anyone here an faa structural der?

[gtbuzz]

anyone here an faa structural der? i've got a question for you!

 

[KLin]

Lurker alert!!

 

[gtbuzz]

how so? i'm just asking a question

 

[Sukhoi]

A what?

 

[gtbuzz]

DER = designated engineering representative

in this case i'm looking for a structural der, someone the FAA has decided has enough experience and knowledge to to approve engineering certification data, etc. for planes certified under FAR (federal aviation regulations) 23/25. basically they're the FAA approval by proxy.

i've only worked in the military world myself so it's a little different. if anyone out there does know, my question had to do with the certification process under far 25. was something i was thinking about on the way home (i'm an engineer. we think about kooky things).

 

[OrganizedChaos]

Originally posted by: gtbuzz
how so? i'm just asking a question

exactly! lurker confirmed.

 

[rahvin]

Originally posted by: gtbuzz
DER = designated engineering representative

in this case i'm looking for a structural der, someone the FAA has decided has enough experience and knowledge to to approve engineering certification data, etc. for planes certified under FAR (federal aviation regulations) 23/25. basically they're the FAA approval by proxy.

i've only worked in the military world myself so it's a little different. if anyone out there does know, my question had to do with the certification process under far 25. was something i was thinking about on the way home (i'm an engineer. we think about kooky things).

I assume when you say structural you mean mechanical who approves plane structures, or are you talking a real structural engineer who deals with structures (buildings, bridges, etc)

 

[Pepsi90919]

a faa structural der. yes that makes lots of sense.

 

[gtbuzz]

Originally posted by: rahvin
I assume when you say structural you mean mechanical who approves plane structures, or are you talking a real structural engineer who deals with structures (buildings, bridges, etc)

well, we're still structural engineers, it's just a different world. what you're thinking of is a civil engineer. when someone signs of on one of those drawing's they usually have a PE (professional engineer) certification. there's all different types of PE's including mechanical, civil, etc, but there's not one specific to the aerospace industry so it really doesn't hold much water. a DER's the closest thing to it but that's only the commercial side - there's not really a military equivalent (the certification process is different).

from a technical aspect, the main difference (the basic theories are the same, but that's about it) is that aircraft structural engineers (as opposed to ones in detroit for the auto industry or civil engineers for buildings) for the most part deal with thin-walled structures. one of the basic assumptions that we can make on a lot of structure is that because it's thin we'll only develop a 2-dimensional stress field (sigma z = 0). that, and you won't see much concrete on planes.

oh and for everybody throwing out "lurker" what in the world is that? this is an off-topic forum isn't it? so whats the big deal - not like i'm posting anything just to rile people up. just a thought - if some makes a fau paux how about just letting 'em know what's up instead of insulting them. just a thought.

 

[Sukhoi]

Lurker just means you've been here a long time and haven't posted much.

And I will be an engineer soon, so I know most of what you're talking about.

 

[gtbuzz]

Originally posted by: Sukhoi
Lurker just means you've been here a long time and haven't posted much.

And I will be an engineer soon, so I know most of what you're talking about.

see, that wasn't too hard now was it? i don't think i've looked at this board in probably a year or two but i figured it was worth a shot. the aviation-related ones are usually to small to garner a bunch of views.

congrats. what kind of engineer?

 

[rahvin]

Originally posted by: gtbuzz
well, we're still structural engineers, it's just a different world. what you're thinking of is a civil engineer. when someone signs of on one of those drawing's they usually have a PE (professional engineer) certification. there's all different types of PE's including mechanical, civil, etc, but there's not one specific to the aerospace industry so it really doesn't hold much water. a DER's the closest thing to it but that's only the commercial side - there's not really a military equivalent (the certification process is different).

I'm well aware of what an Engineer is as I am one, Civil with a PE. What I was trying to point out is that I don't consider you a structural engineer. You're a mechanical engineer.

 

[gtbuzz]

Originally posted by: rahvin
I'm well aware of what an Engineer is as I am one, Civil with a PE. What I was trying to point out is that I don't consider you a structural engineer. You're a mechanical engineer.

that's interesting... when i think mechanical engineer i usually think someone working on gears or something moving. for example the mechanical engineers i work with designed the landing gear mechanism on our plane. they do most of the dynamics-type calculations, whereas i do the static and fatigue life calculations. but i'm sure there'll be someone with 'mechanical engineer' for their title that can jump in and say that's not what they do at all.

'a rose by any other name' huh?

 

[Sukhoi]

I'll be a ME in a semester.

Personally I think an AE is much closer to a ME than a CE.

 

[gtbuzz]

Originally posted by: Sukhoi
I'll be a ME in a semester.

Personally I think an AE is much closer to a ME than a CE.

ae = me much more than ae = ce, that's true. but when you think about it, it's all physics and really similar. when we've got an open req out for an engineer the degree's we look for are ae/me/ce.

good luck out there by the way. also since you're about to graduate, if i can offer a bit of advice - if you're at all thinking about grad school, absolutely without any doubt whatsoever go ahead and do it now. it's 1000x harder to do it after you've been out for a while.

 

[skyking]

PM me your question, or post it here. My partner is a DER.

 

[gtbuzz]

Originally posted by: skyking
PM me your question, or post it here. My partner is a DER.

thanks!

i'm just curious how the certification process works. i've got a friend who does aerial photography out of a few different types of planes. for example if i were to whip up a design for some pod that hangs off the wing or a special window mod (both of which are already commercially available - it's just for curiosity sakes). if it were to go through the full blown process and get an STC, what would i have to do? if it's an aftermarket mod, where do the loads come from? what would it take for me having designed and stressed my own part (and perhaps tested it too) to convince a DER that i did my job right?

as far as the military is concerned, half the time if the customer wants something they go back to the original manufacturer. we've got all the original analysis so that part's easier. basically for us, we'll draw something up, analyze it and convince them that what we did is right. depending on the category of structure we may or may not have to test it.

 

[skyking]

He is also an A&P with IA, and had done dozens of one-time STCs.
It really helps to have a relationship with the local FAA office, when it comes to carving on a certificated aircraft.
The one-time STC is what you are looking for?

 

[gtbuzz]

Originally posted by: skyking
He is also an A&P with IA, and had done dozens of one-time STCs.
It really helps to have a relationship with the local FAA office, when it comes to carving on a certificated aircraft.
The one-time STC is what you are looking for?

well i guess it doesn't really matter - although i'm sure for something that's more than a one and done it would require a bit more substantiation. when my friend was describing how he takes photos, it mostly involved sideslipping the aircraft and aim and shoot. i got to thinking it would be kinda neat if i could fab up something to mount externally. was just curious what it entails to get it approved.

 

[skyking]

There is a great deal to consider. If it hangs down under the wing, you would need to go through all the stall and spin testing, all over again. Test pilots, parachutes, test pitot systems, the works.
Also, how will your friend aim this camera? Having it in-hand is the quickest, most accurate way to align a camera in flight for oblique shots. Try as you might, it is tough to get the wing on-point and also get the light position just right.

 

[gtbuzz]

hah, there's obviously quite a few things i havent considered (being purely hypothetical). i can see the stall/spin testing since it's in the freestream. what if it were something that didn't change the oml, such as a window installed somewhere?

 

[skyking]

Then you'd have to engineer the lost structural from whacking a hole in it. much easier to do
Edit: I fly a c310 with huge camera holes in the belly. They have various added girdles or other members to take up the loads.

 

[Sukhoi]

Originally posted by: gtbuzz

Originally posted by: Sukhoi
I'll be a ME in a semester.

Personally I think an AE is much closer to a ME than a CE.

ae = me much more than ae = ce, that's true. but when you think about it, it's all physics and really similar. when we've got an open req out for an engineer the degree's we look for are ae/me/ce.

good luck out there by the way. also since you're about to graduate, if i can offer a bit of advice - if you're at all thinking about grad school, absolutely without any doubt whatsoever go ahead and do it now. it's 1000x harder to do it after you've been out for a while.

Thanks! It's been rough at times but now I get a semester to coast before the real world. I've actually already applied to grad school. I don't think my grades are high enough to get in, but even if I do I'm not sure I have the drive to do it anymore. Any grad school I do well after graduating is going to be an MBA. I'm not crazy enough to try engineering then.