Single-Engine Or Engine Fire? - safety conditions of a military aircraft

Approach, Nov, 2000 by Clark Childers

It was toward the end of our COMPTUEX at-sea period, in the middle of our workups for WestPac 00. I was a nugget in the squadron, with less than 300 Hornet hours, 50 arrested landings, and about six months in my fleet squadron. I launched from the ship on a CAVU day with three Mk-82s and two drop tanks. My lead was a cruise- experienced JO with about two years in the squadron; he had recently received his section lead qualification. We joined overhead the boat and headed for San Clemente Island for some unit-level training.

Coming off target on our last bombing run, I got a master-caution light and tone. This was the result of an L BOOST LO caution, indicating a loss of left-engine fuel-feed pressure. I continued my left turn and intercepted my lead. During the rendezvous, I called my lead and let him know the status of my airplane. We pointed our noses back toward mother, 40 miles south. As we were breaking out our NATOPS pocket checklist and climbing through 8,000 feet, I got my second indication, an LAMAD caution indicating high oil temperature in the airframe mounted accessory drive. This was about three or four minutes from the first indication of a problem.

I pulled my left throttle back to idle, my wingman gave me the lead, and we continued to go through the procedures. The AMAD caution was the more serious problem, so we decided to go through that procedure first. It recommends that, if conditions permit, you consider shutting down the engine and restarting for landing. We decided to leave the engine running and call lot a rep. About this time, I got a third indication, an LAMAD PR caution, indicating a loss of oil pressure in the AMAD.

Six months into my first squadron. I should be on top of my NATOPS knowledge. However. I didn't recognize this combination of events from the simulator training in the RAG. One thing that I did realize was that I was having multiple indications of a serious problem in the jet, and they weren't erroneous indications. When I got a rep from the tower, I was about 10 miles from mother at 16,000 feet. The tower rep was a familiar voice, the only other JO more junior than myself. He broke out his NATOPS, went through the procedures, and asked if I had shut down the engine yet. Having exhausted our combined experience levels, the rep called down to the ready room and got a department head down to CATCC to provide some advice. At this point, I did not have a game plan in my mind and was not making the important decisions on my own.

The CATCC rep came up on the radio, and I told him my indications. He asked again if the engine was secured. Telling him that it was not, he concurred with our decision and began preparing the ship for the pull forward and the immediate recovery. I remembered hearing that AMADs have come apart in a matter of minutes after an AMAD caution. That concerned me, espcially since I'd had so many indications. The rep told me to prepare to make a half-flap straight in to the boat. He said to bring the engine up off the idle stop just prior to the ball call and to make a normal approach. About five minutes later, after dumping down to max trap for a half-flap approach, I saw that the ship had cleared the landing area, made 35 knots wind over deck, and was prepared to catch me.

My lead was still with me in trail, giving helpful hints over the radio. I thanked him for the help and said I'd see him on deck. I made my straight-in approach to a fair 4-wire, using an updated meatball, lineup, AOA, and fire-light scan. I secured the engine in the landing area and taxied clear.

During my postflight debrief, maintenance said that the AMAD was hot enough to bum your hand through the skin of the airplane and nearly glowing red. It was then that I realized just how close I was to having a real emergency on my hands. The boost pump shaft had sheared, causing a loss of fuel to the oil-fuel heat exchanger. The AMAD worked as advertised, but past emergencies had produced catastrophic results: titanium engine fires caused by hot AMAD parts being injected into the jet engine. The extreme heat in the AMAD during the first few minutes of the emergency caused the AMAD PR switch to fail, giving me the AMAD PR caution.

I began to question the decisions that I'd made in the air. The jet had made it home and flew again that evening. But if NATOPS says to consider shutting down the engine and restarting for landing, should you shut down the engine and then decide? You can restart the engine prior to recovery if the situation warrants. Then again, why restart the engine if you know there is a serious problem with it? On a CAVU day with a steady deck, why not come back single-engine and avoid the possibility of a fire? Is it better to risk the engine and possibly the airframe because of fire or to risk the single-engine landing? Which has the higher risk? With a day straight-in and an LSO who knows you are a nugget, is a single-engine approach safe? On that day, I hadn't wanted to make a single-engine approach, but is that fear worth risking the aircraft? We had decided the landing was the greater risk. If the AMAD had come apart, we may have reevaluated our decision, but we followed NATOPS, and the aircraft made it back to the ship.