Rotor blade painting

[turboheli]

Seeking information about static balancing of rotor blades after local repainting. Thanks in advance

[ScotiaQ]

Sorry but if the procedure for repainting and subsequent balancing is not in the Approved Maintenance Manual, then you cannot do it.

Unless of course you have a C Rating for Blades or you have an overhaul approval, in which case you should have the necessary data.

This assumes of course that you are in EASAland?:=

Sq

[SawThe Light]

If the manufacturer permits blade painting at the operator level the information and tooling you need will be in the maintenance manual. Don't be surprised if it/they require chordwise, mass and and span moments checked.

[170']

Quite a bit here...

http://www.pprune.org/rotorheads/294678-painting-your-blades.html

[Saint Jack]

turboheli: Assuming 'local repainting' refers to the entire blade on-site (as opposed to 'localized repainting' of a small area of the blade) be very careful. As has been pointed out here, if specific approval or procedure is not in the manual then you can't do it. Not just from a legal or procedural standpoint, but from an aerodynamic one also. The weight of the applied paint is often used to make minor adjustments to a blades 'centre of pressure' (I think that's the correct term) and has a direct effect of the flight characteristics of the blade. If this 'centre of pressure' is not where it should be, i.e. it has been moved by the additional weight of paint applied during 'local repainting' then it's entirely possible that no amount of adjustment during dynamic balancing will get the blade to fly properly. Yes, staic balancing will be achievable, but in this case it's essentially meningless. Contact your local Technical Representative and ask - that's what he's there for.

[vfr440]

If you are in striking distance of UK talk to John Hull, QM, down at CTL, Thruxton. He has the expertise, shop facilities, master blades and approvals and IMHO does a very good job - VFR

[What Red Line?]

Tell us what type of helicopter blade. We can then form our own opinions as to the legality/sensibility of what you are proposing.

Following on from previous responses, do you know the possible increase in load on the MRPL if you get the chordwise balance out of limits? Are you aware of the lead/lag load difference if you get the span moment out of limits?

Of course, if the maintenance manual contains the data and approval for you to do to paint, go for it.

WRL

[Hughes500]

Well if your blades are made in California then you will need to repaint them as they are not allowed to use etch primer paint, so the blades will corrode !!!!
:ugh:

[Rocket2]

OEM's don't allow the use of etch primer on blades

[Hughes500]

yes they do ask Robinson and HTC

[Rocket2]

Can't vouch for Robbo blades (not repairable) but HTC now use waterborne primer on there blades as do all the other major OEM's.

[Hughes500]

Rocket 2 which is why the corrode so quickly !

[Rocket2]

Sorry Hughes 500, I know the problems but sadly I don't write the requirements - we merely have to work to them & hands are tied :uhoh:
Cheers
R2

[OZNZengineer]

If they are Bell 412 blades, don't do it...unless you love rotor smoothing flights...lots of them.