01/26/201 0 16:3 9 816329410 6 SA D PAG E 04/0 4 

# O U,S . Departmen t o f Transportatio n Federa l Aviatio n Admlnlstratto n Smal l Airplan e Directorate 90 1 Locust Kanea e City , M O €410 6

•^-fp ' 

### f C
Mr . Ki mHacket t DO A Administrator Cessn aAircraf

t Compan y On e Cessn aBoulevar

d Wichita , KS 67277-7704 Dea r Mr . Hackett ; W c ar e enclosing agran

t o f you r petitio n submittedo

n Novembe

r 4,2009 , requestin g a

n exemption wit

h time-limite d condition s fromthe requirement s o f 1 4 CF Rpar t 23 , § § 23,1549(a) , (b) , an

d (c) . Th e exemption allow s Cessn ato obtai n atyp e certificat e fo r th e Cessnamode

l 525 C airplane s wit

h th e curren

t desig n o f th e lo w pressure rotar

y grou p shaf t spee d (Nl ) an d interstag e turbin e temperatur e (TIT ) indication , which provide s conflicting color indication s i

n certain operationa

l regimes , The exemption permit s typ e certificatio n approva l wit h th e non-complian

t typ e design fo

r alimitedtime . I f

you hav e an

y questions , pleas e contac t

Mr . Pet e Rous e a t th e above addres s o

r call hi mo n 816-329-4135 , Sincerely , 5l^2-Ki mSmit

h Manager, Small Airplane Directorat e Aircraf t Certificatio n Servic e Enclosur eai./z.o/'^ai V ib-.a ^ OiOJZtJtlU O 3HL I t-HU t OZ / ^ Z 

### DS'TOF'nAVSpTAl i Exemption No . 999 7 UNITE D STATE S O F AMERIC

A DEPARTMEN

T O FTRANSPORTATIO

N FEDERA L AVIATIO

N ADMINISTRATIO

N WASHINGTON , D

C 2059 1

In the matte

r of th e petitio n o f CESSN A AIRCRAF T COMPANY fo r a n exemption fro

m§ § 23.1549(a) , (b) , an d (c ) o f Titl e 14 , Cod

e o f Federa l Regulation s Regulatory Docke t No . FAA-2009-117 0

GRANT O F EXEMPTIO N B y lette r dated Novembe

r 04,2009 , Mr . Ki

mHackett , Cessn aAircraf

t Company , On

e Cessn aBoulevard , P.O . Box 7704 , Wichita , Kansa s 67277-770 4 petitione dfo

r a n exemption wit h time-limite d condition s fro m§ § 23.1549(a) , (b) , and(c ) o f Titl e 1 4 o f

th e Cod e of Federa l Regulation s (CFR

) to permit typ e certification of

th e Cessn amodel 525 C airplane s witliou t oi l pressur

e an d temperatur

e indication s specifiedi

n th e rule . Th

e propose d exemption would permit

relie f firomth e requirement s fo

r arrangement , visibility , andcolor s fo r tli e engine oi l temperatur

e an d pressur e indication s fo

r th e mode l 525 C airplanes . The curren t desig n of th e lo w pressur

e rotaiy grou

p shaf t speed(Nl ) an

dinterstag e turbin e temperamr e (ITT) indicatio n o

f th e mode l 525 C airplane s provide s conflicting color indication s i n certain operationa l regimes . Th

e propose dexemption , i f

granted , wouldpermi

t typ e certificatio n approva

l o f th e mode l 525 C airplane s wit

h thi s non-complian

t typ e design fo r alimite d time . Th « petitione r

request s relie f

fro mth e following regulation[s] : Section s 23.1549(a) , (b) , an d (c) , i n pertinen

t part , requir

e certai n arrangement , visibility , an

d color s fo r N l an d IT T indications . Th « petitione r

support s it s reques t

wit h th e followin g information : Cessn aAircraf

t Compan y request s a

n exemption wit

h time-limite dcondition s from th e requirement s o f

1 4 CF R23.1549(a) , (b) , an

d(c ) fo r th e model 525 C to th e exten t necessar y to allo w typ e certification o f th e Cessn amode

l 525 C airplane s wit

h the curren t N l an d ITT displays . A s acondition fo r grantin g th e requestedtime-limite d exemption , Cessn aAircraf

t wil l design an

dcertif y engine N l andITT display s tha t ar eui/'^o/'^ax v IO:KI ^ oioj^i^'+itJ o SHL P rHuc . tij/z z



### complian t wit h th e curren

t FA A interpretatio n o f

1 4 CF R§ 23.1549(a) , (b) , an

d(c ) within 1 5 month s o f

th e granting o f

thi s exemption . Cessn aAircraf t wil l provid

e a servic e bulletin t

o al l field aircraf

t afte r certifyin g th e ne w display . 1 4 CF RReferenc e 1 4 CF R§ 23.1549 : Powerolan

t an dauxiliar y powe r unit insimmpnt B Fo r each required powerplan

t an dauxiliar y powe r unit instrument , as appropriat

e t o th e typ e of instruments

- (a ) Each maximu

mand , i f applicable , minimu

msaf e operating limi

t mus t b e marke d wit h ared radia

l o r ared line ; (b ) Each nonna

l operating rang e mus t

b e marke dwit h agree n ar c o r gree n line , not extending beyond the maximu man dminimu msaf e limits ; (c ) Each takeof

f an d precautionar

y rang e mus t

b e marke dwit h ayello w ar

c o r ayello w lin e Backgroun d Th e cunren t installatio n of

th e Rockwel l Collin s Proline 2 1 syste

mo n th e mode

l 525 C airplane contain s stati c warnin g band s fo r L an dRN l an dfo r L an dRITT . Simila

r installation s ar

e installe d an

d certifiedon othe

r par t 2 3 Cessnaairplane s including the model s 525 , 525A , an

d 525 B tha t have incorporatedthe Collin s Proline 21 , Th e stati c warnin

g band s fo r th e engine N l an

dIT T have considerable field experience ; th e mode

l 52 5 airplane s which incorporat e th e Prolin e 2 1 syste

mhave ove r 426,00 0 fligh

t hours , the mode

l 525 A ha s ove

r 517,000 flight

hours , an dth e mode l 525 B ha s ove

r 250,000 flight

hours . Thi s i s approximatel y 1. 2 million flight hour s fo r thi s typ e of

display . Ther

e have bee n no report s o f

issue s i n th e field related t o how th e engine N l o

r IT T ar e displayed . N l Displa y Discussion : Th e curren t mode l 525 C N l indication i s displayedon th e Multifimctio n Displa y (MFD) , which i s centrall

y locatedo n th e instrumen

t panel . Th e visibilit y an dlocation of the N l displa

y i s simila r t o othe r previousl y certifiedCitatio n aircraft , andha s bee n evaluated during flight

testin g o f the mode l 525C . Th

e cautio n an

dwarning N l limit s ar e transmitte d b

y the Ful l Autliorit y Digita l Electroni c Control (FADEC ) a s listedi n Table 1 .oi/zo/zai o 10:111: 3 oiDJ/^atitJ O 3H U rHw t an/z z

Tabl e 1 : FJ44-4 A N l Limit s 

### N l Limit s Ma x Stead y Stat e Ma x Permissible Transien

t Ma x Transien t Duration N l percen t

104.7 6 percen

t 105.7 6 percen

t (120 Sec ) Th e N l display consist s o f an analo g scal e an d digita l displa y for eac h engine . N l i s displaye do n atape/pointe r display a s apercentag e o f rpm . Th e dat ai s als o displaye d digitall y belo w th e N l scale . Th e analo g scal e rang e i s 1 0 percen t t o 11 0 percen t

wit h tic k mark s a t 20,40 , 60 , 80 , 85,90 , 95,100,105 , an d 11 0 percent . Scalin g i s linea r betwee n 1 0 percen t

an d 8 0 percent , an d betwee n 8 0 percen t an d 11 0 percent . Th e N l digita l displa y i s aboxe d digita l readou t belo w th e N l scal e wit h arang e o f 0 percen t t o 120 percen t

an d aresolutio n o f

0. 1 percent . A s describe d below , th e scal e i s stati c an d wil l display th e sam e markin g durin g al l engin e operations . Thi s scal e markin g consist s o f are d lin e at

th e Max Stead y Stat e Limi t o f 104.7 6 percent . (Refer

t o Figur e 1,

) A s an alternativ e t o thi s display , th e re d lin e fo r th e scal e coul d b e draw n a t th e Ma x Transien t Limi t o f 105.7 6 percent . Thi s woul d the n requir e an ambe r ban d t o b e draw n betwee n 104.7 6 percen t an d 105.7 6 percent . Du e t o th e smal l siz e o f thi s ambe r ban d an d th e limite d visibility o n thi s scale , an d du e t o th e engin e bein g an N l FADE C controlle d engine , whic h woul d requir e afailur e o f th e FADE C syste mt o eve r reac h a n N l o f thi s value , Cessn adecide d t o dra w th e re d lin e at 104.7 6 percent . Thi s choic e result s i n aconservativ e display markin g fo r Nl . Th e tape/pointe r

o n th e display wil l chang e color s base d o n th e FADE C provide d limits . Figure s 1 throug h 4 sho w bot h th e curren t an d propose d N l displa y configuration . Thes e figures represen t

th e operatio n o f

theN l display s fo

r different operatin g conditions . Eac h figure i s precede d b y adiscussio n for th e specifi c operatin g condition . Fo r N l spee d belo w th e Ma x Steady Stat e Limi t (refe r t o Figur e 1) ; Fo r both th e curren t

an d propose d displays , th e tape/pointe r o n th e analo g scal e i s colore d whit e an d th e N l digita l display i s colore d green .a i /

^o / ^ox o iD:a: 3 siDJZ^j'+ia o 3 H U rHwc . t)o / ii z



### Curren t Displa y Propose d Displa y Figur e 1 : N l belo w Ma

x Steady Stat e Limi t Fo r N l spee d betwee n th e Ma x Stead y Stat e Limit an d th e Ma x Transien t Limit fo r les s tha n 12 0 second s (refe

r t o Figur e 2) : Fo r th e curren t display , the tape/pointe

r an ddigita l digit s will tur

n ambe r an d flash fo r five second s an

dthe n go stead y amber . Fo r th e propose d display , th e tape/pointe r an ddigita l digit s will tur

n redan d flash fo r five second s an

dthe n go stead y red .KJi /

ZD / ztJit j ID : K)- 3 aibjz^smej o SMi J rwuc . uo / J:.< ;



### Curreii t D i spla

y Propose d D i spia y Figur e 2 : N l between th e Ma x Steady Stat e Limi t

an dth e Ma x Transien t

Limi t for les s tha n 12

0 sec Fo r N l speed betwee

n th e Ma x Stead y Stat e Limi t an dth e Ma x Transien t Limi t fo r greate r tha n 12 0 second s (refe

r t o Figur e 3) : Fo r the curren t display , the tape/pointe

r an ddigita l digit s wil l tur n redan dflash fo r five second s an

d the n g o stead y red . Fo r the proposed display , the tape/pointe r an ddigita l digit s wil l remain reddue t o alread y having bee

n turnedredpe

r above .tii/zo/zeiiK ) ±o:u: 3 aibJz:3ij.Ki o 3HL P oc / ^/ .

Curren t D i splay Propose d D i splay 

### Figur e 3 : N l between th e Ma x Steady Stat e Limi t

an dth e Ma x Transien t

Limi t fo r greate r than 12 0 se c Fo r N l speed s above the Ma

x Transien t Limi t (refe r t o Figur e 4) : Fo r bot h th e curren

t an dproposeddisplays , th e tape/pointe r an ddigita l digit s will tur n re d an d flash fo r five second s an

dthe n g o stead y red . If th e pointer , tap e an d digita l displa y an dhave alread

y turnedreddu e to being in the transien t zon e fo r mor e tha n 12 0 second s the pointer , tap e an ddigita l displa y wil l remai n astead y redan dnot flash.ai/'zo/'zaiK i iD:t) 3 Biojz^smti o rMijc . oa / z ^



### Current Displa y Propose dDispla y Figur e 4 : N l abov e th e Ma x Transien t Limi t IT T Displa y Discussion : Th e curren t

mode l 525 C IT T indicatio n i s displaye d o n th e MFD , whic h i s centrall y locate d o n th e instrumen t

panel . Th e visibility an d locatio n o f th e IT T display i s simila r t o othe r previousl y certifie d Citatio n aircraft , an d ha s bee n evaluate d durin g flight testil y o f th e mode l 525C . Th e cautio n an d warnin g IT T Hmit s ar e transmitte d b y th e FADE C a s liste d i n Tabl e 2 . Tabl e 2 : FJ44-4 A IT T Limit s IT T Limit s Ma x Steady Stat e Limi t Transien t Limi t 1 : Transien t Limi t 2 : Engin e Runnin g 835* C 855* C ( 0 sec ) 855° C (Dual Engin e - 5 mi n Singl e Engin e - 1 0 min ) Engin e Startin g 840*" C 1000^C(15sec ) 900° C (3 0 sec )

Th e display o f

IT T consist s o f

a n analo g scal e an d tape/pointe r for th e respectiv e engine . Th e IT T tape/pointe r onl y show s whe n IT T i s abov e 100 ^C . Scal e rang e i s 100 ° C t o 1,05 0 °C , with tic k mark s a t 200 , 400,600,650 , 700,750 , 800 , 850 , 900 , 7n x f

i-^i ' ^^xY i iD:tj: 3 Dj.oj.<::3titi D :5HL P rHu t B3 / .i:. ^



### 950 , 1,000 , an

d 1,050 *C . Fou

r linea r scale portion s exist , wit

h scaling chang e above 60 0 "C , 80 0 °C , an d changing again above 90

0 "C . A s described below , th e IT

T limit s ar e dynamic an

dwill displa

y differen t marking s based o n the engin

e stat e (ru n o r starting ) an

dbase don the value of

ITT . Thes e marking s chang e a s required t o mee t th e FADE C providedIT

T limit s a s show

n in Table 2 . Additionally , tli e tape/pointe r wil l chang e color s base don th e FADE C provided limits . Th e followin g discussion provide s detail s on the curren t IT T displa y wit h respect t o th e dynami c scale an

d the tape/pointe

r colo r operation . Du

e to the complexit

y o f the IT T limitation s wit

h respect to variou s transien

t temperatur

e an dtim e limits , Cessn ai s no t able t o provid e aproposa

l fo r acomplian

t displa y a t thi s time . I

n addition , FAA/Cessnacoordination i s requiredbefor e aproposa

l fo r displa y o f IT T ca n b e presented . However, Cessn aAircraf t Compan y i s committedto incorporation of a displa y complian

t t o th e relate dregulations . IT T Displa

y wit h Engine s Runnin g Figure s 5 throug

h 9 show the curren

t IT T displa y configuration wit

h engine s i n th e n

m mode . Thes e figure s represen t th e operation o

f the IT T display s fo

r differen t operating cases . Wher

e necessary , eac

h figure i s precededb y adiscussio n fo r th e specifi c case . Not e tha t fo r Case s 1-5 , IT

T displa y operation i s discussedwit h respec t to dua l engine operation . Fo

r On e Engin e Inoperativ e (OEI) conditions , the IT T displa y operate s th e sam

e except tha t th e engine runnin

g transien t limi t i s te n minute s instea

d o f five a s show

n i n Tabl e 2 . Cas e 1 - IT

T belo w Ma

x Stead y Stat e Limi t (refe r t o Figur e 5 ) Displa y Ite m Tape/Pointe

r Scal e Marking s Displa

y Characteristi c Whit e Ambe r Ban d- 835° C to 855' C Re dLine-855° Cai/'j^b/zui aID:U: 3 oiOJZ^stiti D SH D rwu t la/z z



### Figur e 5 : IT T belo w Max Steady Stat e Limi t Cas e 2 - IT

T betwee n the Ma x Stead y Stat e Limi t an d th e Transien

t Limi t fo r les s tha n thre e minute s (refe

r t o Figur e 6 ) For Case s 2 through 4 , th e FADE C i s transmittin g adua

l engine operation transien t tim e limit of five minutes . Sinc e ther

e ar e operating condition s whe

n a n engine ma

y operat e fo r abrief tim e i n th e cautionar

y range , Cessn adoe s no t immediatel

y tur n the tape/pointe

r to ambe r whe n operating betwee

n 83 5 ' C an d 85 5 "C . Th

e tape/pointe

r will remain whit

e fo r thre e minutes . Afte

r thre e minutes , th

e tape/pointe

r wil l then tur n ambe r an dflash fo r five second s afte

r wliic h i t stay s amber . Thi s allow s th e pilo t to operat e i n the cautionar

y rang e i f required du

e t o ho t da y condition s but

provide s sufficien

t notification prior

t o exceeding th e five minut

e transien t limi t fo r th e pilo t t o tak e corrective action b y reducing the throttle . Thi s displa y philosoph

y i s consisten

t wit h othe r mode l 52 5 serie s display s an

deliminate s the possibilit

y of the distractio n of

a flashing ambe

r IT T tape/pointe

r during takeoff

, especiall y considerin

g tha t a fiill five minute s o

f operation i s allowedi n thi s transien t region .a i /

za/zaiK i IO:KJ ^ aio3Z-3ma o SH U rHuc . 11 / z z

Displa y Ite m Tape/Pointe r Scal e Marking s Displa y Characteristi c White Ambe r Ban d - 835° C t o 855* C Re d Line-855* C

Figur e 6 : IT T betwee n th e Ma x Stead y Stat e Limi t an d th e Transien t Limi t fo r les s tha n thre e minute s Cas e 3 - IT T betwee n th e Max Steady State Limi t an d th e Transien t

Limi t fo r thre e to five minute s (refe

r t o Figur e 7 ) Displa y Ite m Tape/Pointe r Scal e Marking s Displa y Characteristi c Ambe r (Flashe s for

5 se c the n steady ) Ambe r Ban d - 835° C t o 855° C Re d Line-8 5 5* C 

### 1 0Yil i Zm'ZXMY S iD:tlt 3 DiOJZ^tlKJ O SH U rHUc . iz i Z Z



### Figur e 7 : IT T betwee n th e Max Steady Stat e Limi t an dth e Transien t Limi t for thre e to fiv

e minute s Cas e 4 ~ IT

T betwee n the Ma x Stead y Stat e Limit an dth e Transien

t Limi t fo r greate r tha n five minute s (refe

r t o Figur e 8 ) Displa y Ite m Tape/Pointe

r Scal e Marking s Displa

y Characteristi c Red (Flashe s fo r 5 se c the n steady ) Ambe r Ban d- 835° C t

o 855* C Re dLine-855 X

1 1Hii i Zb /

zai v 10:0: 3 oiosz-ama o SH U rnu t i-i/z z



### Figur e 8 : IT T between th e Ma x Steady Stat e Limi t

an dth e Transien t Limi t fo r greate r than fiv e minute s Cas e 5 - IT

T above th e Transien

t Limi t (refe r to Figur e 9 ) Displa y Ite m Tape/Pointe r Scal e Marking s Displa y Characteristi c Re d (Flashe s fo

r five se c the n steady) * Amber Ban d- 83 5 ° C t o 85 5 ° C Re d Line-85 5 ° C 

### * I f th e pointe r an dtap e hav e alread

y turne dreddue t o bein g in the transien

t zon e fo r mor e tha n five minutes , th e pointe

r an dtap e displa

y wil l remain a stead y red an dnot flash.

1 2uii'ZQi'ZKsi u io:u' 3 aioaz^ma o aw u rHuc . m/z z



### Figur e 9 : IT T abov e th e Transien t Limi t IT T Displa

y durin g Engin e Start : Th e ITT displa

y wit h respect t o scale marking s an

dtape/pointe

r operation i s th e sam

e as described above i

n th e IT T Displa y wit h Engine s Running Discussion section of thi s document . Figure s 1 0 throug

h 1 2 sho w the cvuren

t IT T displa y configuration s wit

h engine s i

n the star t mod e a s determined b

y th e FADEC . Thes e figures represen t th e operatio n of

th e IT T display s fo

r differen t operating cases . Pe r the Airplane Fligh

t Manua l (AFM) , th e pilo t

i s responsible fo

r ensuring IT

T limit s ar e not exceeded . Thi s philosoph

y i s consisten

t wit h th e res t of the mode l 525 serie s airplane s a s wel

l a s Cessn aairplane s certificatedunde r th e requirement s of

1 4 CF R par t 25 , Cessn aexperienc e wit

h th e FJ44 Serie s engine s in general , a s well a s wit h th e FJ44-4 A installe d o

n the mode

l 525 C i n particular , i s tha

t ho t engin e start s ar e ver y unusua l an d infrequent .

1 3ai/'zo/'zai aio:o ^ oiDJzatiu o SH U r»>jc . 10/z z



### Cas e 6 - ITT a

t or belo w Ma x Stead y Stat e Startin g Limit

(refe r t o Figur e 10 ) Displa y Ite m Tape/Pointe

r Scale Marking s Displa y Characteristi c Whit e Ambe r Ban d- 83 5 ° C t

o 85 5 " C Red Line-85 5 «

C Red Triangle-100 0 *

C

Figur e 10 : IT T a t

o r belo w Ma x Stead y Stat e Startin g Limi t

1 4ai/'za/'zai a10:0 3 aioj^atio o S H U rHicia. 10/z z



### Cas e 7 - IT

T above Ma

x Stead y Stat e Starting Limi

t (refe r to Figur e 11 ) Displa y Ite m Tape/Pointe

r Scal e Marking s Displa

y Characteristi c Whit e Ambe r Band

- 83 5 " C to 85 5 =

C Re dLine-85 5 ° C Re dTriangle-100 0 ° C

Figur e 11 : IT T abov e Ma

x Steady Stat e Startin g Limi t fo r an y Lengt

h o f Time

1 5eii/^o/zait i 10:0 3 aioJ.i:3mo o rHUC . K/Z Z



### Cas e 8 - IT

T above Ma

x Starting Transien

t Limit (refe r to Figur e 12 ) Displa y Ite m Tape/Pointe r Scal e Marking s Displa y Characteristi c Re d (Flashe s for

five se c the n steady ) Ambe r Ban d- 83 5 ^ C t o 85 5 ° C Re d Line-85 5 * C Re d Triangle-1000-^ C



### Figur e 12 : IT T abov e Ma

x Startin g Transien t

Limi t Petitio n CessnaAircraf

t Compan y request s a

n exemption wit

h time-limite dcondition s firom th e requirement s o f

1 4 CF R§ 23.1549(a) , (b) , an

d(c ) fo r th e model 525 C fo

r th e engine N l an

d IT T display s o n th e mode

l 525C . Thi s exemption wouldallo w typ e certificatio n o

f th e Cessn amode

l 525 C airplane s wit

h tli e curren

t N l an dIT T displays , 1 6oi/'zo/'zai u io:o 3 sioj/^tio o SH U rnuc . 10/.i:. ^

whil e permittin g adequat e tim e t o desig n an d certif y th e propose d scal e display in orde r t o establis h ful l complianc e with th e lates t interpretatio n o f

th e requirement s o f 1 4 CF R§ 23.1549(a) , (b) , an d (c) . A s aconditio n for

grantin g th e requeste d exemption , Cessn aAircraf t wil l desig n an d certif y engin e N l an d IT T display s tha t ar e fiill y complian t

vwt h th e lates t interpretatio n o f

1 4 CF R§ 23.1549(a) , (b) , an d (c ) withi n 1 5 month s o f th e grantin g o f thi s exemption , Th e nex t schedule d versio n o f

th e display softwar

e ftomCollin s (v2.0 ) ha s a certificatio n schedul e for

TS O receip t

b y en d o f yea r 2010 . Du e t o curren t

manpowe r constraint s at

Collins , i t

i s no t feasibl e t o incorporat e th e ne w N l an d IT T display s prio r t o v2. 0 withou t

significantl y delayin g v2.0 . Collin s display software v2. 0 i s require dfo

r EAS A certificatio n an d any delay i n EAS A certificatio n coul d resul t i n significan t financial penaltie s for

Cessn aAircraf

t Company . Cessn aAircraf

t wil l provid e aservic e bulleti n t o al l mode l 525 C fieldaircraf t afte r certifyin g th e ne w display Further , prio r

t o th e installatio n o f

th e servic e bulleti n t o instal l th e newN l an d IT T displays , Cessn aAircraf

t wil l includ e note s i n th e Airplan e Fligh t Manual (AFM ) t o hel p clarif y th e ban d an d tape/pointe r colors . Th e note s wil l b e remove d onc e th e servic e bulleti n i s installed . Th e essenc e o f th e not e wil l b e t o addres s th e followin g item ; th e specifi c wordin g i s t o b e agree d upo n betwee n Cessn aan d FA A a s par t o f th e AF M approval process .

• Th e colo r

band s o n th e vertica l tap e for N l an d IT T wil l no t

chang e t o re d a s th e transien t

duratio n limit s expir e eve n thoug h th e tape s wil l chang e color . Petitioner' s Publi c Interes t Statemen t Cessn aAircraf

t Compan y state s tha t

grantin g thi s exemptio n woul d b e i n th e publi c interes t for th e followin g reasons . 1 . Th e F.T44-4

A engin e FADE C include s man y safet y feature s t o preven t

th e engin e fromexceedin g th e N l an d IT T limits. Thes e includ e th e following :
• Automaticall y reducin g fuel flow a s require d durin g astar t t o activel y limi t ITT . • Fo r engin e spee d abov e idle , th e FADE C activel y govern s th e N l spee d t o th e se t N l schedule . • Th e FADE C wil l shutdow n th e engin e i f i t detect s a n N l overspec d condition . 1 7ai/'zo/'zait i io:o 3 aib-izrima aSH U rnoc . i-:)/z z

2 . Th e curren t

engin e N l display allow s fo r saf e operatio n o f

th e engin e withi n it s operationa l limit s a s show n b y th e 1. 2 millio n flight hour s o f similar display s o n othe r model 52 5 serie s aircraft . Th e curren t displa y provide s tw o visua l cue s tha t wil l aler t th e pilot s tha t

a n engin e N l limi t

ha s bee n exceeded . • Th e tape/pointe r

for tha t engin e wil l tur n th e appropriat e warnin g colo r an d flash for

five seconds , • Th e digita l readou t

for tha t engin e wil l b e displaye d i n th e appropriat e color , flashing for

five seconds . 3 . Th e curren t

engin e IT T display allow s for saf e operatio n o f

th e engin e withi n it s operationa l limit s a s show n b y th e 1. 2 millio n flight hour s o f simila r display s o n othe r

mode l 52 5 serie s aircraft . Th e curren t displa y provide s tw o visua l cue s tha t

wil l aler t th e pilot s tha t

a n engin e IT T limi t

ha s bee n exceeded . • Th e tape/pointe r

fo r tha t engin e wil l tu mth e appropriat e warnin g colo r flashing fo

r five seconds . 4 . Simila

r engin e N l an d IT T display s ar e currentl y i n us e o n othe r mode l 52 5 serie s aircraf

t model s wit h ove r

1. 2 millio n flight

hour s o f fieldservic e experience . Ther e hav e bee n n o report s b y th e pilot s o f confusio n i n readin g an d understandin g th e engin e N l o r IT T display s an d n o report s o f engin e damag e cause d b y misinterpretin g th e engin e N l o r IT T displays . Therefor e field experienc e ha s show n tha t th e curren t

engin e N l an d IT T display s d o not caus e ahazar d t o th e aircraft . 5 . Th e denial o f

thi s petitio n fo

r exemptio n woul d resul t

i n th e delay o f

th e certificatio n o f

mode l 525 C airplane s fo

r approximatel y 1 5 months . Cessn a woul d experienc e alos s o f revenu e o f

at leas t $14 0 millio n i n 201 0 an d $12 0 millio n i n 201 1 du e t o thi s delay . Thi s coul d als o resul t i n numerou s aircraf

t orde r cancellation s increasin g th e financial los s significantly . Thi s woul d als o resul t i n th e los s o f

revenu e for

partner s an d supplier s an d th e potentia l nee d fo r workforc e reductions , al l o f whic h woul d b e counte r

t o th e publi c interest , 6 . Cessna' s customer s hav e mad e utilizatio n plan s based o n th e agree d upo n delivery schedul e o f

thes e airplanes . Delay i n th e delivery dat e du e t o th e redesig n an dretrofi t

o f th e engin e N l an d IT T display s woul d impos e significan t financial penaltie s upo n ou r customer s an d thei r

businesse s withou t acommensurat e safet

y benefit , whic h i s als o counte r to th e publi c interest .

1 8Kii/^o/^oit ) io:o s oioJ^^Hio o SH U rnu t zri/'z z

Notic e an d Publi c Procedur e Provide d A summar

y o f th e petitio n was publishe d o n Decembe r 29 , 200 9 (7 4 F R68914) . N o comment s wer e received . Th e FAA' s analysi s i s a s follows : T o obtai n thi s exemption , th e petitione r mus t show , a s require d b y 1 4 CF Rpar t 11 , § § 11.81(d ) an d 11.8 1 (e) : "(1 ) th e reason s why grantin g you r reques t woul d b e i n th e publi c interest ; tha t

is , ho w i t woul d benefi t

th e publi c a s awhole , an d (2 ) th e reason s why grantin g th e exemptio n woul d no t

adversel y affec t

safety , o r

ho w th e exemptio n woul d provid e aleve l o f safet y a t leas t equa l t o tha t

provide db y th e rul e fromwhic h yo u seek th e exemption. " Th e FA A ha s carefully reviewe d th e infoimatio n containe d i n th e petitioner' s reques t for exemption . Th e FA A agree s wit

h th e petitioner' s reques t

fo r th e followin g reasons : 1 . Th e FJ44-4 A engin e FADE C include s man y safet y feature s t o preven t

the engin e from exceedin g th e N l an d IT T limits . Thes e includ e th e following : a . Automaticall y reducin g fuel flow a s require d durin g astar t t o activel y limi t ITT . b . Fo r engin e spee d abov e idle , th e FADE C activel y govern s th e N l spee d t o th e setN l schedule . c . Th e FADE C wil l shutdow n th e engin e i f i t detect s an N l overspee d condition . 2 . Th e curren t

engin e N l display allow s fo r saf e operatio n o f

th e engin e withi n it s operationa l limit s a s show n b y th e 1. 2 millio n flight hour s o f similar display s o n othe r mode l 52 5 serie s aircraft . Th e curren t display provide s tw o visua l cue s tha t wil l alert th e pilot s tha t

an engin e N l limi t

ha s bee n exceeded , a . Th e tape/pointe r

for tha t engin e wil l tur

n th e appropriat e warnin g colo r an d flash for five seconds , b . Th e digita l readou t

fo r tha t engin e wil l b e displaye d i n th e appropriat e color , flashing for

fiv e seconds . 3 . Th e curren t

engin e IT T display allow s fo r saf e operatio n o f

th e engin e withi n it s operationa l limit s a s show n b y th e 1, 2 millio n flight

hour s o f similar display s o n othe r mode l 52 5 serie s aircraft . Th e curren t displa y provide s tw o visua l cue s tha t wil l aler t th e pilot s tha t

a n engin e IT T limi t

ha s bee n exceeded . a . Th e tape/pointe r

fo r tha t engin e wil l tu mth e appropriat e warnin g color , flashing fo

r five seconds . 1 9oi/^o/zKJi o io:ti s oiojz^tio o SHI. ' ^^'^' ^ zi/z z

b . Simila

r engin e N l an d IT T display s arc currentl y i n us e on othe r mode l 52 5 serie s aircraf

t model s wit

h ove r 1. 2 millio n flight

hour s o f fieldservic e experience . Ther e hav e bee n n o report s b y th e pilot s o f confusio n i n readin g an dunderstandin g th e engin e N l o r IT T display s an d n o report s o f engin e damag e cause d b y misinterpretin g th e engin e N l o r IT T displays . Therefore field experienc e ha s show n tha t th e curren t

engin e N l an d IT T display s d o no t caus e ahazar d t o th e aircraft . 4 . Th e denia l o f

thi s petitio n for

exemptio n woul d resul t

i n th e delay o f

th e certificatio n o f mode l 525 C airplane s for approximatel y 1 5 months . Th e economi c impac t t o Cessn aAircraf

t Corporatio n woul d b e sever e an d resul t i n significan t

reduction s i n Cessna' s workforce . Additionally , th e economi c impac t t o Cessna' s supplier s an d customer s woul d als o b e significant . Th e FAA' s Decisio n I n consideratio n o f

th e foregoing , I findtha t

agran t o f exemptio n i s i n th e publi c interest . Therefore , pursuan t

t o th e authority containe d i n 4 9 U.S.C , § § 4011 3 an d 44701 , delegate d t o m e b y th e Administrator , Cessn aAircraf t Compan y i s grante d an exemptio n with time-limited condition s from§ § 23.1549(a) , (b) , an d (c ) t o th e exten t necessary t o allo w typ e certificatio n o f th e Cessn amodel 525 C airplane s wit h lo w pressur e rotary grou p shaf t spee d (Nl ) an d interstag e turbin e temperatur e (ITT ) indication s no t i n complianc e with th e requirement s o f § § 23.1549(a) , (b) , an d (c ) a s the y relat e t o th e arrangement , visibility , an d colors . Fo r th e mode l 525 C airplanes , thi s exemptio n i s subjec t t o th e followin g condition s an d limitations : Condition s an d Limitation s 1 . Cessn aAircraf

t Compan y mus t

certif y an d incorporat e int o th e productio n lin e requirement s lo w pressur e rotar y grou p shaf

t spee d (Nl ) an d intersts^ e turbin e temperatur e (ITT ) indication s fiJly complian t wit h th e requirement s o f § § 23.1549(a) , (b) , an d (c) , int o th e mode l 525 C airplane s n o late r tha n Apri l 30 , 2011 . 2 . Cessn aAircraf

t Compan y mus t

retrofi t th e mode l 525 C airplane s delivere d unde r th e term s o f

th e exemptio n with th e ne w lo w pressur e rotary grou p shaf t spee d (Nl ) an d interstag e turbin e temperatur e (ITT ) indication s describe d i n Conditio n 1 abov e n o late r tha n Apri l 30,2012 . 3 . Unti l th e incorporatio n o f th e change s require d i n th e abov e Condition s 1 an d 2 o f thi s exemptio n hav e bee n completed , Cessn aAircraf t Compan y ad d t o th e airplan e flight manua l (AFM ) adescriptio n o f th e indication s an d thei r

conflictin g colo r guidance , an d th e necessary instruction s fo r properl y interpretin g th e requirement s lo w pressur e rotary grou p shaf t spee d (Nl ) an d interstag e turbin e temperatur e (ITT ) indications . 4 . Fo r airplane s subjec t

t o Conditio n 2 o f

thi s exemption , th e operatin g limitation s sectio n o f th e airplan e flight

manual (AFM ) mus t

includ e th e followin g statement : 2 0^i,, , rnuc . zz / z z \3i/'zo/'zai a10:0: 3 oioj^tJtiO D sw^ J



### "N o perso n ma

y operat e thi s airplane afte

r April 30,2012 , unles s th e lo w pressur e rotar y grou p shaf t spee d(Nl ) an dinterstag e turbin e temperatur e (ITT) indication s hav e bee

n modifie di n accordanc e wit

h th e temi s o f

Exemption No . 9997. " Thi s statemen

t ma y b e removedfix)mth e AF

M afte r th e require dmodification ha s bee n made . Thi s exemption terminate s o n April 30,2011 , unles s soone r supersededo

r rescinded . Issued i n Kansa s City , Missour i o n Januar y 26 , 2010 ,

Joh n Colom y Actin g Manager , Smal l Airplan e Directorat e Aircraf t Certificacio n Servic e



### 2 1