ETOPs questions?
Join Date: Jul 2000
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>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.
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.
Join Date: Apr 2002
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Ground nav aids for Adequate airports
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
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
Join Date: Jul 2002
Location: birmingham
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etops questions
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?
