Sting Sport Owners: Is Your Nose Your Achilles Heal?

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

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drdehave
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Sting Sport Owners: Is Your Nose Your Achilles Heal?

Post by drdehave »

After 550 hours and my fair share of mechanical issues in 16 months flying my Sting Sport (SN154), I've arrived at a realization: The two most important (besides the 5-yr rubber replacement) Sting Sport Service Bulletins that you (we) have are TL11507 and TL091507, dealing with the nose-gear strut.

Whether you are an owner or prospective buyer, you should go to the Sting + Sirius website and click on “Support,” then “Notices.” Be familiar with these Service Bulletins, dealing with the requirement for a replacement (upgraded) nose gear strut for SNs 161 and below (11507) or, if not replaced (i.e., on SN161 and below), the required 25-hour nose-strut inspections (091507).

Ignoring these bulletins--and good, regular maintenance practices and pre-flighting of the nose-gear--could result in a bad outcome. The attached photos show Sting Sport N2UC's recent bad outcome (cause not yet reported) and it is not the first one to break the nose strut off cleanly in the area of the bolt-travel slot (the main problem area).

Checking and maintaining the nose-gear and strut are really pretty simple and painless. During pre-flights, have one person put his weight on the fuselage, just fore of the tail, to raise the nose-wheel clear of the ground. Have a second person check the nose wheel for any excessive side-to-side “slop.” I do this at a minimum, every 20-25 hours, depending upon whether my landings in the interim have been "nice" or not. If any excess or "new" slop is detected, drop the wheel assembly off the strut tube and check strut components for signs of metal stress and cracks (a simple, 10-minute procedure requiring one bolt to be removed; see instructions under “How To” at the Sting website). It is also a very good idea to periodically replace the nose-gear bolt, because they develop flat spots from getting beat around in the travel slot.

When I purchased my used Sting Sport, it did have the replacement strut. However, it too, was cracked and bent--from some bad landings by somebody before me. The bend in the strut was causing the right rudder to occassionally stick (Oh yes, that felt nice!). This abused strut was replaced 500 hours ago, and thankfully, has been operating like a top every since, handling my 1400 landings safely and soundly--w/ no signs of "stress" yet.

Follow the Bulletins and proper maintenance, and the nose-gear is not the airplane's Achilles heal. Nevertheless, keeping the nose up and light on landings is the best way to avoid serious issues.--RD

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