CF6-80 Thrust reverser deactivation

[muduckace]

Bus429 said it best, no point questioning the functionality of it. If a component that effects airworthiness is removed from the aircraft and it is not covered by the MEL or CDL it is not legal to operate.

Defering the reverser is defering a whole reverser.

[Tinwacker]

Letter

ASFKAP,

You will never ever receive that letter

Maybe not all airlines but mine will produce that letter to cover a deviation from the AMM.

After consultation with Tech Services dept., QA and manufacturer if necessary a letter would be produced that contains itemed instructions for the engineer to adhere to for despatch.
Serialised, time limited and named with a copy to be kept within the tech log for the crews reference.

This has deviated from the original post, so I apologise but going back to the reverser I would have a look in the AMM 71 for any possible relief, cable removal was previously included and screw jacks for some engine types. Finally T/R locked out IAW MEL.

Repeating the comment of GE not allowing two bolts on the lock out plates, there are only two bolts fitted per plate.
I asked GE if one bolt out of the four plates could be ommitted as one anchor nut was damaged and I again had a curt NO....

Lloyd, PM me and I will give you details of T/R lockout procedures and where to look...

And happy New Year from TW

[NWT]

Have to dissagree with that statement. Our MEL clearly says only one lock out plate on each half needs to be fitted.

[kingstonboy]

NWT,
i think clarification required ref lock out plates ie CDU lockout or translating sleeve lock plates in which i believe you are correct.For the record i have locked out T/R with one of CDU lock out bolt location helicoils damaged.Along with associated HP valve and relevant CB`s

[muduckace]

ASFKAP

When someone asks you to do anything that isn't covered by the MEL (or AMM) ask them to fax you a letter signed by the chief engineer and QA manager authorising you to deviate from the approved procedure with step by step instructions detailing exactly what they want you to do......

Yeah, I was going to make the same statement, just my experience especially with our current operator would never recieve this kind of relief. Loved your statement about "step by step instructions". I have refused to go with an E.A. as engineers constantly write them vague leaving ambiguous interpretation of the authority EG: refer back to an AMM that conflicts with the true condition. They have to conform as well to process standards but try to leave the liability on myself, no way my friend..

[Tinwacker]

Lock-out

NWT,

Maybe it's time for me to go back to GE as they have softened.
I was always happy with the idea of a single bolt if situation required as it's still locking the sleeve to the engine frame.

These engines have always been a problem with damaged or hard to access anchor nuts for the locking bolts.

Just our MEL didn't allow - sounds like a useful amendment coming....

Cheers TW

[Perrin]

backup

Yes its so easy writing about it here, try getting help from "the company" at 0400 in the p***ing rain on the ramp.
Keep them up boys.
Peter

[Tinwacker]

Back-up

Perrin,

Still not a problem as I do get full response - Company is in Sunshine land while I'm singing in the rain...
Response is easier during the early hours while the other side of the world is wide awake.

Dam it's wet here,
I must just be lucky...

TW

[Long Bay Mauler]

I would have to agree with Bolty,as that is the procedure for stepping away from the AMM and MEL books in our company.I also think that it would be possible to dispatch the T/Rev locked out with at least one jackscrew missing,even if it was decreed that a "dummy" rod of that length was manufactured and installed for a one off flight or set period.

If you need to configure the aircraft legally in any other way as to what is directed in the AMM or MEL book,you need the services of a professional degree educated engineer to give you the authority to do what is required.

I think that the more people you involve in the process of configuring the aircraft in a particular way and they have their licence/approval number there,that ultimately if its dodgy,then no one will want to put their name to it.

I know it doesnt always happen in the real world,but even having ashtrays missing from around the aircraft really should be added to the technical log defered items with an approval from technical services,as having them missing is a deviation from the aircrafts legal configuration.

To the original poster of this thread,I would say to you to follow what is your company's/national authority's regulations,and that if you dont feel entirely happy with what is being asked of you,then ask your boss to certify for the work.If he/she wont,then that should tell you that there is something wrong with whats wanted.You may get the sack,but surely thats a lot easier to live with than the lives of dead passengers on your conscience.

[Bus429]

Here in EASA land, it's the Part 21 DOA, TC/STC holder (which are Part 21 in EU; US, Can and Bra orgs accepted under bi-lateral) that make the determination often with further approval from the Competent Authority or EASA. Flight outside the MEL? Should that happen?
Fact remains that you cannot generally deviate from approved data. (Having said that, Part 145 does have provision for that under certain circumstances but not those we are discussing here).
You cannot unilaterally alter the aircraft's configuration; the whole basis of approved maintenance is to keep the aircraft at its TC/STC status. I know of an operator that has had its hand smacked for taking units out of aircraft for maintenance and flying with holes in panels and other tricks of that sort.

[cwolfe]

CF6-80 CDU

Hi everyone,

-I know this is going to be a side topic to this discussion, but does the CDU actuator provide the power to move the T/R or is the CDU actuator only used to indicate to the pilot the relevant position i.e. (STOW/DEPLOY POSITION or IN TRANSIT).

I'm curious; if the CDU actuator were to fail would this prevent the T/R from being used?

Also how many CDU are there per engine?

[cedgz]

cdu = center drive unit or master actuator, so this actuator drives the 2 slave actuators(mechanically linked with flex shafts)
and the cdu also provides stow/deploy indication and also has an internal brake to prevent deployment in air)
2 cdu's per engine( 1 per reverser half)
if cdu fails, rev won't work

[spannersatcx]

if cdu fails, rev won't work

rev half won't work.

[cedgz]

"rev half won't work."

yes, but no green rev indication(full indic and not half

[cwolfe]

Center Drive Unit CF6-80

Thanks for the info about the CDU, but just to be clear, if the CDU tension rod assembly which is responcible for the stow, stop, in-transit positions. Should this rod break would the T/R still be able to deploy because the pnematic motors inside the CDU can still provide power to operate the flex drive cables attached to the slave actuators. If this is possible, which is the question at hand, then it would be possible to have a deployed thrust referser, but the pilot be unaware of the thrust reverser position.