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Ground School Exam Questions & Question Banks

an aircraft must clear an obstacle at "###ft ele%ation b& 1###ft Regional(N) is correctl& set at **+mb, the -!T at 3###ft indicated is .1#/ !t 0hatindicated altitude 0ill the 1###ft clearance be achie%ed

2plaination please

14th February 2004, 02:54 #2

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Jet Blast Rat Join Date Jan "##1$ocation arfend.on.ea!ge 33Posts 5,"#1

This is a straightfor0ard indicated to true altitude 6se &our /RP.7b& preference -ther0ise, 4 feet per 1### feet amsl per degree offI! 3### amsl, **+ )Pa is roughl& 37##' 834##', but that is tooprecise9 Pressure !ltitude so I! is + degrees The temperature istherefore 1+ degrees cold, so the correction is 4 1+ 3 : "15feet The 0eather is cold so altimeter is o%er.reading, so &ou areclear at 3"15 feet indicated

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6th February 2005, 16:53 #3

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P of F question

! 82!9 alter 0hen the aeroplanes0eight decreases b& 1*C

a9435C lo0erb9No changec91*C lo0erd91#C lo0er

!ns0er is d ho0 is this 0ored out

Thans in ad%ance

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2/33

6th February 2005,17:55

#4

)igh Eing Drifter

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If old 0eight 0ere 1### then ne0 0eight 0ould be 11*#

(RT811*#F1###9 : 1#*1 8or appro 1#C9

Thin about the classic PP$ eam Guestion of the stall speed at 5# degban in le%el flight The force 0ould be "g or, in other 0ords the 0eight

doubles (RT8"9 : 141stall speed increases b& 41C

High Wing Drifter

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6th February 2005, 18:07 #5

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o it 0ould actuall& be sGrt +1#F1### as the 0eight is beingdecreased /omes out at #* 8*#C9 0hich is 1#C lo0erHPerfect

/heers

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Performance Question

)&

can an&one help me 0ith this one

=or a class < aFc landing on 0et grass the minimumacceptable $D! is times the $D

a 15Bb 1BBc 1+B

d 1*B

official ans0er d

m& ans0er c

/lass < aFc means B#C . 14"+Eet R0& . 117grass . 117

This should gi%e a =actor of 1++H-b%iousl& I did something 0rong, and therefore need some

assistanceHThans a lot

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3/33

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20th February 2005, 15:58 #10

)igh Eing Drifter


I thin it should be 1+* ie0 Public Profile

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20th February 2005, 20:53 #11

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Eould agree 0ith )igh Eing DrifterHH

$D! or: $DR K Eet factor K urface factor K 143$D! or: $DR K 117 K 117 K 143$D! or: $DR K 1+*

23rd February 2005, 20:05 #14

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ATPL met question

)i ;u&s im stud&ing for the !TP$ b& distance learning 8juststarted9 and im tearing m& hair out on a particular GuestionIts been a long da& and ma&be im being a doofus, but ma&be&ou gu&s can point me in the right direction I dont epect&ou to gi%e the ans0er, id onl& be cheating m&selfH

a 1#,### foot mountain has a 7,### foot cloudbase to0ind0ard and a B,### cloudbase to the lee if the 0ind0ardtemp is L"# degrees / 0hat 0ould be the liel& temp to thelee

no0 m& 0oring 0as, assuming temp decrease M D!$R to7,###, then decrease M !$R to 1#,###, then increase M salrto B###, then increase M D!$R bac to surface, &ou come up0ithL"3 degrees / Hthe options for ans0ers area.""4b.15+

c."#4d."75 HHHHH0here the smeg am I going 0rong Hof the possible ans0ers ""4 is the closest, do the& add alittle for the temp drop o%er the top of the mountainho0e%er much that ma& be or ha%e I got some basic thing

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4/33

0rong is there an&thing in the 0ord 'liel&' temp thatdoesnt sound too specific HHH

am reall& enjo&ing m& stud& b& the 0a&HHH

23rd February 2005, 22:29 #16

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it's the foehn effect the& are eamining here ,

62 the D!$R up to 7### then8decreasing9 the salr all the 0a&from 7### on the 0ind side to the top ,then increasing b& salr toB### on the lee side and then D!$R to the surfaceou should come up 0ith ""4 O

regards

ress!"n

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23rd February 2005, 22:39 #1#

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thans gu&s the compan& im 0ith sa&s 3 degrees / for D!$R and 17degrees !$R also, Pressmanho0 I did that and got "3degreestemp at 7### feet 0ind0ard 7 degrees, decreasing to minus "7 at

1#,### then bac to plus " at B### feet on the lee and increasing atD!$R 83degrees per 1### feet9 bac to surface i just cant get thepoint something or other, can &ou sho0 ho0 man& thans onceagain

24th February 2005,04:58

#1$

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our 0oring should loo something lie this

"#.8739:7.871+9:.4L831+9:14L8B39:""4

It is important to remember that the !$R is not constant as 0e gainaltitude $atent heat is released as condensation occurs and the !$R%alue actuall& increases and e%entuall& could eGual the D!$R

Ee can debate this till the co0s come home but at the end of the da& the/!! sa& that the !$R is 1+ degrees per thousand feet

our thining 0as perfectl& correct 1+ is the number to remember

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5/33

fohn wind

This is easierH

Earming temperature :

17 times the difference in cloud bases 8 in thousands of feet9,

B### . 7### : " 17 : 3

!dd to the temperature on the 0ind0ard side, 3 L "# : "3

ou'll ne%er get closer than that 0ithout 0asting %aluable eam timeH

!ll donations gratefull& recei%ed

ge!ini#6

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24th February 2005, 10:42 #22

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Time

This t&pe of Guestion for J!! !TP$ is a 0aste of time, so tr&ing to do itGuicer is a 0aste of time too If J!! e%er as this t&pe of Guestion, I'lleat m& hatH!ll &ou need to no0 about =oehn for the J!! is thisEarmer on ther lee side, higher cloud on the lee side, possible

turbulence on lee side 8from possible mountain 0a%es9 and &ou needto no0 the other names for the =oehn, eg anta !na and /hinooNo0 for some lo%el& spuriouis info The =oehn translated actuall&means )air dr&er in some 2uropean languages, so remember it as a0arm dr& descending 0ind, or a 0arm atabatic

-ne more thing, if &our chool is using 17O/ per 1###ft for the !$Rin their !TP$ notes the& need shooting and the& need to be remindedof the J!! ?2T2-R-$-; -2

;ood luc an&0a&, met can be a nightmare unless &our taught right,0ait till &ou get to 0indsHHH

)a%e fun

ugzi

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24th February 2005,

19:58#23

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thans once again gu&s, %er& much appreciated I can see no0 that if idused 1+ instead of the 17 that is 2>2RE)2R2 in m& manuals 8its e%enin Tre%or Thom for ga0ds saeH9 then id ha%e got the ans0er 0ill be more0ar& in future

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6/33

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tae care and fl& safe

1st March 2005, 09:06 #2$

P;T

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!ot an eas" task# $ut we tr" to %lease

I'%e been going on about pictures for ages 0hen it comes to theseGuestions, so I'm gonna mae &ou dra0 a picture

Dra0 a hori@ontal line and label it (N) sea le%el **+hpaDra0 another abo%e it and label that, height of obstacle $abelthe distance bet0een these t0o lines as "###ftDra0 another line abo%e the height of obstacle line and label thedistance from the height of abstacle line to this ne0 line as1###ftour true distance must be 3###ft abo%e the sea for &ou to clearthe obstacle b& 1###ft This is ob%ious to see The ditance from thebottom line, to the top lineEhat 0e need to 0or out is the indicated distance 80h& the& aredifferent is gonna tae an essa&, or " secs 0ith an instructor96se this formulae=or e%er& 1O/ I! de%iation &our altimeter 0ill be in error from thetrue altitude b& 4ft in e%er& 1###ft of pressure altitude$ets 0or out pressure altitude 8the height abo%e 1#13"hpa9 so

that 0e can start to use this formulaeDra0 another line under the (N) sea le%el **+ line and label thisas 1#13"hpa The distance bet0een this line and the (N) line is4#7ft 8"Bft 17 hpa9 o the pressure altitude of an aircraft thatneeds to clear the obstacle is 34#7ft Please don't loo at thediagram again cos it'll start to mess 0ith &our head Ee ha%e all 0eneed no0 from it-A, 0e ha%e 1*O/ I! de%iation in the eample and 0e ha%e 34#7thousands of feet pressure altitude No0 0e can use that formulae

o, 1*O/ de%iation 4ft gi%es an error per 1###ft of B5ft


7/33

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1st March 2005,12:19

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2rrmmmm, P;T 8and pug@i9, &ou must onl& correct for the depth ofindicated altitude, not for the pressure altitude, so that's 3,### feet not3,4#7 ou are correcting for 4#7 feet of seaH The P! is onl& used for finding

the temperature de%iation

I! is closer to +O than *O at 34## feetH I! de%iation is .1+O orr& to bepedantic, but to a%oid confusion I suspect &ou got &our t0o altitudes the0rong 0a& round in the calculation, as that 0ould account for both errors

ubsidence

If this 0as using a real (N) measured at the top of the obstacle &ou 0ouldbe right !s it is this Guestion uses the horrible 8and incorrect9 termRegional (N) Regional pressre setti!" is not a (N) at all, nor based onthem, hence the militar& do not allo0 their pilots to use the term Regional

(N)H It is calculated from (==sK, 0hich are corrected for off.I!temperature It is also probabl& calculated from measurements 0ell belo0the ele%ation of the obstruction, so e%en using a (N) &ou must account fortemperature bet0een 0here the (N) is measured and the aircraft, not theobstruction height and the aircraft

)ope this clarifiesH

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KRegional pressure setting is the lo0est (== forecast in the region o%er thefollo0ing " hours, and is %alid for 1 hour

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=ound this Guestion

ou're fl&ing 0ith 14 >s Ehat is the maimum ban angle before stalloccursa9 5#Ob9 3#Oc9 3"Od9 44O

I eep getting ans0er a9 5#O but m& feedbac mars d9 as the right one/an an&one help me

subsidence

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25th March 2005, 22:41 #5(

Dnathan


8/33

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3#O ban about BC47O ban about 1*C5#O ban about 41CB7O ban about 1##C

!nd at 5#O ban the load factor is " 8";9, so i 0ould also go 0ith&our conclusion

Dn"th"n

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25th March 2005, 23:36 #5$

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To ans0er the Guestion &ou need to no0 t0o things

819 tall speed increases b& the sGuare root of the load factor

8"9 In a turn, load factor can be calculated using the formula

load factor : 1F8cos angle of ban9

=irstl& 0e 0or out 0hat load factor 0e 0ould need to stall at 14 >s14 14 : " No0 0e no0 that the load factor reGuired is ", 0e can0or out the angle of ban that 0ould achie%e that load factor If 0erearrange the formula 0e get cos angle of ban : 1Fload factor 1F" :#7 /os.1 #7 : 5#, so 8a9 is the correct ans0er

If &ou &ou forget that stall speed increases b& the sGuare root of theload factor, rather than the load factor itself, then &ou get ans0er 8d9

)ope that helps

!l

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6th April 2005, 08:28 #60

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Ehen do &ou use a non.radar separation of 7nm

Ehen do &ou use a radar separation of 7nm

/an't remember 0hich one the Guestion ased, i thin it 0as non radarseparation

a9hea%& hea%&, thin its 4nmb9medium hea%&c9light hea%&

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9/33

d9light medium


10/33

23rd May 2005, 15:19 #66

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Please don't grill me as I'%e tried to fid the details in ;2T?2T and othersources but 0hat does the !6T- and ND> mean in this ?2T!R as Iha%en't seen this before

2;P6 "3147#U !6T- "###3AT ****ND> FF


11/33

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15th u!e 2005, 10:38 #6$

oford blue -%er "7# posts so farPerhaps I should clichere and order a PersonalTitle Join Date =eb "##"

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I suspect that &ou are not appl&ing the correction for compressibilit&

J! L+ M =$3*# is .77V/, as &ou sa& That gi%es 4+" nots beforecorrection for compressibilit& 80ith a /RP.7 . &ou ma& find that an !R/"gi%es a slightl& different ans0er9

Eith compressibilit& corrected,the ans0er comes to about 453 or 454

If &our =T- has not sho0n &ou ho0 to correct for compressibilit&, readthe little boolet that comes 0ith the flight computer

28th u!e 2005, 12:37 ##1

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inst question

the interception of a I$ beam b& the auto pilot taes place !9according to a interception %erces range and angle


12/33

21st uly 2005, 14:54 ##5

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an&one ans0er this for me and 0h&

for a jet cruising at 13" %imd a 7C decrease in 0eight 0ouldgi%e a change of fuel flo0 b& appro

1#C decrease7C decrease7C increase"7C decrease

cheers

"eroste.e

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21st uly 2005, 17:49 ##6

fullrich Instead of being 'justanother number' I couldorder a Personal Title andhelp support PPRuNe Join Date -ct "##3

$ocation ?ainlandPosts "7

'() *md

=uel flo0 at 13" %md 0ill decrease at the sGuare root of the changein 0eight or 8for small changes half the change9

hense "7C

!t >?D the change 0ould be eGual

!t >?P the change 0ould be sGuared8doubled for small change9

=ullrich

13th Au"ust 2005, 18:30 ##(

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he& gu&s and gals

I faild instruments becasue of this Guestion Does an&one no0 ho0 "ans0er it, because m& father and i and a fe0 other gu&s ha%e noclueHH

here it goes

!n aircraft flies a mesured course of 7N? bet0een t0o p&lons atB###ft palt , temp 17deg celcisus in "min47sec fl&ing the re%ers in"min1*sec

if the asi 0as 1##ts the asi error 0as

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13/33

8!9 1ts under read8


14/33

Join Date Dec "##4$ocation 6APosts 45

component9 Therefor, using &our !risto, 1"#Ats T! eGuates to a /! of1#7Ats This gi%es &ou a 7t under read That 0ould be m& reasoning, butit seems as though m& ans0er is incorrect

/)22RHHHI

Last edited by (ba!e# : 14th %"st 2005 at 14:10.

b"nez

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14th Au"ust 2005,13:57

#(4

-ld moe&

-%er 1### posts and Iob%iousl& don't 0ant aPersonal Title 0hich Icould get just b& clicinghere Join Date Jun "##4$ocation ingaporePosts 1,15"

-ss%# Sean#

If indeed &ou did fail instruments because of this Guestion, then &ou ha%ea good case to protest . none of the ans0ers are correct

Please forgi%e the degree of decimal places, included so that this can bepro%en conclusi%el&

The basic mathematics indicate that the said time inter%als ma& onl& beachie%ed at a T! of 11*"*3575 At, and a Eind /omponent of.1#"#"B45*1 At on the first leg, and con%ersl& L1#"#"B45*1 At on thesecond, ie a ;roundspeed outbound of 1#*#*#*#*1 At, and1"*4*54#"* on return !ppl& these ;round peeds to the 7 nmbet0een p&lons 0ithout A!. rounding off of the results .

7 nm at ;F 1#*#*#*#*1 : "47 E/A0TL.

7 nm at ;F 1"*4*54#"* : "1* E/A0TL.

-A, a T! of 11*"*3575 At is pro%en !t B### feet Pressure )eight anda tatic !ir Temperature of L17O/ To achie%e the Guoted T! in theseconditions reGuires 2! 1#4B*, ?ach No #1+#3, or, importantl& for&ou, a /! of 1#4++5+*4*

Thus, if the flight is conducted at 1## AI!, the !I is 1!2E343EA25!G b& 4++5+*4* At, 7 At bet0een friends

N-N2 of the ans0ers are correct Protest the result Sean# protestH

Regards,

-ld moe&

16th Au"ust 2005,00:26

#($

-ld moe& -%er 1### posts and Iob%iousl& don't 0ant aPersonal Title 0hich I

-ss% , /ongratulations on &our pass

0ron, unfortunatel& it cannot be done that 0a&, because as a percentagepenalt& or gain, the same Eind /omponent has a greater effect upon timeas a )ead0ind than 0hen a Tail0ind Thus, the solution can not be found

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15/33

could get just b&clicing here Join Date Jun "##4$ocation ingaporePosts 1,15"

b& taing the total distance against the total time, the T! 0ill al0a&scome out on the lo0 side

/onsider a 1## At T! o%er a 1## mile course In nil 0ind, it comes out at5# minutes both directions, so far so good, but no0 insert a "# At)ead0ind outbound, 0hich becomes "# At Tail0ind for the re%erse directionX

1## nm at ;F +# At : B7 minutes 82!/T$9

1## nm at ;F 1"# At : 7# minutes 82!/T$9

No0, if 0e use &our techniGue of total distance against total time, thatYs X

"## nm in 1"7 minutes : *5 Anots X Erong, 0e ne0 in ad%ance that theT! : 1## At

No0, if instead 0e calculated the ;F in both directions, and found themean, 0e 0ould ha%e the ans0er X

1## nm in B7 minutes : ;F +#1## nm in 7# minutes : ;F 1"#

?ean ;F : 8+# L 1"#9 F " : 1## Ats X /orrectH

8!ll of the abo%e assumes of course, that there 0as no drift, because an&drift 0ill effecti%el& increase the )ead0ind and decrease the Tail0ind9

ItYs because of this t&pe of reasoning that 0e need to use a more compleformula in calculating PNRs, than simpl& taing half of the useableendurance to be used on the out0ard leg

Regards,

-ld moe&

from a EF> problem &ou obtain a 7#t head0ind component, this 0ill KnotK automaticall&turn into a 7#t tail0ind component

$et me do an eample

T! 4## Anots)D; #*# 8T9EF> #5# F 4# Anots

afe 2ndurance B )ours

Ehat 0ould the distance to the Point of afe Return 8PR9 be

o PR : 8 ;round peed )ome K afe 2ndurance 9 F 8 ;round peed )ome L ;roundpeed -ut 9

=irstl& 0e 0ill need to find out the ;roundspeed -ut and ;roundspeed )ome Ee'll needthe /RP.7 for this

Put the central blue dot o%er the T! of 4## nots Then under the Inde put #5# ?ar 4#nots do0n from 4##, so that'll be a mar on 35# nots This is the EF> done

No0 rotate the 0heel so that #*# is under the Inde This 0ill gi%e &ou the drift so 0eshould ha%e 3 degree starboard drift, the heading 0ill thus be #+B degrees and thegroundspeed 0ill be 357 nots

To obtain the groundspeed home

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16/33

The trac home 0ould be "B#, this 0ill gi%e us 3 degrees of port drift and thus the heading0ill be "B3 degrees The groundspeed 0ill be 433 8not much of a difference in thiseample9

;roundspeed -ut 357;roundspeed )ome 433

PR : 8 433 K B 9 F 8 357 L 433 9 : 3#31 F B*+ : 3B*+"47514

=or the distance 0ould be 3B*+"47514 hours K 357 Anots ;

PR : 13+535nm

I 0ould second subscribing to the


17/33

/harlie Uulu I'%e onl& made a fe0 posts soI don't feel the need to ordera Personal Title and helpsupport PPRuNe Join Date Jun "##"$ocation /ardiff, 6A

!ge "*Posts 5+5

up I ept it all true tracs F headings in the eample abo%e to eepit simple

-f course 0hen dealing 0ith run0a& cross0inds F head0inds onecan use a calculator 8I did in the eam and its ?6/) Guicer9

)ead0ind is a function of cos 8cos # degrees is 19/ross0ind is a function of sin 8sin *# degrees is 19

eg

/ross0ind : Eind speed K sin B# degrees difference)ead0ind : Eind speed K cos B# degrees difference

2!d epte$ber 2005, 16:19 #112

end /lo0ns

Jet Blast Rat Join Date Jan "##1$ocation arfend.on.ea!ge 33Posts 5,"#1

ou are used to the Guestion gi%ing the difference bet0een T!and ;F as a 0ind component This 0ind component is simpl&

added to or subtracted from the T! to find the groundspeed Thisis rather a simplification of the issue, to reduce the compleit& ofthe Guestion

In this eample the 0ind component is not gi%en Instead &ou aregi%en 0ind direction and speed and the desired trac to fl&outbound -b%iousl& for a PR the return trac must be thereciprocal of the outbound trac

In this case to calculate the groundspeed, instead of just adding orsubtracting a gi%en component &ou need to 0or on the /RP.7,the %ector.calculator side !ll instructions assume &ou use the0ind.do0n method

1 Place a 0ind mar 8turn the 0ind direction to the True)eading arro0, count do0n from the centre bug b& the 0indspeed and place a small cross9" Place the centre bug on the T!3 Turn the outbound trac to the True )eading arro0 . note thisis onl& an approimate heading as it is the reGuired trac4 =ind the drift under the 0ind cross7 Turn the trac 8to0ards the 0ind cross for the first turn9 untilthe trac sits against the drift on the drift ar at the topcorresponding to the drift under the 0ind cross5 /hec the drift under the 0ind cross, and repeat step 7 and this

step if reGuiredB Read the groundspeed under the 0ind cross

Note this groundspeed as -, the outbound ;FRepeat steps 3 to B using the return trac, note the groundspeedas ), the homebound groundspeed

6se - and ) in the PR formula

Notice that 0ith an& cross0ind component the difference bet0eengroundspeed and T! is not the same on reciprocal tracs, ie the0ind components are not the same but negati%e as the& so often

are on eam Guestions

=or eample, imagine a tail0ind, not a direct tail0ind but atail0ind from the left, on the outbound leg The aircraft 0ould beheading left of trac to account for drift, reducing the tail0indcomponent Re%ersing trac the 0ind is a head0ind from the right

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18/33

The aircraft 0ould be turned a little right to account for drift,increasing the head0ind component Therefore an& head0indcomponent 0ill al0a&s be greater than the tail0ind component ona reciprocal trac, unless the 0ind is straight do0n the trac 0henthe& are eGual

Tr& this eample 8from the J!! Guestion ban9

Eind #47VF7#ts

Trac #*#V out 8so "B#V home9T! 1+# ts)o0 far can &ou go out and return 0ithin 1 hour

=ind groundspeeds, use the PR formula 0ith an endurance of 1hour

ou should find groundspeeds of about 141 ts out, "1" ts home80ithin 1 t9 and a distance of +7 nm 80ithin 1 nm9

end /lo0ns;en Na%

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6th epte$ber 2005, 13:37 #113

berserer Instead of being 'just anothernumber' I could order aPersonal Title and help supportPPRuNe Join Date !ug "##4$ocation scandina%iaPosts 1+

5cin, question6

I am currentl& reading up on aircraft icing and I 0ant to clearif&one thing If ased to hold, 0ould &ou rather hold o%er 0ater or0ould &ou hold o%er land to a%oid icing I ha%e been gi%en %er&0ea ans0ers from m& friends so far /an an&one help me 0iththis

berserer

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6th epte$ber 2005,17:46

#114

)igh Eing Drifter


ou 0ill onl& get icing 80ith the eception of hoar9 in %isible moisture2ssentiall&, &ou 0ill get the most serious icing in cumuliform clouds,so &ou are looing at sta&ing out of con%ecting air Eill it con%ect o%er0ater or land Depends 0here in the Eorld &ou are and 0hat time of&ear and da& it is



19/33

If &ou include orographic con%ection in the eGuation then I suppose&ou 0ould 0ant to sta& a0a& from hills and hence the land, but thatseems a tad tenuous to me

If &ou consider 0hat actions &ou 0ould need to tae if &ou eperiencehea%& icing, then I suppose o%er sea is better because &ou candescend lo0er to 0armer air

If &ou are thining of 0arm front icing then it maes no difference,

because the theoreticall& best action is to climb into the 0arm air

If the choice is the mid !tlantic or the /entral !sia then there 0ouldob%iousl& be less moisture o%er the huge land mass ie0 Public Profile

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8th %ct&ber 2005, 20:00 #153

/harlie Uulu I'%e onl& made a fe0 posts soI don't feel the need to ordera Personal Title and helpsupport PPRuNe Join Date Jun "##"$ocation /ardiff, 6A!ge "*Posts 5+5

)i !3"#',

!s 1#1* is higher than 1#13, 0e shall need to add "B' K 5hPa :15"' onto 13,7## to gi%e us our altitude abo%e sea le%el This gi%esus 13,55"' abo%e sea le%el

)o0e%er the Guestion states that our true altitude is 13,7##'

!s the true altitude is less than our altitude abo%e sea le%el 8truealtitude of 13,7## as opposed to 13,55"9, the temperature must becolder than I!

Remember, if the column of air belo0 &ou is colder than I! then&ou are lo0er than the altitude abo%e sea le%el If the air is 0armerthan I! then &our true altitude 0ill be higher than that indicated


20/33

/harlie Uulu

8th %ct&ber 2005, 21:57 #155

Dic Ehittingham

-%er 17# postsH !bout time Icliced here and ordered aPersonal Title Join Date -ct "###$ocation ie0 Public Profile

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12th %ct&ber 2005, 14:52 #156

!3"#sRcool Instead of being 'just anothernumber' I could order a PersonalTitle and help support PPRuNe Join Date !ug "##7$ocation 22/Posts "+

ATPL 7ET Question True ALT8 tem%

=l&ing =$ 15#-!T L"Bcsea le%el pres 1##38is this (N)9Ehat is tru e !lt

?ust I 15###F"B to get 7*#

and . from 15###

ho0 come the ans is 17#*# in the feedbac Ehat am I doing 0rong

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21/33

12th %ct&ber 2005, 15:25 #160

R>R+## I'%e onl& made a fe0 posts so Idon't feel the need to order aPersonal Title and help supportPPRuNe

Join Date Jan "###$ocation 6APosts B31

Tr" this

0ell &es ;lobal Earming indeed Number/runcher H

man& deaths at the surface that da& due to 'pollution'

..........................

Relationship of true and calibrated 8indicated9 altitude

T!: /! L 8/!.=29K8I!D2>9F8"B3L-!T90here

T!: True !ltitude abo%e sea.le%el=2: =ield 2le%ation of station pro%iding the altimeter setting/!: /alibrated altitude: !ltitude indicated b& altimeter0hen set to thealtimeter setting, corrected for calibration error

I!D2>: !%erage de%iation from standard temperature fromstandard in the aircolumn bet0een the station and the aircraft 8in /9

-!T: -utside air temperature 8at altitude9

sorr& its . "Bc

R>R +## ... thats is definition of all codes but not method for 0oring out this t&pe ofGuestion but thans for &our help

R>R I didnt read ur repl& properl& sorr& ,, just realised ur method. ta 0ill tr&

R>R . 0hat if the Guestion doesnt gi%e me =2 0hat do I do then

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12th %ct&ber 2005, 15:35 #162

Number /runcher -%er 17# postsH !bout time Icliced here and ordered aPersonal Title Join Date Jun "##"$ocation $ondonPosts 17#

-A

The eGuation is as such

15,### . 815K4K.1#9 . 881#13.1##39K"B9 : 17,#*#

15,### is the altitude

815K4K.1#9 8159 is the flight le%el abbre%iated to the first 1 or "

digits ?ultipl& this b& 84c9 84c for e%er& 1,###ft9 ?ultipl& it b& theI! temp de%'n 8.1#9, in this case at 15,### the temp should be.1#, but its ."B

econd part of the eGuation is 1#13 as used for =$'s, then adjust itfor the actual (N), 1##3, and multipl& it b& the standard "B

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22/33

6se this formula for all these t&pes of ('s

;ood luc

Last edited by )*ber +r!cher : 12th ,ct&ber 2005 at

15:47 .

12th %ct&ber 2005, 21:47 #166

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23/33

meridian and that point, ie B7dgs, therefore 1## .B7 is "7o all the de%iation, drift and %ariation is to confuse &ou

0

!t Pressure )eight 15### feet, for (N) : 1##3, Indicated !ltitude: 15###."+11:=:'@ feet

The ?ean I! Temperature of the column of air is 8L1447.155*9F" :4')>0 L "B317 :))'(>C'

The ?ean !ctual Temperature of the column of air is "B"#3OA .1#31 : )?')>C

True !ltitude : 17B1+* "51B" F "B"#3 : =)(') feet

That's %er& close to the standard ans0er of 17#*# feet

The results arri%ed at here 0ere achie%ed using actual almospheric%alues in place of the commonl& used con%enient approimationsThe degree of compleit& 0as not intended as a line shoot, butto mae three points .

D The practical da& to da& approimations used 83# ftFhPa, "Oper 1### feet, etc9, 0hilst not eact, are good practical figuresand ma& be used 0ith confidence

D) For Examiners 4 -ptional ans0ers pro%ided ?6T be eact,0ith allo0ance for small de%iation from the 'absolutel& correct'ans0er It can be etremel& distressing to an eaminee 0ho has0ored hisFher calculation thoroughl&, and finds that none of &ourans0ers 'fit'

D( For Students 4 It's essential in &our learning process that &ousee to understand +9. certain processes are in%ol%ed, instead

of the all.too.common approach of simpl& learning ho0 to do it0ithout an& understanding of the factors in%ol%ed !nunderstanding of +9. certain phenomena occur 0ill last &ou fordecades, 0hereas the simple rote learning of ho0 to do it 0ill bereceding in &our mind the da& after the eamination

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24/33

Regards,

-ld moe&

ld S!oe

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=ind ?ore Posts b& -ld moe&

14th %ct&ber 2005, 21:41 #1#3

po0dermone& -%er "7# posts so far PerhapsI should clic here and order aPersonal Title Join Date ?a& "##7$ocation DublinF=rance

!ge 3BPosts "*#

)i, the 0a& I sa0 it 0as this=irst correct for barometric error, 1# "B : "B#ft

o &our actual alt is 17B3#ft

Temp at 17B3# should be in I! .157 dgs /

Temp is ."B at 17B3#ft so at that le%el its I! .1#7

4C for e%er& dg belo0 isa lea%es at correction of 4"C

17B3# . 84"C of 17B3#9 : 17#B#ft

Is this correct I am not sure 0h& &ou gu&s 0ere 0oring out theI! temp de%iation at =$15#, it's not &our actual altitude Is this0rong on m& part hould &ou first do the temp correction thenbarometric

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25/33

Posts "+ c#+7d "57

I made it "57 as if needle is deflected to right the ac has to follo0needle until centred. am i right so nearest deg is #+7degradial of #+7 is "57 ans0er 8d9In m& notes the feedbac ans is "B7 ho0 come

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20th %ct&ber 2005, 00:22 #1#$

/harlie Uulu I'%e onl& made a fe0 posts soI don't feel the need to order

a Personal Title and helpsupport PPRuNe Join Date Jun "##"$ocation /ardiff, 6A!ge "*Posts 5+5

The >-R --R

This means that although the instrument in the aeroplane is set to#*# the actual radial set on the instrument is the "B#R ou can seethis b& t0isting the --Rs9

o as the needle is deflected right &ou are fl&ing to the left of tracIf &ou are to the left of trac that 0ill put &ou on a radial greaterthan "B#R "B#R plus 7 degree deflection : &ou are fl&ing on the

"B7 Radial

Ch"rlie ulu

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20th %ct&ber 2005, 13:06 #1(0

end /lo0ns

Jet Blast Rat

Join Date Jan "##1$ocation arfend.on.ea!ge 33Posts 5,"#1

ou don't follo0 needles on a /DI to intercept the inbound trac .&ou go further than the indicated de%iationH

The indication is sa&ing that &ou ha%e to trac right of #*#O tointercept the #*#O? inbound trac, and that &ou are 7 degrees offTherefore if &ou trac 7O right of #*#O &ou are directl& inbound, so&ou are on a #*7O? inbound trac, or (D? !s /U sa&s radials areoutbound magnetic bearings 8(DRs9 so &ou are on the reciprocal,"B7O



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Drag Coefficient & Lifting LineTheory

Is there a way to estimate the drag coefficient using Thin Airfoil Theory? I know that lift coefficient isestimated as 2*pi*alpha !ut does Thin Airfoil Theory e"en predict a "alue for the drag coefficient?- Scott

The source of the lift coefficient e#uation that you$"e cited was discussed in a pre"ious #uestion a!out theThin Airfoil Theory% As you imply in your #uestion Thin Airfoil Theory does not predict drag only lift andpitching moment%

owe"er another !asic theory does pro"ide a reasona!le first'order appro(imation for the drag coefficient% Thistechni#ue is called )randtl$s Lifting Line Theory% Thin Airfoil Theory is deri"ed assuming that a wing has an infinitespan !ut lifting line theory applies to a finite wing with no sweep and a reasona!ly large aspect ratio% In simple termsthe wing is modeled as a fi(ed "orte( with a series of trailing "ortices e(tending !ehind it% These trailing "ortices ha"ethe effect of reducing the lift produced !y the wing and creating a form of drag called induced drag%

Creation of trailing vortices due to a difference in pressure above and below a lifting surface

According to Lifting Line Theory the lift coefficient can !e calculated in the following way

where

CL + ,D wing lift coefficient

Clα + 2D airfoil lift coefficient slope

A- + wing aspect ratioα + angle of attack in radians

.ote that this e#uation is of the same form as that deri"ed from Thin Airfoil Theory% In fact the a!o"ee#uation !ecomes identical to that predicted !y Thin Airfoil Theory if we let the aspect ratio go to infinity as

it would for an infinite wing and if we assume the lift cur"e slope of the airfoil section Clα is the theoretical

ma(imum "alue of 2π% If you know the actual lift cur"e slope for the airfoil on a particular aircraft you wish to

http://www.aerospaceweb.org/question/aerodynamics/q0136.shtmlhttp://www.aerospaceweb.org/question/aerodynamics/q0136.shtmlhttp://www.aerospaceweb.org/question/aerodynamics/q0167.shtmlhttp://www.aerospaceweb.org/question/aerodynamics/q0130.shtmlhttp://www.aerospaceweb.org/question/aerodynamics/q0130.shtmlhttp://www.aerospaceweb.org/question/aerodynamics/q0136.shtmlhttp://www.aerospaceweb.org/question/aerodynamics/q0167.shtmlhttp://www.aerospaceweb.org/question/aerodynamics/q0130.shtml


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analy/e you can su!stitute that "alue for a more accurate estimate% owe"er 2π is usually a "ery close

appro(imation%

0or e(ample the "alue 2π is used in the following graphs comparing e(perimental lift coefficients for two aircraft as

measured in a wind tunnel against predictions from !oth Thin Airfoil Theory and Lifting Line Theory% The firstcomparison shows the Cessna 12 with its relati"ely high aspect ratio of %,% .ote that the Lifting Line prediction isonly a slight impro"ement o"er Thin Airfoil Theory when compared to the Cessna wind tunnel data though the slopeof the Lifting Line e#uation does !etter match that of the actual data% Also note that like Thin Airfoil Theory the LiftingLine model is not capa!le of predicting stall and only pro"ides a good estimate of the lift up to the stall angle%

In contrast the Lifting Line model is a significant impro"ement o"er Thin Airfoil Theory in predicting the liftof the Lightning% As was discussed in our pre"ious article on Thin Airfoil Theory that approach !reaks downfor aircraft with small aspect ratio wings like the Lightning with its A- of 2%32% 4"en though the Lifting LineTheory assumes an unswept wing it still produces a good appro(imation of the lift produced !y theLighting$s highly swept'!ack wings%

Lifting Line Theory agrees so much !etter with the Lightning wind tunnel data than does Thin Airfoil Theory!ecause of the introduction of the aspect ratio A-% This "aria!le makes it possi!le to estimate the influenceof trailing "ortices and their downwash on the lift of the wing% This same factor makes it possi!le toappro(imate the induced drag that downwash creates on the wing !y the following e#uation

where


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CDi + induced drag coefficientCL + ,D wing lift coefficient A- + wing aspect ratio

5nowing the induced drag is useful !ut it is only one component of the total drag acting on an aircraft% 0orsu!sonic aircraft the total drag is almost entirely due to the induced drag plus another form of drag calledprofile drag% Com!ining these two forms allows us to estimate the total drag on a wing !y the relationship

where

CD + ,D wing drag coefficientCDmin + minimum ,D wing drag coefficientk + constant of proportionalityCL + ,D wing lift coefficient A- + wing aspect ratio

δ + ratio of induced drag to the theoretical optimum for an elliptic wing

6ince many of these "aria!les are nearly constants the a!o"e e#uation can !e simplified !y introducing anew constant called 7swald$s efficiency factor 8e9 in their place

where

CD + ,D wing drag coefficientCDmin + minimum ,D wing drag coefficientCL + ,D wing lift coefficient A- + wing aspect ratioe + 7swald$s efficiency factor

:e now ha"e a useful e#uation for estimating the drag of an aircraft% The minimum drag coefficient C Dmincan !e estimated relati"ely easily% A good "alue to use is around ;%;23 for su!sonic aircraft and ;%;


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Con"air ; 0our Eet'engine airliner %2; ;%;2


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4(amples comparing the e(perimental drag coefficients of the Cessna 12 and the Lightning against theresults predicted !y Lifting Line Theory are presented a!o"e% .ote that the lifting line appro(imationmatches up against the wind tunnel results #uite well%

- answer by Jeff Scott , 11 July 2004

Related Topics:

- gu&s 8Zgirls9, so &ou are going to maintain the last assigned heading for 3 mins andcrash into a hill

;otta be 1 alsohould an aircraft communications failure occur 0hile the aircraft is being %ectored on one

of these approaches, separatel& or as part of a T!R, the pilot is epected to compl& 0iththe communications failure procedure b& selecting the transponder to ?ode !F3 /ode B5##immediatel& Pilots should al0a&s be a0are of the traffic situation =or eample, !T/ ma&ha%e indicated that &our aircraft 0as second for an approach to Run0a& #5$ under thesecircumstances, the flight should be continued along the route that normall& 0ould ha%ebeen epected under radar %ectoring In some cases of communications failure, pilots ma&need to dead recon, or DR, a route to the final approach course It is important to otheraircraft and !T/ for the aircraft eperiencing a communications failure to continue theflight along a route that 0ould permit the aircraft to conduct a straight.in approach andlanding 0ithout unepected man[u%ring Pilots are epected to eercise good judgment inthese cases 6nepected man[u%res, such as turns a0a& from the final approach course,ma& cause traffic disruptions and conflictsIf the communications failure occurs 0hile being %ectored at a radar %ectoring altitude thatis lo0er than a published I=R altitude 8eg, minimum sector altitude "7 N?9, the pilot shallimmediatel& climb to and maintain the appropriate minimum I=R altitude until arri%al at afi associated 0ith the instrument procedure?odern technolog& has introduced ne0 on.board communications capabilities, such asairborne telephone communications Pilots 0ho are confronted 0ith an aircraftcommunications failure ma&, if circumstances permit, use this ne0 on.board technolog& toestablish communications 0ith the appropriate !T/ units N!> /!N!D! publishes thephone numbers of !//s, control to0ers, and = units in the /=R!/ . 5# INTR6?2NT =$I;)T R6$2 8I=R9 X ;2N2R!$

httpFF000tcgccaF/i%il!%iationFpuF5.1htmS5.3."

;- =-R " -R $-2 ! ?!RA, T)INA $-;I/!$$ =-$AHH

also, remember 3 mins at jet speed of "1# ts 8slo0 and clean ie no flap etc9 or 37nmls Fmin : 1# miles or 0ell on &our 0a& to being out of the ?in afet& !rea altitudeIts

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ob%ious its ", an&one going for 1 needs to redo their license


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8th March 2006, 19:34 #302

degothia Instead of being 'justanother number' I couldorder a Personal Title andhelp support PPRuNe

Join Date No% "##7$ocation 17 feet amslPosts 1B

Ground School Exam Questions

)elloHI need help 0ith a Guestion in Principles of =light

=ull span Areuger flaps 0ill lateral stabilit&!9 Impro%e


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2!d April 2006, 09:33 #320

;rass strip basher Instead of being 'justanother number' I couldorder a Personal Title and help supportPPRuNe Join Date No% "##4$ocation $ondonPosts **

Not sure on the first t0o but thin the ans0ers to the third one is normalto the airflo0 and the last one is just abo%e mach 1 8according to ans0ersto feedbac Guestions I ha%e done9 but I ha%e been no0n to be0rong good luc tomorro0 b& the 0a&
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