2 issues I can think of …
1) if the decal detached, would it affect continued safe flight ?
2) if a decal detached would it damage the paint and not be walk round evident ?

would you add an ICA to check (visually) the decals at A-checks ?

another day in paradise, or is paradise one day closer ?

Looking at https://multimedia.3m.com/mws/media/1007582O/produ... it appears quite deep in disclaimers and recommendations that direct contact with regulatory agencies is required.

Quote (3M)

•This film is only for exterior aircraft graphics. However, the aircraft operator is responsible for determining if installing this product requires regulatory approval from the operator's authorizing agent or appropriate aviation authorities. •The use of graphic films on aircraft can alternatively be realized by qualifying a concept with the local aircraft homologation authorities. Usually an engineering change request procedure must be engaged and completed prior to proceeding with the approved process to apply graphic film onto aircrafts. For the avoidance of confusion, 3M specifically disclaims any warranty that the product satisfies or is in compliance with any aviation authority regulations.

"homologation " ??

This smells of they got burned by someone.

another day in paradise, or is paradise one day closer ?

decals have been on planes since Wilbur say the advertising possibilities. Maybe talk to your local cert people … what do you guys want to see ? Maybe (if in US) you can find a local DER who'll 8110 it ?

another day in paradise, or is paradise one day closer ?

Peel-n-stick Vinyl and polyurethane decals ['decalcomania'] have been used on MIL Acft for decades for stars/bars, letters, numbers, warning placards, paint replacement, etc.

I think Hill AFB [OC-ALC] has even tried full body decals on F-16s ILO Camo paint. The decals were installed in strip-segments for draping/nesting-together over complex curvatures. Unsure of results.

'How-To' ??? … this is our primary maintenance reference...

USAF T.O. 1-1-8 APPLICATION AND REMOVAL OF ORGANIC COATINGS, AEROSPACE AND NON-AEROSPACE EQUIPMENT
CHAPTER 7 - APPLICATION AND REMOVAL OF DECALS AND SILK SCREENING
https://www.robins.af.mil/About-Us/Technical-Order...

Para 7.1 points to some VERY important application issues [restrictions/concerns]...

7.1 DECALS - GENERAL
NOTE
… ...

Decals are specially prepared plastic film containing designs,
words, numerals, or colored marking stripes, which may be
applied or attached to Air Force equipment as a method of
marking or identification. Decals can be used in lieu of paint
for internal and external markings and insignia as authorized
in Chapter 8. Decals shall conform to CID A-A-59485 or
commercial equivalent and are available in solid or perforated
film. Decals with perforations shall only be applied
over fully painted surfaces. For application to pressurized
areas on aircraft exteriors, prepared (factory) perforated film
shall be used to prevent blistering due to leaking rivets,
seams, etc. Non-perforated, premasked decals may be applied
directly to the primer prior to applying the topcoat.
Decals applied prior to the topcoat must be premasked with
low tack translucent application/mask tape, leaving a 1/16
inch uncovered lip around the decal edge. This lip will allow
the topcoat paint to seal the edge of the decal, eliminating
the need for edge sealer. The mask is removed after the topcoat
paint is allowed to cure. Decals are not authorized on
unpainted surfaces.

Closing Comments/NOTES.

WORKMANSHIP is everything!

Decal edges must be sealed [special sealants or clear polyurethane paint] to prevent air/moisture peel-up.

Decal corners that are rounded are 'most peel resistant'.

Perforated decals MUST be installed over [epoxy] primed AND [polyurethane] top-coated surfaces. This layering provides necessary moisture/corrosion resistance and [Duhh] colored primer might be visible thru the perforation spots [very odd appearance]. Perforations allow pressurized air-leaks to bleed thru the decal and vent to the atmosphere... without forming a 'bubble'.

Non-perforated decals can be applied to epoxy primer. These decals must be perfectly smooth and remain air-bubble free [prick all trapped air bubbles with a pin and flatten]. Even small bubbles will tend to expand with altitude... and as the decal becomes brittle with low-pressure cold air/ozone... and eventual dust/sand/ice/rain/etc impacts... will eventually become worse and likely 'tear/peel'.

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

For some reason it occurs to me that a photoshop effort of B-17s going down the line next to a swimming pool with decals floating off the decal paper and 12 guys lifting the roundels from the water and squeegeeing them onto the finished planes would be interesting.

I saw the Vin Fiz Flyer in the Smithsonian Quonset hut (before there was an Air and Space Museum) and I believe it was hand painted, so perhaps a different Orville was using decals.

3DD... Funny...

I've been dealing with these large-area MIL decalcomanias for decades... love saying 'decalcomania'...

These are definitely NOT plastic model airplane decals.

As I recall the F-16C and D OMLs were 3D modeled... then sliced into strips based on allowed compound curvature of strip segments. Individual flat decal pieces were cutout on an NC GERBER [knife cutter] or water-jet plotter. The cut-pieces were then carefully fitted/applied piece-by-piece... like 'paint by numbers'... then over-coated with lusterless 'clear polyurethane to seal it together... I think...

Pressurization, extreme thermal exposure/expansion/contraction, solar-radiation [at altitude], abrasive impacts of all kinds - inorganic/organic + rain/snow/ice, cleaning/deicing solutions, application defects, etc... are unique for aircraft.

EASY-peasy to wrap a pickup truck or car body... not so an aircraft airframe... and make it last.

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

The airframe OEM's often have QPL's for Vinyl Wrap.

For the aerospace Vinyl Wrap 3M will only train / approve a limited number of shops to sell the aerospace Vinyl Wraps within a region.

In addition to WIl's comments, UV light durability is also a significant consideration. Definitely 2nd the edge sealing.


From practical experience (discovering someone had applied Vinyl Wrap markings across a fleet without any approvals, they keep fading / coming off the B737s), for GA aircraft etc that don't exceed the about the 18000 ft (limit due to fading) & less than about 180 - 200 knts (tends to tear) 3M Controltac180 works nicely, also meets interior burn regs, plus it can be ink jet printed rather than screen printed.

I also use a slightly different drawing style for decals, so that if the drawing is sent out as a Vector graphic the print shop can pull the graphic straight from the drawing without having leaders, etc over the decal, it reduces the errors measuribly.

I was visiting a friends shop and looking at one of their helicopters... thing was completely covered with a wrap. It was beautiful.
Me being me asked... how was the sign off done to make it legal? I got some noise along the lines of Bell said.... blah blah...

About a week later it was removed and I never got an answer.

I'd love to know.

If you're considering a large decal on damage tolerant structure/fatigue-critical baseline structure, then it's worth considering the impact to inspectability of the underlying structure.