Go Back  PPRuNe Forums > Non-Airline Forums > Private Flying
Reload this Page >

Pencil dropped in PA38 tank

Wikiposts
Search
Private Flying LAA/BMAA/BGA/BPA The sheer pleasure of flight.

Pencil dropped in PA38 tank

Thread Tools
 
Search this Thread
 
Old 26th Oct 2014, 18:28
  #21 (permalink)  
 
Join Date: May 2001
Posts: 10,815
Likes: 0
Received 0 Likes on 0 Posts
Fakepilot if you want I can send you 100 authentic Scottish fag lighters if you like call it 10$ each.
mad_jock is offline  
Old 26th Oct 2014, 19:05
  #22 (permalink)  
 
Join Date: Sep 2002
Location: Garstang, Preston, UK
Posts: 97
Likes: 0
Received 0 Likes on 0 Posts
Lost the flexible end of a jerry can filler pipe in a Jodel fuel tank. Got it out using one of the flexible claw tools with a small web cam taped to it. Drained the tank first.

Last edited by baldwinm; 26th Oct 2014 at 19:06. Reason: Duplication
baldwinm is offline  
Old 26th Oct 2014, 21:31
  #23 (permalink)  
 
Join Date: Oct 2009
Location: Northamptonshire
Posts: 50
Likes: 0
Received 0 Likes on 0 Posts
I have just purchased a Borascope from Aldi for £60 and has a colour screen , one meter long flexi approx 10 mm wide with built in internal Led lights at camera end , comes with a few hook attachments but you could adapt your own or use in conjunction with a three claw grabber .

Just had a though " how about using suction if you can locate it in the tank"
Use a fuel pump to suck it out ?


Good luck Austerwobbler
austerwobbler is offline  
Old 27th Oct 2014, 07:36
  #24 (permalink)  
 
Join Date: Jan 1999
Location: north of barlu
Posts: 6,207
Likes: 0
Received 0 Likes on 0 Posts
Is this a crisis ? Most club Cessna 152's have at least one fuel measuring tool in the tank and they don't seem to fall out of the sky !
A and C is offline  
Old 27th Oct 2014, 09:08
  #25 (permalink)  
 
Join Date: Apr 2003
Location: Midlands
Posts: 2,359
Likes: 0
Received 0 Likes on 0 Posts
I helped a friend remove the tank from his Jodel yesterday. He appeared quite surprised when I shook it and it rattled. Most older aircraft have "stuff" in the tank. My old AA5 had quite a bit in one side and nothing in the other. A check in the paperwork showed it had had a seep and been removed not long before I got it.

Rod1
Rod1 is offline  
Old 27th Oct 2014, 10:25
  #26 (permalink)  
 
Join Date: Jul 2007
Location: Netherlands
Posts: 135
Likes: 0
Received 0 Likes on 0 Posts
first question is does it need to be removed?

If the outlet pipe stands up say 1 cm and has a mesh covering, I would suggest it is safe to leave it.
Otherwise I would say it should be removed as a low tank could pull the pencil in.

In theory it should float, but once fully saturated, it may lose most of its floatation ability.

Seems to me one could be lucky with the floatation method mentioned above. I would be cautious of expecting success.
Otherwise drain the tank, vent it as best one can and use a borascope/ mirror and claw.
A further alternative is to slide the tank out of the wing. This is not such a big job as one may think.

I would avoid switching the lights on or off while in the presence of fuel or fuel vapours (the switch spark is the danger).

Good luck

Flyme
flyme273 is offline  
Old 27th Oct 2014, 10:55
  #27 (permalink)  
 
Join Date: Jan 2008
Location: Canada
Posts: 631
Likes: 0
Received 0 Likes on 0 Posts
first question is does it need to be removed?

If the outlet pipe stands up say 1 cm and has a mesh covering, I would suggest it is safe to leave it.
There is a lot of practical truth in this. This type of "in the tank" thinking stretches our tolerance of the relationship between "safe" and "airworthy".

Would I fly a plane home with a pencil in the fuel tank? Yup, without a worry in the world. Would I try to get it passed during a scheduled inspection that way? Nope, it just would not pass!

Yes, I too, have found some rather surprising things in fuel tanks, and between them and structure. The plane had flown safely up to that point, but not "airworthy".
9 lives is offline  
Old 27th Oct 2014, 11:03
  #28 (permalink)  
 
Join Date: Aug 2007
Location: Plumpton Green
Age: 79
Posts: 1,035
Likes: 0
Received 0 Likes on 0 Posts
If you can't find a torch to look for the pencil you could use a lighter or a match.
The Aerial Arts Chaser POH included this: "WARNING - Smoking can be bad for your health - Do not smoke while refuelling."
patowalker is offline  
Old 27th Oct 2014, 11:19
  #29 (permalink)  
 
Join Date: Jul 2007
Location: Netherlands
Posts: 135
Likes: 0
Received 0 Likes on 0 Posts
Extract from AAIB Special bulletin 01/2008 G-YMMM incident:-

In the area of the left main tank water scavenge pump inlet:A piece of black plastic tape (3M 226HD) approximately 52 mm x 50 mm (2 inch tape). The tape had a number of circular marks similar in size and layout to the holes on the water scavenge pump inlet. It was likely that the tape was left in the tank during the construction of the aircraft.
A piece of brown paper the same shape and size as the black plastic tape. The paper had two circular marks similar to those on the plastic tape and is believed to be the adhesive backing for this piece of tape.A piece of yellow plastic approximately 10 mm x 12 mm. The plastic was similar in appearance to electrical cable identity tape.


A small piece of fabric/paper was found in the inlet gate/guillotine valve of the right centre OJ pump.

flyme

flyme273 is offline  
Old 27th Oct 2014, 11:42
  #30 (permalink)  
 
Join Date: Jan 2008
Location: UK
Posts: 266
Likes: 0
Received 0 Likes on 0 Posts
Does a pencil float on avgas? Anyone tried it?
worrab is offline  
Old 27th Oct 2014, 13:26
  #31 (permalink)  
 
Join Date: Feb 2007
Location: Amsterdam
Posts: 4,598
Likes: 0
Received 0 Likes on 0 Posts
Does a pencil float on avgas?
Good question.

According to How pencil is made - material, manufacture, making, history, used, processing, steps, product, machine, Raw Materials, The Manufacturing Process of pencil, Colored pencils, Quaility Control, pencils are typically made from Cedar wood. Dry Cedar has a SG of .38 (Specific Gravity Of Wood Table).

The SG of the graphite core is less readily available, but is apparently between 1.9 and 2.3. (Graphite: The mineral Graphite information and pictures)

The thickness of a pencil is 6mm (radius 3mm) so by a first approximation the cut-through area is 3^2*pi = 28.3 mm2. The lead core has a diameter of 2mm (radius 1mm) so that area is 3.14 mm2.

This means the worst-case SG of the pencil is approximately ( (.38 * (28.3-3.14)) + (2.3 * 3.14) ) / 28.3 = .59. The SG of avgas is .72 so the pencil should float. But this does not take into account the weight of the varnish and a possible eraser. Or what happens when the wood soaks up the avgas, or the effects of a potential chemical reaction between the graphite core and the avgas. Or the fact that if you sharpen the pencil, you remove relatively more wood than graphite core so the SG goes up.

So I would not automatically assume a pencil floats in avgas.
BackPacker is offline  
Old 27th Oct 2014, 14:17
  #32 (permalink)  
 
Join Date: May 2001
Posts: 10,815
Likes: 0
Received 0 Likes on 0 Posts
you could drop one in a pa38 fuel tank and see.
mad_jock is offline  
Old 27th Oct 2014, 14:21
  #33 (permalink)  
 
Join Date: Feb 2001
Location: Cardiff, UK
Age: 62
Posts: 1,214
Received 0 Likes on 0 Posts
Believe it or not, there is a Pencil Museum in the UK, somewhere around the Lake District as I recall.

If you do manage to fish the pencil out, I suspect it could become the museum's star attraction
Mariner9 is offline  
Old 27th Oct 2014, 14:33
  #34 (permalink)  
 
Join Date: May 2001
Posts: 10,815
Likes: 0
Received 0 Likes on 0 Posts
I have been to said Museum its not bad actually.
mad_jock is offline  
Old 27th Oct 2014, 14:51
  #35 (permalink)  
 
Join Date: Apr 2003
Location: Midlands
Posts: 2,359
Likes: 0
Received 0 Likes on 0 Posts
"Does a pencil float on avgas? "

I think we know a man who will have an answer to that

Rod1
Rod1 is offline  
Old 27th Oct 2014, 19:09
  #36 (permalink)  
 
Join Date: Oct 2009
Location: Northamptonshire
Posts: 50
Likes: 0
Received 0 Likes on 0 Posts
Will a pencil break down over time ? Bung up any gauze fuel pipe filters or even block a jet , I'd fly it home but I'd want it out ASAP , heaven forbid anything happend to the aircraft and the AAIB found it in the tank , the insurance company would love that " any excuse not to pay"
Austerwobbler
austerwobbler is offline  
Old 27th Oct 2014, 19:13
  #37 (permalink)  
 
Join Date: Dec 2004
Location: Under the clag EGKA
Posts: 1,026
Received 0 Likes on 0 Posts
Trouble us that the paint will flake off.
effortless is offline  
Old 27th Oct 2014, 21:27
  #38 (permalink)  
Thread Starter
 
Join Date: Jun 2001
Location: UK
Posts: 3,982
Likes: 0
Received 1 Like on 1 Post
The engineers extricated said pencil today - not sure how but will ask them - they didn't take long!

Thanks for all the help and suggestion.
fireflybob is offline  
Old 27th Oct 2014, 21:39
  #39 (permalink)  
 
Join Date: Jan 2008
Location: UK
Posts: 266
Likes: 0
Received 0 Likes on 0 Posts
Hurrah!

(But do tell, did it float?)
worrab is offline  
Old 27th Oct 2014, 21:43
  #40 (permalink)  
 
Join Date: Feb 2001
Location: Cardiff, UK
Age: 62
Posts: 1,214
Received 0 Likes on 0 Posts
So you got your fuel draw back









I'll get my coat.....
Mariner9 is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.