We track hundreds of thousands of flights every day and invariably a few will declare an emergency and possibly “squawk 7700” during the day. This common occurrence often leads to numerous questions about what the flight is doing and why. We field many inquiries each time a flight declares an emergency, so we spoke with pilot Ken Hoke to understand more about what is happening on the flight deck during an emergency situation. Captain Hoke is a Boeing 757/767 captain for a package express airline and also runs the website AeroSavvy.

From the time an issue is detected to the time an emergency is declared, generally, what are the pilots doing?

This really depends on the type of emergency. If we have an engine failure just after takeoff, the pilot-monitoring will immediately key the microphone and declare an emergency. In this situation, the crew knows they have a serious problem and will need the immediate assistance and cooperation of Air Traffic Control to assure a successful outcome. In most “emergencies,” we aren’t in a big hurry. Unless it’s smoke, fire, or low on fuel, we can usually take our time to evaluate the problem. If we are in cruise flight and get a warning message of some sort, we may spend several minutes working the problem with a checklist. If time permits, we can contact dispatch and maintenance personnel via radio or SatComm to get additional guidance. If we determine that the capabilities of the aircraft have been reduced, we may elect to declare an emergency and figure out the best place to land.

A couple of years ago while flying a 757 to Osaka, Japan, we discovered a leading edge slats problem as we prepared to land. We told the controller that we may have a problem and needed time to sort it out. The controller vectored us around Osaka Bay while we ran the checklist. We were able to extend the slats using a back up system. It wasn’t a big deal, we were able to get the aircraft in a normal landing configuration.

The next thing we did was tell the controller we were ready for the approach and… we declared an emergency. Our aircraft had lost important functionality and we were using a back-up system. Control of the flaps and slats was limited and we didn’t know exactly why the slats didn’t originally extend or if the problem may have damaged something else. We fully expected the landing to be uneventful, but just in case, we wanted the runway all to ourselves. We wanted to make sure the controller understood that we might need extra time on the runway and that a missed approach could complicate matters. Declaring an emergency makes all this very clear to the controllers. With fire trucks watching from the taxiway, we made a perfect landing and taxied to parking.

Most aircraft “emergencies” work out like this one. Crews run into a minor issue and declare an emergency to be extra cautious. Definitely not worthy of CNN or a Michael Bay movie.

From a pilot’s perspective, what is the process for diverting to an alternate airport due to an emergency situation?

This varies depending on why the aircraft needs to divert. Any time a diversion becomes necessary, the first priority is to get the aircraft on the ground safely. Some problems require the crew to identify the nearest piece of concrete and land without regard for customer convenience. The crew will communicate to ATC the extent of the problem and receive priority routing to the alternate that is chosen. If time permits (it often does), the crew will contact the company to discuss diversion options. Airline dispatchers are a great resource and can help flight crews determine suitable alternates based on weather, customer handling needs, maintenance availability, and air traffic congestion.

How do you work with air traffic control to land safely and as quickly as necessary?

When an emergency is declared, air traffic control (ATC) gives the flight “priority.”  Saying the magic words “declare an emergency” (or “Mayday”) makes an aircraft the most important thing in the sky. If need be, ATC will move other traffic out of the way so the emergency aircraft can get to the runway as quickly as possible. ATC provides the crew with current weather, vectors (guidance) to the runway, navigation frequencies, they will contact emergency services (an ambulance if it’s a medical emergency), they can even notify airline management personnel to alert them of the problem if the crew doesn’t have time. For pilots, air traffic control is our “one-stop-shopping” link to services on the ground. They are awesome.

Breaking the rules!

One nice perk of declaring an emergency is that the pilot-in-command of the aircraft can do whatever he/she deems necessary to keep the aircraft safe. That includes breaking Federal Aviation Regulations. Speed limits and airspace rules all go out the window once you declare an emergency. This rule encourages crews to declare an emergency even if the issue seems minor. It’s a good way for the crew to cover themselves in case they accidentally break a rule while trying to deal with a problem.

What’s the biggest challenge in dealing with an emergency?

Managing workload is one of the biggest challenges when handling an emergency. There are usually only two pilots up front and we stay pretty busy on a typical flight. When a problem occurs, our workload can increase by a huge factor. Much of our simulator training involves increased workload so we can fine tune task delegation and prioritization.

How do pilots train for emergency situations?

Pilots constantly review emergency procedures. Depending on the airline, pilots do simulator training every 6 months to a year. Guess what we do in the sim? Emergency drills! Every year, there are different emphasis items that we review and practice. While in training we practice emergency procedures at home, in the car, at the dinner table, in the classroom, and finally in the simulator.

What is the significance of “Squawking 7700” and when is 7700 needed?

Declaring an emergency means the crew determines they have an “urgency” or “distress” situation. “Urgency” means the crew is concerned about the safety of the flight and needs timely (but not necessarily immediate) assistance. A “distress” condition means that the flight is in serious and/or imminent danger and requires immediate assistance. The radio call “Pan-Pan” declares an urgent situation: “Pan-Pan, Pan-Pan, Transglobal 124 requests lower altitude due to cracked windshield.” “Mayday,” declares a distress situation: Mayday, Mayday, Mayday, Transglobal 142, engine fire, returning to Metropolis.” In the United States it’s more common for pilots to use the term “Declaring an emergency” even though Pan-Pan and Mayday are the accepted international phrases. If a crew resets their transponder to the emergency code of 7700 (squawking 7700), all air traffic control facilities in the area are immediately alerted that the aircraft has an emergency situation. It’s up to the crew to let ATC know what the exact situation is. It may be an aircraft problem, medical issue, or something else. In some cases, a crew may not elect to change their transponder to 7700 (it’s not required). If I’m talking to Chicago Approach and have a problem, I’ll tell them the problem, declare an emergency over the radio and get vectors to land immediately. In an international environment where language and communication may be challenging, squawking 7700 makes it very clear to ATC that the crew needs priority and assistance.

What is the one thing you would want passengers or people tracking a flight to know about aircraft emergencies and the 7700 squawk code?

Ninety-nine percent of the “emergencies” observed on websites like FlightRadar24 are very benign events. Unfortunately, Twitter seems to go nuts when an aircraft squawks 7700. “Emergency” doesn’t necessarily mean passengers and crew are in a life and death struggle worthy of the evening news. Most of the time, the crew is using an abundance of caution and letting ATC know that they are working with an abnormal situation.

You can read more from Captain Ken Hoke on his website AeroSavvy.com and follow him on Twitter.