Subject:

bearings/seals

Selected material regarding source of air contamination on BAe 146.

1. NJS hansard 1/2/00- p139- " the 502 can leak from the fan area...a No. 9 bearing seal, and that oil can be re-ingested into the core. That is only a very very slight leak, and it is quite evident on the ground if it occurs. You can actually see oil leak into the bypass of the engine. Another area is the No.1 seal. It is inside the compressor  core of the engine  and that is extremely difficult to pinpoint on the ground. It normally shows itself either by a report of the cabin smell or an increase in oil consumption..... There is another area that is even harder. It is the diffuser and that is only visible if you physically do a bore-scope inspection of the engine..... Some of these leaks are quite evident and some of them are not so evident."

p 134- " A major leap forward in the reliability of the engine oil seals  can be identified as a result of the Allied Signal... Honeywell, XRP extended reliability program for the engines......All the bearing oil seals are replaced by new parts rather than being installed after the existing seals have been inspected".

2. C.Van Netten   Air Quality and Health Effects Associated with the Operation of the BAe 146-200 Aircraft"- Appl. Occup. Environ. Hyg 13(10) 1998
" ...the air quality complaints have been traced to leaky oil seals associated with bearings 1 and 9 of the jet engines."

3. BAe submission to Australian Senate-3/9/99-
 Cabin  air quality -“in 1992 reports of cabin odours appeared in Australia and investigation established that small quantities of oil could migrate through the Auxiliary Power Unit (APU) and engine bearing seals into the air conditioning system. ….In response the engine and APU manufacturers have since introduced modifications, which are being embodied worldwide….”
-“British Aerospace has throughout remained  sensitive to its customer needs and concerns, and has in particular worked with the manufacturers of the engines and the APU to produce a package of optional modifications in1992, and more recently working with Ansett to produce a suite of customer enhancements to improve the cabin environment”

4. BAe Hansard- 2/11/99-
p 85 " As recently as 1996-97 we continued to improve the sealing properties of the bearings and seals."

5a. BAe senate submission volume 4
'Chronology of BAe modifications and enhancements introduced since 1990 relevant to cabin air quality issues' see attached: engines, APU & Environmental Control System


5b. Ansett Pilot Union submission , volume 2
'Ansett Inter-office  memorandum, 26 May 1998- BAe 146 Cabin odours'- Brief summary of initiatives introduced by engineering to combat the problem of cabin odours and fumes on the BAe 146 fleet.

6.  CASA Airworthiness Directive 30 March, 2001
 http://www.casa.gov.au/avreg/aircraft/ad/OVER/BAE146/B146-086.htm
AD/BAe146/86  'Environmental Control System  Inspection for Contamination'
....At any time cabin air contamination is suspected to be associated with engine oil, carry out the inspections specified in British Aerospace Inspection Service Bulletin ISB.21-150, Paragraph 2A and 2B and the associated flow chart............
BAe 146/RJ Service Information Leaflet No21-45 and BAe146/RJ Operational Notice OP 16 contain information with respect to required aircrew action in the event of a suspected cabin air contamination event.  Such action includes specific provisions for oxygen usage by the flight crew..........

7.  Mr. Williams-BAe- Senate Hansard 10 April ,2000
 " We all acknowledge....... that the modifications will not solve the problem completely. They are to reduce the number of events, and that is what is important."
“the modifications …are really around the reliability of the seals and making sure that they do not fail as frequently. So they are improvements to reliability, rather than improving the quality of sealing.."
 
refers to BAe ISB 21-150 & SIL 21-45 on source of fumes/ oil contamination & modifications- bearings & seals

 http://www.basi.gov.au/occurs/ob200000176.htm
NJS - Senate Hansard- 10/4/00-p218/219- "for a very short period a bluish haze went down the cabin for about 90 seconds or so... there was no requirement to deploy oxygen masks in the cabin.... The number 2 bearing package, which was the cause of the problem in the engine, they have redesigned a locating pin.

 

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