As a passenger, you might see the word “ETOPS” (pronounced Ē-Tops) stenciled on airplanes. Occasionally, you’ll hear about it in the news. Follow a few AvGeeks on Twitter or Facebook and you’ll most definitely see this term used, joked about, and misused. What does ETOPS mean and why is it important?
[Author’s note: Information in this article is based on United States air regulations. ETOPS rules and terminology may differ in other countries]
Terminology:
ETOPS: Acronym for Extended Operations. ETOPS is a set of rules that enhance safety when flying over areas of the world that have few airports that can be used in an emergency.
Suitable Diversion Airport (sometimes call an alternate): A preselected place to land in the event an airliner has a problem during a flight. A diversion airport must have appropriate facilities to handle the aircraft and meet minimum weather criteria.
The 60 Minute Rule
Airliners with two engines can fly any route that remains within 60 minutes flying time of an airport that is adequate for landing in the event of an emergency. The 60 minute distance is calculated using the aircraft’s speed with one engine inoperative in still air (no wind). As an example, the 60 minute distance for the 767 I fly is about 430 miles.
North America and Europe have numerous airports that can handle airliners. When flying over these continents, it’s unusual to be farther than 60 minutes from a place to land in an emergency.
Extra minutes for extra engines: The same regulation that limits two-engine airplanes to the 60-minute rule allows passenger jets with more than two engines (like a 747 or A340) to venture as far as 180 minutes from an airport. 180 minutes gives these aircraft access to 95% of the earth’s surface. Aircraft with more than two engines are rewarded with a longer leash due to increased engine and systems redundancy.
More Than 60 Minutes in a Twin = ETOPS
What happens if we want to fly a two-engine aircraft, like a Boeing 777, out over the ocean? The 5 1/2 hour flight from Los Angeles to Hawaii takes us way beyond 60 minutes from an airport. For a two-engine aircraft to exceed the 60 minute rule, we need… more rules!
ETOPS to the rescue!
Over the past few decades, aircraft systems and engines have become amazingly reliable. Because of this reliability, ETOPS rules were created to allow two-engine airliners to fly beyond 60 minutes from an airport. The same regulations allow passenger aircraft with more than two engines (like the 747 and A380) to fly beyond 180 minutes from an airport.
There are different ETOPS ratings available. Typical two-engine ratings are ETOPS-120 (minutes) and ETOPS-180. The higher the rating, the more difficult and costly it is to receive and maintain approval.
120 minute ETOPS works well for many long flights, including most routes over the North Atlantic. If an airline wants to fly more remote routes, like the Pacific ocean, it needs approval for 180 minute ETOPS. Hawaii and Asia are just too far from the U.S. mainland for an ETOPS-120 rating.
Part 1. Aircraft Type Approval
Aircraft Type Approval is the first step of the two part ETOPS approval process. The aircraft model type must be approved for extended operations. To gain approval, manufacturers must include extra redundancy for key systems like electrical, hydraulics, fire suppression, and communications.
Based on the design of the plane and engines used, federal agencies (like the FAA or EASA) will grant the aircraft model an ETOPS “type approval” that designates how many minutes it can safely operate with one engine inoperative. The Boeing 777 ETOPS models have a type approval of ETOPS-330. The Airbus A350XWB was granted ETOPS-370. These two aircraft are certified to fly over 5 hours from an emergency diversion airport – on one engine. Thousands of hours of engine performance and maintenance data are required before and airplane can acquire these impressive ratings.
Part 2. Operational Certification
Once the aircraft has ETOPS type approval, airlines must receive their own approval based on the routes they plan to fly. Aircraft certified for ETOPS have demanding maintenance requirements. Airlines must develop a special maintenance program for the aircraft they want certified. The higher the ETOPS rating, the more stringent the maintenance requirements. Frequent inspections for key aircraft systems with special attention to the engines are necessary. Airlines must also fly validation (test) flights on proposed ETOPS routes to demonstrate procedures to federal regulators.
ETOPS also requires special flight crew and dispatcher training, additional weather planning, special fuel quantity considerations, and enhanced communication capabilities (satellite communication is often used). A very important requirement for each ETOPS route flown is a passenger recovery plan.
Passenger recovery plan?
That sounds pretty ominous. No worries! The passenger recovery plan details how the airline will manage its passengers in the unlikely event of an emergency landing at an ETOPS diversion airport.
When an airline plans an ETOPS flight, they have to select suitable diversion airports to use in an emergency. Diversion airports must have the infrastructure necessary to handle passengers, often in remote areas of the planet. A little airstrip with one outhouse won’t work when flying over the North Atlantic in January. That’s why Halifax, Nova Scotia and Keflavik, Iceland are popular diversion choice for Atlantic routes. They can handle an extra 300 passengers in the event an A330 drops in with a problem. A recovery plan doesn’t have to promise everyone a room at the Ritz-Carlton, only that passengers will be reasonably comfortable and that basic physiological needs are met (safety, shelter, food, and bathroom facilities). The passenger recovery plan assures that passengers arrive at their final destination within 48 hours of the diversion.
ETOPS Trivia:
The very first FAA approved ETOPS flight was operated by a TWA Boeing 767-200 on February 1st, 1985 from Boston to Paris. TWA was first granted an ETOPS-90 rating. After an evaluation period, TWA’s rating was extended to ETOPS-120.
ETOPS Navigation Charts
Airlines are quickly moving to paperless cockpits. Thanks to advanced systems in newer jets and tablet computers (like the iPad), we pilots do a lot less navigation work than we used to. One task many airlines still require is plotting ETOPS data on a paper chart. The nice thing about paper is that it doesn’t need batteries and still works after I spill coffee on it!
Below is an example of a plotting chart for a Los Angeles to Honolulu flight. We use a fresh chart for each flight. Using different colored highlighters is not only fun, but makes the chart easy to read. In the example, our planned route is highlighted in yellow and the 180 minute circles around our ETOPS diversion alternates are in green. This chart is custom printed for my airline; the ETOPS circles are the correct 180 minute no-wind distance for our Boeing 767 aircraft. There is a circle for each diversion airport we are approved to use. We simply highlight the circle (or arc) for the diversion airports our dispatcher selects for each flight.
After we highlight the route and diversion arcs, we plot our ETOPS Entry Point where we fly outside of the 60 minute rule, and the Equal Time Point where the flight time to either diversion airport is the same. These points are provided to us on our computer generated flight plan. Knowing the ETP helps our decision-making in the event of an in-flight emergency. During the journey, we check our position about 10 minutes after passing each named intersection on the route. We take the present latitude and longitude from our navigation computer and plot that point on the chart. If the point is exactly on our yellow highlighted route, we know we are on course!
At the end of a flight, the ETOPS plotting chart makes a wonderful memento of the journey; suitable for framing. Usually, we throw it in the trash.
ETOPS: Engines Turn Or Passengers Swim?
An old airline joke is that ETOPS stands for “Engines Turn Or Passengers Swim.” It’s sort of funny (until you’ve heard it a few dozen times), but also misleading. ETOPS rules have nothing to do with flying over water! Different regulations govern over-water flights. There are several overland routes across Antarctica, Australia, Asia and Africa that require ETOPS rules due to the lack of adequate diversion airports.
ETOPS for airplanes with more than two engines?
Why mention airplanes with more than two engines (like the 747 and A380) in an article about ETOPS? Doesn’t the T in ETOPS stand for Twin Engine?
The old acronym was:
Extended-range Twin-engine Operational Performance Standards.
A few years ago, ETOPS rules were updated to include passenger airplanes with more than two engines. These long range jets routinely fly super-long routes over the Arctic, Antarctica and across the southern Pacific ocean. Government regulators felt that expanding ETOPS rules to include these aircraft would benefit safety. Thus, ETOPS now means: Extended Operations.
American Airlines Flies the Wrong Jet to Hawaii
In late August of 2015, American Airlines mistakenly flew a non-ETOPS certified aircraft from Los Angeles to Honolulu. Was this a big deal? Yes, it was. Was passenger safety compromised? Statistically, there may have been a slight increase in risk to the passengers. Would I have been worried if I were on board? Probably not. The flight crew was ETOPS qualified. ETOPS dispatch, fueling, and navigation procedures were used, and the airplane likely had an ETOPS pre-departure maintenance check. The airplane in question was, no doubt, in tip-top shape. The problem was that the aircraft wasn’t listed on American’s ETOPS operating certificate so it wasn’t required to be in the airline’s ETOPS Maintenance Program.
American Airlines notified the FAA of the error while the aircraft was en route and immediately took steps to ensure a similar mistake would not happen again. After arriving safely in Honolulu, the aircraft was ferried empty back to LAX.
ETOPS is a game of risk analysis and statistics. The rules are designed to eliminate as much risk as reasonably possible to assure a successful flight. The farther an airline wants to fly from a diversion alternate, the more strict the maintenance requirements are to minimize risk. An aircraft in an ETOPS maintenance program should have a statistically higher probability of a problem-free flight than one that is not.
[Update: There has been some confusion about how the aircraft that flew to Hawaii was equipped. According to the LA Times, the aircraft did have life rafts but did not have the correct quantity of emergency oxygen and fire suppression canisters onboard. This is a serious breach of safety that further highlights the importance of ETOPS rules.]
ETOPS Rules: Making extended operations safe!
ETOPS was first introduced in 1985. For over 30 years, the rules have succeeded in making long-range air travel for two-engine (and now four-engine) aircraft reliable and safe. Bravo, ETOPS!
Further Reading About ETOPS:
Great Circle Mapper: Interactive tool for displaying great circle routes and ETOPS circles.
Wikipedia ETOPS Entry: Lots of historical information on ETOPS.
PDF Files (useful for insomnia):
FAA InFO – New ETOPS Regulations: 2007 FAA publication outlining new ETOPS rules.
FAA Advisory – ETOPS and Polar Ops: Guidance for airlines requesting ETOPS approval.
Boeing AERO – The New FAA ETOPS Rule: In-depth article about the 2007 ETOPS rules.
More About Navigation:
Straight Talk on Great Circle Routes: Why airplane routes look funny on maps.
How do pilots find their way? Airliner navigation.
Well that was super interesting. And I feel even safer now….but…..I have a question. You talk about no wind. So, here’s my stupid question but I need to ask because I’m not sure what it means. And what happens if it turns out you have wind pushing you back in the direction you need to go? Then you won’t have enough?. Or will you? What? I’m confused.
Gemma,
The “no wind” stuff just means we can use perfect circles around the diversion airports. The idea is to have airports always within a reasonable distance and time, the numbers don’t have to be exact. The FAA decided not to complicate this rule by taking into account wind. If we have a head wind, it will take a little longer get to an alternate. A tail wind will reduce our time to an alternate.
Fuel won’t be a problem. We are required to carry fuel reserves for several different scenarios. All fuel calculations are based on forecast winds so there will never be a problem getting to a diversion alternate if we need to.
Thanks for reading!
You don’t mention the fact that the AAL flight that was non-ETOPs did not have life rafts for the passengers in the event the aircraft had to ditch in the ocean……That is one of the ETOPS requirments.
Hi Jim,
According to the LA Times and a couple other sources I checked, the aircraft did have rafts. This aircraft was used for over-water routes. Rafts are an over-water requirement, not an ETOPS requirement. Remember, there are ETOPS flights that don’t go over water and over-water flights that don’t require ETOPS 🙂 .
The LA Times also stated that the aircraft did not have the extra passenger oxygen capacity and extra cargo fire suppression required by ETOPS. If true, that’s a pretty serious breach in safety.
At my airline we have to put the plotting chart in our paperwork folder that gets “maintained by the company” for 30 days after the flight. Also (I fly for a foreign carrier) we’ve switched to the new ICAO term EDTO.
Hi Brad,
Great comment! My airline used to require that all paperwork be turned in as well. We changed procedures a few years ago. Now, we only need to turn in the paperwork if a navigation problem was encountered during the flight.
Aviation folks love coming up with new acronyms! For those not familiar, “EDTO” stands for Extended Diversion Time Operation.
Airbus proposed the acronym: LROPS (Long Range Operational Performance Standards).
Another acronym (used until the 1980’s) was EROPS (Extended Range Operations).
All these acronyms mean essentially the same thing.
Thanks for reading!
Ken
This was a great read and very informative. Keep up the greast articles, they’re good for us novice type to learn from.
Hi Ken,
Glad you enjoyed it!
Happy flying,
Ken
Hi! Captain, Its a nice article on ETOPS it gives a clear understanding how it works…..
Thank you, Mussavir!
I appreciate the nice feedback.
Ken
Another informative lesson! As a novice aviation geek, am I correct in assuming that when an airline places a new order with say Boeing for x amount of 737s, that airline has to specify how many need to be configured for ETOPS? Or can the planes be reconfigured by maintenace crews for ETOPS at a later date?
Hi John,
This is outside of my expertise, but I believe most of the 2nd generation ETOPS aircraft, like the 777 and A330 come standard from the factory ready for ETOPS without modification. Early models, like the 767 and A310 needed some modifications to be certified.
Thanks for reading!
Great article. Thanks for making this so easy to understand. I knew ETOPS had to do with long distance flights, but that’s it.
Hi Jessica,
Glad you liked the article. Thanks for reading!
-Ken
Great article and easy to understand. As a Avionics engineer, I have one question, do we have any display in cockpit to show ETOPS circle? Any device that can show or draw ETOPS circle around aircraft in realtime?
On the older 767-300 that I fly, there isn’t anything that automatically draws ETOPS Circles. Some crews will use the FMC Fix page to draw a 180 minute (1312 mile) circle around the ETOPS alternates for situational awareness. This is probably close to what you have in mind. We also have the alternate circles printed on our ETOPS plotting charts.
I can’t speak about other, newer generation airplanes; there might be something fancy available on those.
Thanks for reading!
Ken
Thank you Ken!
Thanks for reading!
-Ken
Hi Captain Hoke,
I truly enjoyed reading your articles. I’ve been an AvGeek since I was a young boy and I am lucky to have taken well over 100 “pleasure flights” and 0 “business-related flight.” Every single one of them was as exciting as my very first flight in 1978.
In early 2000’s I flew long-haul from Shanghai to San Francisco on a B747-400. About 5 hours into our 12-hour plus flight across the vast Pacific Ocean when most of my fellow passengers were already asleep (that US-based B747-400 plane was not equipped with PTVs!) this ETOP flight had an interesting event that happened. I was awakened from my light sleep when I heard all of the 4 engines’ sound turned to higher pitch. Soon afterward I felt the G-force forcing me to the side of my seat as our B747-400 turned to the right, then again, and again. I estimated we made a full 360 degree turn to go back to our original heading. I’ve never experienced a G-force quite that high on a plane before nor after that particular flight.
If you were going to make an educated guess, what do you think happened captain? Was that event triggered by a TCAS alert, in the middle of the Pacific Ocean? Or did our plane entered the “Coffin Corner”?
Thank you again captain,
Elwyn
Hi Elwyn,
I can’t say for sure what the reason was. It definitely wasn’t a TCAS maneuver. This article explains how TCAS works: https://aerosavvy.com/tcas/
It also had nothing to do with coffin corner.
My best guess is that the pilots changed to a higher altitude for better winds or to avoid turbulence. The 360 turn may have been necessary for proper spacing at the new altitude. That’s my best guess (and could be completely wrong)!
Great Article! (as all of your articles are, I just discovered your site a few weeks ago and I am having quite a good time reading through them).
I just wanted a quick clarification on ETOPS:
Is it applicable to commercial passenger flight only? Do cargo flights have something equivalent? Private or corporate passenger aircraft must abide to equivalent rules?
Thanks a lot,
Esteban
Hello Esteban,
ETOPS rules apply to all passenger transport aircraft regardless of the number of engines. ETOPS rules apply to all cargo aircraft with less than 3 engines. There are special rules for all aircraft (passenger & cargo) flying polar routes. When I fly my cargo 767 over the Pacific, we operate under ETOPS-180 minute authorization. I believe business/corporate aircraft must follow ETOPS rules as well, but I’m not 100% sure.
Thanks for reading!
Ken
If an airline has ETOP’s approval, say for the 767 and they then get A321’s, does the certificate cover the new aircraft or does the airline have to apply for approval for the new aircraft?
Hi Mac,
The airline has to get certification/approval for the new aircraft type. They need to demonstrate to the regulatory agency that they have the proper maintenance program in place (certified personnel, parts inventory, documented procedures, etc) and can operate the new aircraft model safely in the proposed ETOPS environment. It’s a really big deal to get a new aircraft type ETOPS approved.
Thanks for reading!
Ken
Hi Captain,
That was an extremely informative article. Before this article I thought that etops only applied to overwater flights. Didn’t realize that there was an airport requirement in there that would make a lot of Australia and Africa etops as well. Is this airport requirement only apply to US carriers? Would this requirement also apply to an Asian carrier flying from let’s say Malaysia or Singapore to Australia?
And what is EROPs how is it related to ETOPs.
Hi Sapan,
The International Civil Aviation Organization (ICAO) recommends procedures and guidelines for airlines to follow. Most every country that has an international airline is a member of ICAO and follows its rules. ICAO has something very similar to ETOPS called “Extended Diversion Time Operations” (EDTO). EDTO and ETOPS are essentially the same. Most carriers in Asia, especially the international carriers, would follow EDTO rules.
EROPS (Extended Range Operations) is an old acronym that was phased out in the 1980’s.
Thanks for reading!
Ken
Hi Capt!
Super informative and great lessons! Really appreciate it. However, I have a question.
For Part 1. Aircraft Type Approval, 2nd paragraph, “The Boeing 777 ETOPS models have a type approval of ETOPS-330. The Airbus A350XWB was granted ETOPS-370. These two aircraft are certified to fly over 5 hours from an emergency diversion airport – on one engine.”
What does it mean by a 777 ETOPS model having a type approval of ETOPS-330 and so forth?
Hi Danial,
The Boeing 777 aircraft has been approved to fly 330 minutes from a suitable airport that it can use in an emergency. The Airbus A350 has been approved to fly 370 minutes from a suitable alternate airport.
I hope that makes it more clear. Thanks for reading!
Hi Ken, is ETOPS a planning requirement or does it also apply to enroute deviations? Say I am planned Non-ETOPS and I need to divert around weather which takes me beyond 60 minutes of an adequate landing aerodrome. Should I plan my diversion to remain within 60 minutes? Do you have any references to to support your thoughts? Any help would be appreciated!
ETOPS is a planning requirement. I don’t know of a reference that covers your exact situation. If you aren’t ETOPS approved, you should be planning your route conservatively. Careful preflight planning should help you avoid getting into this sort of situation. That being said, if unexpected weather pops up that requires a deviation, FAR 91.3 can help.
A daft question I’m sure, but I assume the APU isn’t included in the engine count?
Correct. The APU is not included as an engine. It’s only used for a tertiary source of pneumatic and electric power.
ETOPS= “Extended-range twin-engine operational performance standards”
This acronym definition is incorrect and obsolete.