What constitutes an "emergency" in flight procedures?

Question

In reading through the more informal literature (Wikipedia, FAA PDFs, Av.SE), I often come across a caveat to standard flight rules and procedures: "unless an emergency exists". The intention is obvious; ATC is going to prioritize helping an aircraft that encounters a situation that simply cannot be ignored. However, most such resources don't go into specifics about what kind of situations constitute an "emergency". There are obvious emergency scenarios, like a "dead stick", and there are obvious non-emergencies like "I have to be on the ground by 5:00 to beat traffic home". Then there are grey areas like "I fought a headwind the whole way here, I'm low on gas and now my home field is IFR and won't grant me SVFR. I might make it to my alternate even further upwind that's clear, but I really think it's best to set down here even if I can't see the far end of the runway".

So, the questions:

• What kinds of things constitute a genuine emergency, and what will get a pilot laughed at by ATC (or worse)? Where's the line?

• Is ATC allowed to judge what is or is not an actual emergency, or must they prioritize any aircraft declaring one?

• Does fault or blame matter at the time the emergency is declared? Will ATC de-prioritize a situation that is obviously the pilot's fault, like flying into the only cloud for 50 miles in any direction?

• Is there anything you still can't do as PIC in an emergency situation? Apparently in an emergency you can do a lot of things that would get your license pulled in any other scenario, like violating separation minimums, entering airspace that's normally off-limits like R-zones and Class A space, running on instruments without a rating, etc. While these things are still dangerous, it is apparently the pilot's prerogative to resolve the emergency however he can. Is there anything a plane declaring an emergency still must do other than fly the plane, or conversely something he still cannot do like get too close to Air Force One?

• After declaring an emergency in flight, what should be done after the plane's back on the ground (hopefully safely)?

Answer 1

There is a really good explanation of emergency situation over at the SkyBrary:

An emergency situation is one in which the safety of the aircraft or of persons on board or on the ground is endangered for any reason.

An abnormal situation is one in which it is no longer possiible to continue the flight using normal procedures but the safety of the aircraft or persons on board or on the ground is not in danger.

Emergency or abnormal situations may develop as a result of one or more factors within or outside an aircraft, for example:

• Fire on board the aircraft;
• Aircraft component failure or malfunction (e.g. engine failure, landing gear malfunction or loss of pressurisation);
• Shortage of fuel (or other essential consumable substance);
• Flight crew uncertain of position;
• Worsening weather;
• Pilot incapacitation (e.g. as a result of illness);
• Aircraft damage (e.g. as a result of collision, bird strike or extreme weather;
• Illegal activity (e.g. bomb-threat, wilful damage or hi-jacking).

So in short, anything that puts the flight in danger can be considered an emergency.

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Is ATC allowed to judge what is or is not an actual emergency, or must they prioritize any aircraft declaring one?

If the pilot declares emergency, ATC will provide assistance and support to the flight without judging whether it is an actual emergency or not. ATC cannot know in most cases, nor are they really required to analyse the situation to come to that conclusion. Their whole responsibility is to ensure the flight receives all required information and support to either end the abnormal/emergency situation or land at a suitable airport.

Does fault or blame matter at the time the emergency is declared? Will ATC de-prioritize a situation that is obviously the pilot's fault, like flying into the only cloud for 50 miles in any direction?

No, they will not de-prioritize based on the type of emergency. Even if a pilot flew VFR into IMC conditions, he is still in a life-threatening situation from which he needs to recover, so assigning blame or guilt is not helpful here, nor would that be the ATC's job. This is the Civil Aviation Authorities' responsibility, once the flight is back in safe conditions. ATC may file a report, though, but not during the emergency, but as an aftermath.

Is there anything you still can't do as PIC in an emergency situation? Apparently in an emergency you can do a lot of things that would get your license pulled in any other scenario, like violating separation minimums, entering airspace that's normally off-limits like R-zones and Class A space, running on instruments without a rating, etc. While these things are still dangerous, it is apparently the pilot's prerogative to resolve the emergency however he can. Is there anything a plane declaring an emergency still must do other than fly the plane, or conversely something he still cannot do like get too close to Air Force One?

Technically, once you have declared an emergency, you can do whatever is required to keep the flight safe and prepare for an emergency landing. If you need to enter otherwise controlled or restricted airspace, this will be made possible by ATC via coordination with adjacent units. Without knowing FAA regulations on this specifically, I would daresay that distress traffic could have priority over the Air Force One.

After declaring an emergency in flight, what should be done after the plane's back on the ground (hopefully safely)?

Unless your CAA or their respective investigative service is not already waiting for you, you should remain with your aircraft (unless being treated for medical issues and taken to a hospital) and wait for them to arrive. If in doubt, you can call the police and they will notify the relevant authorities.

Answer 2

WITH DUE RESPECT I DIFFER A BIT

I am an ICAO controller. We classify flight status as follows:

1. Normal= Self-explanatory.

2. Abnormal: Abnormal reading/performance but no danger present yet- time for anticipation

3. Local Standby (urgency FAA): potential safety issue of the aircraft or of persons on board and requires timely assistance.

4. Full emergency (distress FAA)= An emergency situation is one in which the safety of the aircraft or of persons on board or on the ground is endangered for any reason. A full emergency is imminent danger and requires immediate assistance.

On the other hand, we should:

1. GET INFO Unless clearly stated by the flight crew, take all necessary steps to ascertain aircraft identification and type, the type of emergency, the intentions of the flight crew as well as the position and level of the aircraft in order to handle the emergency intelligently

2. SEPARATE: Upon receipt of information that an aircraft is having an emergency, all possible action shall be taken immediately to safeguard all aircraft concerned. Establish/maintain separation with other aircraft and terrain!

3. ASSIST: Decide and deliver upon the most appropriate type of assistance which can be rendered

4. COORDINATE: The air traffic controller concerned shall inform and enlist the aid of any other air traffic controllers and control sectors which may be affected.

To respond to an emergency, we (AIR TRAFFIC CONTROLLERS - ATCOs) should demonstrate problem-detection, anticipation of threats, planning, decision-making, resilience, error management, task distribution, teamwork and performance abilities. Re-planning is part of the ATCOs duties since, as an occurrence evolves over time, new threats may appear whilst current threats may change their demands.

Answer 3

After having a problem that I did not declare an emergency, a very wise 15,000hr airline pilot friend told me there is a very good rule of thumb - I now live by it.

"An emergency is anytime the weather or aircraft does not operate as intended or expected that jeopardizes the safety of flight."

Later I ran across some FAA information of interest. (Aim pg 220) For ATC purposes (maneuvering), a pilot is required to notify ATC whenever their aircraft is unable to climb or descend at least +-500fpm. An airplane that can not meet those requirements is not necessarily an emergency but is a "problem".