Chapter eight covered emergencies from the approach controller's seat, where a flight in trouble is still twenty miles out and there is time to set up a final. The tower's version is shorter and closer. The most common one starts a few seconds after a takeoff clearance: a flock of birds in the climb-out, a bang, an engine that stops producing thrust or starts shaking, and a crew that needs to put the aeroplane back on the runway it just left. Everything in this chapter happens within five miles of the tower and inside ten minutes.
Bird strikes are ordinary events. Thousands are reported every year and most do no damage worth a return. The ones that matter to the tower are the strikes that damage an engine at low altitude, where the crew has little height, a HeavyUnited Four Heavy, Bayview Approach.A wake-turbulence class carried in the callsign of aircraft able to take off at 300,000 pounds or more, because the wake they leave behind is a hazard to whoever follows.Open in the glossary aeroplane full of fuel, and a checklist to run. That is the case this chapter works through.
The call
A crew in distress says MaydayMayday, mayday, mayday.The distress call: the aircraft is in grave and imminent danger and needs priority over everything.Open in the glossary three times, then who it is calling, then its callsign and the problem. A crew with a problem that is serious but not yet a threat to the aeroplane says Pan-panPan-pan, pan-pan, pan-pan.The urgency call: a serious problem, but not yet a distress. It outranks everything except a mayday.Open in the glossary three times instead. The manual leaves the choice to the pilot: an aeroplane is in an emergency when the crew says it is, and the tower does not ask it to justify the word. A pan-pan can become a mayday later if the engine gets worse, and the tower treats the upgrade the same way it treated the first call.
Mayday, mayday, mayday, Bayview Tower, United four five two, bird strike, engine failure, request immediate return.
United four five two, roger mayday.
The acknowledgement comes first and it is short. The crew is flying an aeroplane on one engine at a thousand feet, and every word the tower adds is a word the pilot flying has to listen to. The manual lists what the tower needs before it starts helping, and it is a short list:
Start assistance as soon as enough information has been obtained upon which to act. Information requirements will vary, depending on the existing situation. Minimum required information for inflight emergencies is: Aircraft identification and type. Nature of the emergency. Pilot's desires.
The mayday call above already carries all three: the callsign, a bird strike with an engine failure, and a request to come back. The tower has enough to act on before it has asked a single question. The longer list in the same paragraph, which includes fuel remaining and the number of people on board, is gathered after action has started and when the crew can answer.
Priority and the runway
The rule that governs the next ten minutes is in chapter one's paragraph on operational priority:
An aircraft in distress has the right of way over all other air traffic.
At Bayview that means the returning flight gets the runway it wants, when it wants it. A crew coming back with an engine out wants the runway most nearly into the wind, or the longest one, and it will say which if asked. The tower can ask, clear the runway the crew prefers, or offer the choice:
United four five two, say runway preference.
We'd prefer runway two five right, into the wind, United four five two.
United four five two, runway two five right, cleared to land.
Cleared to land runway two five right, United four five two.
"Any runway, Cleared to landRunway two five right, cleared to land.The runway is yours to land on. It may be issued while the aircraft ahead is still clearing, on the judgement that the runway will be free at the threshold.Open in the glossary" is heard at real towers in an emergency and leaves the choice with the crew. It is only safe when every runway on the field is free: nothing on it, nothing lined up, nothing on a short final. The controller who says it has checked all of them first.
The crew flies its own way back. A departure that has just lifted off from two five right climbs straight ahead to a safe height, turns onto a downwind on the side away from the tower's other traffic, and turns base and final for the runway it was cleared to. The tower does not vector it. The circuit is the crew's, flown by eye with the field in sight, and the tower's work is keeping the runway and the airspace around it free.
A pan-pan crew may want time before it lands: to run the engine checklist, to brief the approach, sometimes to burn down weight. The tower gives it a place to do that over the field and asks to be told when it is ready. A mayday crew with an engine gone does not want to hold, and will say UnableUnable.I cannot comply with that instruction. Information, not defiance; it forces a new plan, fast.Open in the glossary if asked.
United four five two, make left orbits, advise ready.
Orbiting over the field, will advise ready, United four five two.
Rolling the equipment
Every airport with scheduled airline service has its own rescue and fire fighting crew, with trucks built to reach a runway in minutes and put foam on a burning aeroplane. The tower calls them. One call rolls the equipment; the trucks leave their station and position themselves beside the runway near where the aeroplane is expected to stop, off the pavement, facing it. The fire chief chooses the positions; the tower's part is the call and keeping traffic out of the trucks' way.
The crew can be asked whether it wants them, and the answer is usually yes. The trucks roll either way for an engine failure: a mayday in the tower's hands is one the equipment attends.
United four five two, do you require the equipment?
Affirmative, request the equipment standing by, United four five two.
United four five two, roll the equipment.
The trucks need the number of people aboard before they reach the aeroplane, and the crew has a moment to give it on the downwind. The same call asks for fuel remaining in time, which tells the trucks how much there is to burn.
United four five two, say souls on board and fuel remaining.
One four two souls on board, fuel remaining two hours one zero minutes, United four five two.
The manual gives the tower the job of keeping the ground clear for the responders as well as the air:
When an emergency occurs on the airport proper, control other air and ground traffic to avoid conflicts in the area where the emergency is being handled.
Holding the field
While the emergency is airborne and near the field, nothing else takes off. A departure rolling toward the same runway, or climbing out into the circuit the returning flight is flying, adds traffic exactly where the crew least needs it. The departures at the Holding pointThe marked position at the runway entrance where a departure waits for its clearance. Crossing the marking without one is a runway incursion.Open in the glossary wait, and so do the arrivals: the approach controller holds them outside the area until the emergency is down.
When the aeroplane lands the runway it used closes. Parts of an engine and what is left of the birds may be on it, and a tyre or a brake may have been damaged on the rollout. The runway stays closed until the airport has inspected and swept it, and the recording says so for every aircraft that listens:
Attention all aircraft, information Tango current, runway two five right closed.
A closed runway is not given to anybody, for a takeoff, a landing or a crossing. The departures that waited during the return keep waiting if it is the only runway, or taxi to another one if the field has it.
After the landing
An aeroplane that lands on one engine may stop on the runway and be unable to move, or may roll out and turn off like any other. The tower asks which:
United four five two, are you able to taxi?
Unable to taxi, we require a tow, United four five two.
A tug comes from the ramp to tow it off. The trucks drive onto the runway to the aeroplane and stay with it until it is clear. When it is clear they drive the length of the runway looking for debris, and when they call the runway clear the tower reopens it and the departures start again.
The trucks and the tug are ground traffic like any other vehicle on the movement area. A truck on its way to a runway that is closed for it drives straight there; a truck that has to cross another runway waits for it the same way an aeroplane does, and the tower keeps traffic off that runway until it has crossed.
In the Sim
In ATC Simulator the bird strike happens to departures in the tower seat. A ready-room setting chooses how often, from never to most shifts, and it works offline. Lesson 21 walks through one from the takeoff clearance to the tow. The departure declares mayday or pan-pan a few seconds after it lifts off, then flies its own circuit back, and you can watch it from the cab: the climb, the turn onto the downwind, the base and the final. Until you clear it to land it holds over the field; a mayday left waiting for three minutes lands on its own authority as soon as its runway is free.
What is scored is what this chapter describes. Acknowledging the call quickly earns points, and so do asking for the souls on board and whether the crew wants the equipment, rolling the equipment before the aeroplane lands, and asking after the landing whether it can taxi. Holding every departure while the emergency is in the area earns points. Releasing one costs points, and so does clearing anybody onto the closed runway, or clearing the emergency onto a runway that is in use. Landing it before its deadline carries the largest award.
The sim's trucks and tug are real traffic on the field. The trucks leave their station with lights and sirens, wait beside the runway, attend an aeroplane stopped on it, sweep the runway and reopen it; the tug tows a disabled aeroplane to a gate. Where the sim simplifies: the vehicles drive straight across the grass between their positions rather than along service roads, the tower cannot yet talk to them directly, and "any runway" is accepted without the phraseology bonus because the manual always names the runway.