Chapter 16
The Emergency Return
Acknowledge an airborne emergency, clear every conflicting runway and taxiway, roll the fire trucks, and recover the aircraft safely to the ground.
Distress, urgency, and the first reply
Chapter 8 covered an in-flight emergency from the radar room, where an aircraft is miles away and needs vectors, a lower altitude, and a clear approach course. In the tower cab, an emergency often starts in front of your window. You clear an airliner for takeoff from Runway 25R, watch it rotate and climb through a few hundred feet, and hear the crew call before switching to departure.
Radio procedure divides emergency calls into two levels. Speaking "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 declares distress: grave and imminent danger requiring immediate assistance. Speaking "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 declares urgency: a condition concerning the safety of the aircraft or someone on board that does not yet need immediate assistance. Either call starts emergency handling, and so does a plain statement from the pilot that they have an emergency. The pilot's word decides which level applies, and the pilot in command may deviate from any rule to the extent the emergency needs.
Consider the flight deck right after a bird strike and an engine failure on climb-out. One pilot is hand-flying 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 aircraft on one engine close to the ground, holding rudder against asymmetric thrust and pitching for single-engine climb speed, while the other pilot silences warnings and runs memory items. A long transmission from the tower forces the crew to split their attention between flying the aircraft and copying instructions.
Your first transmission back is the shortest one that tells the crew they have been heard ("RogerRoger.I received your whole transmission. It does not mean yes, and it is not a readback.Open in the glossary mayday"), followed by whatever lets them land: the surface wind, the runway, and a landing clearance. Wait to ask questions until you have issued the landing clearance and the crew has started the turn back.
Mayday, mayday, mayday, Bayview Tower, United Four Five Two, bird strike, engine failure, request immediate return.
United Four Five Two, Bayview Tower, roger mayday, wind two four zero at one two, runway two five right, cleared to land.
Runway two five right, cleared to land, United Four Five Two.
What to ask and when to ask it
Once you have acknowledged the declaration and issued a clearance, the FAA manual sets the order for gathering information.
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.
In the call from United Four Five Two, the pilot gave you the callsign, what failed, and what the crew wants to do, while the flight progress strip shows the aircraft type. You have all three minimum items before keying the microphone, which is why assistance starts on your first transmission.
Paragraph 10-2-1 also lists items to obtain after acting, as the situation needs: altitude, fuel remaining in time, pilot-reported weather, the number of people on board, the point of departure and destination, and the emergency equipment on board. Of that list, you ask only the items that apply to the situation at hand.
For an airport return, the fire crews waiting beside the runway want two numbers before the aircraft crosses the threshold, and you ask those questions after the crew has turned onto the return leg and finished the immediate cockpit actions. The headcount is requested as "souls on board" and includes the crew alongside the passengers. Fuel remaining is given in time ("two hours ten minutes"), which tells you how long the aircraft can stay aloft and tells the firefighters how much fuel is in the tanks. When the nature of the trouble leaves any doubt about whether trucks are needed on the surface, you can also ask whether the crew requires the emergency equipment.
United Four Five Two, say souls on board.
One four eight souls on board, United Four Five Two.
United Four Five Two, say fuel remaining.
Two hours ten minutes of fuel, United Four Five Two.
United Four Five Two, thank you, the equipment will be standing by for runway two five right.
Giving the crew the field
Normal tower control runs on a first-come, first-served basis, weaving departures and arrivals together as chapters 11 through 13 covered, until a distress call overrides that sequence.
Provide air traffic control service to aircraft on a "first come, first served" basis as circumstances permit, except the following:
An aircraft in distress has the right of way over all other air traffic.
Under that priority, the returning flight gets the runway and flight path it needs: a crew with a sick engine or degraded controls will often prefer the longest runway or the one aligned into the wind, and may tell you so. Climbing out of Runway 25R at Bayview, a crew may fly a circuit back to 25R or request Runway 33 if it offers a shorter turn from their present position. When the crew names a runway, you clear them to land on it, or you can issue "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" as your acknowledgement that the crew chooses the surface. Once you say those words, you are responsible for stopping any movement on any runway until the crew commits to one approach.
Separation for an emergency's landing clearance uses the anticipated separation rule from chapter 12. Traffic that will be clear of the runway by the time the aircraft arrives need not hold up the clearance, such as an arrival rolling out well ahead or a departure that will be airborne and gone. Anyone lined up and waiting, crossing downfield, or stopped on the runway must be cleared off before the emergency arrives.
Whether you can hold the aircraft over the airport depends on the declaration: a distressed mayday aircraft needs the ground immediately and is not asked to hold, whereas holding an urgent pan-pan aircraft in left or right orbits over the field lets the crew run a checklist and prepare the cabin before starting the approach.
Clearing the path and rolling the trucks
While the emergency aircraft flies its circuit, you clear the conflicting traffic in the air and on the ground.
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. This also applies when routes within the airport proper are required for movement of local emergency equipment going to or from an emergency which occurs outside the airport proper.
Workload permitting, monitor the progress of emergency vehicles responding to a situation. If necessary, provide available information to assist responders in finding the accident/incident scene.
Departures holding short at the Runway 25R hold bars on Alpha stay behind the line. Launching traffic into the pattern while an emergency is turning back puts another aircraft into the airspace the returning crew needs. Arrivals on final that conflict with the return are sent around, and approach holds inbound flights clear until the emergency is down.
You also alert the Airport Rescue and Fire Fighting (ARFF) service by a direct line or alarm and pass the landing runway, the aircraft type, the nature of the trouble, the souls on board, and the fuel remaining. The trucks drive out over the taxiways and stage beside the runway near the expected stopping point. Paragraph 10-1-6 has you control ground traffic to avoid conflicts with the routes the emergency equipment uses, so you hold taxiing aircraft short of any intersection the responders need.
Rescue, roll the equipment, runway two five right.
Rescue rolling, runway two five right.
Delta Eight Eight, hold short of runway two five right, emergency aircraft returning.
Holding short of runway two five right, Delta Eight Eight.
On the runway after touchdown
After touchdown, the aircraft still has to be checked and moved. A returning crew with a failed engine, hot brakes, or a hydraulic failure will normally brake to a full stop straight ahead on the runway, avoiding high-speed turns onto taxiways before the aircraft has been checked from the outside.
Once the aircraft stops, the runway closes and you clear the staged fire trucks onto the pavement. The trucks drive up and look the aircraft over for fire, smoke, and fluid leaks while the crew waits on the runway.
After the trucks report no fire and no leaks, you ask the pilot whether they are able to taxi. The pilot in command decides. If the crew can taxi under their own power, you issue a route off the runway to the ramp. If steering or hydraulics are out, the crew declines to taxi and asks for a tow, and a tug comes out to hook up and tow the aircraft off the runway.
Bayview Tower, Rescue One is on scene, no fire, no leaks.
United Four Five Two, Rescue reports no fire and no leaks, are you able to taxi.
Affirmative, able to taxi, United Four Five Two.
United Four Five Two, turn left at delta, taxi to the ramp via alpha, charlie, bravo, hold short of runway three three, remain this frequency.
Left at delta, to the ramp via alpha, charlie, bravo, hold short of runway three three, remaining this frequency, United Four Five Two.
A runway on which an emergency has landed is inspected before reuse. A bird strike or engine failure can leave metal, rubber, or hydraulic fluid on the concrete, so the trucks sweep the surface to check for debris, fluid, and damage. The runway stays closed until that inspection is done and all vehicles are off the pavement.
In the Sim
In ATC Simulator, tower emergencies happen to departures shortly after liftoff and to arrivals on final. The four causes are a bird strike, an engine failure, smoke in the cockpit, and a hydraulic failure. Only turboprops and medium, heavy, and super aircraft have them; light singles and fighters do not. How often they happen is controlled by the unusual occurrences setting (off, rare, normal, or frequent, with normal as the default for a new player), which runs on its own random stream without an online director. Each event is a mayday or a pan-pan depending on the cause, and smoke in the cockpit is always a mayday.
A bird-strike mayday sounds like the call from United Four Five Two at the top of this chapter, requesting an immediate return, while a pan-pan crew asks for a return to the field. The crew never volunteers souls on board or fuel remaining without being asked. Saying "roger mayday" (or "roger pan pan") within twenty seconds of the call scores ten points when it is the first acknowledgement. Asking "say souls on board" scores ten points, "say fuel remaining" scores five points (answered in hours and minutes), and "do you require the equipment" scores five points, each paid for the first asking only.
The returning aircraft flies a visible circuit back to the runway it prefers by wind or length. You can clear it to land on a named runway or issue "any runway, cleared to land", which is non-standard in everyday FAA operations but accepted in the simulator so the crew can take its preference. Offering a landing clearance or "any runway" while a runway is in use costs thirty points; anticipated separation applies, so an arrival well ahead of the emergency or a departure that will be gone does not count against you. A pan-pan aircraft can be told "make left orbits, advise ready" (or right orbits), and it will fly a racetrack over the field at three thousand feet until calling "checklist complete, ready for the approach". A mayday crew refuses an orbit with "mayday, we need to land immediately". Leave a crew too long without a clearance and it lands on its own authority when the runway is free, charging you for late handling.
Where a working tower cab alerts ARFF by direct line and coordinates with approach, the airport operator, and other positions by landline, the simulator puts the call to the fire station on your frequency and shows the vehicles on the surface. You say "Rescue, roll the equipment, runway two five right", and the station answers "Rescue rolling, runway two five right" without the flight crew hearing or reading back the call. Rescue One and Rescue Two drive out over the taxiways and stage at the exit behind the likely stopping point. Rolling them before touchdown scores ten points; if you have not called them once the aircraft is within two miles of the runway, the field's emergency plan rolls them automatically for zero points. While the emergency is in the air, the traffic generator holds back new arrivals, and releasing no takeoff within six nautical miles of the emergency earns twenty points, whereas each departure cleared with the emergency in that area costs twenty-five points.
At touchdown the runway closes automatically (the ATIS updates with a new letter and a "RUNWAY ... CLOSED" notice) and every returning emergency brakes to a full stop on the runway and waits. Once the trucks look it over and report "on scene, no fire, no leaks", asking "are you able to taxi" scores five points on the first asking; ask too early and the crew answers "StandbyAmerican Two One Five, standby.Wait, something higher priority comes first; call again if the delay runs long. A standby is not a clearance and not an answer.Open in the glossary". An aircraft that cannot taxi says so and asks for a tow, and a tug comes out, hooks up, and tows it off the runway. The trucks then sweep the runway and report "inspection complete, runway is clear, all vehicles off the runway" to reopen the surface; clearing anything onto the closed runway costs fifty points. Handling the emergency within ten minutes for a mayday or fifteen minutes for a pan-pan earns fifty points, while finishing late costs twenty. Training 21, "Birds on the climb-out", puts you in the tower seat when a routine departure suffers a bird strike and engine loss after liftoff: you acknowledge the mayday, clear the immediate return, roll the trucks, ask for souls on board, hold the next departure, clear the truck onto the runway, and ask whether the aircraft can taxi.