non metallic structures Flashcards
are mineral streaks in a piece of structural aircraft wood reason for rejecting the wood
no, if there is no evidence of decay in the wood
how is compression wood identified
it has a high specific gravity, it appears to have an excessive growth of summerwood, and has little contrasst between springwood and summerwood
is a hard knot that is 1/2-inch in diameter allowed if it is in the web of the wing spar
no, 3/8- inch diameter is the maximum allowable knot, and it must meet severe restrictions
are pin knot clusters allowable in aircraft structural wood
yes, if they cause only a small effect on grain direction
what paperwork must be completed if an aircraft that was originally covered with grade A cotton fabric is re covered using synthetic fabric
the covering must be done according to supplemental type certificate, and a form 337 must be executed, stating that all materials and processes complied with the requirements of the STC
when is the finishing tape applied to a fabric-covered wing when it is being recovered
after the second coat of dope has dried and the nap of the fabric has been sanded off
when are drainage grommets applied when an aircraft is being re-covered
the are laid into the third coat of dope, at the same time the surface tape is applied
what will happen if the dope is sprayed over an enameled surface
the thinner in the dope will penetrate the enamel surface and cause it to swell
what can be done to remedy blushing that has formed on a doped surface that has just been sprayed
spray a very light mist coat of a mixture of one part retarder to two parts of thinner over the blushed area. allow it to dry and spray on another coat. if this does not remove the blush, the blushed dope will have to be sanded off and new dope applied
what is a rejuvenator
a slow drying finishing material that has potent solvents and plasticizers that softer a dried surface film and restore resilience to the film
why is the first coat of dope brushed onto the fabric
to ensure thorough penetration and encapsulation of all the fibers
what is the general reason for runs and sags in a finish that is being sprayed onto a flat surface
too much dope is being applied. the film is too thick
what is the most common cause for dope roping
the dope was improperly thinned or it was too cold
what causes pinholes in a dope finish
excessive atomizing air pressure on the spray gun
why should the first coat of dope be thinned
to ensure thorough penetration and encapsulation of all the fibers
