777/GE90 Emergency AD
Usual disclaimers apply!
Joined: Nov 1999
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From: EGGW
Shades of previous GE90 'rollback' and IFSD from the early days 
Only difference was in those cases it was in cruise and was caused by moisture freezing in the P3B and PS3 lines to the FADEC...........solved by increasing the tubing diameters
Firewalled the T/L's maybe
Only difference was in those cases it was in cruise and was caused by moisture freezing in the P3B and PS3 lines to the FADEC...........solved by increasing the tubing diameters
In both cases, the engine recovered to the proper N1 thrust level as the airplane climbed beyond 400 feet above ground level
Joined: Nov 1999
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From: Mk. 1 desk at present...
R1
Joined: Feb 2006
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From: Somewhere between the Airfield ops and 26L
[quote=Ranger One;2888630]Fun... . Wonder if there have been any problems with noise abatement procedures?
As this rule is implemented by an AD,based on safety, it would take precidence over any local restrictions. I have no doubt that all the operators concerned would have let the airport authorities, also affected, know about the situation. Therefore common sence suggests that a relaxation would be imposed on the 777-200LR and 777-300ER's . However, that is based on the assumtion that the airports also use common sence and logical thought. mmmm.
As this rule is implemented by an AD,based on safety, it would take precidence over any local restrictions. I have no doubt that all the operators concerned would have let the airport authorities, also affected, know about the situation. Therefore common sence suggests that a relaxation would be imposed on the 777-200LR and 777-300ER's . However, that is based on the assumtion that the airports also use common sence and logical thought. mmmm.
Joined: Oct 2006
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From: Ohio
Symptom
I had read and understood that the potential fault is likely only at an hieght of less than 400 feet, therefore during take-off and not in climb mode.
"In both cases, the engine recovered to the proper N1 thrust level as the airplane climbed beyond 400 feet above ground level."
Have I misunderstood the EAD?
"In both cases, the engine recovered to the proper N1 thrust level as the airplane climbed beyond 400 feet above ground level."
Have I misunderstood the EAD?
Joined: Oct 2006
Posts: 22
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From: 34S
To add: TOGA thrust settings are still order of the day on ALL GE90115B equipped aircraft, that being the B773 ER only, until GE comes up with a revised/improved software for the FADEC(so they say).
This anomoly apparently can only, & has only(twice) occurred during derated T.O. thrust settings, which to date have almost always been the case(other than wet weather, adverse effects or just the will to feel what they can do), due the immense thrust these BRT's can deliver!
Apparently at TOGA setting, the calculation matrix of the selected de-rated thrust desired, in the FADEC, is by-passed, preventing this from occurring again until a proven SW replacement is issued.
As far as noise abatement goes... I marvel daily, at the incredible "silent power" these machines deliver @ full rated thrust!
There is still no noise, other than the vibration of the nearby earth.
All one can hear is the N1 spin up then it all goes quiet as the monster launches itself like a short sectored B767 -200 PW4060.
Very Impressive, to put it mildly!
Although, I dont want to comment on what it is doing for the life of these engines???
I think GE are going to cough big time, if a fix does not appear SOON.
This anomoly apparently can only, & has only(twice) occurred during derated T.O. thrust settings, which to date have almost always been the case(other than wet weather, adverse effects or just the will to feel what they can do), due the immense thrust these BRT's can deliver!
Apparently at TOGA setting, the calculation matrix of the selected de-rated thrust desired, in the FADEC, is by-passed, preventing this from occurring again until a proven SW replacement is issued.
As far as noise abatement goes... I marvel daily, at the incredible "silent power" these machines deliver @ full rated thrust!
There is still no noise, other than the vibration of the nearby earth.
All one can hear is the N1 spin up then it all goes quiet as the monster launches itself like a short sectored B767 -200 PW4060.
Very Impressive, to put it mildly!
Although, I dont want to comment on what it is doing for the life of these engines???
I think GE are going to cough big time, if a fix does not appear SOON.
Joined: Jun 2003
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From: Hong Kong
......
Joined: Oct 2006
Posts: 22
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From: 34S
UPDATE: All may be pleased to hear, or re-assured now that the latest arrivals to EK's B773ER fleet EBU & EBV,(yes that's 22) have the new version of software loaded in the fadec for reduced thrust take off calculation, & mandatory TOGA take offs are no longer required.
Joined: Jul 2000
Posts: 1,598
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From: Down south, USA.
That is an excellent discovery.
Another topic here, but an entirely different sort of 4-engine rollback, and known about for many years, caused by a synchrophaser malfunction cost the lives of almost an entire C-130 crew in the 90s.
The call-sign was King 56, and they had departed Portland, OR.
Read up on what John Nance and others said about many amateurish, botched Air Force safety investigations.
What a senseless tragedy that the Air Force could have modified the systems many years ago. Never mind the need to retrofit standby ADIs.
"4-engine rollback": "wweek.com".
Another topic here, but an entirely different sort of 4-engine rollback, and known about for many years, caused by a synchrophaser malfunction cost the lives of almost an entire C-130 crew in the 90s.
The call-sign was King 56, and they had departed Portland, OR.
Read up on what John Nance and others said about many amateurish, botched Air Force safety investigations.
What a senseless tragedy that the Air Force could have modified the systems many years ago. Never mind the need to retrofit standby ADIs.
"4-engine rollback": "wweek.com".
Joined: Oct 2006
Posts: 22
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From: 34S
As an average passenger, one wouldnt know any difference, other than exceptional acceleration & a mean initial climb rate on short to medium sectors.
As mentioned before, these engines before the rollback incident were almost always taking off at reduced take off thrust levels, for fuel saving & engine life purposes! One just doesnt need the power which is on tap, for NORMAL everyday operations.
To date, my experience with the new GE115B(that is 115000 lbs of capable thrust, by the way) has been very good & reliable unlike the teething problems encountered with the 94B!
Couple of regular service bleed problems & naturally engine cowling; opening & closing problems, simply due to its shear size, weight & 14 cowl latches; but no engine problems, besides this Fadec software issue.
I believe Etihad report having had 2 engines with vibration problems, requiring removal?
If so please share the knowledge .
As mentioned before, these engines before the rollback incident were almost always taking off at reduced take off thrust levels, for fuel saving & engine life purposes! One just doesnt need the power which is on tap, for NORMAL everyday operations.
To date, my experience with the new GE115B(that is 115000 lbs of capable thrust, by the way) has been very good & reliable unlike the teething problems encountered with the 94B!
Couple of regular service bleed problems & naturally engine cowling; opening & closing problems, simply due to its shear size, weight & 14 cowl latches; but no engine problems, besides this Fadec software issue.
I believe Etihad report having had 2 engines with vibration problems, requiring removal?
If so please share the knowledge
.
