UNITED STATES DEPARTMENT OF AGRICULTURE 
, BULLETIN No. 1128 
Washington, D. C. PROFESSIONAL PAPER February 20, 1923 
DECAYS AND DISCOLORATIONS IN 
AIRPLANE WOODS 
By 
J. S. BOYCE, Pathologist 
Office of Investigations in Forest Pathology 
Bureau of Plant Industry 
CONTENTS 
Page Page 
Introduction ..... Ey eeretersiictioh a 1 Chemical Discolorations ...... . 23 
Genera] Considerations ........ 2 Discolorations Caused by Fungi. ... 24 | 
Woods Used for Airplane Construction 3 Sap-Stain .....-2-+-+-2-22e- 25 
General Defects of Airplane Woods .. 5 Brown-Oak Discolorations .... 29 
Color Comparisons .........- 14 | Decay Discolorations ......-- 30 
Discolorations Caused by Wounds .. 17 | Decay in Finished Airplanes .... - oe 
Lightning Wounds ........ 17 | Summary PA REPRER AER et Lg aati Ae 42 
Sapsucker Wounds ........ 20 epersarney wes aS Sk ae ale 
Pitter Mecka|s © .°.). 01.0, 20 Defects of Wood Referred to in This 
Bulletin, Arranged by Species .... 50 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1923 
