429 

Federal Aviation Administration, DOT 

Pt. 25, App. F 

(a) 

Definitions. 

Burnthrough time 

means the time, in sec-

onds, for the burner flame to penetrate the 
test specimen, and/or the time required for 
the heat flux to reach 2.0 Btu/ft

2

sec (2.27 W/ 

cm

2

) on the inboard side, at a distance of 12 

inches (30.5 cm) from the front surface of the 
insulation blanket test frame, whichever is 
sooner. The burnthrough time is measured at 
the inboard side of each of the insulation 
blanket specimens. 

Insulation blanket specimen 

means one of 

two specimens positioned in either side of 

the test rig, at an angle of 30

° 

with respect to 

vertical. 

Specimen set 

means two insulation blanket 

specimens. Both specimens must represent 
the same production insulation blanket con-
struction and materials, proportioned to cor-
respond to the specimen size. 

(b) 

Apparatus. 

(1) The arrangement of the 

test apparatus is shown in figures 1 and 2 and 
must include the capability of swinging the 
burner away from the test specimen during 
warm-up. 

VerDate Sep<11>2014 

12:50 Apr 30, 2019

Jkt 247046

PO 00000

Frm 00439

Fmt 8010

Sfmt 8002

Y:\SGML\247046.XXX

247046

spaschal on DSK3GDR082PROD with CFR