diff --git a/app/Http/Controllers/AircraftController.php b/app/Http/Controllers/AircraftController.php
index 29172f5..ca20897 100644
--- a/app/Http/Controllers/AircraftController.php
+++ b/app/Http/Controllers/AircraftController.php
@@ -175,6 +175,7 @@ public function create(Request $request) {
                 'mtow' => 'nullable|integer|min:0|max:1000000',
                 'mzfw' => 'nullable|integer|min:0|max:1000000',
                 'mlw' => 'nullable|integer|min:0|max:1000000',
+                'service_ceiling' => 'nullable|integer|min:1000|max:60000',
                 'remarks' => 'nullable|string|max:1000',
                 'current_loc' => 'required|max:4',
             ]);
@@ -243,6 +244,7 @@ public function edit(Request $request, Aircraft $aircraft) {
                 'mtow' => 'nullable|integer|min:0|max:1000000',
                 'mzfw' => 'nullable|integer|min:0|max:1000000',
                 'mlw' => 'nullable|integer|min:0|max:1000000',
+                'service_ceiling' => 'nullable|integer|min:1000|max:60000',
                 'remarks' => 'nullable|string|max:1000',
             ]);
 
@@ -269,6 +271,7 @@ public function edit(Request $request, Aircraft $aircraft) {
             $targetAircraft->mtow = $request->post('mtow');
             $targetAircraft->mzfw = $request->post('mzfw');
             $targetAircraft->mlw = $request->post('mlw');
+            $targetAircraft->service_ceiling = $request->post('service_ceiling');
             $targetAircraft->status = $finalStatus;
             $targetAircraft->remarks = $request->post('remarks');
 
diff --git a/app/Http/Controllers/Api/V1/AircraftAPIController.php b/app/Http/Controllers/Api/V1/AircraftAPIController.php
index 2114077..4b63bdb 100644
--- a/app/Http/Controllers/Api/V1/AircraftAPIController.php
+++ b/app/Http/Controllers/Api/V1/AircraftAPIController.php
@@ -140,6 +140,7 @@ public function show(Request $request, Airline $airline, Aircraft $aircraft)
      * @bodyParam mtow integer Max take-off weight (kg), 0-1000000. Example: 78000
      * @bodyParam mzfw integer Max zero-fuel weight (kg), 0-1000000. Example: 62500
      * @bodyParam mlw integer Max landing weight (kg), 0-1000000. Example: 66000
+     * @bodyParam service_ceiling integer Service ceiling (ft), 1000-60000; PIREPs with a higher cruise altitude are rejected. Example: 41000
      * @bodyParam remarks string Free-text remarks, max 1000 chars. Example: Delivered new.
      *
      * @response 201 {
diff --git a/app/Http/Controllers/Api/V1/FlightAPIController.php b/app/Http/Controllers/Api/V1/FlightAPIController.php
index 5436c40..6ae1691 100644
--- a/app/Http/Controllers/Api/V1/FlightAPIController.php
+++ b/app/Http/Controllers/Api/V1/FlightAPIController.php
@@ -100,8 +100,8 @@ public function index(Request $request, Airline $airline)
      * @bodyParam callsign string required Radio callsign, 1-4 digits optionally followed by up to 2 letters. Example: 421
      * @bodyParam crzalt integer required Cruise altitude in feet, max 50000. Example: 36000
      * @bodyParam blockoff string required Block-off time (UTC), format Y-m-d H:i:s. Example: 2026-07-11 10:00:00
-     * @bodyParam blockon string required Block-on time (UTC), format Y-m-d H:i:s. Example: 2026-07-11 11:30:00
-     * @bodyParam burned_fuel number required Fuel burned. Example: 4200
+     * @bodyParam blockon string required Block-on time (UTC), format Y-m-d H:i:s. Must be after blockoff; flight duration may not exceed 26 hours. Example: 2026-07-11 11:30:00
+     * @bodyParam burned_fuel integer required Fuel burned, in the airline's unit (min 1, max 600000). Example: 4200
      * @bodyParam route string required Filed route string. Example: SOVAT UL610 KONAN
      * @bodyParam online_network_id integer required Online network ID (must exist in online_networks). Example: 1
      * @bodyParam remarks string Optional remarks (letters, digits, spaces, . , -). Example: Smooth flight.
diff --git a/app/Http/Controllers/FlightController.php b/app/Http/Controllers/FlightController.php
index 235f494..65461ac 100644
--- a/app/Http/Controllers/FlightController.php
+++ b/app/Http/Controllers/FlightController.php
@@ -15,6 +15,7 @@
 use App\Notifications\PirepRejected;
 use Illuminate\Support\Facades\Notification as NotificationFacade;
 use App\Support\ActivityLevel;
+use App\Support\FlightSanity;
 
 class FlightController extends Controller
 {
@@ -174,7 +175,7 @@ public function addFlight(Request $request)
                 "crzalt" => "numeric|max:50000|digits_between:1,5|required",
                 "blockoff" => "required",
                 "blockon" => "required",
-                "burned_fuel" => "numeric|required",
+                "burned_fuel" => "required|integer|min:" . Flight::MIN_BURNED_FUEL . "|max:" . Flight::MAX_BURNED_FUEL,
                 "route" => "required",
                 "online_network_id" => "required",
                 "remarks" => [
@@ -198,6 +199,17 @@ public function addFlight(Request $request)
                 ]);
             }
 
+            // Physical sanity: ordering, not-in-future, and within the max duration
+            $timingError = FlightSanity::timingError(
+                $request->post("blockoff"),
+                $request->post("blockon"),
+            );
+            if ($timingError !== null) {
+                throw ValidationException::withMessages([
+                    "blockon" => $timingError,
+                ]);
+            }
+
             // Check if the aircraft is indeed part of the active airline AND is active
             $aircraft = Aircraft::query()
                 ->where("id", "=", $request->post("aircraft_id"))
@@ -210,6 +222,17 @@ public function addFlight(Request $request)
                 ]);
             }
 
+            // Physical sanity: cruise altitude must not exceed the airframe's service ceiling
+            $altitudeError = FlightSanity::altitudeError(
+                (int) $validated["crzalt"],
+                $aircraft->service_ceiling !== null ? (int) $aircraft->service_ceiling : null,
+            );
+            if ($altitudeError !== null) {
+                throw ValidationException::withMessages([
+                    "crzalt" => $altitudeError,
+                ]);
+            }
+
             // Location continuity: the flight must depart from where the airframe currently is
             if ($tempAirline->location_continuity
                 && strtoupper($validated["departure_icao"]) !== strtoupper((string) $aircraft->current_loc)) {
diff --git a/app/Http/Requests/Api/V1/StoreAircraftRequest.php b/app/Http/Requests/Api/V1/StoreAircraftRequest.php
index 3aa7f63..aa355f9 100644
--- a/app/Http/Requests/Api/V1/StoreAircraftRequest.php
+++ b/app/Http/Requests/Api/V1/StoreAircraftRequest.php
@@ -32,6 +32,7 @@ public function rules(): array
             'mtow' => 'nullable|integer|min:0|max:1000000',
             'mzfw' => 'nullable|integer|min:0|max:1000000',
             'mlw' => 'nullable|integer|min:0|max:1000000',
+            'service_ceiling' => 'nullable|integer|min:1000|max:60000',
             'remarks' => 'nullable|string|max:1000',
             'current_loc' => 'required|max:4|exists:airports,icao_code',
         ];
diff --git a/app/Http/Requests/Api/V1/StoreFlightRequest.php b/app/Http/Requests/Api/V1/StoreFlightRequest.php
index e3eeda1..6dc7e33 100644
--- a/app/Http/Requests/Api/V1/StoreFlightRequest.php
+++ b/app/Http/Requests/Api/V1/StoreFlightRequest.php
@@ -4,6 +4,8 @@
 
 use App\Models\Aircraft;
 use App\Models\Airline;
+use App\Models\Flight;
+use App\Support\FlightSanity;
 use Illuminate\Foundation\Http\FormRequest;
 use Illuminate\Validation\Validator;
 
@@ -40,7 +42,7 @@ public function rules(): array
             'crzalt' => 'numeric|max:50000|digits_between:1,5|required',
             'blockoff' => 'required|date_format:Y-m-d H:i:s',
             'blockon' => 'required|date_format:Y-m-d H:i:s',
-            'burned_fuel' => 'numeric|required',
+            'burned_fuel' => 'required|integer|min:' . Flight::MIN_BURNED_FUEL . '|max:' . Flight::MAX_BURNED_FUEL,
             'route' => 'required',
             'online_network_id' => 'required|exists:online_networks,id',
             'remarks' => 'nullable|regex:/^[\pL\s\d\.\,\-]+$/u',
@@ -70,6 +72,15 @@ function (Validator $validator) {
                     return;
                 }
 
+                // Physical sanity: ordering, not-in-future, and within the max duration
+                $timingError = FlightSanity::timingError(
+                    $this->input('blockoff'),
+                    $this->input('blockon'),
+                );
+                if ($timingError !== null) {
+                    $validator->errors()->add('blockon', $timingError);
+                }
+
                 $aircraft = $this->aircraft();
                 if ($aircraft === null) {
                     $validator->errors()->add('aircraft_id', 'This aircraft is not available or not owned by your airline.');
@@ -77,6 +88,15 @@ function (Validator $validator) {
                     return;
                 }
 
+                // Physical sanity: cruise altitude must not exceed the airframe's service ceiling
+                $altitudeError = FlightSanity::altitudeError(
+                    (int) $this->input('crzalt'),
+                    $aircraft->service_ceiling !== null ? (int) $aircraft->service_ceiling : null,
+                );
+                if ($altitudeError !== null) {
+                    $validator->errors()->add('crzalt', $altitudeError);
+                }
+
                 // Location continuity: the flight must depart from where the airframe currently is
                 if ($this->airline()->location_continuity
                     && $this->input('departure_icao') !== strtoupper((string) $aircraft->current_loc)) {
diff --git a/app/Http/Resources/V1/AircraftResource.php b/app/Http/Resources/V1/AircraftResource.php
index 8c46abe..0d93d07 100644
--- a/app/Http/Resources/V1/AircraftResource.php
+++ b/app/Http/Resources/V1/AircraftResource.php
@@ -29,6 +29,7 @@ public function toArray(Request $request): array
             'mtow' => $this->mtow,
             'mzfw' => $this->mzfw,
             'mlw' => $this->mlw,
+            'service_ceiling' => $this->service_ceiling,
             'remarks' => $this->remarks,
 
             // We don't have to return this, since this can only be accessed through a route, which already specifies the airline.
diff --git a/app/Models/Aircraft.php b/app/Models/Aircraft.php
index 5a5e90d..0733200 100644
--- a/app/Models/Aircraft.php
+++ b/app/Models/Aircraft.php
@@ -24,6 +24,7 @@ class Aircraft extends Model
         'mtow',
         'mzfw',
         'mlw',
+        'service_ceiling',
         'remarks',
         'current_loc',
         'used_by',
diff --git a/app/Models/Flight.php b/app/Models/Flight.php
index d596984..6fb9552 100644
--- a/app/Models/Flight.php
+++ b/app/Models/Flight.php
@@ -14,6 +14,24 @@ class Flight extends Model
 {
     use HasFactory, LogsModelActivity;
 
+    /**
+     * Physical sanity bounds enforced when a PIREP is filed. These are universal
+     * aviation limits, not per-instance policy, so they live as constants.
+     *
+     * The longest airliner flight on record is the Boeing 777-200LR ferry (2005,
+     * ~22h42m airborne); ~23h airborne + taxi, rounded up with a safety net.
+     */
+    public const MAX_DURATION_MINUTES = 26 * 60;
+
+    /** Fuel must be positive; 0/negative is nonsense. */
+    public const MIN_BURNED_FUEL = 1;
+
+    /**
+     * Generous upper ceiling to catch typos in either unit: an A380 holds
+     * ~256 t (~564,000 lb) of fuel, so this clears every real airframe.
+     */
+    public const MAX_BURNED_FUEL = 600000;
+
     protected $fillable = [
         'airline_id',
         'callsign',
diff --git a/app/Support/FlightSanity.php b/app/Support/FlightSanity.php
new file mode 100644
index 0000000..336fb0a
--- /dev/null
+++ b/app/Support/FlightSanity.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace App\Support;
+
+use App\Models\Flight;
+use Carbon\Carbon;
+use Carbon\Exceptions\InvalidFormatException;
+
+/**
+ * Physics-grounded sanity checks shared by both PIREP filing paths (the web
+ * FlightController and the API StoreFlightRequest), so the rules live in one
+ * place. Fuel bounds are plain field rules; the timing and altitude checks are
+ * cross-field / model-aware and live here.
+ */
+class FlightSanity
+{
+    /**
+     * Small grace to absorb clock skew between an ACARS/browser client and the
+     * server (and the minute-truncated form prefill). Gross future timestamps -
+     * the "planning a flight that hasn't happened" case - are still rejected.
+     */
+    private const FUTURE_TOLERANCE_MINUTES = 5;
+
+    /**
+     * Validate the block-off/block-on pair. Returns a human-readable error when
+     * the pair is invalid, or null when it is within bounds. Checked in order:
+     * block-on strictly after block-off, block-on not in the future (a PIREP
+     * records a flight that already happened - YAAMS has no flight planning),
+     * and the duration within Flight::MAX_DURATION_MINUTES.
+     *
+     * Flight times are Zulu (UTC), so both the input and "now" are compared in
+     * UTC. Both the API (`Y-m-d H:i:s`) and the web `datetime-local` input
+     * (`Y-m-d\TH:i`, no seconds) formats are accepted via Carbon::parse().
+     */
+    public static function timingError(?string $blockoff, ?string $blockon): ?string
+    {
+        if ($blockoff === null || $blockon === null) {
+            return null;
+        }
+
+        try {
+            $off = Carbon::parse($blockoff, 'UTC');
+            $on = Carbon::parse($blockon, 'UTC');
+        } catch (InvalidFormatException) {
+            // Unparseable timestamps are the field rules' job to report.
+            return null;
+        }
+
+        if ($on->lessThanOrEqualTo($off)) {
+            return 'Block on time must be after block off time.';
+        }
+
+        if ($on->greaterThan(Carbon::now('UTC')->addMinutes(self::FUTURE_TOLERANCE_MINUTES))) {
+            return 'Block on time cannot be in the future - a PIREP records a flight that already happened.';
+        }
+
+        $maxHours = intdiv(Flight::MAX_DURATION_MINUTES, 60);
+
+        if ($off->diffInMinutes($on) > Flight::MAX_DURATION_MINUTES) {
+            return "Flight duration exceeds the maximum of {$maxHours} hours.";
+        }
+
+        return null;
+    }
+
+    /**
+     * Reject a cruise altitude above the aircraft's service ceiling. The ceiling
+     * is optional per airframe (nullable column): when it is not set, no
+     * per-aircraft limit applies and only the global crzalt field rule governs.
+     * Returns a human-readable error or null.
+     */
+    public static function altitudeError(?int $crzalt, ?int $serviceCeiling): ?string
+    {
+        if ($crzalt === null || $serviceCeiling === null) {
+            return null;
+        }
+
+        if ($crzalt > $serviceCeiling) {
+            return 'Cruise altitude exceeds the service ceiling of this aircraft ('
+                . number_format($serviceCeiling) . ' ft).';
+        }
+
+        return null;
+    }
+}
diff --git a/database/factories/AircraftFactory.php b/database/factories/AircraftFactory.php
index 7550c3a..3a86382 100644
--- a/database/factories/AircraftFactory.php
+++ b/database/factories/AircraftFactory.php
@@ -25,9 +25,18 @@ public function definition(): array
             'current_loc' => fn () => Airport::factory()->create()->icao_code,
             'used_by' => Airline::factory(),
             'status' => Aircraft::STATUS_ACTIVE,
+            'service_ceiling' => 41000,
         ];
     }
 
+    /**
+     * Pin the service ceiling (feet).
+     */
+    public function serviceCeiling(int $ft): static
+    {
+        return $this->state(fn () => ['service_ceiling' => $ft]);
+    }
+
     /**
      * Park the airframe at a specific, already-existing airport.
      */
diff --git a/database/migrations/2026_07_22_000000_add_service_ceiling_to_aircraft_table.php b/database/migrations/2026_07_22_000000_add_service_ceiling_to_aircraft_table.php
new file mode 100644
index 0000000..b4d3c97
--- /dev/null
+++ b/database/migrations/2026_07_22_000000_add_service_ceiling_to_aircraft_table.php
@@ -0,0 +1,24 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('aircraft', function (Blueprint $table) {
+            // Service ceiling in feet; nullable - when unset, no per-aircraft
+            // altitude limit is enforced on PIREP filing.
+            $table->integer('service_ceiling')->nullable()->after('mlw');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('aircraft', function (Blueprint $table) {
+            $table->dropColumn('service_ceiling');
+        });
+    }
+};
diff --git a/resources/views/fleet/create.blade.php b/resources/views/fleet/create.blade.php
index e4882b3..916acf9 100644
--- a/resources/views/fleet/create.blade.php
+++ b/resources/views/fleet/create.blade.php
@@ -155,6 +155,16 @@
                                 <div class="form-text fs-7">Maximum Landing Weight</div>
                             </div>
                         </div>
+                        <div class="row g-3 mt-1">
+                            <div class="col-md-4">
+                                <label for="service_ceiling" class="form-label fw-semibold">Service Ceiling <span class="text-muted">(Optional)</span></label>
+                                <div class="input-group">
+                                    <input type="number" class="form-control" id="service_ceiling" name="service_ceiling" value="{{ old('service_ceiling') }}" min="1000" max="60000" placeholder="e.g. 41000">
+                                    <span class="input-group-text bg-light text-muted">ft</span>
+                                </div>
+                                <div class="form-text fs-7">Max cruise altitude; PIREPs above it are rejected</div>
+                            </div>
+                        </div>
                     </div>
                 </div>
             </div>
diff --git a/resources/views/fleet/detail.blade.php b/resources/views/fleet/detail.blade.php
index da77f4a..9b6b474 100644
--- a/resources/views/fleet/detail.blade.php
+++ b/resources/views/fleet/detail.blade.php
@@ -204,6 +204,12 @@
                                         {{ $aircraft->mlw ? number_format($aircraft->mlw) . ' kg' : 'N/A' }}
                                     </td>
                                 </tr>
+                                <tr>
+                                    <td class="text-muted ps-4 py-2.5">Service Ceiling</td>
+                                    <td class="fw-semibold text-dark py-2.5" colspan="5">
+                                        {{ $aircraft->service_ceiling ? number_format($aircraft->service_ceiling) . ' ft' : 'N/A' }}
+                                    </td>
+                                </tr>
                             </tbody>
                         </table>
                     </div>
diff --git a/resources/views/fleet/edit.blade.php b/resources/views/fleet/edit.blade.php
index c8f1d33..79c2401 100644
--- a/resources/views/fleet/edit.blade.php
+++ b/resources/views/fleet/edit.blade.php
@@ -133,6 +133,16 @@
                                 <div class="form-text fs-7">Maximum Landing Weight</div>
                             </div>
                         </div>
+                        <div class="row g-3 mt-1">
+                            <div class="col-md-4">
+                                <label for="service_ceiling" class="form-label fw-semibold">Service Ceiling <span class="text-muted">(Optional)</span></label>
+                                <div class="input-group">
+                                    <input type="number" class="form-control" id="service_ceiling" name="service_ceiling" value="{{ old('service_ceiling', $aircraft->service_ceiling) }}" min="1000" max="60000" placeholder="e.g. 41000">
+                                    <span class="input-group-text bg-light text-muted">ft</span>
+                                </div>
+                                <div class="form-text fs-7">Max cruise altitude; PIREPs above it are rejected</div>
+                            </div>
+                        </div>
                     </div>
                 </div>
             </div>
diff --git a/resources/views/flights/add.blade.php b/resources/views/flights/add.blade.php
index dc04c0e..dcda498 100644
--- a/resources/views/flights/add.blade.php
+++ b/resources/views/flights/add.blade.php
@@ -141,7 +141,7 @@
                         <div class="col-md-4">
                             @php $isLbs = session('activeairline')->unit_is_lbs; @endphp
                             <label for="burned_fuel" class="form-label">Burned Fuel ({{ $isLbs ? 'LBS' : 'KG' }})</label>
-                            <input type="number" class="form-control font-monospace" min="0" placeholder="{{ $isLbs ? '36000' : '5900' }}" required name="burned_fuel" id="burned_fuel" value="{{ old('burned_fuel') }}">
+                            <input type="number" class="form-control font-monospace" min="1" placeholder="{{ $isLbs ? '36000' : '5900' }}" required name="burned_fuel" id="burned_fuel" value="{{ old('burned_fuel') }}">
                         </div>
                     </div>
                 </div>
diff --git a/tests/Feature/Api/FlightApiTest.php b/tests/Feature/Api/FlightApiTest.php
index 478a8a4..621d13a 100644
--- a/tests/Feature/Api/FlightApiTest.php
+++ b/tests/Feature/Api/FlightApiTest.php
@@ -71,6 +71,118 @@ public function test_a_member_can_file_a_pirep(): void
         ]);
     }
 
+    public function test_non_positive_fuel_is_rejected(): void
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        Sanctum::actingAs($pilot);
+
+        $this->postJson(
+            route('api.v1.airlines.flights.store', $airline),
+            ['burned_fuel' => 0] + $this->payload($aircraft),
+        )
+            ->assertStatus(422)
+            ->assertJsonValidationErrors('burned_fuel');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_absurd_fuel_is_rejected(): void
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        Sanctum::actingAs($pilot);
+
+        $this->postJson(
+            route('api.v1.airlines.flights.store', $airline),
+            ['burned_fuel' => 9_000_000] + $this->payload($aircraft),
+        )
+            ->assertStatus(422)
+            ->assertJsonValidationErrors('burned_fuel');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_block_on_before_block_off_is_rejected(): void
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        Sanctum::actingAs($pilot);
+
+        $this->postJson(route('api.v1.airlines.flights.store', $airline), [
+            'blockoff' => '2026-07-11 11:30:00',
+            'blockon' => '2026-07-11 10:00:00',
+        ] + $this->payload($aircraft))
+            ->assertStatus(422)
+            ->assertJsonValidationErrors('blockon');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_flight_longer_than_the_max_duration_is_rejected(): void
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        Sanctum::actingAs($pilot);
+
+        // 27 hours, above the 26-hour cap.
+        $this->postJson(route('api.v1.airlines.flights.store', $airline), [
+            'blockoff' => '2026-07-11 10:00:00',
+            'blockon' => '2026-07-12 13:00:00',
+        ] + $this->payload($aircraft))
+            ->assertStatus(422)
+            ->assertJsonValidationErrors('blockon');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_a_flight_in_the_future_is_rejected(): void
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        Sanctum::actingAs($pilot);
+
+        $off = now('UTC')->addDays(2);
+        $on = $off->copy()->addMinutes(90);
+
+        $this->postJson(route('api.v1.airlines.flights.store', $airline), [
+            'blockoff' => $off->format('Y-m-d H:i:s'),
+            'blockon' => $on->format('Y-m-d H:i:s'),
+        ] + $this->payload($aircraft))
+            ->assertStatus(422)
+            ->assertJsonValidationErrors('blockon');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_cruise_altitude_above_the_service_ceiling_is_rejected(): void
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->serviceCeiling(41000)->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        Sanctum::actingAs($pilot);
+
+        $this->postJson(
+            route('api.v1.airlines.flights.store', $airline),
+            ['crzalt' => 45000] + $this->payload($aircraft),
+        )
+            ->assertStatus(422)
+            ->assertJsonValidationErrors('crzalt');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
     public function test_location_continuity_is_enforced_on_the_api(): void
     {
         $airline = Airline::factory()->locationContinuity()->create();
diff --git a/tests/Feature/FlightSanityWebTest.php b/tests/Feature/FlightSanityWebTest.php
new file mode 100644
index 0000000..018a584
--- /dev/null
+++ b/tests/Feature/FlightSanityWebTest.php
@@ -0,0 +1,144 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Aircraft;
+use App\Models\Airline;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\Concerns\SeedsDomain;
+use Tests\TestCase;
+
+/**
+ * Physical sanity guards on the web PIREP filing path (parity with the API in
+ * tests/Feature/Api/FlightApiTest.php): fuel must be positive and within a
+ * ceiling, block-on must be after block-off, and the duration is capped.
+ */
+class FlightSanityWebTest extends TestCase
+{
+    use RefreshDatabase, SeedsDomain;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->seedReferenceData();
+    }
+
+    /**
+     * @return array{0: Airline, 1: Aircraft, 2: User}
+     */
+    private function airlineWithAircraft(): array
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        return [$airline, $aircraft, $pilot];
+    }
+
+    private function payload(Aircraft $aircraft, array $overrides = []): array
+    {
+        return $overrides + [
+            'flightnumber' => 421,
+            'departure_icao' => 'EDDF',
+            'arrival_icao' => 'EGLL',
+            'aircraft_id' => $aircraft->id,
+            'callsign' => '421',
+            'crzalt' => 35000,
+            'blockoff' => '2026-07-11 10:00:00',
+            'blockon' => '2026-07-11 11:30:00',
+            'burned_fuel' => 5000,
+            'route' => 'DCT',
+            'online_network_id' => 1,
+        ];
+    }
+
+    private function file(User $pilot, Airline $airline, array $payload)
+    {
+        return $this->actingAs($pilot)
+            ->withSession(['activeairline' => $airline])
+            ->post(route('flightadd'), $payload);
+    }
+
+    public function test_non_positive_fuel_is_rejected(): void
+    {
+        [$airline, $aircraft, $pilot] = $this->airlineWithAircraft();
+
+        $this->file($pilot, $airline, $this->payload($aircraft, ['burned_fuel' => 0]))
+            ->assertSessionHasErrors('burned_fuel');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_absurd_fuel_is_rejected(): void
+    {
+        [$airline, $aircraft, $pilot] = $this->airlineWithAircraft();
+
+        $this->file($pilot, $airline, $this->payload($aircraft, ['burned_fuel' => 9_000_000]))
+            ->assertSessionHasErrors('burned_fuel');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_block_on_before_block_off_is_rejected(): void
+    {
+        [$airline, $aircraft, $pilot] = $this->airlineWithAircraft();
+
+        $this->file($pilot, $airline, $this->payload($aircraft, [
+            'blockoff' => '2026-07-11 11:30:00',
+            'blockon' => '2026-07-11 10:00:00',
+        ]))->assertSessionHasErrors('blockon');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_flight_longer_than_the_max_duration_is_rejected(): void
+    {
+        [$airline, $aircraft, $pilot] = $this->airlineWithAircraft();
+
+        // 27 hours, above the 26-hour cap.
+        $this->file($pilot, $airline, $this->payload($aircraft, [
+            'blockoff' => '2026-07-11 10:00:00',
+            'blockon' => '2026-07-12 13:00:00',
+        ]))->assertSessionHasErrors('blockon');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_a_flight_in_the_future_is_rejected(): void
+    {
+        [$airline, $aircraft, $pilot] = $this->airlineWithAircraft();
+
+        $off = now('UTC')->addDays(2);
+        $on = $off->copy()->addMinutes(90);
+
+        $this->file($pilot, $airline, $this->payload($aircraft, [
+            'blockoff' => $off->format('Y-m-d H:i:s'),
+            'blockon' => $on->format('Y-m-d H:i:s'),
+        ]))->assertSessionHasErrors('blockon');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_cruise_altitude_above_the_service_ceiling_is_rejected(): void
+    {
+        $airline = Airline::factory()->create();
+        $aircraft = Aircraft::factory()->serviceCeiling(41000)->create(['used_by' => $airline->id]);
+        $pilot = $this->memberOf($airline, 'Pilot');
+
+        $this->file($pilot, $airline, $this->payload($aircraft, ['crzalt' => 45000]))
+            ->assertSessionHasErrors('crzalt');
+
+        $this->assertDatabaseCount('flights', 0);
+    }
+
+    public function test_a_valid_flight_is_still_accepted(): void
+    {
+        [$airline, $aircraft, $pilot] = $this->airlineWithAircraft();
+
+        $this->file($pilot, $airline, $this->payload($aircraft))
+            ->assertRedirect(route('flightlist'));
+
+        $this->assertDatabaseCount('flights', 1);
+    }
+}
diff --git a/tests/Unit/FlightSanityTest.php b/tests/Unit/FlightSanityTest.php
new file mode 100644
index 0000000..0371080
--- /dev/null
+++ b/tests/Unit/FlightSanityTest.php
@@ -0,0 +1,98 @@
+<?php
+
+namespace Tests\Unit;
+
+use App\Support\FlightSanity;
+use Carbon\Carbon;
+use Tests\TestCase;
+
+/**
+ * Pure timing/altitude sanity logic - no database involved. Dates are relative
+ * to now so the "in the past / not in the future" checks are stable whenever
+ * the suite runs.
+ */
+class FlightSanityTest extends TestCase
+{
+    private function ago(int $days): Carbon
+    {
+        return Carbon::now('UTC')->subDays($days)->startOfHour();
+    }
+
+    public function test_a_normal_flight_passes(): void
+    {
+        $off = $this->ago(2);
+        $on = $off->copy()->addMinutes(90);
+
+        $this->assertNull(FlightSanity::timingError($off->format('Y-m-d H:i:s'), $on->format('Y-m-d H:i:s')));
+    }
+
+    public function test_the_web_datetime_local_format_is_accepted(): void
+    {
+        // datetime-local inputs post `Y-m-d\TH:i` with no seconds.
+        $off = $this->ago(2);
+        $on = $off->copy()->addMinutes(90);
+
+        $this->assertNull(FlightSanity::timingError($off->format('Y-m-d\TH:i'), $on->format('Y-m-d\TH:i')));
+    }
+
+    public function test_exactly_the_max_duration_passes(): void
+    {
+        // 26 hours on the nose is allowed.
+        $off = $this->ago(3);
+        $on = $off->copy()->addHours(26);
+
+        $this->assertNull(FlightSanity::timingError($off->format('Y-m-d H:i:s'), $on->format('Y-m-d H:i:s')));
+    }
+
+    public function test_one_minute_over_the_max_duration_is_rejected(): void
+    {
+        $off = $this->ago(3);
+        $on = $off->copy()->addHours(26)->addMinute();
+
+        $this->assertNotNull(FlightSanity::timingError($off->format('Y-m-d H:i:s'), $on->format('Y-m-d H:i:s')));
+    }
+
+    public function test_block_on_before_block_off_is_rejected(): void
+    {
+        $off = $this->ago(2);
+        $on = $off->copy()->subMinutes(90);
+
+        $this->assertNotNull(FlightSanity::timingError($off->format('Y-m-d H:i:s'), $on->format('Y-m-d H:i:s')));
+    }
+
+    public function test_equal_block_times_are_rejected(): void
+    {
+        $off = $this->ago(2);
+
+        $this->assertNotNull(FlightSanity::timingError($off->format('Y-m-d H:i:s'), $off->format('Y-m-d H:i:s')));
+    }
+
+    public function test_a_flight_in_the_future_is_rejected(): void
+    {
+        $off = Carbon::now('UTC')->addDays(2);
+        $on = $off->copy()->addMinutes(90);
+
+        $this->assertNotNull(FlightSanity::timingError($off->format('Y-m-d H:i:s'), $on->format('Y-m-d H:i:s')));
+    }
+
+    public function test_missing_timestamps_defer_to_the_field_rules(): void
+    {
+        $this->assertNull(FlightSanity::timingError(null, '2026-07-11 11:30:00'));
+        $this->assertNull(FlightSanity::timingError('2026-07-11 10:00:00', null));
+    }
+
+    public function test_altitude_within_the_service_ceiling_passes(): void
+    {
+        $this->assertNull(FlightSanity::altitudeError(35000, 41000));
+    }
+
+    public function test_altitude_above_the_service_ceiling_is_rejected(): void
+    {
+        $this->assertNotNull(FlightSanity::altitudeError(45000, 41000));
+    }
+
+    public function test_altitude_check_is_skipped_when_no_ceiling_is_set(): void
+    {
+        $this->assertNull(FlightSanity::altitudeError(45000, null));
+    }
+}