Bad-weather CV approaches - ORM corner - operational risk management and constant velocity

Approach, July, 2003 by Brian Schrum

Trapping aboard the carrier has to be the most thrilling challenge experienced by carrier-based naval aviators. The last 15 to 18 seconds of a flight are intense. However, the Case I, II, or III approach leading up to the ball call, at three-quarters of a mile, requires as much concentration and discipline as the trap. Perfecting the skills to operate in this environment puts aviators to the test each day and night, in all weather conditions.

During our squadron ORM sessions, we learn how to identify hazards and risks, make risk decisions, implement controls, evaluate our changes, and offer recommendations to avert disaster and foster a safer evolution. I hope this article spurs ready-room conversations on a topic not often discussed during preflight briefs or squadron LSO lectures: Low-ceiling and low-visibility approach hazards. A recent air-wing recovery showed how inclement weather caused havoc to an unprepared naval aviator and LSO.

I had not given much thought to approach minimums during a Case III arrival to the boat until, as an LSO, I experienced the mass confusion that can occur during bad weather. We often work in a benign weather environment, but we always should be prepared to handle weather contingencies.

We were deployed on board USS George Washington (CVN 73) in the Northern Arabian Sea, in support of Operation Enduring Freedom. It was the end of July, and C-17 had finished our first week of ops. 'Throughout the week, a low-pressure system dominated the area with ceilings at 1,000 feet or less, and visibility at two to five miles with mist and haze. Because of the poor weather, we conducted Case III approaches every recovery.

A Case III approach is flown when the weather is less than 1,000-foor ceiling or five-mile visibility, or during night CV operations. The approach typically consists of marshalling aircraft behind the ship at various altitudes and distances. Each aircraft is given an approach time to sequence to the deck in a safe and expeditious manner. Pilots fly a standard-descent profile, dirty-up, and intercept a 3.5-degree glide slope at three miles--that should lead to an on-and-on start. Once inside seven miles, pilots can reference ILS (bull's-eye) and/or ACLS (automatic-carrier-landing system or "needles") to guide them. If the pilot does not have either ILS or ACLS, he then relies upon CATCC (carrier-air-traffic control) azimuth and glideslope calls, plus his self-contained approach numbers, to get him to an on-and-on start. On a standard flight, pilots will use all of these aids to get aboard. If one aid is malfunctioning, the approach may be off parameters. If we factor bad weather into the mix, a pilot could have their hands full, as they did on our LSO team's particular wave day.

During these poor conditions, the CAG and squadron paddles step up and keep their fellow aviators off the ramp. Normally, paddles only passes "roger ball" and the occasional "power" calls to approaching aircraft. But, under degraded conditions, a paddles talk-down can be a rewarding experience. Such was the case that July afternoon when weather conditions suddenly deteriorated to one one-quarter-time visibility and ceilings at 350 feet or lower.

Our team was scheduled to wave a midday recovery and found the weather to be a safety factor. Paddles made the call for all aircraft to have their taxi light on, so the aircraft would be visible earlier. Before the first plane arrived at the ball call--at one and a half miles--we would break out and make an arrestment. CATCC called the first jet on and on at three-quarters of a mile, and told the pilot to call the ball. "Clara" was all we heard. Cricket.... Cricket....

The hairs on the back of our collective necks stood straight up. We heard nothing for two or three seconds until, suddenly, a jet appeared out of the haze, only moments away from taking a trap. CAG paddles gave appropriate calls to the pilot and received good responses; he safely trapped. Great, we have one aboard and seven more to go. We brought three more aircraft down before the weather closed in on the ship, and we went below minimums. With more aircraft left to land, we thought about our options. The ship was working blue-water operations, and our nearest suitable divert airfield was 200 miles away.

Aircraft were returning from long missions, some with ordnance aboard, which presented us with low-fuel states and maximum-trap weights. Fuel was airborne but in short supply. The next event's launch was on hold while the ship and air-wing leadership decided what to do. Vulture's row saw more action as people wanted to watch the excitement and experience the deteriorating weather. Meanwhile, four aircraft tried to break out and finish the recovery.

Let's stop right here and ask the question, "With the weather minimums continuing to drop, just how far along an approach can we wave an aircraft without a paddles contact?"

"Paddles contact" refers to a call the LSOs can make to "grab" an aircraft from CATCC and talk him down to the landing area. To help answer this question, here are some ORM controls for the bad-weather hazard: