Warnings, Cautions, and Notes

- James Albright (a former G450 driver)

Updated: 2016-10-04

You may know someone who says you can dispatch with a blue CAS, in fact some training vendors will tell you that. But we know this isn't true. What about:

• AGM 1 FAIL?

• Engine ALT Control?

• Engine Maintenance LTD?

• FMS 1-2-3 Fail?

• Hydraulic Temp Sen Fail?

• Mach Trim Fail?

• NRC 2 Fail?

And there are others. The reason for this nonsense is the AFM used to preach it. But that has changed. Now we just have to get the word out.

Everything here is from the references shown below, with a few comments in an alternate color.

 Warnings, Cautions & Notes

Let's trace the problem from a while back to today . . .

[G450 AFM, §01-45-50]

• [1 June 2006] Amber CAS messages are DO NOT DISPATCH messages. Blue CAS maintenance messages allow dispatch as the systems that generate these messages are fault tolerant. Dispatch with an active amber or blue message shall be with reference to the MEL.

  I don't think that was true back then, so we pushed for change . . .

• [5 December 2013] Amber CAS messages are considered DO NOT DISPATCH messages. Blue CAS maintenance messages may allow for dispatch as the systems that generate those messages are fault tolerant. Dispatching with an active amber or blue message shall be referenced to the MEL.

  This is a move in the right direction.

• [22 July 2016] The Crew Advisory System (CAS) messages are color-coded to provide different priority levels: red (Warning), amber (Caution), and blue (Advisory). Advisory messages are further classified into 'Status', 'Information', and 'Maintenance' messages. For airplane dispatch capability, refer to the MEL and MMEL Policy Letters PL-25, PL-34 and PL-36.

  You should also look at the particular message in the QRH where you are often given pretty specific instructions regarding dispatch.

 Red, Amber, and Blue

[G450 AOM, §2A-31-70 ¶1] If a CAS threshold is exceeded, the MWS prompts the display of the appropriate text message on the cockpit Display Unit (DU) configured for CAS messages. The messages are displayed in red, amber or blue text appropriate to the urgency of the malfunction and arranged chronologically with the most recent message at the top of the category.

• Red text for warnings indicating a condition that may result in injury or loss of life

• Amber text for cautions indicating a condition that result in damage to or loss of equipment

• Blue text for advisories indicating a condition degraded from normal operational specifications

References:

FAA MMEL Policy Letter 25, MMEL and MEL Definitions

FAA MMEL Policy Letter 34, MMEL and MEL Preamble

FAA Policy Letter 36, FAR Part 91 MEL Approval & Preamble

Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.

Gulfstream G450 Airplane Flight Manual, Revision 24, September 18, 2009

Gulfstream G450 Airplane Flight Manual, Revision 36, December 5, 2013

Gulfstream G450 Airplane Flight Manual, Revision 41, July 22, 2016