The Importance Of An ETP


The Importance of an ETP

UAS Operations | - 03/17/2016
Go back to main page
Featured, Planning and Operating

When do you need an ETP – or Equal Time Point? When you are going from the United States to Europe of course! You coast out at Gander, coast in at Shannon, and include Keflavik of Reykjavik for good measure – and voila, your ETP planning is done! False! This just-pick-these-cities-and-go approach is dangerous and, unfortunately, far too common an occurrence, specifically in general aviation.

Just as a refresher, an ETP is a point along the route from which it takes the same amount of time to return to your departure airport as it would to continue to your destination airport. However, in our industry, the term has been expanded to hold much greater meaning. Typically, the calculation is done based on suitable airports along the route, called the “coast-out” and “coast-in” airports, and sometimes includes a diversionary airport, or “tertiary airport” nearer to the midpoint of the flight.

Simply put, if you have a problem, it tells you which airport you should go to. These problems are typically:

  • An onboard medical emergency
  • The decompression of cabin pressure of the aircraft
  • The loss of an engine or engines

Let’s remember one thing about ETP scenarios: They are emergencies. Whether they are medical or mechanical, enacting an ETP protocol will most likely constitute an emergency.

Ask yourself the following questions:

  • Do you want to chance your airport selection in the event of an emergency?
  • Do you want to fly a zero-visibility approach into a snow- and ice-covered Goose Bay on one engine?
  • Do you want to divert to a location with subpar medical services when you have a critical patient on board?

The answer to these questions should be an overwhelming “no.”

When selecting ETPs, you need to take a number of factors into consideration. The following are just a few examples of what you should consider when you plan for the worst:

  • Will the weather conditions make a stressful situation even worse?
  • Does the forecast include anything that would challenge your ability to land at the diversion airport?
  • Does the forecast include anything that would challenge your ability to bring in a supplemental lift, another airplane, or even a replacement part?
  • Do the NOTAMs paint a picture of additional stress?
  • Does the airport have the infrastructure that is needed to support your aircraft, crew, or passengers?
  • Does the airport offer robust emergency services?
  • Is the airport located in a place that would be easy to transfer crew or passengers onto airline service?
  • Is the airport located in a place that you would feel safe to ride out an AOG scenario?
  • How is the local healthcare system? Would you trust your health and wellbeing to the local hospitals?
  • Is the airport located in a country where it would be difficult to source or import an aircraft part during an AOG situation?
  • Will you be overflying an area where terrain presents a problem for lower altitude flying?
  • Will you be overflying an area where ground-based weapons systems may present a safety concern when flying at lower altitudes?

Also, you need to consider the areas you fly. All too many times, we hear customers only using ETPs for overwater flying. That isn’t sufficient. ETPs can be used on just about any flight plan.

Picture this scenario: You are flying a leg between Santiago, Chile, and Asunción, Paraguay in IFR conditions, where you face an explosive decompression and lose cabin pressurization. You don the oxygen masks, begin your rapid descent, and alert a sparse ATC as to your situation. You level off at the predetermined initial flight level, which, for most business jets is between 10,000-14,000 feet. The problem is that you are flying over the Andes mountain range and Aconcagua stands at an oppressive 22,837 feet. If you are in the soup without the aid of certain avionics and situational displays, the prospect of summiting the world’s second tallest peak at 250 plus knots becomes a sightseeing trip much more rewarding with a carabineer, nylon rope, and pick axe.

Or, how about a desert? Is 100,000 square miles of sand any different than 100,000 square miles of water? Maybe slightly, but again, you’d probably rather see these magnificent sights in a Land Rover with a tour guide.

How about war zones? Areas of unrest? Volcanos?

The scenarios above are presented in a tongue-in-cheek manner, but they could become operational realities if you do not plan your ETPs accordingly.

ETP selections should be an active conversation when planning all flights. They also should be included in any robust Safety Management System (SMS) or abnormal operations plan.

The proper selection of ETP airports can make the difference between a solution to an emergency event or an increasingly harrowing experience.

Bonus Question:

Do you need a landing permit for your ETP airport?

Bonus Answer:

Typically no, because the enacting of an ETP scenario constitutes an emergency. If you declare an emergency, the permit process becomes null and void.