Here at the Smart Aviator we’re delighted to already hear from supportive readers asking for more maintenance and shop-related content. We agree—there needs to be more of it and our staff techs are ready to deliver.
One fan wrote with an interesting question worth talking about. His airplane has been sitting for much longer than it should, and based on the number of birds we see in our travels parked with flat tires and bird droppings on the cowling, it’s too common. He asked for some basic tech tips to consider when flying the airplane for the first time after it’s been sitting dormant for nearly five months parked in the tiedown. A lot of it is common sense.
Look It Over—Closely
Clearly, there are several important steps to perform before launching on the first flight, which should start with a careful fuselage check for damage, corrosion or critters camping out in places where they don’t belong. Tires need to be carefully inspected for sidewall cracking that occurs while sitting. Hopefully, you ensured that your tires never got to the point of becoming completely deflated, because if they did there is a distinct chance that you damaged your tubes by pinching them on the rims or damaged the cord of the tires. We see plenty of it.
Be sure to check the sidewalls especially carefully for cracking, and while some cracking is permitted, the basic guideline is if any cord shows through a crack the tire is history. And of course, be sure to check and inflate the tires back to book values before flying.
Got Enough Juice?
If you wanted to give max life to your battery, you removed it before letting the plane sit and put it in a climate-controlled area and on a battery tender. If not, be sure to properly charge it up with a bench charger the first time so the full reserve power is available if the charging system should give out. If you have a flooded battery, be sure to check and service it with distilled water before bench charging. Follow this with a check of specific gravity using a hygrometer. If there’s any doubt, bring it to a shop for testing.
Will It Roll?
Another problem area is air/oil type struts, whether just the nosewheel as on many Cessnas or all three wheels with air/oil struts as with many Pipers. Prolonged sitting promotes them losing air or oil or both, causing them to go flat. If there is no sign of oil on the strut, possibly servicing with only air will do the job. One thing that you do not want to do is taxi with a totally flat strut—even a short distance across the ramp. Without the cushion effect of the strut, amazing G loads are transferred to the airframe with any bumps in the taxiway. A portable air bottle (nitrogen) with an appropriate regulator can easily get the strut back to serviceability—if only to get it to the shop to determine if more than air loss is the problem.
Before springing for a strut overhaul (see what we did there?) give a shot of Granville strut seal a chance to work its magic. If the problem is seals that have become a bit hard and not wholesale corrosion of the strut or seals, then strut seal is a low-cost cure. This is one case of snake oil that does do the job when used appropriately.
Lubrication Matters
Even if you changed the engine oil prior to putting the bird up for long-term storage, we and the manufacturers unanimously recommend that you change the oil before that first start. Oil sitting for months will deteriorate in a crankcase due to the natural processes of acidification from combustion by-products and moisture.
Of course, if you did the proper thing and actually followed manufacturer guidelines for 30 days of storage or more (we’ll cover that in detail in a future report) there will be several additional steps to perform in getting the engine ready to run. Check with the appropriate engine manufacturer for the latest service letters dealing with long-term storage.
Regardless, if you have not run the engine in several months the best thing you can do is motor the engine with the starter to develop oil pressure before the regular start. Otherwise, you will be subjecting the engine to a substantial amount of time running without any oil on the cylinder walls or other vital areas.
Avionics Don’t Like To Sit
Last, do a good ground run and systems check before launching. This includes looking closely at gyros and autopilot operation. Follow the preflight check in the flight manual or flight manual supplement if it’s an aftermarket system. You want to be sure the servos engage and disengage properly and that you can pull power off the system should it malfunction. Check the trim system (electric or manual) for binding and proper operation, and get a radio check from the tower or someone else on the ground to make sure it all works. Moisture doesn’t do good things to electronics and it’s a problem when sitting for long periods.
Choose Your Battles
Finally, be smart and don’t fly the aircraft on a long trip (or in IMC) on the first flight after storage. Shake it down locally and in decent weather—you’ll have more confidence in it when you do launch and with luck, no unexpected failures.
Check and double check for water in your fuel tanks and gascolator. Ensure your pitot tube isn’t home to bugs etc.
The most important point mentioned in this article is “if you did the proper thing and actually followed manufacturer guidelines for 30 days of storage or more…”
After preflight, ground run and peer into same places looking for things that don’t belong, only then Day/VMC shake it out above origin’s traffic pattern so gliding back to runway is easily made, land back at origin and look again in same places.
Hopefully you have a good relationship with your annual mech; ask him to come over, he’ll appreciate not being tasked with mishap paperwork/interviews later.
Be sure the fuel is fresh as it ages in the tank. At least add new fuel (which you were probably going to do anyway if they were low). If tanks were full and sat for an extended time (year plus?) I’d drain at least half and replace with fresh fuel.