ETOPS and LROPS Loss of cabin pressure or Fire

[alistomalibu]

1-Does ETOPS and LROPS include the possibility of suffering a total loss of pressurization exactly at the ETP (Equal time point) between 2 suitable airports?

2-What equipment must have the aircraft to mitigate this situation?
(Example: More than normal oxygen to fly a portion of the flight at higher altitudes than 10.000 feet, in order to burn less fuel, etc.?)
What if the air inside the cabin cannot be conditioned? Too many hours at temperatures below zero could generate hypothermia

3-I think it´s obvious, that ETOPS and LROPS don´t take into account the possibility of a serious fire onboard. So, what type of equipment is necessary to mitigate it?
(Example: More than normal fire suppression bottles, etc.?)
Thanks

[Matey]

Under ETOPS 3 scenarios have to be considered and fuel on board at the equal time point be sufficient for diversion to the suitable enroute alternate, approach,go around, hold 15 minutes, approach and land under the most limiting condition:

Engine failure and descent, followed by diversion.
Decompression and descent followed by two engined diversion
Simultaneous engine failure and decompression followed by descent and diversion.

Generally the most limiting is a decompression and descent followed by two engined diversion.

[alistomalibu]

Thanks Matey

Does this apply for LROPS flights (4 engines)

Must they have enough fuel to fly from the ETP to the enroute alternate at 10.000 feet?

Example: From Ezeiza to Sydney. I think they have only 2 options (New Zealand and Punta Arenas or Ushuaia). The ETP is in the middle of nowhere...Probably 5 hours away from any airport

http://blogs.crikey.com.au/planetalking/files/2010/11/EZESYD.jpg

[Matey]

Having only ever flown ETOPS I leave that to an LROPS expert!

[Wizofoz]

3-I think it´s obvious, that ETOPS and LROPS don´t take into account the possibility of a serious fire onboard. So, what type of equipment is necessary to mitigate it?
(Example: More than normal fire suppression bottles, etc.?)


There's no extra cabin equipment AFAIK, but cargo holds have to be ETOPS certified, meaning they should be able to supress and contain a fire for the period of the ETOPS diversion.

[BuzzBox]

Does this apply for LROPS flights (4 engines)

Must they have enough fuel to fly from the ETP to the enroute alternate at 10.000 feet?

I haven't seen any 'LROPS' specific rules, but generally speaking, a flight must be able to divert from any point en-route to the nearest suitable airport and arrive with the specified reserves under the most limiting of the scenarios outlined by Matey, usually all-engines, depressurised.

The aircraft that operate the routes you mentioned (ie B744, B77W, A343, etc) are typically configured with additional oxygen bottles that would allow an initial descent to FL140 following a depressurisation, cruise at FL140 for several hours, followed by a descent to 10,000ft once the passenger oxygen was depleted. The fuel calculations would be based on shutting off 70% of the oxygen masks following the initial descent to FL140.

[mustafagander]

Alistomalibu, on the EZE-SYD flights that I operated we had a longest ETP of just under four hours. A bit scary if you think about it too much! There was always McMurdo ice runway but you'd need to be desperate to go there. SYD-DFW gets into some lonely airspace too. Our B744 can make any decompression diversion at F140. The "Silk Route" was the joker in that pack with truly horrendous lengths of time above F200 to get to the diversion airports. Luckily it was rarely used and now never used, the A380 can't do it.

[alistomalibu]

I appreciate all the comments. Thanks!

A few more questions:

1-Why decompression and descent followed by two engined diversion is the most limiting scenario?

Should not be the option 3 indicated by Matey? - Simultaneous engine failure and decompression followed by descent and diversion?

2-Does the fuel calculations for the diversion at FL140 or FL100 take into account the use of engine anti-ice and wing anti-ice during all the diversion time?

3-What does generate more burn of fuel?

A. Flying at FL250 on one engine (Twin engine aircraft). I have read, that this generates approximate 30% more of fuel burn.

B. Flying at FL140 - FL100 with all the engines operative. Does somebody know the approximate % of increase in fuel burn?

Thanks!

[mustafagander]

1/ When operating at such low levels the engine rotor speeds are so low that the engine is operating way off design criteria. Translated - it gets thirsty.
2/ Yes, depending on forecasts.
3/ I don't know the numbers but the flight plan often has a fuel build up to cover it.

[Onceapilot]

You can only calculate specific fuel burn and altitude scenarios with the type ODM. There may be situations with low altitude transit after depressurisation where you achieve a greater ANM/KG with engine(s) shut down although, I believe the spirit of the regulations is that you maintain all servicable powerplants in operation during diversion (for fuel planning/TOPL before flight).:ok:

[BuzzBox]

1-Why decompression and descent followed by two engined diversion is the most limiting scenario?

The more critical scenario really depends on the aircraft type - for the 744 and A343, the all-engines depressurised scenario is more limiting, whereas for the 77W it's the one-engine inop depressurised scenario that is more limiting. Theoretically, the aircraft should be slightly more efficient at low altitude with one engine shutdown because the remaining engine(s) is(are) operating at a more efficient thrust range. I'm not sure why that's not the case for the 77W, possibly something to do with the whopping great fan on the GE-90 engine. It's not just the fact it's a twin, because the all-engines depressurised scenario is more limiting for the RR-powered 772/773.

2-Does the fuel calculations for the diversion at FL140 or FL100 take into account the use of engine anti-ice and wing anti-ice during all the diversion time?

Yes, if icing is forecast.

3-What does generate more burn of fuel?

B. - Flying at FL140 - FL100 with all engines operating burns approximately 15-20% more fuel than flying at FL250 with one engine inoperative. Flying at FL250 with one engine inoperative burns approximately 30% more fuel than all engines normal cruise (FL370-ish).

[Matey]

Just for illustration purposes as my current type is 737NG, on this aircraft in ISA conditions at 10000 ft the fuel burn per air nm is about 7% greater on two engines than one. The B767-300 was most limited by two engine burn also.

[alistomalibu]

Again, I appreciate all your comments!
Thank you very much

Interesting to know about this approximate percentages:

By Buzzbox
"Flying at FL250 with one engine inoperative burns approximately 30% more fuel than all engines normal cruise (FL370-ish)"

By Buzzbox
"Flying at FL140 - FL100 with all engines operating burns approximately 15-20% more fuel than flying at FL250 with one engine inoperative."

By Matey
"Flying at 10.000 ft the fuel burn is about 7% greater on two engines than one"

More comments about ETOPS and LROPS will be appreciated

[BuzzBox]

More comments about ETOPS and LROPS will be appreciated

Sorry, I don't understand. Do you have any other specific questions about ETOPS/LROPS?

[alistomalibu]

Negative..
Thanks for your help

[JammedStab]

Does this apply for LROPS flights (4 engines)

Must they have enough fuel to fly from the ETP to the enroute alternate at 10.000 feet?

Example: From Ezeiza to Sydney. I think they have only 2 options (New Zealand and Punta Arenas or Ushuaia). The ETP is in the middle of nowhere...Probably 5 hours away from any airport

http://blogs.crikey.com.au/planetalking/files/2010/11/EZESYD.jpg

My answer is for 3 and 4 engine aircraft.....ETOPS(Or whatever it is called) begins at 180 minutes from a suitable airport based on all engine cruise speed. Only decompression is accounted for, not engine failure. At the ETP, a descent is made to 10'000 feet for a pax flight or 14,000 feet for a cargo flight. Have to have fuel to make it to your alternate with fuel to do an approach plus a measly 15 minutes holding fuel at 1500' AAE. However, there is not too much of an area requiring this ETOPS scenario.

But this is subject to confirmation by people more in the know and up to date.

[mustafagander]

The B744 can crz at F140 with the legal number of pax on oxy for a very long time, long enough for us to divert to where ever. Hence we do the sums based on F140 which really helps our range at such a low alt.

[Onceapilot]

Mustafa, are your pax on a gaseous emergency oxy? The chemical emergency oxy I am familiar with is 15min? Cheers

[BuzzBox]

are your pax on a gaseous emergency oxy?

Yes, the B744 pax oxygen system uses a number of oxy bottles - 13 if I remember correctly. They allow for extended depressurised flight above 10,000ft, eg oceanic sectors, flights over high terrain where immediate descent to 10,000ft isn't available.

[mustafagander]

These bottles sometimes blast a hole in the hull too!! Check VH-OJH just on five years ago near Manila.

[JammedStab]

Yes, the B744 pax oxygen system uses a number of oxy bottles - 13 if I remember correctly. They allow for extended depressurised flight above 10,000ft, eg oceanic sectors, flights over high terrain where immediate descent to 10,000ft isn't available.

I think the number of O2 bottles is a customer option with those choosing more bottle having the capability to use 14000' for an altitude for emergency descent with Pax onboard