Phrase 1 of 3Diversion
Diversion
Use this when you cannot reach or use your destination safely or legally: weather below landing minima, a runway that is not available, too little fuel, a technical defect or an urgent medical need. Name the alternate, say why, and ask for the route or flight level you want. ATC gives you the new clearances, and keeps giving you priority while a MAYDAY or PAN PAN is still in force.
station, callsign, reason, request diversion to alternate, routing, level
callsign, cleared routing alternate, level instruction, squawk, contact unit frequency
- You
Hyderabad Control, SpiceJet 318, Bengaluru runway closed, request diversion to Chennai, direct, flight level two nine zero
- ATC
SpiceJet 318, Hyderabad Control, cleared direct Chennai, descend flight level two nine zero, squawk six seven two four, contact Chennai Control one three two decimal five five, advise endurance and persons on board
- You
Cleared direct Chennai, descend flight level two nine zero, squawk six seven two four, Chennai Control one three two decimal five five, endurance one hour one five minutes, persons on board one seven nine, SpiceJet 318
- You
Chennai Control, SpiceJet 318, diverting from Bengaluru, direct Chennai, flight level two nine zero, information Delta
- ATC
SpiceJet 318, Chennai Control, descend flight level one five zero, expect ILS approach runway two five, QNH one zero zero nine
- You
Descend flight level one five zero, expect ILS runway two five, QNH one zero zero nine, SpiceJet 318
- ✓Give the cause in the first diversion call. The controller distinguishes weather, fuel, technical and medical cases because each may need different coordination. A serious defect may prompt a check of rescue and firefighting readiness, while routine weather avoidance does not automatically require an emergency response. Update the controller if the situation changes.
- ✓If a MAYDAY or PAN PAN was declared before the diversion, a change of destination does not cancel it. ATC continues the applicable priority handling until the pilot formally cancels the emergency or normal handling resumes. Report the alternate and any new failure, such as an engine fire, while retaining the earlier declaration.
- ✓On the first call to a new unit, give your callsign and level. Give the ATIS letter for the alternate once you have copied it: MATS asks for it on first contact with the approach unit or tower (MATS 9.1.5.7.2), and here the crew gives it to Chennai Control already. The controller then knows you have the runway in use, QNH, weather and any temporary restrictions.
- ✓Recalculate fuel for the revised route and ETA once diversion is confirmed. Compare forecast landing fuel at the alternate with the applicable final reserve and any company or regulatory requirement. If the required reserve would not remain at landing, or fuel endurance becomes critical, declare MAYDAY MAYDAY MAYDAY FUEL at once. A diversion report alone does not tell ATC that a fuel emergency exists.
- ✓Notify the operator's operations centre in parallel through ACARS, SATCOM or the company frequency. Staff can then arrange ground handling, passenger assistance, customs clearance and any technical or fuel support required at the alternate before arrival.
Now say it out loud, with the examiner playing ATC.
Practise in the simulator