Boeing (767) thrust reversal deferral and EICAS messages
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Boeing (767) thrust reversal deferral and EICAS messages
A question to my fellow aviators regarding the Boeing 767. It might apply to other Boeing types as well, I'm not sure.
In the event of a thrust reverser deferral, several circuit breakers are required to be collared by maintenance in addition to mechanically securing the T/R. This should result in several flight deck indications: a center pedestal "REV ISLN" indicator light illuminated after engine start, a L or R REV ISLN EICAS advisory message, and a L or R REV ISLN Status message.
Now, let's say hypothetically that Maintenance claims to have deferred the T/R on the airplane and complied with their procedure for securing the T/R. However, this status message is not displayed nor is the Center pedestal light or EICAS advisory after engine start. Logically this would lead one to suspect that they had not in fact complied with the procedure to secure the T/R. Maintenance claims that they cleared all these messages in the process of troubleshooting other problems.
What would you do? Refuse the airplane prior to blockout because there is no status message? Return to chocks after engine start because there is no center pedestal light or REV ISLN advisory after engine start? Take them at their word, ignore the Dispatch Deviation Guide (MEL) that states that these messages should be present, and depart as scheduled? Obviously you can check to see that they've collared the circuit breakers, but it is difficult to verify the rest of their tasks.
Thanks.
In the event of a thrust reverser deferral, several circuit breakers are required to be collared by maintenance in addition to mechanically securing the T/R. This should result in several flight deck indications: a center pedestal "REV ISLN" indicator light illuminated after engine start, a L or R REV ISLN EICAS advisory message, and a L or R REV ISLN Status message.
Now, let's say hypothetically that Maintenance claims to have deferred the T/R on the airplane and complied with their procedure for securing the T/R. However, this status message is not displayed nor is the Center pedestal light or EICAS advisory after engine start. Logically this would lead one to suspect that they had not in fact complied with the procedure to secure the T/R. Maintenance claims that they cleared all these messages in the process of troubleshooting other problems.
What would you do? Refuse the airplane prior to blockout because there is no status message? Return to chocks after engine start because there is no center pedestal light or REV ISLN advisory after engine start? Take them at their word, ignore the Dispatch Deviation Guide (MEL) that states that these messages should be present, and depart as scheduled? Obviously you can check to see that they've collared the circuit breakers, but it is difficult to verify the rest of their tasks.
Thanks.
Last edited by RandomPerson8008; 20th Dec 2017 at 21:18.
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Maintenance control are the ones that gave the excuse saying the messages were cleared inadvertently while troubleshooting a separate unrelated problem and can't be brought back. So they're basically telling you to go without the messages.
From our 767 MEL:
“The red deactivation plates are designed as lock out
indicators; they are not lock out retention devices.
Installation of at least one plate is recommended, but not
required.”
So, if on the walk round the red deactivation plates were visible on the engine I’d be happy to go. If they weren’t, I’d investigate further at that point.
“The red deactivation plates are designed as lock out
indicators; they are not lock out retention devices.
Installation of at least one plate is recommended, but not
required.”
So, if on the walk round the red deactivation plates were visible on the engine I’d be happy to go. If they weren’t, I’d investigate further at that point.
Maintenance control are the ones that gave the excuse saying the messages were cleared inadvertently while troubleshooting a separate unrelated problem and can't be brought back. So they're basically telling you to go without the messages.
It sounds like there is a concerning lack of trust towards your Engineers/Maintrol...particularly if you have to resort to this forum for advice!
It sounds like there is a concerning lack of trust towards your Engineers/Maintrol...particularly if you have to resort to this forum for advice!
If 'latched' status messages are cleared, they are cleared. In order for them to re-appear the associated fault needs to occur. For engine related faults that usually means an engine run. Even if the valve is deactivated, the EICAS logic will often inhibit setting the message if the engine is not running. That's part of the reason for having 'latched' messages. (BTW, on a 767 you can override the EICAS engine running logic by setting the fuel switch to RUN and leaving it there for at least 5 minutes but you need to use care when doing that - it can also turn on things like probe heat that can quickly overheat - that's why it's a MM procedure with the associated warnings, not something we tell the pilot about).
Not sure about this, but back in the deep recesses of my memory I'm thinking Boeing got rid of the Isolation valve light as part of the post-Lauda sync lock mod...
Not sure about this, but back in the deep recesses of my memory I'm thinking Boeing got rid of the Isolation valve light as part of the post-Lauda sync lock mod...
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Maintenance control are the ones that gave the excuse saying the messages were cleared inadvertently while troubleshooting a separate unrelated problem and can't be brought back. So they're basically telling you to go without the messages.
It sounds like there is a concerning lack of trust towards your Engineers/Maintrol...particularly if you have to resort to this forum for advice!
It sounds like there is a concerning lack of trust towards your Engineers/Maintrol...particularly if you have to resort to this forum for advice!