January 20, 2012
The European Aviation Safety Agency (EASA) issued an Airworthiness Directive (AD), ordering inspection of certain Airbus A380 aircraft for the possible presence of cracks in the wing rib feet.
The AD states:
Following an unscheduled internal inspection of an A380 wing, some rib feet have been found with cracks originating from the rib to skin panel attachment holes (Type 1 cracks according to Airbus All Operator Telex (AOT) terminology).
Further to this finding, inspections were carried out on a number of other aeroplanes where further cracks have been found. During one of those inspections, a new form of rib foot cracking originating from the forward and aft edges of the vertical web of the rib feet has been identified (Type 2 cracks according to Airbus AOT terminology). The new form of cracking is more significant than the original rib foot hole cracking. It has been determined that the Type 2 cracks may develop on other aeroplanes after a period of time in service.
This condition, if not detected and corrected, could potentially affect the structural integrity of the aeroplane.
For the reasons described above, this AD requires a Detailed Visual Inspection (DVI) of certain wing rib feet. This AD also requires reporting the inspection results to Airbus.
This AD is considered to be an interim action to immediately address this condition. As a result of the on-going investigation, further mandatory actions might be considered.
The cracks were discovered by Airbus engineers while performing repair work to a Qantas A380 that had suffered an uncontained engine failure near Singapore’s Changi Airport. Singapore Airlines also discovered some cracks in on the L-shaped feet of the wing ribs. The feet attach the rib, a vertical fixture, to the cover of the wing.
On January 9th a spokesman for the Australian Licensed Aircraft Engineers Association demanded that all A380 aircraft should be grounded for inspections. Airbus reported that all planes were safe to fly and that the cracks did not pose a safety threat.
June 30, 2011
The European Aviation Safety Authority (EASA) issued an emergency Airworthiness Directive (AD) effecting specific Airbus A330 and A340-200/-300 aeroplanes. EASA requires reduction of the existing main landing gear (MLG) bogie beam life limits and replacement of each MLG bogie beam that has already exceeded the new limit.
During ground load test cycles on an A340-600 aeroplane, the MLG bogie beam prematurely fractured.
The results of the investigation identified that this premature fracture was due to high tensile standing stress, resulting from dry fit axle assembly method.
Improvement has been introduced subsequently with a grease fit axle assembly method.
Analysis was performed on other bogie beam with dry fit axles. It has been determined that MLG bogie beams with specific part numbers are more likely to suffer from standing stress generated by dry-fit axles because these bogie beams are stiffer between the axle sockets. These two part numbers are fitted on A330, A340-200 and -300 series aircraft.
Fracture of a MLG bogie beam under high speed could ultimately result in the aeroplane departing the runway, or in the bogie detaching from the aeroplane, or MLG collapse, which could cause structural damage to the aeroplane and injury to the occupants.
June 17, 2011
A Dassault-owned Falcon 7X arrives at Rotterdam Airport (EHRD) on the day following the lifting of the ban (Photo: Harro Ranter, 17 June 2011)
On May 26, 2011 all flights involving Dassault Falcon 7X jets were prohibited following the EASA’s issuance of emergency AD 2011-0102-E. This suspension is now lifted for certain aircraft as of June 16, 2011.
The suspension of flight operations was considered to be an interim measure pending the outcome of an investigation into a serious incident involving an uncontrolled pitch trim runaway during descent.
The initial results of the investigations are showing that there was a production defect in the Horizontal Stabilizer Electronic Control Unit (HSECU) which could have contributed to the cause of the event. One specific HSECU is potentially affected by this production defect. Investigations are continuing to confirm this cause.
In the meantime, to allow re-starting flight operations and providing protection against further pitch trim runaway events, Dassault Aviation have developed two modifications which are implemented through accomplishment of Dassault Service Bulletin (SB) F7X-211. In addition, it has determined that the flight envelope must be restricted, compared to the original certified flight envelope.
For aeroplanes equipped with HSECU P/N 051244-02, this AD, which supersedes EASA AD 2011-0102-E, requires:
- accomplishment of two Dassault Aviation modifications,
- amending the AFM and installing a placard in the cockpit,
- amending the Minimum Equipment List (MEL), and
- implementing an operational test of the HSTA electric motors reversion relays.
For aeroplanes equipped with HSECU P/N 051244-04, the prohibition of flights is maintained.
Download PDF: EASA EAD 2011-0114-E
May 26, 2011
A Falcon 7X jet (photo: Jerome K. /CC: by-nc-nd)
The European Aviation Safety Agency (EASA) issued an Emergency Airworthiness Directive (AD), prohibiting flight operations of Dassault Falcon 7X jets.
The AD is considered to be an interim measure pending the outcome of an investigation into a serious incident currently carried out by the manufacturer. Further AD action is expected to follow when additional information is available.
The incident involved a Falcon 7X which experienced an uncontrolled pitch trim runaway during descent. The crew succeeded in recovering a stable situation and performed an uneventful landing. Analysis of the Digital Flight Data Recorder (DFDR) and Fault History Database (FHDB) confirmed the event, but did not allow explaining the origin of the pitch trim runaway.
This condition, if occurring again, could lead to loss of control of the aeroplane. To address this potential unsafe condition, Dassault Aviation has proposed to EASA to prohibit, from the effective date of this AD, any flight operations of Falcon 7X aeroplanes, to which EASA agreed by issuing this AD.
April 5, 2011
The U.S. FAA issues an emergency directive that will require operators of specific early Boeing 737 models to conduct initial and repetitive electromagnetic inspections for fatigue damage. This action will initially apply to a total of approximately 175 aircraft worldwide, 80 of which are U.S.-registered aircraft. Most of the aircraft in the U.S. are operated by Southwest Airlines.
The FAA airworthiness directive will require initial inspections using electromagnetic, or eddy-current, technology in specific areas of the aircraft fuselage on certain Boeing 737 aircraft in the -300, -400 and -500 series that have accumulated more than 30,000 flight cycles. It will then require repetitive inspections at regular intervals.
In November 2010, the FAA published a rule designed specifically to address widespread fatigue damage in aging aircraft. The rule requires aircraft manufacturers to establish a number of flight cycles or hours a plane can operate and be free from fatigue damage. The rule requires aircraft manufacturers to incorporate the limits into their maintenance programs.
November 22, 2010
The European Aviation Safety Agency (EASA) issued a new emergency airworthiness directive (2010-0242-E) for Rolls Royce RB211 Trent 900 series engines following a recent incident involving such an engine on a Qantas A380. This AD supersedes a previous emergency AD ( 2010-0236-E) that was issued on Novemer 10, 2010.
Since issuance of AD 2010-0236-E, the incident investigation has progressed and inspection data from in-service engines has been gathered and analysed.
The results of this analysis show the need to amend the inspection procedure, retaining the inspection of the air buffer cavity and focusing on the oil servicetubes within the HP/IP structure.
This AD partially retains the requirements of AD 2010-0236-E, which is superseded, and requires implementation of the amended procedure and accomplishment of the associated inspections.
October 19, 2010
Transport Canada issued an emergency airworthiness directive (EAD CF-2010-36) for several models of the Canadair / Bombardier RegionalJet following main landing gear extension problems.
Transport Canada reports two cases of main landing gear (MLG) failure to fully extend on CRJ aircraft. Preliminary investigation has shown that interference between the MLG door and the MLG fairing seal prevented the MLG door from opening. This directive mandates the inspection and rectification, as required, of the MLG fairing and seal, MLG door, and adjacent structures.
Affected are the following models:
- CL-600-2C10 (CRJ-700 series), serial numbers 10003 and subsequent
- CL-600-2D15 (CRJ-705 series)
- CL-600-2D24 (CRJ-900 series), serial number 15001 and subsequent
The AD does not specify the two occurrences, but one of those was probably an incident that occurred on September 25, 2010 involving an Atlantic Southeast Airlines CRJ-900. The airplane landed on at New York-JFK with the right MLG fully retracted.