EASA AD on SZD-55-1 "ATA 27 – Flight Controls – Elevator Control System / Vertical Tail – Inspection" Issued

As expected, EASA issued the AD - 2018-0081 - 11 April 2018, with an effective date of 25 April, with 60 days to accomplish a one-time inspection. If discrepancies are noted, repairs must be completed before the next flight.

I include a link to the AD on the Transport Canada AD website http://wwwapps3.tc.gc.ca/Saf-Sec-Sur...U2018-0081.pdf . I imagine there is a similar link on an FAA site.

There's one in our club and it passed the inspection. Actually I would be interested to know if any 55's except the accident glider have had the opening on top of the fin enlarged as it did. I'm amazed that even one glider had been hacked away at in that manner.

On Monday, April 16, 2018 at 3:36:42 AM UTC-4, wrote:
There's one in our club and it passed the inspection. Actually I would be interested to know if any 55's except the accident glider have had the opening on top of the fin enlarged as it did. I'm amazed that even one glider had been hacked away at in that manner.

From the AAIB report: "...One other SZD-55-1 glider in the UK fleet inspected by the AAIB, also appeared to have a marginally enlarged elevator slot, of which the owners were unaware. These findings indicate the possibility that such modifications may have historically been considered acceptable among glider owners...".

On Monday, April 16, 2018 at 12:36:42 AM UTC-7, wrote:
There's one in our club and it passed the inspection. Actually I would be interested to know if any 55's except the accident glider have had the opening on top of the fin enlarged as it did. I'm amazed that even one glider had been hacked away at in that manner.

The elevator hookup of the SZD-55 is not visible, so it cannot be inspected after assembly. The only means of verification is a positive control check.. The report does not mention if this was performed.

My old DG400 has a similar elevator hookup. DG, however, included a plexiglas inspection window in the tail so that the proper assembly could be verified. Nonetheless, I know of at least one flight where the glider was misassembled, and the elevator lever was jammed next to, and not in, the pushrod horn. The pilot flew the glider in this condition successfully, and did not learn of the problem until he derigged the glider. Having had one accident due to this exact situation (ASW19), I was particularly careful in ensuring this, and all other, assembly steps were properly completed. Perhaps the SZD-55 could use an inspection window like the DG400.

FWIW, this may be one of those situations when "It goes without saying,"
doesn't, so...

A positive control check isn't - or shouldn't be - "merely a control
resistance" check; it's (easily - and should be) also a "control position
check," as everyone who's ever built flying model airplanes intuitively knows.
Use the next unflyable day - or boring day at work - and play with paper
airplanes to help burn this "goes without saying" truism into your neurons!

Bob W.

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On Mon, 16 Apr 2018 10:06:28 -0600, BobW wrote:

Use the next unflyable day - or boring day at work - and play with paper
airplanes to help burn this "goes without saying" truism into your
neurons!

Or, for something fractionally more advanced than folded paper, try
making one or two of Chuck Marcos 'Easy Mini' catapult gliders. These
will teach you a lot about control surface effects and also fly well
enough to vanish upwards if you launch then into thermals.

See the AMA magazine "Model Aviation", May, 1999, pages 45-48 for a full-
size plan and instructions.

If you can't get hold of the magazine article, my website has copies of
the plan in various formats along with information about the tools and
materials needed to build them plus guidance on building and flying:
https://www.gregorie.org/freeflight/easymini/


--
Martin | martin at
Gregorie | gregorie dot org