Manual deployment & Stowing of Blocker Door of CFM 56 Engine

Manual deployment/stowing of T/R Blocker door on CFM 56 Engine

Refer AMM 

1. T/R Manual deactivation:-

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2. Manual deployment of Blocker door:-

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3. Manual stow of Blocker door:-

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4. Operational test of TR through CFDS:-

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Deactivate T/R for maintenance by pulling HCU lever away from the flight position.

Remove the Stow pin from its Stow position and put this pin in while the lever is away from the flight position.

HCU lever is located at 1 O’ Clock  aft looking fwd.

Manual unlock Shaft:-

Manual UNLOCK SHAFT as shown in picture is accessed and unlocked by the use of a 5/16 inch wrench.

Blocker door is unlocked by getting lock released from hook and one can see the gap of about 1 inch of Blocker door from its initial Locked position.Once it is done you move to the next step to unlock manual unlock Square.

This is done only after removing the Thermal Blanket which is wire locked in 3 parts over the UNLOCK SHAFT.

There are 4 unlock Shafts and 4 Manual unlock Squares.

The process is repeated on each shaft and square to Deploy or Stow all the 4 Blocker doors in each engine.

Manual unlock Square:-

This Square is to be placed by the wrench to the UNLOCK position and at the same time BLOCKER DOOR TO BE PULLED OUT by hand and to deploy.

The blocker door gets deployed.

NOTE:- FOR STOWING THE BLOCKER DOOR MANUALLY,EACH DOOR IS PUSHED IN WHERE AS IT IS PULLED OUT WHILE MANUAL SQUARE IS PLACED IN UNLOCK POSITION.

 while it is stowed,it may not get fully flushed with a surface which gets properly seated when T/R test is conducted through MCDU.

For conducting Test follow MCDU procedure by pressurizing Electric Pump and putting the relevant engine FADEC ON.

Once the test is done T/R moves physically to Deploy and Stow position and Blocker Door seated properly.You will get Test OK or Failure msg.

This is a simple guidance to do the job,refer to the applicable manual.