# Proposed AD FAA-2004-19761: Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2005-07-15
- Products: Bombardier
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: December 7, 2004, 69 FR 70566
- Comments due: January 6, 2005
- Became: [AD 2005-07-15](https://openairdocs.org/ad/2005-07-15)
- Docket: FAA-2004-19761 (https://www.regulations.gov/docket/FAA-2004-19761, where comments are filed)
- Project: 2003-NM-167-AD
- FR document: 04-26798
- Official PDF: https://openairdocs.org/files/sha256/7d/a7/7da7e1e413a4928759a0a859fa544b14aff7d25a08baaae81f4fc96f4cbdc445 (from https://www.govinfo.gov/content/pkg/FR-2004-12-07/pdf/04-26798.pdf)
- Federal Register: https://www.federalregister.gov/documents/2004/12/07/04-26798/airworthiness-directives-bombardier-model-cl-600-2b19-regional-jet-series-100-and-440-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E103DC30DCC9340286256F63005BA8CA.0001
- Page: https://openairdocs.org/proposed/FAA-2004-19761

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 and 440) airplanes. This proposed AD would require modification of the Auxiliary Power Unit (APU) cooling air exhaust. This proposed AD is prompted by reports of incomplete drainage of the APU enclosure. We are proposing this AD to prevent a negative pressure condition from developing in the APU enclosure when the APU is operating on the ground, which could create a potential fire hazard if flammable liquid leakage occurs inside the APU enclosure and cannot be drained overboard.

## Notices in this docket

- Dec 7, 2004: Notice of proposed rulemaking (NPRM). (first notice), FR document 04-26798, comments due Jan 6, 2005 (https://www.federalregister.gov/documents/2004/12/07/04-26798/airworthiness-directives-bombardier-model-cl-600-2b19-regional-jet-series-100-and-440-airplanes)

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.