* AvCanada's Home Page * Photo Gallery * Topsites *Weather * Media Kit
It is currently Mon Apr 21, 2014 7:43 am



All times are UTC - 8 hours [ DST ]





Post new topic Reply to topic
 [ 7 posts ] 
Author Message
 Post subject: STC required?
PostPosted: Sat Jul 16, 2011 6:30 am 
Offline
Rank 3
Rank 3

Joined: Wed May 07, 2008 8:44 pm
Posts: 196
Just wondering...

If an aircraft for example has a standard fuel cell (for example Cessna 172N), but for that model/year Cessna offered an optional higher capacity fuel option (eg 1979, it offered a 66 gallon capacity).

Will it generally require a STC at this time to move from the standard cell to Long Range fuel cell? Not talking about going from bladder to wet wing. Or is it reasonably straightforward, from a paper perspective, to make the change?



Top
 Profile  
 
 Post subject: Re: STC required?
PostPosted: Sat Jul 16, 2011 12:31 pm 
Offline
Rank 11
Rank 11

Joined: Sun Jun 19, 2005 6:43 am
Posts: 3069
Location: Canada
Your first step is to see if Cessna has a service bulletin to embody that modification. If they don't then you pretty much need to go the STC route and that might not be easy.

Cessna might have made specific changes to the structure or fuel delivery system to accommodate the extra fuel capacity. An STC would need to consider all aspects of the modification without the benefit of Cessna's engineering.



Top
 Profile  
 
 Post subject: Re: STC required?
PostPosted: Sat Jul 16, 2011 1:06 pm 
Offline
Rank 4
Rank 4

Joined: Thu Jun 16, 2011 11:04 am
Posts: 238
Location: Central Canada
You do not STC something that is on the type certificate.

_________________
If we can put oil in the engine while we're flying then we have absolutely no problem at all.


Top
 Profile  
 
 Post subject: Re: STC required?
PostPosted: Sat Jul 16, 2011 2:03 pm 
Offline
Top Poster
Top Poster
User avatar

Joined: Tue Apr 15, 2008 12:25 pm
Posts: 6372
Location: The Misty Mountains...
You don't need an STC to have something that is already incorporated in the type design, but you need to incorporate everything that is in the type design when installing it, and it might not be very easy to find that data. The first person who says 'just use the IPC' gets 50 lashes with a wet noodle! :D

Due to the huge amount of modification required, probably the only practical way to do it would be to find a set of wings with LR tanks installed and perform the necessary maintenance required to install them (installing control cables, controls, flap motor, testing fuel tanks, vents, and sending units, wiring if it has been damaged or removed, probably a zillion other small details). Still not an easy undertaking.

I would imagine a ship set of good wings with LR tanks commands a premium over standard tanks.

This is probably why there are lots of STCs for LR tanks out there, like Flint Tips for the 172.

http://www.flintaero.com/Cessna_150-205.htm


_________________
Geez did I say that....? Or just think it....?


Top
 Profile  
 
 Post subject: Re: STC required?
PostPosted: Sat Jul 16, 2011 6:23 pm 
Offline
Rank 11
Rank 11

Joined: Wed Feb 18, 2004 7:17 pm
Posts: 3700
Location: West Coast
I believe there is an STC that adds the L shaped extensions to the standard 38 gal system tanks to make them the same as the 49 gal factory long range tank. As I understand it you get a appropriately approved shop to weld on the extension and then do the necessary wing sheet metal work to fit it. I have no idea who has the STC but you could try talking to the cessna type club.


Top
 Profile  
 
 Post subject: Re: STC required?
PostPosted: Sun Jul 17, 2011 7:29 am 
Offline
Rank 3
Rank 3

Joined: Wed May 07, 2008 8:44 pm
Posts: 196
Thanks. My take away: possible, but not straight forward or necessarily easy/cheap.


Top
 Profile  
 
 Post subject: Re: STC required?
PostPosted: Sun Jul 17, 2011 6:06 pm 
Offline
Rank 11
Rank 11

Joined: Sun Jun 19, 2005 6:43 am
Posts: 3069
Location: Canada
A couple of people stated that you don't STC something on the type certificate. That is true. If you can get a copy of the installation data and it's eligible for installation on your specific serial number.

But (as I stated) if your serial number isn't covered, you can STC it using the installation data but you'll have to come up with engineering data.

It's a fairly common myth that if you can make it look like the IPC you can install it. Not true. Systems that are approved under the type certificate may have specific additional requirements to accommodate the modification. That's why the first place to go is the manufacturer and see if a service bulletin is available for post production installation. If not.....STC like I said.



Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 


All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 6 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group

 
For questions/comments please send them to
webmaster@avcanada.ca


AvCanada Topsites List
AVIATION TOP 100 - www.avitop.com Avitop.com

While the administrators and moderators of this  forum will attempt to remove or edit any generally objectionable material as  quickly as possible, it is impossible to review every message. If you feel a  topic or post is inappropriate email us at support@avcanada.ca .  By reading these forums you acknowledge that  all posts made to these forums express the views and opinions of the author and  not the administrators, moderators or webmaster (except for posts by these  people) and hence will not be held liable. This website is not responsible or liable in any way for any false or misleading messages or job ads placed at our site.   

Use AvCanada's information at your own risk!

We reserve the right to remove any messages that we deem unacceptable.
  When you post a message, your IP is logged and may be provided to concerned parties where unethical or illegal  behavior is apparent. All rights reserved.