ETOPs questions?

[SkyCruiser]

Please could someone tell me about ETOPs.

What is an adequate/suitable aerodrome?

What things are considered for an airline to be certified for 180 mins ETOPs?

What are the various ETOPs categories?

Thanks

[PCav8or]

Try this

http://www.avweb.com/articles/etopsman/

or this

http://members.aol.com/safeflt/etops.htm

[Bally Heck]

Skycruiser.

An adequate aerodrome is one which is available at the anticipated time of use, and has navaids, ATC safety cover etc.

A suitable aerodrome is an adequate aerodrome with weather reports/forecasts that are likely to be at or above the relevant operating minima.

Not sure what is required for approval but suitable SOPs, engineering support and experience are sure to be in there (along with suitable aircraft)

[SkyCruiser]

Cheers Bally

[mutt]

Please could someone tell me about ETOPs.

HISTORY
The “60 Minute Rule”
The FAA created the requirements found in FAR section 121.161 as early as 1936. The initial regulation applied to all aircraft regardless of how many engines they had. The regulation restricted operations to an en-route area that was within 100 miles of an adequate airport. In 1936, 100 miles equated to about 60 minutes flying time if one engine was inoperative.
The initial FAA “60 minute rule” was established in 1953. The rule was written based on the reliability of the piston engines being used during the late 1940’s and early 1950’s. It restricted twin engine aircraft to areas of operations that were 60 minutes from an adequate airport at the one engine inoperative cruise speed, in still air, at standard atmospheric conditions. The Rule was flexible in that it permitted operations beyond 60 minutes if special approval was obtained from the FAA. The approval took into consideration the character of the terrain, the kind of operation, and the performance of the aircraft.
The purpose of the rule was to restrict the flying time to the alternate. This, in turn, would reduce the risk to an acceptable level. In other words, the rule addressed the lower end of reliability in piston power plants to ensure that if an engine failed at any point along the route, the aircraft could proceed to and land at the alternate before losing the remaining engine.

High Bypass Engines and the Wide Body Twin Aircraft
The early 1980’s showed great advances in the aircraft operational environment, design reliability and integrity. These advances were made possible by the highly satisfactory JT8D experience and the knowledge gained from the operational introduction of the Pratt & Whitney JT9D, the General Electric CF6, and the Rolls Royce RB211 large high bypass engines.
Wide body jets started service in 1974 and operators took advantage of the ICAO 90 minute rule where, by the old rules, they were forced to use three and four engine aircraft. It was found that jet engine power and size did not appear to have any noticeable impact on failure rate. The failure rates of some of the large high bypass engines were almost as good as the JT8D and nearly ten times better than piston engines.

Interest in the “120 Minute Rule”
Operations in the North Atlantic Track System (NATS) generated an interest in 120 minutes ETOPS. NATS operations were, by their nature, extremely competitive and the concept of using wide body twin engine aircraft was a very attractive proposition. This was especially true in light of the fact that the old “60 minute rule” required indirect routings (random routes) and the use of en-route alternates that had limited airport services and facilities and were subject to frequent weather limitation
Operations under a “120 Minute Rule” would allow for the use of minimum cost routings (Organized Track System) and enable the use of alternates that were properly equipped.
The aviation industry realized that all twinjets could now be designed with performance and safety improvements that permitted them to safely conduct operations that had been previously restricted to three and four engine aircraft. The new generation of aircraft with their efficiency, safety, range and payload capabilities made the old “60 Minute Rule” inappropriate.
Early in 1980, ICAO formed a study group to examine the feasibility of extended range operations with the new generation twinjets. They also set out to define the criteria that should be met to ensure that these operations were conducted with the highest possible level of safety. Around the same time the FAA began initial work on what would become Advisory Circular (AC) 120-42. This circular presented the U.S. Criteria for ETOPS. The ICAO study group recommended the establishment of a new ICAO rule to recognize the capabilities of the new generation aircraft and the limitations of the older aircraft.

120 Minute ETOPS Operations
In 1985, the FAA issued AC 120-42 which set the criteria for the approval of a deviation in accordance with FAR 121.161 to increase the ETOPS area of operations to 120 minutes at the single engine cruise speed under standard conditions in still air. The AC also permitted areas of operation as great as 138 minutes if additional criteria were met. Several other aviation authorities issued ETOPS criteria including CAA UK, DGAC France, DOT Canada, and DOT Australia.

180 Minute ETOPS Operations
The experience with 120 minutes ETOPS led the governing authorities and industry to consider the feasibility of 180 minutes ETOPS. Operators were most interested in the “180 Minute Rule” because it meant that almost any route in the world could be economically serviced by twinjets.
On 30 December 1988 the FAA issued AC 120-42A which provided criteria for 75, 120 and 180 minute ETOPS operations. On 18 January 1989, the FAA approved the first 180 Minute ETOPS operations.
240 Minute ETOPS Operations
Airline manufactures and a number of airlines are presently requesting the governing authorities to consider the feasibility of 240 minutes ETOPS. This would allow ETOPS operations across the Pacific Ocean.

What is an adequate/suitable aerodrome?
Bally Heck already answered that…

What things are considered for an airline to be certified for 180 mins ETOPs?

These actually apply to all ETOPS certification; the maximum IFSD rate varies with the level of approval.
Type Design Approval
To achieve type design approval, the essential airframe systems and propulsion system should be designed to fail safe criteria and through service experience it should achieve a defined level of reliability. This should include the availability of electrical power for essential flight instruments, warning systems, avionics, communication, navigation, oxygen requirements, and cargo fire protection system capability.

Operational Approval
Continuing airworthiness maintenance of aircraft, flight dispatch procedures, Minimum Equipment List, Communication and Navigation facilities, fuel supply, alternate airports operating minima and flight crew training are required to obtain operational approval.


What are the various ETOPs categories?

90mins, 120 mins, 138 mins, 180 mins, 240 mins.



One would never guess that I work for an airline that received ETOPS 120 minutes approval two weeks ago….. :)


Mutt.

[Frank M]

The B-777 has limited approval for 207-minute ETOPS for x-ing the Pacific. The details are on ALPA Site (http://www.alpa.org/internet/news/1999news/NR99017.HTM)

Hope this helps.

[Semaphore Sam]

I don't know much about Etops. About suitable diversion airports; is Sondestrom considered usable as an alternate, regardless of the experience level of the crews who would be expected to use it, with possible single engine go-around? If Kef & Reyk are down for wx, does that put the kabosh on Etops, if the only diversion airfield is Sondy? Thanks.

[Bally Heck]

No it doesn't Semaphore.

Other ETOPS alternates exist. Such as Bangor, Bermuda, Shannon, Boston, Gander, Lajes, St Johns, etc. If you look at a North Atlantic Plotting chart with 1200nm range rings from each field you will see a considerable amount of overlap. I don't believe that ETOPS has ever been suspended due to no suitable alternates existing.

[Semaphore Sam]

Thanks Mutt & BH, Further Questions

1. Any idea if Sondestrom is considered as a viable alternate (for Etops); if not, would it be overflown as 'not suitable for diversion'?

2. I understand a count of engine shutdowns is made; is this for the eintire airline, or only for specific aircraft type? What are the formulas? In other words, how many engine shutdowns, or ratios of shutdown to flights, lose an airline its Etops certification?

3. I've heard of a general desire by Boeing to ease Etops requirements, or to scrap Etops restrictions entirely. Do Boeing & Airbus have positions on this? Thanks again, guys. Sam

[mutt]

Sam,

We don’t consider Sondrestrom as an enroute alternate.......... (this week :))

I'm not too sure if the desire is to ease the ETOPS requirements or to make you 4 engine guys play by the same rules, especially in relation to fire suppression.

Mutt. http://www.stopstart.fsnet.co.uk/mica/FarSMutt.gif

[Bally Heck]

Semaphore.

Sondrestrom is listed as an ETOPS diversion field. But the minima are very high....2635ft and 3600m. I haven't seen it used as a suitable airfield on any flight plan I have used as there are invariably better choices. I imagine the facilities for 300+ passengers are fairly limited also.

Don't know about question 2, but for question 3, see Frank M's reply below.

[M.Mouse]

Is it correct that if an engine is shut down before entering the area of ETOPS operation it does not count as an IFSD?

Also, is it correct that if an engine is run at idle and considered unusable for whatever reason that is also not considered an IFSD?

Just curious, I do actually fly ETOPS so have no real axe to grind.

[mutt]

M.Mouse,

No to your first question, IFSD’s count regardless of where the engine was shut down.

Yes to your second question, the engine must be shut down for it to count, retarding the power lever isn’t counted as an IFSD.

Mutt. :)

[Frank M]

Semaphore Sam,

Our company does indeed use Sondrestrom/Kangerlussuaq as ETOPS alternate, indeed the minima are quite high, but somehow the weather is usually not too bad. And about the facilities for pax, I suggest reading the following article (http://www.smartcockpit.com/operations/Sondrestrom%20Diversion.PDF)

Happy ETOPS'ing.

[Semaphore Sam]

That was a really comprehensive review of what to expect at Sondy, Frank. Mutt, are there any plans to verbally brief crews planning Etops in that area about high minimums & terrain features of Sondy? For example, the 'crowned' feature of the runway caused one Aircraft Commander to try a go-around after landing; he thought he'd run out of runway, went around, saw the high terrain straight ahead and stalled, causing total loss-of-hull and only one survivor out of many crew. In fact, he had plenty of runway, but didn't know this until too late. I'd think that any Etops in that area would include an 'Area Briefing' which would incorporate such info.

In a similar vein, how about briefing crew about Lajes Field, the natural diversion for South Atlantic flights, where high terrain has, over the years, caused grief to many flights.

Or are all such Etops procedures considered spurious, considering the high reliability to-date of ops, so that such efforts can be 'pencil-whipped'? Sam

[None]

Sondre is normally open 1100-2000 UTC Monday-Saturday. Therefore, it is typically closed for eastbound flights and westbound flights on Sunday. The only time I have used it as an ETP airport is when regulations required its use due to 60 minute ops (partial nav failure prior to entering tracks westbound). In the case of 60-minute ops, there are no exceptions (as in 120 ETOPS)...you must continuously remain within 60 minute arcs, and Sondre was the only way to comply with this.

[Tim Zukas]

What single-engine cruise speeds are assumed for 757/767/777? The same for all operators of a given model?

[Glonass]

From what I understand, each Cie establishes its own assumed single-engine speed. Although I'm not sure. Here on the 763ER we use 434 kts.

Regards,

[Jinkster]

It stands for 'engines turning or passengers swimming' does ETOPS :D :D

[mutt]

Glonass,

What is the KIAS of a B767 at 10,000 feet?

Thanks

Mutt

[None]

>Tim Zukas: What single-engine cruise speeds are assumed for 757/767/777? The same for all operators of a given model?

For ETOPS planning, each operator chooses their own speed. The actual speed flown depends on the situation. A primary concern during a single engine divert in a 767 is to stay out of icing conditions because there is no way to de/anti-ice the inop engine. Flying at a lower speed may allow a cruise altitude above the icing. There may also be a benefit from nice tailwinds at higher altitudes.

The determination of an ETOPS area of operation is a relatively simple matter of referring to a table which Boeing has produced for its customers as part of the aircraft's ETOPS certification. The table is based on a theoretical straight line, no wind, standard day driftdown. The table is entered with an engine type, an assumed initial altitude and gross weight, and a driftdown speed chosen by the airline. This is all for flight planning, and the numbers generated are pesimistic; based on an instantaneous descent, anti-ice on, etc.

[Career Command]

In recent times the notams indicate navigation aids "awaiting flight check, ground checked only"

The company negates these aids and subsequently nominated another airport to meet the 120 mins.

However we then used a place in which the functioning aid was infact a Localizer. [surrounded by high terrain]

My query is this: how do we find our way back to this airport if the wonders of IRS/GPS should fail.

At least with an NDB or DME we could fly a heading and run a stopwatch to get us within a distance to bracket the aid and home in.

I realise ETOPS is all predicated on probablilty, none of us want to be the statistical first

Any guidance appreciated

[kouldurepeat]

Flying down a fjord like Sondrestrom in a widebody must be hair raising seat of the pants stuff! What about the airfields in North Canada surely they are for twin otter types not Etops aircraft?