No Moon, No CSC - Brief Article

The Hornet's advanced systems can give a false sense of security. The loss of one system interface can affect many displays and aircraft capabilities. It's up to the pilot to realize the effects on the aircraft and fall back on basic aviation skills and systems knowledge to bring the jet back on deck.

As a brand-new fleet FA-18 pilot, starting workups off Virginia, I was on my first mission of the line period. There was a 2,000-foot, broken-to-overcast layer for the Case III launch and recovery. After the cat shot, I heard the master-alert tone and noticed that I had CNI and VOICE AURAL cautions. With nothing but a pitch-black, moonless night in front of me, my biggest concern was flying away from the water.

I climbed through 2,500 feet and reported, "On top, kilo." As departure cleared me to switch to Strike, I called up the BIT page, then switched to the preset radio frequency. After transmitting on what I thought was Strike, departure told me I was still on their frequency. Then I saw indications of a Control Signal Converter (CSC) MUX FAIL.

I reported my situation and told departure I would remain overhead and troubleshoot. Comm 2 was completely out, and comm 1 would not change from the preset frequency. Also, the TACAN and up-front control panel didn't work even though the TACAN bit showed "GO." I had to come up with an alternative navigation plan.

I broke out my pocket checklist and looked up CSC FAILURE. The PCL simply states some or all of the comm and nav systems may be out. Fortunately, my squadron had just had pilot training and discussed CSC problems. From that, I knew that UFC backup wouldn't work but thought I'd try it anyhow. The training was right: it didn't work.

Through the broken layer, I kept the ship in sight and remained overhead until the end of the cycle. Departure then asked me to hold 20 miles aft of the ship. An air-to-ground radar lock helped find the ship as I began my approach, referencing the ship's final bearing on my track symbology. I realized that my ILS wouldn't be displayed on the HUD, and I couldn't get an ACLS lock-on. I would have to rely on my systems, along with the controller, on a mode III approach. The landing was uneventful.

Before this experience, I had very limited knowledge of the CSC and indications of its failure. With the loss of so many critical NAV systems at once, the pilot must recognize the cause of the problem early and come up with a plan to recover the aircraft.

The CSC interfaces with navigation and communication systems. This interface converts analog signals to a digital format and digital back to analog. If the CSC fails, you may not be able to communicate and operate the TACAN, ILS, beacon, ADI, altimeter, IFF, and comms. Some or all of these systems may be completely out, and there is no way to know for sure which ones. The problem may be a result of the box itself failing or an individual comm/ nav component transmitting bad data and affecting the entire system.

The most recent NATOPS change provides for a good discussion of the CSC MUX failure. I also recommend getting with your squadron's aviation technicians. They know the CSC and related systems inside and out.

Lt. Bronk flies with VFA-83.

COPYRIGHT 2000 U.S. Naval Safety Center
COPYRIGHT 2004 Gale Group