Dg300 spar problem - sn

[[email protected]]

Is it known which serial numbers actuallly had spar problem?
Conversely is it known which serial numbers were found to be ok after inspection?

A

[[email protected]]

The T/N and AD apply to all serial numbers. Elan didn't keep track of when they started deviating from the approved method of making the parts and substituted their own whimsical idea so the only way to find out is to open the wing up and look. By doing this you can tell if a particular DG300 has the spar problem or not but you can't tell by serial number.

The AD doesn't reduce the usability of the glider that much if so it probably isn't worthwhile cutting things apart for inspection to determine if a particular DG300 has a spar conforming to the original design or not. Might be worth looking around in there if you're already doing a serious wing repair as a result of an accident though.

[[email protected]]

Yes I know, but having this info might be an indication of since when this practice has been started by ELAN

S

[Bruce Hoult]

On Wednesday, October 19, 2016 at 6:56:39 PM UTC+3, wrote:
> Is it known which serial numbers actuallly had spar problem?
> Conversely is it known which serial numbers were found to be ok after inspection?

I hadn't previously been aware of this and was puzzled by this message. If anyone else is in the same situation, here is a description of the problem by our own Bob K from 2007:

http://www.hpaircraft.com/misc/dg300spars.htm

[[email protected]]

On Thursday, October 20, 2016 at 5:43:58 AM UTC-7, wrote:
> Yes I know, but having this info might be an indication of since when this practice has been started by ELAN
>
> S

Yes it would, but ELAN never kept track of when they started doing it. The only way to find out now would be to cut into every DG300 wing and see. Aside from the glider in which the defect was initially discovered I haven't heard of any other DG300 owner opening up their wings so we don't have a significant amount of data as to which gliders have been proven to have the problem.

[Bruce Hoult]

On Friday, October 21, 2016 at 7:02:44 AM UTC+3, wrote:
> On Thursday, October 20, 2016 at 5:43:58 AM UTC-7, wrote:
> > Yes I know, but having this info might be an indication of since when this practice has been started by ELAN
> >
> > S
>
> Yes it would, but ELAN never kept track of when they started doing it. The only way to find out now would be to cut into every DG300 wing and see. Aside from the glider in which the defect was initially discovered I haven't heard of any other DG300 owner opening up their wings so we don't have a significant amount of data as to which gliders have been proven to have the problem.

Assuming they simply started this construction technique at some point in time, and didn't start-stop-start it, you don't have to open EVERY wing.

If the wing of SN #N is opened for any reason and found to be ok, then you can assume that all lower SNs are ok too. Conversely, if it's not ok, then you can assume that all higher SNs are bad too.

[Tango Whisky]

> Assuming they simply started this construction technique at some point in time, and didn't start-stop-start it, you don't have to open EVERY wing.
>
> If the wing of SN #N is opened for any reason and found to be ok, then you can assume that all lower SNs are ok too. Conversely, if it's not ok, then you can assume that all higher SNs are bad too.

No, you can't. If for some reason (end of shift, lunch break,...)there was more time between the epoxy filling and the lay-up of the spar cap, there wouldn't be any ondulations.
The only valid assumption is that all S/N's are affected.

[Bruce Hoult]

On Friday, October 21, 2016 at 11:26:02 AM UTC+3, Tango Whisky wrote:
> > Assuming they simply started this construction technique at some point in time, and didn't start-stop-start it, you don't have to open EVERY wing.
> >
> > If the wing of SN #N is opened for any reason and found to be ok, then you can assume that all lower SNs are ok too. Conversely, if it's not ok, then you can assume that all higher SNs are bad too.
>
> No, you can't. If for some reason (end of shift, lunch break,...)there was more time between the epoxy filling and the lay-up of the spar cap, there wouldn't be any ondulations.
> The only valid assumption is that all S/N's are affected.

Even given what you say, if you find a bad one then all later ones are at least suspect.

[Tango Whisky]

> Even given what you say, if you find a bad one then all later ones are at least suspect.

Absolutely.

[Eric Munk]

At 13:13 21 October 2016, Bruce Hoult wrote:
>On Friday, October 21, 2016 at 11:26:02 AM UTC+3, Tango Whisky wrote:
>> > Assuming they simply started this construction technique at some
point
>in time, and didn't start-stop-start it, you don't have to open EVERY
wing.
>> >
>> > If the wing of SN #N is opened for any reason and found to be ok,
then
>you can assume that all lower SNs are ok too. Conversely, if it's not ok,
>then you can assume that all higher SNs are bad too.
>>
>> No, you can't. If for some reason (end of shift, lunch break,...)there
>was more time between the epoxy filling and the lay-up of the spar cap,
>there wouldn't be any ondulations.
>> The only valid assumption is that all S/N's are affected.
>
>Even given what you say, if you find a bad one then all later ones are at
>least suspect.
>

I would agree with the manufacturer's findings saying that ALL DG-300's are
suspect, regardless of s/n. That is why the TN applies to all aircraft.

I know of three DG300 that have had the wings opened up (a costly affair).
Two of them were found to have issues that needed rectification. The OK one
had a higher s/n than the ones which needed work.