Lugano’s new steep approach halts Saab 2000 operations

 - March 19, 2008, 9:34 AM

Swiss authorities have implemented plans for a six-degree approach angle at Lugano Agno Airport, effectively banning the airplane most frequently used there–the Saab 2000 turboprop. The rule change came as several parties jockeyed for position to start new regional operations into Lugano with Saab 2000s after Swiss International Airlines announced plans to severely curtail its service there.

Lugano Agno, situated in a mountainous region of Southern Switzerland, opened in 1938. The airport later extended its Runway 01/19 to 4,430 feet with a hard surface, and in the early 1980s Runway 01 received an ILS at the request of Swiss regional airline Crossair. Because terrain obstacles prevented the installation from meeting all requirements of an ILS approach, authorities classified it as an instrument guidance system (IGS) in 1983, and set the glideslope at 6.65 degrees. The approach path features a missed approach point (MAP) at 1,174 feet agl and 1.5 nm from the threshold, marking the last moment when landing Category A aircraft can safely overshoot without hitting mountains on the other side of the runway.

At the MAP, pilots must switch to the precision approach path indicator (PAPI) set at an angle of 4.17 degrees for the final segment of the approach to Runway 01, because trees interfere with the ILS signal at low altitude. Pilots and aircraft landing under IGS at Lugano must get special authorization from the Swiss Federal Office of Civil Aviation (FOCA).

During a routine check last year of procedures at Swiss airports with regard to JAR-OPS 1 rules, FOCA experts discovered that regional airliners had to dive at angles of up to 11.85 degrees–far outside the certified flight envelope–to establish the proper path for the final PAPI approach segment after the MAP. FOCA announced a change in the landing aid alignment this past August, effectively excluding the Saab 2000 from Lugano, and gave interested parties only a week to comment.

Following protests against the rule change after years of tolerance, the head of FOCA resigned in early September. His interim successor, Max Friedli, decided to impose a moderate change for a two-year period starting this November 1, followed by stricter rules in November 2005.

As a first step, the PAPI angle will increase to six degrees to limit the dive angle at the MAP to 7.2 degrees. Extended visibility limits as defined by an August 22 notam allowing pilots to see the runway from the MAP will continue. During the interim two-year period, aircraft certified for glideslopes of six degrees will be allowed to land at Lugano. This includes many business jets and regional airliners such as the de Havilland Dash 8 series and the Avro 85/100, but rules out the Saab 2000, which is certified for 5.5 degrees.

In November 2005 the PAPI will be realigned to 6.65 degrees, which will also represent the glideslope angle throughout the final approach. As a result, most business jets and regional airliners will not be allowed to fly into Lugano. FOCA cites the Dassault Falcon 50, the Falcon 2000 and the de Havilland Dash 7 as the only aircraft weighing more than 12,500 pounds that could meet the requirements, but estimates that OEMs could recertify many other types for 6.65-degree glideslopes within two years.

After FOCA rejected its appeal for an alternative flight profile with a final approach angle of 5.5 degrees, Saab last month said it would consult with its customers to determine whether recertifying the Saab 2000 makes economic sense. According to FOCA, it fully appreciates the economic damage caused by the ban on many executive jets and regional airliners. However, the rulemakers insist that safety considerations must come first.