As one might intuitively guess, maintaining floatplanes and amphibians – particularly those which routinely operate commercial charters or scheduled services and need to provide very high levels of operational reliability – is a rather more specialized and MRO-intensive business than is maintaining aircraft which fly only from runways on land.
Interviewed by MRO Network at the Caribbean Aviation Meetup conference in Sint Maarten this week, John Kelly, CEO of East Haven, Connecticut-based Cessna Caravan floatplane operator Shoreline Aviation, says that for every water landing one of its seven aircraft makes, the company puts the Caravan floatplane through three hours of MRO.
Floatplanes and other seaplanes of necessity require more maintenance than do land-based aircraft for two reasons, says Kelly. One reason is that, every night, when one of Shoreline’s seaplanes returns from water-based operations to one of Shoreline Aviation’s two main bases – one is in East Haven and the other is at the Bohlke International Airways FBO in St. Croix in the US Virgin Islands – two employees must hose down the exterior surfaces of the aircraft with fresh water and give its PT6A-114A or PT6A-140 turboprop engine a thorough compressor wash. (Shoreline Aviation has four Caravan floatplanes with 675shp PT6A-114As installed and three fitted with 867shp PT6A-140s.) In total, these daily processes, required to prevent salt crystals from building up on the compressor blades and to prevent airframe corrosion, take from 45 minutes to an hour.
The second reason is that aircraft which land on bodies of water – particularly salt water – require much more preventive maintenance in general than do land-based aircraft, according to Kelly. This is partly because they must be extremely reliable when operating to and from remote beach locations. “The aircraft is taking off from and landing in locations where you have no support and where it is difficult to get support to,” he says.
If a floatplane becomes unserviceable at a remote beach on a remote, uninhabited island in the Bahamas or the Caribbean – the type of destination served frequently by Shoreline Aviation and Tropic Ocean Airways, a Fort Lauderdale-based Caravan EX floatplane operator which brought an aircraft to the Meetup for demonstration flights – then it could be out of service for several days. This potentially disastrous situation makes it imperative for floatplane operators such as Shoreline and Tropic Ocean to adopt extremely conservative practices with regard to their inspection intervals and replacement of life-limited parts.