LAA Aircraft ID plates

tim · Post by **tim** » Tue May 12, 2009 6:27 pm

Just considering an LAA Aircraft ID plate but as the requirement is for a fireproof plate (and when I studied engineering, aluminium, while not exactly flammable had a low melting point) I assume that I will still need a stainless steel plate in addition?

If so, just what is the point of the LAA version?

Sandy Hutton LAA372 · Post by **Sandy Hutton LAA372** » Tue May 12, 2009 9:43 pm

Previously discussed here.http://www.lightaircraftassociation.co. ... .php?t=757

tim · Post by **tim** » Tue May 19, 2009 9:54 am

Sandy,

Thanks for the link, interesting but still nothing definitive has come out of the threads.

I would also correct Brian Hopes reply in that discussion when he states that stainless steel has never been specified as the material... Brian please check one of your organisations documents TL1.06 Issue 3 1st Jan 2008 paragraph 2.9.

"A stainless steel plate upon which the aircraft registration is engraved should be fitted to the cockpit"

Now that's what I call definitive and confirms that the LAA ID plate (aluminium) STILL needs augmenting with a SS plate!

Sandy Hutton LAA372 · Post by **Sandy Hutton LAA372** » Tue May 19, 2009 12:08 pm

Well Tim, if I was your Inspector, I'd be looking for a Steel plate in or around the cockpit in plain view. If you had an LAA aluminium one present as well I'd certainly admire it for a moment but I don't think I'd be particularly fussed unless it was fastened to some primary structure or hanging off.

Never mind what Mr Hope says, he's not part of the certifying arrangements in the LAA engineering dept, he can only express his opinion which you can accept or dismiss. I'm with Stuart Mac.

Cheers
Sandy

Rod1 · Post by **Rod1** » Tue May 19, 2009 12:37 pm

The argument for LAA Aircraft ID plates appears to revolve around how it “makes your aircraft look more professional”. I struggle with this concept as I work on the “simplicate and add lightness” approach and a bit of alloy with no practical purpose would not pass this test even if it was free of charge. However, if many 1000’s of people rush out and buy them it will help keep the cost of full membership plus down, so lets hope it makes a big fat profit and does not cost us money!

Anybody know hoe many we have sold so far?

Rod1

macconnacher · Post by **macconnacher** » Tue May 19, 2009 10:11 pm

These plates serve two purposes. The ID plate is just that and EAA have been selling them for years. It is the Rating plate of the aircraft with the data you see on all cars, Cessnas and in my own industry the fridge (just by the salad bins!) It give the permanent details of the aircraft its type, constructers number etc on the aircraft including that "Fred Bloggs" built it.

The stainless plate is an international requirement to replicate the registration marks so that in the event of an accident anywhere in the world the plate should survive enabling the authorities to identify the aircraft. This plate will remain in place as long as it remains with that registration marks or sold abroard when it will be required to carry the new marks allocated.
If you import an aircraft then you must remove the old marks both painted on the structure and the stainless plate.

I am not sure it has to be stainless but the ICAO Annex 7 does state that to meet the requirements of a "fireproof plate" it must be capable of coping with a defined temp which I believe is in Annex 7 and since it was about 20 years ago when I got the CAA to just accept registration marks on the plates, I seem to remember that it was 900 degrees C. Thus Stainless Steel is acceptable and aluminium is not. Brass may not be although I have some plates of the 1940s that are brass.

In an ICAO Booklet on ANNEX 7
to the Convention on
International Civil Aviation
Aircraft Nationality and Registration Marks it states:

This Annex also calls for the registration of the aircraft, and provides a sample of this certificate for use by ICAO Contracting States (never seen it required in the UK-but required in the USA). This certificate must be carried in the aircraft at all times, and an identification plate, bearing at least the aircraft's nationality, or common mark and registration mark, must be affixed in a prominent position to the main entrance.

If someone wants to visit the CAA library or pay $10 to ICAO they can check.

I trust this helps as I said previously.

J.C. · Post by **J.C.** » Wed May 20, 2009 7:56 am

How do you know the LAA one won't stand up to a fire? have you burnt your plane with one in it to see?

macconnacher · Post by **macconnacher** » Wed May 20, 2009 2:16 pm

Melting point of Al = 660 degrees C - Stainless Steel 1510 degrees C

Look in Kay and Laby - Now available on line at http://www.kayelaby.npl.co.uk/chemistry/3_1/3_1_2.html
or
http://www.engineeringtoolbox.com/melti ... d_860.html

Which one is greater than 900 degree C?

I admit that "Fireproof" is a depricated Fire Engineering term but when you relate it to a temp such as 900 degrees then Aluminium is out but Brass is just in and Stainless is fine.

No need to burn an aeroplane. I will ask someone to check the full ICAO Annex 7.

J.C. · Post by **J.C.** » Wed May 20, 2009 4:11 pm

Spoilsport ! Burn the plane..much more fun!

tim · Post by **tim** » Wed May 20, 2009 9:47 pm

If you have ever seen the alloy wheels on a burnt out car that will confirm that aluminium won't stand up to the fire. They generally end up as large 'pools' on the floor, and quite often the alloy engine block follows suit.

Also 'alloy' wheels are an alloy of aluminium and when you add an impurity to a pure metal the melting point rises therefore if alloy wheels melt then aluminium certainly will!

And remember that 100LL has a higher calorific value than 95 unleaded so will burn hotter.

Interestingly my plane (imported) only has the aluminum (note the correct spelling as the metal was born in the US) and no SS plate as suggested was an international requirement. Just remind me... is the US 'international' any more?

Finally I just remembered that my English teacher told me never to start a sentence with 'also' or 'and'. Sorry Sir.

mike newall · Post by **mike newall** » Wed May 20, 2009 11:15 pm

When they quell the smoke and flames, leave it to cool down, they reach into the pit and say - Wow - this was Fred's aeroplane - Bugger, he was a decent dude, glad he left a stainless plate, we can put it on his box........... well, it will be a small box I guess

Steve Brown · Post by **Steve Brown** » Wed May 20, 2009 11:38 pm

'And remember that 100LL has a higher calorific value than 95 unleaded so will burn hotter.'

Not convinced this is necessarily so - the 95 and the 100 refer to the anti detonation properties ie via anti knock additives like lead or other non lead substitutes - not their inherent volatility or CV.

I think 100LL AVGAS is safer to fly (crash) with than MOGAS because it is less volatile than MOGAS and less likely to ignite.

Diesel has a higher calorific value than petrol but it is far less volatile and hence the fire may be more controllable despite the higher CV.

Discuss.

Sandy Hutton LAA372 · Post by **Sandy Hutton LAA372** » Thu May 21, 2009 12:53 am

Gosh Steve, I'm impressed; you were paying attention to the talk at Turweston last week.

Ian Melville · Post by **Ian Melville** » Thu May 21, 2009 9:57 am

tim wrote: Also 'alloy' wheels are an alloy of aluminium and when you add an impurity to a pure metal the melting point rises therefore if alloy wheels melt then aluminium certainly will!

Depends on what it is alloyed with. IIRC Wheels use magnesium, which your chemestry teacher would have shown you how that soft metal burns

6061 melts between 1080 and 1206 degrees F, which is a lot closer to stainless than you think. Not sure if it counts as fireproof though.

macconnacher · Post by **macconnacher** » Thu May 21, 2009 12:08 pm

Not really Stainless is 2750 F