AD tout Turbofan confondus

FAA proposes $20 million fan spinner directive
By John Croft

The US FAA is proposing that operators of 1,600 Rolls-Royce AE3007-powered aircraft replace the fan spinners on the turbofan engines at a total cost of approximately $21 million across the fleet.

The proposed airworthiness directive (AD), to be published tomorrow, resulted from an incident in which the fan spinner released from an AE3007A turbofan engine in flight. The crew shut down the engine after noticing "noise and vibration" and performed an uneventful landing, says the FAA. The regulator did not provide details on the operator or when the event occurred.

Investigators determined that the left engine's fan spinner popped off, causing damage to the engine's fan blades. Debris from the spinner penetrated the forward engine cowl in three locations and cut through the aircraft outer skin in two locations.

At the time of the incident, the left engine had accumulated 11,682 operating hours and 8,535 cycles since new, indicating that the operator was likely an airline. The AE3007 engine is used on the Embraer ERJ regional jet line, including the ERJ145, as well as the Cessna Citation business jet.

During spin pit testing in the aftermath of the incident, Rolls-Royce found a high stress concentration in a bolt arrangement holding the spinner to the engine, a condition the FAA says could "potentially develop" into low-cycle fatigue cracks, adding, "This condition, if not corrected, could result in the fan spinner releasing, which could result in injury, damage to the engine and damage to the airplane".

The proposed fix, a replacement spinner, is expected to cost $12,943 per engine. That amount includes all the hardware but not the expected 1h labour cost to perform the change. Fleet wide, the cost would be nearly $21 million, according to FAA estimates. Operators would be required to install the new hardware at the next shop visit or within 1,500 additional cycles of the final issue date of the AD.

Jun 24, 2009 (FIND, Inc. via COMTEX) -- GE | Quote | Chart | News | PowerRating -- SUMMARY:
The FAA proposes to adopt a new airworthiness directive (AD) for General Electric Company (GE) GE90-110B1, GE90-113B, and GE90-115B series turbofan engines with stage 6 low-pressure turbine (LPT) blades, part number (P/N) 1765M37P03 or P/N 1765M37P04, installed. This proposed AD would require initial and repetitive inspections for shroud interlock wear of the stage 6 LPT blades. This proposed AD would also require replacing those blades with stage 6 LPT blades eligible for installation at the next engine shop visit as terminating action to the repetitive blade inspections. This proposed AD results from eight reports of GE90-115B stage 6 LPT single-blade separation events. We are proposing this AD to prevent failure of stage 6 LPT blades, which could result in uncontained engine failure and damage to the airplane.
EFFECTIVE DATE: We must receive any comments on this proposed AD by August 24, 2009.

Discussion

Since December of 2007, GE reported eight instances of stage 6 LPT single- blade failures in some GE90 series engines. GE's investigation indicated that excessive wear at the shroud interlock of stage 6 LPT blades, P/N 1765M37P03 or P/N 1765M37P04, caused the failures. The interlock surface wears during operation which results in a loss of axial preload (contact between two surfaces) between two adjacent stage 6 LPT blades. This wear leads to increased tip deflection and blade stress. This condition, if not corrected, could result in failure of stage 6 LPT blades, which could result in uncontained engine failure and damage to the airplane.

Relevant Service Information

We have reviewed and approved the technical contents of GE Service Bulletin No. GE90-100 SB 72-0260, Revision 6, dated May 1, 2009. That SB describes procedures for inspecting stage 6 LPT blades, P/N 1765M37P03, and P/N 1765M37P04, for shroud interlock wear.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require initial and repetitive inspections for shroud interlock wear of stage 6 LPT blades, P/N 1765M37P03 and P/N 1765M37P04. This proposed AD would also require replacing those blades with stage 6 LPT blades eligible for installation, at the next engine shop visit, as terminating action to the repetitive blade inspections. The proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

We estimate that this proposed AD would affect four GE GE90 series engines installed on airplanes of U.S. registry. We also estimate that it would take about 18 work-hours per engine to perform one inspection of the stage 6 LPT blades, and that the average labor rate is $80 per work-hour. Replacement stage 6 LPT blades would cost $258,280 per engine. We estimate that no additional labor costs would be incurred to perform the required blade replacements, because the replacements would be done at the time of the engine shop visit. Based on these figures, we estimate the total cost of the proposed AD for one inspection to U.S. operators to be $1,038,880.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that the proposed AD:

1. Is not a "significant regulatory action" under Executive Order 12866;

2. Is not a "significant rule" under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. You may get a copy of this summary at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

The Proposed Amendment

Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

[Section] 39.13 [Amended]

2. The FAA amends [Section] 39.13 by adding the following new airworthiness directive:

General Electric Company: Docket No. FAA-2009-0143; Directorate Identifier 2009-NE-05-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by August 24, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to General Electric Company (GE) GE90-110B1, GE90-113B, and GE90-115B series turbofan engines with stage 6 low-pressure turbine (LPT) blades, part number (P/N) 1765M37P03 or P/N 1765M37P04, installed. These engines are installed on, but not limited to, Boeing 777-200LR, 777-300ER, and 777 Freighter series airplanes.

[Page Number 30022]

Unsafe Condition

(d) This AD results from eight reports of GE90-115B stage 6 LPT single- blade separation events. We are issuing this AD to prevent failure of stage 6 LPT blades, which could result in uncontained engine failure and damage to the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

Inspections

(f) Before accumulating 3,000 engine operating hours time-since-new, or 400 engine cycles-since-new, whichever occurs first, inspect the stage 6 LPT blades, P/N 1765M37P03 or P/N 1765M37P04 for shroud interlock wear. Thereafter, reinspect within every 1,000 engine operating hours, or within 125 engine cycles-since-last inspection, whichever occurs first. Use paragraphs 3.A. through 3.A.(3)(g)(12) of the Accomplishment Instructions of GE Service Bulletin (SB) No. GE90-100 SB 72-0260, Revision 6, dated May 1, 2009, to do the inspections.

Terminating Action

(g) At the next engine shop visit, replace stage 6 LPT blades, P/N 1765M37P03 or P/N 1765M37P04, with stage 6 LPT blades eligible for installation as terminating action to the repetitive inspections required by this AD.

Installation Prohibition of Affected Stage 6 LPT Blades

(h) After the effective date of this AD, do not install any stage 6 LPT blades, P/N 1765M37P03 or P/N 1765M37P04, onto any engine.

Previous Credit

(i) An inspection performed before the effective date of this AD using GE SB No. GE90-100 SB 72-0260, Revision 4, dated October 8, 2008, or Revision 5, dated November 7, 2008, satisfies the initial inspection requirement of this AD.

Definition

(j) For the purpose of this AD, an engine shop visit is induction of the engine into the shop for any cause.

Alternative Methods of Compliance

(k) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(l) Contact Barbara Caufield, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: barbara.caufield@faa.gov; telephone (781) 238- 7146; fax (781) 238-7199, for more information about this AD.

(m) Guidance on stage 6 LPT blades that are eligible for installation can be found in GE Service Bulletin No. 72-0279, Revision 1, dated December 11, 2008, and GE Service Bulletin No. 72-0313, dated March 18, 2009.

(n) Contact General Electric Company via GE--Aviation, Attn: Distributions, 111 Merchant St., Room 230, Cincinnati, Ohio 45246; telephone (513) 552-3272; fax (513) 552-3329, for a copy of the service information identified in this AD.

Issued in Burlington, Massachusetts, on June 17, 2009.

Carlos Pestana,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

[FR Doc. E9-14807 Filed 6-23-09; 8:45 am]

Admin a écrit:Rebonjour,

http://www.flightglobal.com/articles/2009/06/23/328732/faa-proposes-20-million-fan-spinner-directive.html

1 heure de main d'oeuvre pour changer ce couvre chef.

Dommages collatéraux assez significatif effectivement en cas de rupture.

Depuis l'AD doît être parue

Bonne journée à tous.

EASA alerts A320 operators of CFM56 anomaly
By John Croft

EASA today issued a safety information bulletin alerting operators of CFM56-5A turbofan engines of an unexplained anomaly that on 30 June caused an aircraft on departure to return to the airport.

CFM says there are more than 1,100 of the engines in service, built specifically for the A320 series aircraft, with a cumulative total of 32 million flight hours and dispatch reliability of more than 99.9%.

According to the EASA report, the engine in question during takeoff experienced a stall and in-flight shutdown with an accompanying exhaust gas temperature (EGT) over limit and high vibrations.

Mechancis conducting a borescope inspection after the incident found that the engine's low-pressure turbine (LPT) section had been damaged, with several blades broken off. The engine had accumulated 39,808h and 30,980 cycles since new but only 21h and 15 cycles since its last shop visit.

EASA did not report which airline or maintenance shop was involved.

Upon disassembly, a preliminary examination of the LPT and high-pressure turbine (HPT) revealed overheating, suggesting a "cooling deficiency by hot gas ingestion into the turbine rotor air cooling system", says EASA. "The cause of this overheat condition has not yet been identified."

The disk, identified as the LPT stage 1 disk, had fractured with "one full radial separation", says EASA. "The disk remained in one piece, expanded but fully contained."

EASA, FAA and CFM continue to investigate the maintenance shop that performed the most recent work, and the airline involved. "This investigation will determine whether any recommendations or mandatory actions are necessary."

CFM could not be immediately reached for comment.

Trent icing modification likely to extend to Airbus fleet
By David Kaminski-Morrow

Airbus A330s and A340s fitted with Rolls-Royce Trent engines appear likely to require the same anti-icing modifications to fuel-oil heat exchangers already demanded on Trent 800-powered Boeing 777s.

Ice build-up on Trent 800 heat exchangers is suspected in two engine roll-back events on 777s, including last year's British Airways crash at London Heathrow. The modification to the exchanger's front face - mandated by the European Aviation Safety Agency - is designed to prevent this ice congestion.

But in a submission to the US FAA, Airbus has revealed that the modification is likely to extend to Trent 700s, an option on A330s, and Trent 500s which are the sole powerplant on the A340-500/600.

It follows an incident involving an Etihad Airways A330-200 which performed a go-around at Manchester on 19 May this year.

Both Trent 700 engines initially responded correctly but, as the aircraft climbed away, the left-hand powerplant "stagnated" before recovering after being throttled back, says the Airbus document.

Airbus states that investigations point to fuel-flow restriction as the "probable cause of the roll-back". While there were differences in the Trent 700's response, compared with the earlier Trent 800 events, restriction from icing "cannot be ruled out".

"Given the ongoing investigation into this phenomenon, Airbus has taken a precautionary approach by adding [the Etihad event] to the numerical risk analysis," says the airframer.

European Aviation Safety Agency regulators mandated the Trent 800 change through an airworthiness directive on 13 July.

But Airbus says: "It is intended to issue a similar [airworthiness directive] on Airbus aircraft applicable for the Trent 500 and the Trent 700 engines."

It is seeking approval from the FAA to install modified heat exchangers on Trent 700- and Trent 500-powered aircraft. The airframer has requested a two-year window, starting in October, in order to allow certification of the improved heat-exchanger face at aircraft level.

"Even if the scale of the threat has still to be defined, the enhanced [exchanger] has more capability to sustain ice release from the aircraft fuel system and its introduction is a good precautionary measure," adds Airbus.

art_way a écrit:Salut Poncho !!!

Merci, Oui je viens de voir ça.

Cela prouve que ce n'est pas que le couple Moteur/Airframe mais bien la conception du moteur qui est en cause.

art_way a écrit:Non pas faux, loin de là. Même Airbus prend les devants.

art_way a écrit:Le moteur RR est plus sensible et ne réchauffe pas aussi bien que les GE ou le PW.

art_way a écrit:Ce n'est pas grave, ils vont régler le problème chez RR, ce sont des professionnels et ils ne trahissent pas leurs clients.

art_way a écrit:Et même si le problème est global (airframes + Moteur RR), le problème est plus facilement réglé au niveau du moteur qu'ailleurs.

art_way a écrit:De plus, pourquoi devrais-je lire sous d'autres cieux ce qui est dit ici ?

art_way a écrit:Avez-vous un blog à me suggérer ?

Bonne journée.

sevrien a écrit:Bonsoir. Mieux vaudrait lire et comprendre le dernier rapport d'étape de l'AAIB.

sevrien a écrit: Erreur d'interprétation. Mieux vaut connaître d'abord le dossier.

sevrien a écrit: Vous faites fausse route ! Lire le rapport d'étape précité.
Votre remarque met en relief un manque de connaissances & de compréhension. Il y a du boulot à faire !

sevrien a écrit:
Vous n'avez pas vu que le problème est réglé? C'est le rétrofit qui est
en cours, et qui a besoin d'un délai, déjà indiqué.
Ce sont les Airframers qui doivent "produire", maintenant, pour l'avenir ! Et tout
le monde reconnaît que cela va être plus long !

sevrien a écrit: Vous ne comprenez toujours pas que la modification du FOHE (face frontale) du RR Trent 895 n'est que ;
-- une mesure conservatoire (et non pas un rémède apporté à la "root cause"), ....
-- facilement adaptable aux autres RR Trent, notamment aux Trent 700 & 500, ....
--
et une mesure dont la réussite déjà prouvée et établie offre l'avantage
de pouvoir remplacer le design du FOHE actuel, pour aider à
rationaliser la gestion des pièces et des opérations de production et
d'entretien pour des milliers de moteurs, sur des centaines d'airframes
(même > 1,000 airframes), .......
-- sans le poids & la
complexité des mètres de tuyauteries nécessaires dans les moteurs GE et
P&W rivaux, qui ont eu à apporter d'autres "fixes", pour
neutraliser des défauts de "design" par ailleurs.

Aussi,
indépendamment de l'accident à "haut profil" du vol BA 038, une
différence fondamentale est que RR et les acteurs britanniques
déclarent leurs incidents promptement et en toute transparence,
contrairement à certains acteurs américains (pas tous, bien sûr ! ).

La CAA n'a jamais été pris en flagrant délit de laxisme et de connivence,
comme la FAA, toujours sous surveillance rapprochée du NTSB ! Certains
des Forumistes feraient mieux de mettre à jour leurs références !
Pour le moment, la FAA n'en est pas une, malgré les changements apportés à
son équipe dirigeante, à son organisation, et à sa façon de conduire
ses opérations et ses relations avec l'industrie du Transport aérien
(même le Président G.W. BUSH s'en était mêlé ; c'est dire .... )!
Quel manque de crédibilité chez la FAA (je n'ai pas dit le NTSB
) ! L'AD de la FAA au sujet des RR Trent a été rendu caduc par RR
lui-même, la CAA et l'EASA (le rapport de l'AAIB étant en harmonie avec
les actions menées par des derniers) , avant qu'il n'ait pu être
appliqué, et même par les Cies. aériennes, surtout par celles qui ont
des B777-200 dans leur flotte, dont certains sont à moteurs GE &
d'autres à moteurs RR.

sevrien a écrit: Par exemple, pour pouvoir apprendre et comprendre les faits qui précèdent.

sevrien a écrit:Vous
savez que je ne lis presque jamais les Blog. Surtout pour ces sujets.
J'ai mes travaux, sources et contacts là où il faut. Pour un paquet
d'autres sujets, aussi. ¨

sevrien a écrit:Enfin,
à ce que l'on constate, les faits restent toujours plus utiles que les
idées reçues, et affirmations infondées, non étayées et non étayables !

Vector a écrit:Bonjour Art_Way,
Juste deux remarques :
1) A quoi sert de débattre si on est d'accord ?
2) Un minimum de respect des opinions de l'autre facilite bien le débat
Pour les ailes, je n'ai pas eu le temps de répondre à Yan car je suis bien occupé, mais je le ferai la semaine prochaine.
Je te souhaite un excellent week-end

SUMMARY: The FAA is superseding an existing airworthiness directive (AD) for Rolls-Royce plc RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent 895-17 turbofan engines with high-pressure (HP) compressor rotor rear stage 5 and 6 discs and cone shafts,
part numbers (P/Ns) FK25230 and FK27899 installed. That AD currently requires removal from service of these HP compressor rotor rear stage 5 and 6 discs and cone shafts before reaching newly reduced life limits. This AD requires removing these parts at new reduced cycle limits. This AD
results from Rolls-Royce plc reducing the lives of these parts and changing the life calculating method to use ''Standard Duty Cycles'' with ''Multiple Flight Profile Monitoring'' and ''Flight Cycles'' with ''Heavy Flight Profile Monitoring''. We are issuing this AD to prevent stage 5 and 6 disc crack
initiation and propagation that might lead to uncontained disc failure and damage to the airplane.
DATES: This AD becomes effective November 20, 2009.