Safety bulletin N1 from 11/17/2001

Dear Friends,

We are addressing this message to Aeros' distributors and dealers, owners of Aeros' trike wings and all trike pilots regardless of what wing they fly.

There was a catastrophic failure of a Stream 16 leading edge in the USA on November 17, 2001. At this point, the exact cause is undetermined.

The wing was manufactured in September 1999.

The manager of Aeros Ltd. Alexander Voronin, who in the past was a structural engineer at the Antonov Design Bureau, visited the USA at the end of February 2002, attending EAA meeting and intending to inspect the wreckage. Unfortunately he wasn't given an opportunity to do this.

There is also a report that another Stream 16 wing was found with what looks like a flaw in the leading edge, at or near the location of the previous problem. We have no reasons to associate the flaw discovered in this second wing with the leading edge failure of the first wing, simply because we don't have enough information at the moment.

However, being cautious - without alarm - is prudent.

Any engineer knows that upon inspection, the fracture pattern will show clearly and unambiguously if the reason of the failure was a crack. To determine if this is the case, it is necessary to inspect the wreckage.

When either we or our distributor in the US - Richard Helm of Sabre Aircraft have such opportunity, we will inspect this wreckage. You can rest assured that further information will be posted by Aeros on this website and others.

In the meantime, we would like to avoid speculation and stop rumors, we would like to inform you as follows:

Before 2000, the tubing used in the construction of Aeros trike wings was anodized in a manner that left cosmetic flaws on the tubing. This anodizing method has since been changed, but it is important that when inspecting your wing, that you know the difference between a cosmetic flaw and a flaw that affects the structural integrity of the aircraft. We have posted a photo of a tube with a cosmetic flaw on our website. Do not be alarmed if your 'pre - 2000' wing has this surface flaw. Click here

If you have concerns about an area of question, feel free to send the tube to your local dealer or an Aeros distributor for inspection. Also, you may email us or our distributors any digital photo of an area of concern for a more professional assessment.

Feel free to contact either of the following for advice on your tubing:

Aeros Ltd: aerosint@aerosint.kiev.ua
Richard Helms - Sabre Trikes: sales@sabretrikes.com 623-393-0234
G.W. Meadows - U.S. Aeros: gw@justfly.com 252 480 3552

We would like to point out that a problem of concern with our tubing would be rare and we do not expect an ongoing problem. However it is important to exercise caution until the exact cause of failure is determined. We would like to remind you that wing checks should be performed on a regular basis, this concerns not only checking the tubing, but other parts of the wing as well.

Section 4 of the Aeros Stranger/Stream trike wings manual reads as follows:


Section 4. INSPECTION OF THE WING

The sail should be inspected once every three months or after each 50 flying hours. The frame should be inspected once a year, after every 100 flying hours, and after every hard landing.

4.1. SAIL CHECK-UP

4.1.1. Sail seam and cloth strength are assessed by testing the strength of the control clouts on the top surface (TS) of the wing. The control clouts are incorporated in the cloth piece (designated by letters UV) that is sewed onto the trailing edge close to the keel tube. For sail assessment cut control clout in the drawing and forward it to your Aeros dealer or directly to Aeros. The first sample is to be cut out after 300 flying hours and thereafter a sample must be submitted after every 150 flying hours.

4.1.2. Checking the sail surface and seams. There should be no cuts, ruptures, threadbare holes and torn seams on the sail. Any torn seams should be re-stitched. Cuts and ruptures on the fairing and bottom surface (BS) of the sail that are not longer than 30 mm can be patched up with self-adhesive Dacron. The Dacron must be of a weight of not less than 100 g/m. Larger cuts and ruptures are to be repaired by stitching on a reinforcing piece of the same fabric (stitched along the edges). Any rupture shorter than 50 mm can be repaired in this manner, but more complicated repairs should be carried out in the workshop of producing company. If any of the batten tightening cords are torn or heavily worn they must be replaced.

4.1.3. Keep an eye on the sail grommets/eyelets and all areas of the sail that are subject to extra stress, especially the keel section, the nose section of leading edge and the outer tip section of leading edge.

4.2. CABLE SYSTEM

The cables must be checked for broken wires. If any defect on a wire is observed, no matter how small, the cable in question MUST BE REPLACED. It is recommended that the entire cable system be replaced once every two years irrespective of service conditions.

4.3. CHECKING THE TUBINGS

To check the condition of the wing tubes the sail should be removed from the wing frame and the tubes should be detached at the joints. The tubes are to be inspected visually. When there is suspicion of damage, the points in question should be inspected using a magnifying glass of (5-10)X magnification. There should be no trace of corrosion, cracks, bends or dents.

4.4. CHECKING THE BATTENS

The batten profiles should be checked against the template and the bends should be adjusted if necessary. Check all the plastic batten heads and tails and replace if necessary.

4.5. FASTENERS

Check all fasteners (bolts, screws, rollers, nuts, splint pins etc.) for corrosion. Any corroded fasteners should be replaced. Bolts should not be worn and/or bent. Key bolts should be checked most thoroughly for cracks between the head and the bolt body. These are the bolts at the control bar side and bottom joints, the central spreader bar tensioning cable attach point and the rear cable attachment point on the keel tube. If any cracks are observed - REPLACE IMMEDIATELY!

 

Observing these requirements you ensure your own safety and safety of your customers. In view of the abovementioned we at Aeros address all our distributors, dealers and customers to make a thorough check of your wings, especially the tubing, paying most attention to the outer leading edge tube (leading edge tube No. 3) before the next flight. If customers are unable to perform checks themselves, this should be done by Aeros' dealers. Should any cracks be discovered in the tubing in Aeros' wings, such tubes will be replaced by Aeros free, including transportation, through the network of dealers. In case a pilot finds abrasions on the tubes which occurred in the process of normal use of the wing, the replacement tubing can be ordered through the dealers' network.

Wishing you safe and enjoyable flights,
Aeros team