).toEqual({
+      ok: false,
+      reason: "pilot-resting",
+    });
+    expect(check({ ship: { inShopUntil: now + 1 } })).toEqual({
+      ok: false,
+      reason: "ship-in-shop",
+    });
+    // The same pair, empty tank and all, can complete it.
+    expect(permanentFailure(contract, { ...courier, fuelFu: 0 }, undefined, content)).toBeNull();
+  });
+});
+
+describe("qualifying fleet (Step 19.1, decision 0.5.115)", () => {
+  const PERIOD_END = 10_000;
+  const ship = (id: string, over: Partial<FleetShip> = {}): FleetShip => ({
+    id,
+    modelId: "courier",
+    locationId: "earth",
+    ...over,
+  });
+  const pilot = (id: string, over: Partial<FleetPilot> = {}): FleetPilot => ({
+    id,
+    skills: { [id]: 1 },
+    assignedShipId: null,
+    locationId: null,
+    ...over,
+  });
+  const fleet = (input: {
+    locationId?: string;
+    ships: FleetShip[];
+    pilots: FleetPilot[];
+    bays?: string[];
+  }) =>
+    qualifyingFleet({
+      locationId: input.locationId ?? "earth",
+      ships: input.ships,
+      pilots: input.pilots,
+      bayLocationIds: new Set(input.bays ?? []),
+      periodEndsAt: PERIOD_END,
+    });
+
+  it("takes ships at the location with their assigned pilots", () => {
+    const result = fleet({
+      ships: [ship("a"), ship("b", { modelId: "clipper", locationId: "moon" })],
+      pilots: [pilot("pa", { assignedShipId: "a" }), pilot("pb", { assignedShipId: "b" })],
+    });
+    expect(result).toEqual({
+      members: [{ modelId: "courier", skills: { pa: 1 } }],
+      wholeFleet: false,
+    });
+  });
+
+  it("counts ships landing here before the period ends, not after", () => {
+    const flying = (id: string, arrivalAt: number) =>
+      ship(id, { locationId: null, destinationId: "earth", arrivalAt, modelId: "clipper" });
+    const result = fleet({
+      ships: [ship("a"), flying("soon", PERIOD_END - 1), flying("late", PERIOD_END + 1)],
+      pilots: [
+        pilot("pa", { assignedShipId: "a" }),
+        pilot("ps", { assignedShipId: "soon" }),
+        pilot("pl", { assignedShipId: "late" }),
+      ],
+    });
+    expect(result.members.map((m) => m.skills)).toEqual([{ pa: 1 }, { ps: 1 }]);
+  });
+
+  it("pairs unassigned pilots here with the ships here, only where the player has a bay", () => {
+    const ships = [ship("a")];
+    const pilots = [pilot("spare", { locationId: "earth" })];
+    expect(fleet({ ships, pilots, bays: ["earth"] }).members).toEqual([
+      { modelId: "courier", skills: { spare: 1 } },
+    ]);
+    // No bay here: the spare can't be assigned, so nothing qualifies here.
+    expect(fleet({ ships, pilots }).wholeFleet).toBe(true);
+  });
+
+  it("falls back to the whole fleet, wherever it is, when nothing qualifies here", () => {
+    const result = fleet({
+      locationId: "mars",
+      ships: [
+        ship("a"),
+        ship("b", { modelId: "clipper", locationId: null, destinationId: "moon", arrivalAt: 5 }),
+      ],
+      pilots: [pilot("pa", { assignedShipId: "a" }), pilot("pb", { assignedShipId: "b" })],
+    });
+    expect(result).toEqual({
+      members: [
+        { modelId: "courier", skills: { pa: 1 } },
+        { modelId: "clipper", skills: { pb: 1 } },
+      ],
+      wholeFleet: true,
+    });
+  });
+
+  it("carries upgrades and fuel into the snapshot", () => {
+    const result = fleet({
+      ships: [ship("a", { upgrades: { "cargo-bay": 1 }, fuelFu: 12 })],
+      pilots: [pilot("pa", { assignedShipId: "a" })],
+    });
+    expect(result.members).toEqual([
+      { modelId: "courier", skills: { pa: 1 }, upgrades: { "cargo-bay": 1 }, fuelFu: 12 },
+    ]);
+  });
+});