Engineering Sign-offs

[Steak&Kidney_Pie]

Morning all.

A quick question for the experts out there. My aircraft owner friend is thinking about a mod to his aircraft, which involves flying the aircraft out to the states for a "engineering sign off" to complete the work with a US outfit. The company do not currently hold an STC on type, for the mod. Where do we stand in EASA land? The aircraft is on the Manx Reg. I thought that only STCs could be used in EASA land? Am I confused?

Thanks for any help and advice,

SKP

[Genghis the Engineer]

Is it an EASA aeroplane?

Also, what's the nature of the mod?

Finally, surely it's cheaper and safer to have the DER fly to the IOM/UK than take the aeroplane to the US?

G

[Steak&Kidney_Pie]

Genghis,

It is an EASA aircraft, its a mod to reduce the cabin noise by replacing the cabin insulation/lining, to reduce cabin noise by 28%. Its STC'd in the States on other types, but not ours. They said they can do it, but only on an engineering sign-off. Hence where my confusion began. Where do I stand over in EASA land?

As for the US, we may be going over there for a while anyhow, so its not too much of a problem. As a matter of interest, and excusing my lack of knowledge, but who/what is a DER?

Kind Regards, SKP

[Mr @ Spotty M]

My understanding is that you can not if the STC does not have an EASA approval number.
However you can if you get a EASA approved company (Part 21 l think) to produce the mod.
This is not my field but Genghis will confirm my opinion or put me right, as he is the expert on these matters.

[om15]

IOM Registry Certification

SKP,

If your aircraft is registered on the IOM Register the EASA Rules do not apply, the reference documents that detail the requirements are the IOM ANO and the Registry Publications ( RPs), the RP9 gives full information on this, basically as below

Changes (modifications/repairs)
The Aircraft Registry normally accepts modifications and repair data produced and approved under the control of the Type Certificate Holder and the regulatory system of the state of design. Changes approved in accordance with EASA and FAA rules are normally accepted; however a review of Supplemental Type Certificate (STC) will be completed for suitability and compatibility with the aircraft in question. For further information concerning Acceptable Means of Compliance (AMC) with the Air Navigation (Isle of Man) Order 2007, please review the documents in the Airworthiness Information section of ‘Registry Publications’ at www.aircraft.im

If you need further information regarding IOM certification requirements please pm me with a specific question and I will try to help,

BR om15

[Genghis the Engineer]

This is not my field but Genghis will confirm my opinion or put me right, as he is the expert on these matters

Unfortunately not true - CAA trust me as a design and flight test signatory up to part 23, which I manage to navigate my way around. Whilst the engineering process is substantially the same, the EASA paperwork/regulatory process leaves me as bewildered as anybody else.

One of many criticisms that you could place on EASA is that they have historically made little of the effort that other more mature authorities do to explain their processes for aircraft owners. To be fair to them (and I rarely am), they seem to be working on that - for example here, although it's far from complete.

On which subject, the basic description of the modification sounds like a minor-change, not an STC to me, which should be pretty straightforward to get through EASA, in theory at-least.

A DER is an FAA-authorised independent design signatory who can approve modifications on behalf of the FAA. It actually standards for "Designated Engineering Representative", it's an interesting system with both strengths and weaknesses - but regardless, there's no equivalent system in Europe, so it's not available and means that many FAA approved mods are very hard to implement over here.

G