Why are all Singapore Airlines 777-200ER but some with derated engines?

[wsssaero]

Can they use the extra fuel tanks on those with derated engines?

They wouldn't need to on those regional flights.

[FN-GM]

Can they use the extra fuel tanks on those with derated engines?

[belumosi]

How is the range of derated 777?

[zvezda]

Refer to post #7.

I've tried.

I meant Boeing built B772s.

I still don't know what you mean. All 777s have been built by Boeing.

SQ have never had any 777-200s that were not built as 777-200ERs. All SQ 777-200s are consider by Boeing to be 777-200ERs.

[boing]

All of SQ's 777-200s have centre tanks because Boeing built them as 777-200ERs.

Yup, am aware of that. Refer to post #7. I meant Boeing built B772s.

[zvezda]

Yup, I meant SQ's "B772"s. If I'm not mistaken, Boeing built B772s have no centre tanks in them.

All of SQ's 777-200s have centre tanks because Boeing built them as 777-200ERs.

[boing]

If by "B772" you mean SQ's derated 777-200ERs, then you're right, there are no structural differences. If you mean 777-200s, then you're mistaken, there are substantial structural differences. If 777s that Boeing built as 777-200s cannot be upgraded to 777-200ERs. SQ had Boeing build 777-200ERs for them and then bought them as 777-200s so that they can be uprated later (for more money).

Yup, I meant SQ's "B772"s. If I'm not mistaken, Boeing built B772s have no centre tanks in them.

[zvezda]

There is a 100,000 lbs difference in the MTOW of the B772 and B772ER. Surprising, since there is no structural limitations to the B772 to not carry the difference in the MTOW. Just a paper limitation.

If by "B772" you mean SQ's derated 777-200ERs, then you're right, there are no structural differences. If you mean 777-200s, then you're mistaken, there are substantial structural differences. If 777s that Boeing built as 777-200s cannot be upgraded to 777-200ERs. SQ had Boeing build 777-200ERs for them and then bought them as 777-200s so that they can be uprated later (for more money).

[boing]

Can't say for sure there. Their fuel capacity is the same, so I think the MTOW of the a/cs would be the same between the 772 and 772ER.

There is a 100,000 lbs difference in the MTOW of the B772 and B772ER. Surprising, since there is no structural limitations to the B772 to not carry the difference in the MTOW. Just a paper limitation.

[sunnyday]

yes they can

Thanks for all people who have posted



Ah i didnt know that. One question thats going slightly off topic. Can a pilot who pilots the 777 pilot all 3 types SQ have. Do they have a generic type rating. Can a 777 pilot operate the 777-200, 777-200ER, 777-300 & 777-300ER? Or because some have different engines does this not make it possible?

Thanks very much

[FN-GM]

Thanks for all people who have posted

The 773 and 773ERs are completely different with different engines( for SQ) and some major structural differences. Moreover, 773ER wasn't available when SQ got their 773s.

Ah i didnt know that. One question thats going slightly off topic. Can a pilot who pilots the 777 pilot all 3 types SQ have. Do they have a generic type rating. Can a 777 pilot operate the 777-200, 777-200ER, 777-300 & 777-300ER? Or because some have different engines does this not make it possible?

Thanks very much

[zvezda]

I think they also reduced MTOW which can equal lower landing fees. The inspection and maintenance intervals will also likely be longer on the "derated" Trents.

That's correct. The purchase prices were also lower for both the frames and the engines. If SQ (or a later owner) would like to, they can pay the difference to Boeing and to RR for higher MTOW and thrust, respectively.

[mr_botak]

I think they also reduced MTOW which can equal lower landing fees. The inspection and maintenance intervals will also likely be longer on the "derated" Trents.

[boing]

Do you know the fuel capacity are the same for 777-200(not derated) and 777-200ER?

The Boeing manufactured 772s and 772ERs have different fuel capacities between them. SQ's degraded 772s and 772ERs have no difference in their fuel capacity.

What gain do they get by derating them appose to leaving them as standard ER?

Can't say for sure there. Their fuel capacity is the same, so I think the MTOW of the a/cs would be the same between the 772 and 772ER. The only reason I can think of is the fuel consumption of the a/c on the degraded 772s would be more suitable for short haul trips compared to flying a fully rated 772ER.

Why didn't they do this with the 777-300's?

The 773 and 773ERs are completely different with different engines( for SQ) and some major structural differences. Moreover, 773ER wasn't available when SQ got their 773s.

[FN-GM]

Yer sorry about that

What gain do they get by derating them appose to leaving them as standard ER?
Why didn't they do this with the 777-300's?

Thank you