"Demon bird".

In four years of active service and duty in two Hornet commands, I've seen Hornets hit deer on a runway and pressurized drop tanks spinning out of control on a flight line. The following story tops all my other experiences. Here's how a simple engine drop became an epic battle.

"How did we end up with so many gripes on one jet in less than a month?" I asked myself, looking at a long list that included multiple main fuel-control (MFC) changes, variable exhaust gripes, fuel-inlet tubes (FITs) rubbing on bell cranks, and an engine that shifted in flight.

It all started during night check when we had to drop the port-side engine on Dragon 304--a simple TFOM job. The night crew easily had dropped the engine and inspected the engine cavity. Having the engine out also gave us a chance to replace the FITs. One of the mechs found a FIT rubbing against a bell crank, which eventually could have made a hole in the FIT and started a horrendous fuel spill.

After a couple days and a move to the flight deck, it was time to return the engine, do the leak checks, and return 304 to flight status. While turning 304, I saw the nozzle-position indication on the starboard engine had a reading of 67 percent, which was below limitations for the ground-idle throttle position. Meanwhile, our CDI noticed the MFC on the port engine was leaking. We decided to shut down the aircraft so we could remove the fuel control and change the packings.

We replaced them, reinstalled the MFC, and I did another leak-check turn, only to find the MFC still was leaking. To make matters worse, the starboard engine now had a nozzle reading of 57 percent (16 percent under the ground-idle limit). Our next step was to remove and replace the MFC and redo the throttle rigging for the starboard engine.

Then the day got even worse. After replacing the MFC, we opened the starboard engine bay to check the throttle rigging and saw an unusual amount of residual fuel coming out the door. My LPO traced the leak to an after-burner (AB) fuel control. We installed a new one and did the op-leak check.

The night crew started dealing with the nozzle-position issue on the starboard engine. First, they removed and replaced the variable-exhaust-nozzle (VEN) power transmitter and rigging for the throttles. During the next op-leak-check turn, the position of the VEN matched with the port engine, but the nozzle position read 86 percent, with the throttle at the AB position.

The night crew then decided to jump the ECA, which again resulted in the nozzle position reading 67 percent at the ground-idle position. We then tried a variety of troubleshooting steps. We rigged the VPT, swapped one of the engine ECA cables, changed the signal-data computer (SDC), swapped the port VPT to starboard, and even removed and replaced the VEN power unit. All these efforts failed to give us the desired results. In fact, Dragon 304 ended up spitting the new VPU in our faces when it failed the op-leak check.

With frustrations mounting, we removed and replaced the VPU. It passed the op-leak check, but the nozzle still was reading below limitations. Thanks to the excellent troubleshooting abilities of my shop, we then decided to rob the VEN manifold line and another MFC from Dragon 307 and install them on 304. When we did a low-power turn, both checked good, and we thought it was time to place 304 on a pro turn.

When the aircraft returned from its flight, the plane captain (PC) found the port engine wasn't sitting right in the weather seal. We ended up removing the engine again and reseating it inside the seal. We also noticed that the FIT we had replaced a week ago once again was rubbing the bell crank that sits on the inboard side of the FIT. We ended up removing and replacing the FIT and the bell crank to see if that fixed the problem.

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With all that work done, we thought we finally could concentrate on other aircraft and programs. Five days after we had fixed the weather seal, though, Dragon 304 returned from a sortie, at which time the PC noticed that the port engine had shifted during flight.

Once again, we had to drop the port engine. We also had to get another FIT because of the same problem we'd had the last two times. We originally had suspected that the engine's shifting was a result of worn bushings from the outboard engine mount, but further examination by the CDI revealed that the engine was creating a groove on the inboard engine mount.

All of our attention now turned to the inboard mount. More examination by the CDI showed that one of the nuts connecting the mount to the airframe didn't have a torque seal and was sitting loosely on the bolt. When we had removed the mount, we found that two of the three mount bolts were warped and cracked. This discovery explained the shifting of the engine, as well as the issue we had been having with the FIT rubbing on the bell crank.

Finding the warped bolt holes turned the heads of our Maintenance Master Chief, MMCO, QA, and even depot-level civilians because the mounts are in solid steel.

The problems with 304 taught me how valuable thorough troubleshooting, attention to detail, and patience are to getting jets into the air and back on deck safely. Thanks to these habits, we eventually found the "demon" that was manifesting itself within Dragon 304.

Petty Officer Yamada works in the power plants shop at VFA-192.

By AD3 Ryan Yamada