DUSSELDORF AIRPORT'S attempt to ban all flights by turboprop airliners is embodiment of the worst fears of the world's regional airlines. The airlines immediately affected by the ban will, rightly, do everything to have it overturned. They should be, supported by all their regional allies around the world, but they should be supported, by the major airlines as well.

The arguments offered up against turboprops by the more congested airports are as compelling at first glance as they are fatuous on closer examination. A turboprop occupies the same valuable landing slot as a Boeing 747, but brings in only a small number of passengers. Turboprops are generally smaller than turbofan-powered aircraft, so they generate less in landing fees. Turboprops mess up the approach and departure regimes because they travel slower than their turbofan-powered cousins. Turboprops don't fit jetways, don't make good use of ground-handling and cargo-handling services, and their passengers don't buy as many duty-free goods before flying, so they're no good for the airports' contractors either. These are the arguments, and they mostly don't add up to much.

Very few congested airports worldwide are more significant as end destinations than they are as hubs. Hubs depend on feeder services in and out, and so do the airlines, which use them. If they were reduced to handling passengers only in 747-size batches, they would very soon run out of customers.

In general, operators of turboprops pay more per passenger in landing fees than do operators of 747s - one of the reasons why feeder-service fares are usually much higher per kilometre than are long-haul fares. Passengers on turboprops are likely as not to be joining or leaving a long-haul flight, so the airport actually extracts more in landing fees from them than from those who catches a cab to or from the airport.

A turboprop on approach can be very nearly as fast as a turbofan over the threshold: it is only significantly slower if it is forced to join the landing pattern 50km out where the turbofans are still using their greater cruise and descent speeds. On departure, a turboprop is slower in both speed and climb than the average turbofan, but the difference is only important if, again, the turboprop is forced to follow the same path. In practice, as turboprops are less noisy, they can often be routed away from the main departure path early. Of course, they can also operate outside the restrictive hours to, which their inherent noise confines even the quietest of turbofans.

Turboprops are largely independent of ground services - they're rarely the ones left occupying valuable parking slots because the tow tractor hasn't arrived on time for a push back. The upside of their not carrying much cargo is that their part of the passenger-terminal apron isn't cluttered up with cargo containers or aircraft held up waiting for them to be loaded or unloaded.

Passengers departing on turboprop feeder services might not buy a great deal in the airport shops: those who arrived on turboprop feeders, to fly out on major services, will probably end up spending more time than they ever wanted to in the shops while they wait for their flights.

In short, turboprop operators don't need to cause disruption to airport services, nor do they necessarily represent lost revenues for airport operators. Before trying to restrict or ban turboprop services, airport operators should consider whether they are blaming turboprops for their own inability to run flexible, efficient services.

If any airport is foolish enough to pursue this policy, it will not only be acting against the best interests of the airlines, which are its customers and the passengers, which are their customers. In the end it will be acting against itself, through cutting its own vital lifelines to the regional feeder services which are what attract those customers in the first place.

Source: Flight International