The previous shift had found damage on the nose cowl section of the left engine. This damage is non-repaireable and not allowed according the manuals so the engine cowl has to be replaced. We had an aircraft sitting at the other side of the hangar that was in for a big inspection and didn't need to fly any time soon so the decision to 'rob' the engine cowl of one of this aircrafts engines was pretty obvious.
My colleague and me get started on removing the good engine cowl from the aircraft at the other side of the hangar while another colleague is driving in from home. He wanted the day off but due to this job now has to come in to work.
We bring the tools that we need for the job over to the aircraft and get the hangar and connect the hoist to the engine cowl.
We move the crane to the correct position without aiding it ourselves because otherwise the engine cowl would 'jump' when the cowl is disconnected. We then take the slack out of the cable's of the hoist because we obiously don't want the engine cowl to drop when we remove the bolts.
We now need to remove the connecting parts of the engine cowl, first we have to remove the engine anti ice duct. (When the flight crew selects engine anti ice to on, the engine anti ice valve should open and hot bleed air blows into the engine cowl's, through piccolo tubes and out of small escape holes, this heats up the engine cowls and prevents for ice build up on the cowls).
There.... 2 clamps and the duct comes right out, I wish everything in life were this easy.
Next up is the electrical temperature sensor, the T2 sensor.
This sensor is installed with high vibration mounting to minimize the shaking of the engine on the sensor.
The sensor is a part of the engine and not of the engine cowl, therefore on the engine is a mounting plate to install the sensor for shipping.
The sensor is directly in the intake airflow of the engine to measure the temperature most accurately (this temperature is ofcourse important for thrust settings, lower temperature gives a higher thrust at lower N1 rpm, This will all be explained in the 'engine's section on this site). But for now it's important to know that this sensor is installed with aerodynamic sealant.
We need to break the sealant in order to push the sensor out of it's position to remove it but fortunately my colleague tells me that he has a trick to do this.
and he gently pushes the sensor out.
We connect this sensor to the engine on the shipping mount.
With this T2 sensor now removed we now only have a hydromechanical temperature sensor remaining. To remove this one its pretty much the same as the electrical sensor and is removed without much difficulty.
I incorperate my new trick....
and this sensor is now also out of the cowl and connected to it's shipping mount.
My other colleague now arrives and we get right on removing the bolts that connect the cowl to the engine.
We remove all of the bolts that hold the cowl to the engine.
And the cowl comes right off......
We now have to get the engine cowl onto a cart of some sort.
We hunt around the hangar for a bit and we find a cart that is actually made to transport engine cowls on.
This is what the engine looks like without the engine cowl by the way.
My colleague allways seems to be happy when he get's to operate heavy machinery.
We put the engine cowl onto the transport platform, wheel it over to the other side of the hangar and hoist it back into another crane and plant it onto the engine.
The engine's electrical generator gets in the way...
And we are mis alligned a bit.
But we get there
Here's me tightening bolts.
And here's my colleague that had to come from home tightening the other side.
at least he's still smiling.
There, the bolts are installed, now we need to install the sensors again.
We install the sensors and do a check on the engine, time is now running out if we want to testrun this engine before nightfall. We decide to skip our break and continue to work on the engine.
My colleague discovers that there is little or no oil in the starter motor, we need to fill this up later, for now we have to install the fan cowls (the doors that cover the fan case.
In this case, the doors were a bit of pain.
The fan cowl doors and behind that are the thrust reverser halfs.
My colleague removes the thrust reverser locks so that we can close the thrust reverser doors.
Both my colleagues pumping pressure in the hydraulic actuators to disengage the thrust reverser door lock.
Tommy is still smiling ;-)
And down it goes...
We now have both the engine cowl's installed and the thrust reverser doors closed, we fill the starter motor with oil.
tommy is still smiling...
We are good on schedule but time is running out for testrunning so we close the doors and prepare for towing and testrunning.
My colleague Rob get's to play with heavy machinery again, this time his favorite one's, jet engine's, at high power.
We spent more then half an hour running both engine's to complete all the tests that we needed to do and here's a short clip of Rob finishing the last bit of the test running session.
Click play to start.
The aircraft passes the test and we can finish off the job.
We apply some aerodynamic sealant on the sensors.
After 8 hours of work, Tommy get's to put on some more sealant onto the cowling and that should finish our shift for the day, note that he is still smiling.
Now that's tight sealing.
The day is at an end, the sealing needs to dry, we finished this job and we can go home. The nightshift get's in. We leave the aircraft outside with just a couple of small job's that needs doing to it.