1. ET PS Briefing
ETOPS HIST RY
Delhi - February 1999

2. Definitions What is the meaning of ETOPS?
 Extended range with Twin engine aircraft OPerationS
What is the scope of ETOPS?
 Operation of twin engine aircraft on routes that go further than 1 hour from a diversion airfield

3. Definitions
60’ circles
KHI
BOM
SLL
JIB
CMB
NBO
Non ETOPS flight

4. Definitions
60’ circles
KHI
BOM
SLL
JIB
CMB
NBO
ETOPS flight

5. Definitions ETOPS regulations are applicable to:
 Overwater operations
 Overland operations (desert areas...)
What is the meaning of EROPS?
 Extended Range OPerationS
 EROPS describes the applicability of ETOPS requirements to any aircraft, regardless the number of engines

6. History Extended range “operations“ started very early:
1909: first English Channel crossing (L. Bleriot)
1919: first North Atlantic Ocean crossing (J. Alcock & A. Brown)

7. History Extended range “operations“ started very early:
1927: first non-stop New York - Paris (C. Lindbergh)
first US Cost-Hawaï crossing (A.Hegenberger & L.Maitland)
first South Atlantic crossing (D. Costes & J. Le Brix)

8. History Extended range “operations“ started very early:
1928: first Pacific Ocean crossing (C.K. Smith & C.T. Ulm)
1930: first non-stop Paris - New York (D. Costes & M. Bellonte)

9. History
“Extended range” commercial operations started in the late 1930s:
1936: first trans-Pacific commercial flights
1939: first trans-Atlantic commercial flights

10. History
These types of flights required large multi- engined flying-boats:
poor engine reliability and performance could not allow design of equally efficient twin engine aircraft

11. History Piston engine reliability
The following chart (1953 ICAO report) gives the probability of failure for piston engines vs power at 1000 constant rpm:
the probability of failure increases as power is increased

12. History Piston engine reliability (cont’d)
The ICAO report shows that for the same amount of installed horsepower, the risk of an engine failure is greater on a 2 engine design than on a 4 engine design: design required hp

13. History As reliable and reasonably light engines had limited power:
design of long range aircraft (high weight) implied installation of several engines (more than two)
twin engine aircraft had limited payload/range performance and were only operated on short flights

14. History
In 1953, further to a review of the piston engine reliability, the FAA published the initial “60 minutes” rule:
applicable to three (until 1964) and two engine aircraft
special approval for operations beyond 60 minutes
At the same time, ICAO issued its “90 minutes” recommendations:
no airplane shall be operated beyond 90 min (all engines operative) from a diversion airfield, except if the route can be flown with two engines inoperative
common interpretation was that twin engine aircraft could be operated on 90 minutes routes

15. History
Until 1952, all commercial flights were operated with piston engine powered airplanes:
1952: first commercial operation with jet airplane (DH Comet 1)
1958: first transatlantic commercial jet operation (DH Comet 4)
Since 1960, jet engine powered aircraft progressively replaced piston engine powered aircraft:
on all long range routes
on most of regional routes

16. History
Higher performance of jet engines allowed operations of twins on 90 min routes (Caribbeans, Africa, Bay of Bengal, North Atlantic, South China Sea, ...)

17. History Jet engine reliability
More than 40 years of jet operations have shown that unlike piston engines, jet engine failure probability is not affected by the thrust or the size of the engine:
Therefore, the probability of an engine failure is now higher on a quad-jet than on a twin-jet
(for 1000 FH)

18. History
The introduction in the 1980s of twin aircraft (A310, B767) powered with modern (fuel efficient) turbofan engines made the old 60/90 minute rules inadequate:
1984: ICAO ETOPS study group amend Annex 6
1985: FAA publishes first ETOPS regulation to address 120 min operations
1985: first ETOPS operation (SIA/A310 - TWA/B767)

19. History
In 1988, the Authorities published rules for minutes ETOPS based on the very good experience with 120 minutes operations:
today, ETOPS operation is representing over 60% of North Atlantic operations
Regulatory discussions are on-going to assess:
extension of the ETOPS limit beyond 180 minutes
increase of the non-ETOPS threshold above 60 minutes