285 

Federal Aviation Administration, DOT 

§ 23.1045 

is requested, and after normal engine 
and auxiliary power unit shutdown. 

[Doc. No. 26344, 58 FR 18973, Apr. 9, 1993, as 
amended by Amdt. 23–51, 61 FR 5137, Feb. 9, 
1996] 

§ 23.1043

Cooling tests. 

(a) 

General.  Compliance with § 23.1041 

must be shown on the basis of tests, for 
which the following apply: 

(1) If the tests are conducted under 

ambient atmospheric temperature con-
ditions deviating from the maximum 
for which approval is requested, the re-
corded powerplant temperatures must 
be corrected under paragraphs (c) and 
(d) of this section, unless a more ra-
tional correction method is applicable. 

(2) No corrected temperature deter-

mined under paragraph (a)(1) of this 
section may exceed established limits. 

(3) The fuel used during the cooling 

tests must be of the minimum grade 
approved for the engine. 

(4) For turbocharged engines, each 

turbocharger must be operated through 
that part of the climb profile for which 
operation with the turbocharger is re-
quested. 

(5) For a reciprocating engine, the 

mixture settings must be the leanest 
recommended for climb. 

(b) 

Maximum ambient atmospheric tem-

perature.  A maximum ambient atmos-
pheric temperature corresponding to 
sea level conditions of at least 100 de-
grees F must be established. The as-
sumed temperature lapse rate is 3.6 de-
grees F per thousand feet of altitude 
above sea level until a temperature of 
¥69.7 degrees F is reached, above which 
altitude the temperature is considered 
constant at ¥69.7 degrees F. However, 
for winterization installations, the ap-
plicant may select a maximum ambi-
ent atmospheric temperature cor-
responding to sea level conditions of 
less than 100 degrees F. 

(c) 

Correction factor (except cylinder 

barrels).  Temperatures of engine fluids 
and powerplant components (except 
cylinder barrels) for which temperature 
limits are established, must be cor-
rected by adding to them the difference 
between the maximum ambient atmos-
pheric temperature for the relevant al-
titude for which approval has been re-
quested and the temperature of the am-
bient air at the time of the first occur-

rence of the maximum fluid or compo-
nent temperature recorded during the 
cooling test. 

(d) 

Correction factor for cylinder barrel 

temperatures.  Cylinder barrel tempera-
tures must be corrected by adding to 
them 0.7 times the difference between 
the maximum ambient atmospheric 
temperature for the relevant altitude 
for which approval has been requested 
and the temperature of the ambient air 
at the time of the first occurrence of 
the maximum cylinder barrel tempera-
ture recorded during the cooling test. 

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as 
amended by Amdt. 23–7, 34 FR 13094, Aug. 13, 
1969; Amdt. 23–21, 43 FR 2319, Jan. 16, 1978; 
Amdt. 23–51, 61 FR 5137, Feb. 9, 1996] 

§ 23.1045

Cooling test procedures for 

turbine engine powered airplanes. 

(a) Compliance with § 23.1041 must be 

shown for all phases of operation. The 
airplane must be flown in the configu-
rations, at the speeds, and following 
the procedures recommended in the 
Airplane Flight Manual for the rel-
evant stage of flight, that correspond 
to the applicable performance require-
ments that are critical to cooling. 

(b) Temperatures must be stabilized 

under the conditions from which entry 
is made into each stage of flight being 
investigated, unless the entry condi-
tion normally is not one during which 
component and engine fluid tempera-
tures would stabilize (in which case, 
operation through the full entry condi-
tion must be conducted before entry 
into the stage of flight being inves-
tigated in order to allow temperatures 
to reach their natural levels at the 
time of entry). The takeoff cooling test 
must be preceded by a period during 
which the powerplant component and 
engine fluid temperatures are sta-
bilized with the engines at ground idle. 

(c) Cooling tests for each stage of 

flight must be continued until— 

(1) The component and engine fluid 

temperatures stabilize; 

(2) The stage of flight is completed; 

or 

(3) An operating limitation is 

reached. 

[Amdt. 23–7, 34 FR 13094, Aug. 13, 1969, as 
amended by Amdt. 23–51, 61 FR 5137, Feb. 9, 
1996] 

VerDate Mar<15>2010 

10:12 Mar 18, 2014

Jkt 232046

PO 00000

Frm 00295

Fmt 8010

Sfmt 8010

Y:\SGML\232046.XXX

232046

pmangrum on DSK3VPTVN1PROD with CFR