This story is part of AIN's continuing coverage of the impact of the coronavirus on aviation.
With the Covid-19 pandemic showing no signs of a quick easing, business aircraft could be parked longer than their owners and operators originally expected. What may have first been anticipated as a temporary interruption lasting a few weeks has evolved into a situation where a company’s multi-million-dollar asset could be sitting for several more months or even longer. That has given rise to the need for owners and operators to understand that parking an airplane for a period of time goes well beyond towing it into a hangar and putting covers on the engines and pitot tubes.
“The modern business jet doesn’t like to sit around,” Thoroughbred Aviation founder and president Nathan Winkle said during an April 9 NBAA webinar on maintaining parked aircraft. “We’re going to have some issues. I think it would be naïve of operators and owners to think on the day of the all-clear that we can just return back to full flying.”
Those issues will be compounded and become more costly and time-consuming if operators and owners don’t ready their airplanes for a period of inactivity—and perform maintenance before and during the period they are idled, Winkle and other maintenance experts said on the webinar and also in interviews with AIN.
First, it's important for the owner or operator to determine whether the aircraft is going to be parked or stored, Kasey Harwick, Duncan Aviation v-p of aircraft services in Lincoln, Nebraska, told AIN. Parking an aircraft for the short-term requires different maintenance measures than does storing an aircraft for the long term, which calls for specific preservation actions to the airframe and engines that are generally outlined by airframe and engine OEMs in their maintenance manuals.
For short-term parking, Harwick recommended putting the aircraft in a hangar. If a hangar isn’t available, parking it on a level surface and into prevailing winds as well as mooring it—especially for instances of severe weather—is the next best option, he said. Also, install safety equipment such as landing gear lock pins, chock the landing gear and ensure all access doors and panels are secure. Static and protective covers for engine inlets and exhaust should be installed as well as on pitot probes. Operators should also attach an aircraft grounding cable, set all master switches and controls in the flight compartment to off or neutral, and center control surfaces and use gust locks if available. Harwick added the airplane’s batteries should also be disconnected and tires maintained at the manufacturer’s specified pressures.
In addition to those recommendations, Harwick and others suggested “exercising” the airplane every week or two that it is idle. That means pulling the airplane out of the hangar and onto the ramp and running every system as well as taxiing it, which gets fluids running through the aircraft and the wheels moving to avoid the formation of flat spots on its tires (those can also be avoided by regularly rotating its tires). Such actions should also include running the airplane’s lavatory and environmental control systems as well as its satcom and wireless internet, in case there are software updates that need to be downloaded. “Just like us human beings, it’s good to get out, stretch and get some exercise,” Western Aircraft director of aircraft services Jody Harris told AIN.
For aircraft that are stored long term, experts recommend following OEM guidance on the airframe, engines, and APU since each aircraft model is unique. But along with that, Harwick suggested routinely draining water from the airplane’s fuel tanks and performing a fuel contamination test, if possible. He also noted that some engines require using desiccant placed on a rack in the inlet and exhaust of the engine, followed by placing a humidity indicator card in them to ensure excessive moisture isn’t accumulating, and masking the inlet and exhaust off with plastic. Lastly, it’s very important to continue to conduct regularly scheduled inspections while the aircraft remains in long-term storage, Harwick added.
One area that can be overlooked when parking or storing an aircraft is the preservation of its exterior and interior, according to Immaculate Flight director of operations Phillip Hoyme. Hoyme, whose company specializes in aircraft cleaning, said that it means having a professional clean and apply protection to the aircraft’s exterior and interior before parking or storing it. Doing so will help ensure the paint remains undamaged and prevent things like mold and mildew developing in the cabin.
“You would much rather protect than restore on the back end,” he said. Hoyme added that keeping an aircraft parked or stored in a cool environment is optimal for its preservation and return to service. That includes putting a sunscreen in place in the cockpit and lowering the window shades in the cabin.
Desiccant can also be used inside the airplane to prevent any moisture build-up as long as the bags are changed once full. Moreover, he said, it’s a good idea to regularly air out the cabin of the airplane by opening all access points, including the baggage compartment. “You really want to make sure you’re getting air moving through the cabin as much as possible,” Hoyme said.
Perhaps just as important is documenting everything that is done to the airplane while it is parked or stored, Winkle suggested during the webinar. Doing so could avoid a lot of hassles later on for the owner or operator when it comes to selling the aircraft.
“It’s important to document that stuff, and document what you’re doing right now so that you’re not challenged,” Winkle said. “Because it could have an impact on value, it could have an impact on your deal down the road.”