From 4b07609c525e9644b08881886c3be56504abadde Mon Sep 17 00:00:00 2001
From: leubeem <emanuel@binder-leube.de>
Date: Mon, 29 Jun 2026 10:17:52 +0200
Subject: [PATCH] feat(pm): VFR registration callsigns and pronunciation (#28)

- VFR scenarios get a German D-registration (e.g. D-EKLM) and its
  abbreviated form (callsign_short, D-EKLM -> D-LM) instead of the airline
  callsign; the pilot's first call uses the full registration, ATC uses the
  short form thereafter.
- radioSpeech: spell aircraft registrations phonetically for TTS
  ("D-EKLM" -> "Delta Echo Kilo Lima Mike", "D-LM" -> "Delta Lima Mike").

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 app/pages/pm.vue            | 15 +++++++++++++++
 shared/utils/radioSpeech.ts |  7 +++++++
 2 files changed, 22 insertions(+)

diff --git a/app/pages/pm.vue b/app/pages/pm.vue
index f1674d7..b35a16e 100644
--- a/app/pages/pm.vue
+++ b/app/pages/pm.vue
@@ -3538,6 +3538,21 @@ const startMonitoring = async (flightPlan: any, scenario: Scenario) => {
     approach_freq:    v.approach_freq    || '119.000',
     handoff_freq:     v.handoff_freq     || '131.150',
   }
+
+  // VFR flights identify by aircraft registration, not an airline callsign.
+  // Assign a German D-registration and its abbreviated form (D-EMIL -> D-IL,
+  // first letter + last two), which ATC uses after the first call. Mirror it
+  // into the local engine vars and HUD so the display matches the radio.
+  if (scenario.startFlow.startsWith('vfr')) {
+    const pool = ['D-EMIL', 'D-EKLM', 'D-ENNY', 'D-ELLA', 'D-EOMT', 'D-ELPC', 'D-EMTO', 'D-EBRA']
+    const reg = pool[Math.floor(Math.random() * pool.length)]
+    const short = `D-${reg.replace(/^D-/, '').slice(-2)}`
+    backendVariables.callsign = reg
+    backendVariables.callsign_short = short
+    patchVariables({ callsign: reg, callsign_short: short })
+  } else {
+    backendVariables.callsign_short = backendVariables.callsign
+  }
   pmLog.info('backend variables payload:', backendVariables)
 
   // 4. Create a backend session with the flight-plan-derived variables
diff --git a/shared/utils/radioSpeech.ts b/shared/utils/radioSpeech.ts
index 7fdba52..039b2ad 100644
--- a/shared/utils/radioSpeech.ts
+++ b/shared/utils/radioSpeech.ts
@@ -741,6 +741,13 @@ export function normalizeRadioPhrase(text: string, options: NormalizeRadioOption
     out = out.replace(/\b(wind\s+)(\d{3})\/(\d{2,3})(?:KT)?\b/gi, (_m, prefix: string, dir: string, spd: string) =>
         `${prefix}${spellIcaoDigits(dir)} degrees, ${spellIcaoDigits(spd)} knots`);
 
+    // Aircraft registration callsign: "D-EMIL" → "Delta Echo Mike India Lima",
+    // abbreviated "D-IL" → "Delta India Lima". Single prefix letter, hyphen, then
+    // 1–5 registration letters, each spelled phonetically. Runs before airport/
+    // callsign expansion so the registration body isn't read as an ICAO code.
+    out = out.replace(/\b([A-Z])-([A-Z]{1,5})\b/g, (_m, prefix: string, body: string) =>
+        spellIcaoLetters(prefix + body));
+
     if (opts.sidSuffixIcao) {
         out = out.replace(/\b([A-Z]{4,6})\s*(\d)\s*([A-Z])\b/g, (_match, prefix: string, digit: string, letter: string) => {
             return sidSuffixSpeak(prefix, digit, letter);