Sunday, August 29, 2010

Multiple Approaches


Flight level 330...Mach .76...clearance to cross Baton Rouge at FL230. We were at the top of descent, planning our arrival and approach to New Orleans when I requested a weather report and sent notification to the station personnel on the ground that we’d be touching down a little after 10 pm. The weather was forecast to be marginal at best, but conditions at the airport were better than planned with high ceilings and light winds. The temperature and dew point were within one degree, an indication that fog was a possibility, but there was no restriction to visibility mentioned in the current report. Due to the chance of poor weather conditions, we were carrying enough fuel to safely continue on to Houston if we were, for any reason, unable to land in New Orleans.

It was my leg, so as we began our initial descent, I briefed the Captain on the localizer approach to runway 19 and set up all the appropriate speed and altitude bugs. With light winds, we would typically land on runway 10, a longer runway with a better approach system, but that runway was closed for renovation. It was crazy dark, with high overcast clouds and no moon and we were able to see the glow of New Orleans on the horizon from over 100 miles out and would have a clear view of the runway at about 30 miles. With the weather as it was, it seemed clear that this approach would terminate as a visual procedure. However, company policy is to fully brief an instrument approach when landing at night, even when the weather supports a visual procedure, so that‘s what I did. In hindsight, I must admit that while I technically fulfilled the requirement to brief the approach, I was not fully committed to the idea of actually flying an instrument approach…nor was I mentally prepared for what was about to happen.

The minimum altitude on this approach is 340 feet above the ground which we round up to the nearest hundred. So in this case, we could descend no lower than 400 feet before we would be required to see the runway. If at 400 feet we could not see the runway and were not in a position to land, a go-around would be required. To further complicate matters, the missed approach altitude for the approach is only 2000 feet. So consider this, you’re descending on the approach at a speed of about 140 knots, you reach 400 feet with no visual and execute a missed approach. On the MD80, when the pilot pushes the throttles up to go-around power and pitches the nose skyward, the vertical speed could easily reach 4-5000 feet per minute in the initial stages of the climb. Needless to say, 2000 feet comes very, very fast and you had better be ready to level off. Add to this the fact that the missed approach procedure to this runway requires an climbing left turn to intercept a VOR radial that you wouldn’t already have tuned in and holding at a startlingly close intersection and you can imagine how busy things could get.

Approach control vectored us in over Lake Pontchartrain and lined us up along side the Causeway bridge where we joined the final approach course to runway 19. We had a clear view of the runway at this point so I was a little surprised that the approach controller cleared us for the Localizer approach instead of the visual. I think he knew something we didn’t. As we continued inbound, I was concentrating on the approach and the step down altitudes approaching the final approach fix when the Captain commented that the runway seemed too close to the lake. The airport is about 2 miles from the south shore of the lake, but tonight, the lake looked to be immediately off the end of the runway. Weird…but at this point, I was focused on configuring the aircraft for landing and beginning our final descent as we crossed the final approach fix. I took a look outside and noted the proximity of the lake to the airport, but I was confident in the fact that we had identified the approach and that we were in fact lined up to the correct airport, so I chalked it up to optical illusion and continued the approach.

We crossed the final approach fix at 2000 ft., fully configured for landing and began our final descent, we continued past SHORE intersection at 700 ft. at which point we unexpectedly entered a cloud layer and lost visual contact with the runway. As it turns out, there was a fog layer moving in from the north which we had noticed from a few miles out, but mistook for the lake. At this point we were still 300 feet above the minimum descent altitude, so we continued the approach in hopes that we would descend below the clouds and regain visual flight, but that didn’t happen. We reached 400 feet while still solidly in the clouds and the Captain reported “minimums.” I called out “go-around” as I pressed the TOGA buttons on the throttles which commanded go-around thrust and moved the Flight Director command bars to a go-around pitch attitude…about 20 degrees nose up. I commanded “flaps 15, positive rate, gear-up” and asked the Captain to engage NAV, which would mercifully guide us through the lateral portion of the missed approach procedure.

As we began climbing we almost immediately broke out of the clouds and could see that the entire southern half of the airport was in the clear. It was obvious to us that we could execute a visual approach to the airport from the south and easily land. But since half the airport was covered in clouds, the controller would not allow us to fly a visual approach and instead vectored us to the south the fly the ILS approach to runway 1. This would be the same runway we just attempted to land on, but from the other direction. Now if you know anything about instrument flying then you know that an ILS approach will generally get you much closer to the ground than the localizer approach we just flew. Typically, an ILS approach will get you down to 200 feet. But in this case, the minimums for the ILS approach to runway 1 at MSY are only 381 feet…barely an improvement over the 400 foot restriction on the localizer. That said, we thought if we could get back around to the airport fast enough, that we would beat the fog and land.

We were vectored well south of the airport and, you guessed it, by the time we got back to the airport, the fog had covered the south end of the field. We flew the ILS, entering the clouds at about the same time as before and executed the missed approach when we reached 381 feet with no view of the runway. This time, as we began our climb, we broke out of the clouds and could clearly see the NORTH side of the airport in the clear. Everything had flip flopped. There appeared to be patches of fog out over the lake that could impact another attempt to runway 19, but we thought it was worth the try, so again, we were vectored out for another approach to the south. Same song, third verse, we continued the approach, began our descent and lost visual with the airport once again, at about 700 feet, reached minimums at 400 feet without any indication that we were about to break out and executed the missed approach. We were getting very good at missed approaches at this point.

By now, we had exhausted our patience with the fickle New Orleans weather and had used up all our reserve fuel flying multiple approaches. We made the decision to divert and headed for Houston, which was a long way to go, but it was the closest airport with weather good enough to be a legal alternate. We received a current weather report and were pleased to see that Houston was reporting visual conditions…not much better weather than New Orleans had been reporting an hour ago, but the forecast did not call for impaired visibility or low ceilings. We were expecting a simple, straight forward arrival.

By now it was about 11:30 at night. The leg to New Orleans was our third of the day, so we had already endured a lengthy duty day. We were tired and ready for a comfortable bed. When we checked on with Houston approach, the first words out of the controllers mouth were “what visibility do you need to land?” A little over thirty minutes had elapsed since we received our last report on the Houston weather and during that time, unforecast fog had formed over the airport reducing visibility to 1000 RVR. RVR (Runway Visual Range) is a measurement of forward visibility, reported in feet, taken on or next to the runway. The minimum RVR for our intended runway was 600 feet, so we had the visibility we needed to land, but the visibility was low enough that we were required to fly an auto-land approach where the airplane‘s autopilot flies the entire approach, lands the aircraft and stops on the centerline without any assistance from the pilot. Of course the pilot must program the autopilot to fly this approach, but after that he’s just along for the ride. The pilots both have important jobs during an auto-land, but they are related to monitoring the approach and manually executing a go-around if things do not go as planned. There wasn’t much traffic at that time of night, so we were vectored in for the approach without delay and successfully shot the CATIII ILS to runway 26L and for the first time in what seemed like forever…landed.

The station manager met us on the jet bridge with paper work in hand and a fuel truck standing by to fill our empty tanks. But by this time, the weather at New Orleans was getting worse and forecast to stay that way and more importantly, we were near the end of our legal duty day and would be “pumpkins” before we could get back off the ground. That would be all for tonight.

The next morning, we loaded our weary passengers and took to the skies…after all, we had promised these poor people a trip to New Orleans. You might think the story was over at this point, but you would be mistaken. The weather conditions and forecasts were remarkably similar to the reports from a day earlier. A fact that wouldn’t have garnered more than a passing thought on any other day, but today was cause for concern. We pressed on with the past nights experience fresh on our minds. About 30 minutes before landing we received a weather report that indicated deteriorating weather conditions at the airport that would require us to again fly the localizer approach to runway 19. The longer runway, runway 10 was still closed.

I had flown all the approaches the night before except for the auto-land, which of course was flown by the auto pilot. Today, it was the Captain’s turn. We joined the final approach course with a sense of déjà vu and entered the clouds a little earlier than we had the night before. The tower controller assured us that aircraft had been landing all morning long and, in fact, another airline had landed just five minutes earlier. The ceiling (or base of the clouds) was reported to be at 1000 feet, so I was surprised to see rain on the windshield instead of the runway coming into view as we passed though 1000 feet. We continued the approach….900...800...700...I remember thinking “you gotta be kidding me” as we continued passed 600...500...and reached minimums at 400 feet with nothing to see past the windshield but rain and clouds…go-around! We flew the missed approach, a procedure we were very comfortable with at this point, and were assured by the tower that the bases were ragged and that we would most likely get in if we attempted the approach a second time. But he had no sooner finished his report to us when the aircraft behind us went around for the same reason.

In the time it took us to get vectored around for another attempt, 3 jets missed the approach. Which, frankly, was a bit of vindication at that point…I was beginning to feel a bit deflated. It really shouldn’t be this hard. We flew the localizer a second time with the same results as the first and had just about decided to head home when the Continental 737 flying the approach behind us was able to land. We had the fuel, so we reluctantly agreed to give it one more try. The Captain indicated that he was fed up and transferred control of the aircraft to me…“give it one more try if want, then we’re heading home.” Localizer 19 approach…for the umpteenth time in two days.

We joined the final, configured for landing and began our descent at the final approach fix. As we continued our descent, things didn’t look any different than before. Rain began falling as we passed through 1000 feet…900...800...700...I was running through the missed approach procedure in my head just in case…600...500...I started to reach for the TOGA buttons for one last go-around when the Captain announced “runway in sight.” The rain intensified as we continued, but we were able to maintain visual contact with the runway…automated callouts from the jet announced 50...40...30...20...10 followed by a smooth touch down and the roar of applause from the cabin.

I like to attribute the reaction from our passengers to that of Stockholm Syndrome, a phenomenon in which a hostage begins to identify with and grow sympathetic to his or her captor. Every single passenger shook my hand or had some sort of positive comment to make as he or she exited the aircraft. I felt like I had tortured these people for 2 days. I expected angry outbursts, not congratulatory high fives and admiration. It felt good. Things certainly didn’t go as planned, but we all did our jobs, did them well, and deposited 140 happy people on the New Orleans economy.

Oddly enough, we were supposed to spend the night in New Orleans the night before. A nice long downtown layover that I was sorry to miss. The last day of this three day trip was a mid morning departure from New Orleans to Chicago followed by a short sit and one last leg home to DFW. We finally arrived in New Orleans an hour before our scheduled departure to Chicago…which we flew. No rest for the weary.

0 comments:

Post a Comment