JET EXAM - Study Portal ONLY

[azax]

Please do no post queries about your reference no.
or examination centers. :=

Let this be a thread to share only exam oriented knowledge.

Thank you.

P.S.

indian airways limit
46,000' / 49,000' ???

[v1_rotate]

FlightLevel 460

[cvchetan]

Tech is basic of a/c structure, controls, Engines including jet engines, Basics of different systems etc.

For Nav they'll ask from everything including CP/PNR. Then numericals will be of very simple numbers and will be there to judge if your concept is right.

Radio aids will focus on workings, errors etc of various devices and again numericals will be very basic in nature.

[harsh786techy]

Ques-what is the requiremnets for
1. CAVOK
2. SKC

I think cavok is 10 km vis and no clouds base below 5000 and no TS FG etc.
But can someone put some light on SKC

[azax]

they will try to cover most subjects in a variety of questions...
brushing up everything you have learned is the way to go.
cp pnr is one of the key concepts of flying ... which cannot be not-asked in selection examinations.

anyway

SKC is sky clear ... no clouds
is used to indicate the cloud amount
amongst sct bkn ovc
or
sky conditions
amongst cb tcu clr-sky clear below 12000' AGL i.e. because when u speak of clouds its always above ground level.

CAVOK
is ceiling and visibility ok
which indicates VIS is 10k+ with no shallow fog
usage mostly vfr
no cloud below 5000' or lowest safe which ever is higher

CAVU
is c & V unlimited
same thing but no clds below 10000'
usage mostly ifr

[Uniform.]

Does the radio nav includes the basic equipment like NDB/ADF, VOR, ILS, MLS, DME, TCAS etc :E

or we have to study others like INS, IRS, GPWS, EFIS, FLIGHT warning also???? :sad:

[harsh786techy]

ok, so if conditions are
8km+ Vis and NO CLOUDS what would be mentioned in METAR?

Is it still going to CAVOK or SKC

[azax]

its an indian airline recruiting -
so i think they might require indian pilots to know nav topics that
the dgca expects us to know...
so i am guessing yes questions on all nav and radio aids could be asked

but certainly not IRS and |INS


and as for the forecast

VIS 8K
or 8000
SKC

both will be mentioned

[alpha_victor_romeo]

stall speed at 8000ft 45kts...
stall speed at 20000ft ???

[alpha_victor_romeo]

Guys which books are you referring for the study of tech ??

plz tell me asap

[t.a]

stall depends on angle of attack and not on airspeed. so will stall at the same IAS at any given altitude.

[DJ Flyboy]

What is the primary role of the turbine in
Turboprop
Turbofan

[flyinghigh89]

There is a question in the other thread which is raising alot of confusion..I would like to ask it here-

Will an aircraft descend faster in headwind/tailwind?

[shanx]

stall speed at 8000ft 45kts...
stall speed at 20000ft ???
An airplane can stall at ANY speed at ANY altitude.

As long as Angle of Attack is exceeded, the airplane will stall.

The question doesn't make sense unless of course it has been taken from some DGCA "question bank".

[Sierra2467]

where does the stall on a wing occur first? wing tip/wing root?
does it differ for swept wing/washout wing?
thnx in advance

[v1_rotate]

Yup.

The Indicated Stall Speed would always remain the same , its just that the TAS would be higher at higher altitudes.

How to put an exact figure to it based on the data given i do not know. :confused:

[cvchetan]

wing roots are the first to stall.. that is because in case of a stall, the ailerons which are at the wing ends will still be functional..

[shanx]

There is a question in the other thread which is raising alot of confusion..I would like to ask it here-

Will an aircraft descend faster in headwind/tailwind?

As far as RATE OF DESCENT is concerned, winds have no effect.

(If that is what you're trying to mean by asking which aircraft will "descend faster").

[shanx]

The Indicated Stall Speed would always remain the same , its just that the TAS would be higher at higher altitudes.Not really.

The airplane can be made to stall at various indicated airspeeds.

[v1_rotate]

Ideally we would want the wing root to stall first, so we still have aileron effectiveness to help in a stabilized recovery.

In swept back wings , unfortunately there is a tendency for the wing tip to stall first due to span-wise flow. One solution considered was using forward swept wings, but this causes excessive 'wingtwist'

Stall strips, Washout etc are used to ensure that the airfoil would stall first at the wingroot

[v1_rotate]

Yes true and correct, sorry about that.

The Stall speed (IAS) does increase times the square root of the load factor.

[Sierra2467]

@cvchetan v1_rotate
Ok, so incase they ask- a wing stalls at the root first,unless "swept wing" is specified in which case the wing stalls at the tip first, right?
thnx again :)

[shanx]

@v1 rotate

Yes. Was just going to add ...

Stall speed depends on load factor.

So as an example, an aircraft that normally stalls at 70 KIAS, can be made to stall at 90 or 100 Kts (Indicated) by forcefully yanking back the controls.

(in other words, inducing more Gs hence .. increasing load factor)

[v1_rotate]

@Sierra2467

Yes, although I dont think they would ask the question that bluntly, because its still rather ambiguous. The planform is also a factor, The stall characteristics of an elliptical wing for example are not as favorable as a rectangular wing.

And also this unfavorable tendency on swept back wings can be minimized with Washout, stall strips , wing fences etc...

[SuperflyTNT]

When in ground effect - Lift increases and Induced drag decreases. So, when out of ground effect, Lift decreases and Induced drag inc. ? Is that right?

[Sierra2467]

are you guys doing the questions from oxford series? those who appeared last time said that oxfords level is too high for jet exam?!
any suggestions plz?

[t.a]

@flyinghigh89
I am not sure if my thinking towards this answer is appropriate or not.
But would like to recall that, on an ILS if there is a change in wind direction which if resulted in change in Ground speed, then to remain on the glide slope, then if Gs decreases then ROD decreases and if Increases then ROD Increases.(which is derived from the formula angle*100*Gs/60)

so applying this principle to your Question, when an aircraft is descending in a still air and later observed a wind change, then if we apply the vice-versa of the above (since u are not giving a correction in this scenario) and the above law is to stay on the Glide slope.

So the resultant would be that, on a Head wind (Gs Decreases ) so the rate of descent increases.

Please correct me, if u find a mistake.

Thanks.

[djajay.jayaraj]

In the last Jet Exam, Was there Any Questions Bases on Mass & Acceleration, If so anyone remember what it was ?

I remember seeing it somewhere on the Jet Air-Thread, But unable to Find it now..

AJ

[alpha_victor_romeo]

I still didn't get the answer ??:confused:

Does Stall Speed change with height..??

BTW This is a question was asked to me by my friend who appeared Indigo exam last time and recollected this question..:ok:

So if you guys could help...

Also Shape of Earth : Ellipsoid or oblate spheroid..??:confused:

Wat is TVMDC type ques..??

What is geomertic Pitch..??

any idea bout Magnus Effect..??

Wat are ACW Generators..??

These are ques frm INDIGO exam first session.. Kindly post any info you might have on any of the above topics.....:ok:

[tmbpilot]

@alpha_victor_romeo-----stall speed increases with alt....description is quite theoretical ,from what i remember is it falls a little as we climb and then starts to increase and becomes more than the original stall speed....correct me if im wrong


shape of the earth strictly speaking its an oblate spheriod

geometric pitch of a prop is the horizontal distance a free propellor will cover in one rotation....effective is the actual distance and the diff between them is slip...


what an unnecessary question:ugh: but magnus effect takes place when when an object is rotating it causes an whirlpool around it ...quite like shaktimaan used to do:cool:

ACW or AC wild type generators have an changing frequency ...as this generator speeds up or slows down freq changes..

@DJ Flyboy
in an turboprop ac turbine is used to drive the prop ,,in an turbojet its used to drive an compressor

correct me if im wrong anywhr

[planeboy_777]

@alpha_victor_romeo-----stall speed increases with alt....description is quite theoretical ,from what i remember is it falls a little as we climb and then starts to increase and becomes more than the original stall speed....correct me if im wrong


thats incorrect my friend........ Stall is dependent on the Dynamic pressure....which is IAS (.5x[row]x [TAS]x[TAS]) ..

the green arc in your ASI never changes if you ever notice:pp

:ok::ok::ok::ok::ok::ok::ok:

[alpha_victor_romeo]

@ above Thank you for your response.... if you dnt mind me asking

could you please refer me the books you study from... you seem to have a good understanding of the subject...

[alpha_victor_romeo]

guys i still need some formula if u claim .... it will change with altitude pls tell me the value how much if 45 kts at 8000ft 20 000 ft how much..??

[planeboy_777]

The Formula is Lift = .5 x [Density] x TAS x TAS x S x Cl(co-efficient of lift)



Stall will occsur just after when Cl reaches its Max so itzz constant for a wing...the only variable is Density and TAS

at high altitudes Density Decreases and TAS is increased automatically increased so the dynamic pressure aka IAS aka .5 x [Density] x [TAS] x [TAS] remains contant

[tmbpilot]

@planeboy_777 at lower range of altitude stall speed does not vary with alt,this is because at these low altitudes the mach number is less than 0.4 m too low for compressibility to be present.at 30000ft the mach number has increased to such an extent the rise in stall speed becomes apparent.......so rephrasing my reply"as alt inc,stall speed is initially constant then increases due to compressibility".......if u have an oxford book refer pg 7-35......

[cyrilroy21]

@tmbpilot

Are referring to IAS or TAS when it comes to stall speed ?

[Pulkdahulk]

Stall speed IAS remains the same at all altitudes.

Please refer

http://www.pprune.org/tech-log/10859-high-altitude-stall.html

[SuperflyTNT]

Can anyone share the METAR and TAF minimums over here? Thanks.

[shanx]

@Pulkdahulk

Stall speed IAS remains the same at all altitudes.

Incorrect.

You can stall the airplane at a much higher IAS by inducing more G's.

Which is why an airplane would stall at a higher IAS, when in a really steep turn, or if the yoke is yanked back real hard.

[neels0908]

guys....
with regard to the question on stall speed,

the formula for lift is : LIFT= (C.L) * {(0.5) * (rho) * (TAS) * (TAS)}
where {(0.5) * (rho) * (TAS) * (TAS)} is the dynamic pressure, which gives the indicated airspeed.

So, from the above equation, when we equate for {(0.5) * (rho) * (TAS) * (TAS)} , it will be : (dynamic pressure) = LIFT/(C.L)

and stall occurs when the coefficient of lift is maximum.
Hence, during stall, (dynamic pressure) =LIFT / (C.L max)

and since C.L max is constant for an aerofoil and the load factor is directly proportional to the Lift produced during straight and level flight, if the load factor acting on an A/c is the same, it will always stall at the same IAS.

Also, when (C.L) = (C.L max) , that is the AoA at which the A/c will always stall irrespective of the Altitude or the speed. { Please note that whenever most of the books say speed, they mean the TAS (v) }

Now , from the very first equation , if we equate for the speed {i.e TAS (v)}, we get

(TAS) * (TAS) {or (v squared)} = [ LIFT / { (C.L max) * (0.5) * (rho) }]


hence TAS {or (v)} will be equal to the square root of the expression on the right hand side of the above equation.

From the derived equations for the TAS {or (v)} and the IAS , we see that density (rho) is involved only in the equation,

So.... Under constant load factor, the IAS at which an A/c will stall will always remain constant, but the TAS will vary inversely with density

i.e , the A/c will stall at a higher TAS at higher altitudes, since density is lower.


Hope this helps .
Best o Luck to all u guys.... :ok:

[DJ Flyboy]

stalling speed remains same in terms of IAS for the same config, but in terms TAS, stall speed increases as altitude increases

[mike_sierra]

1) What is Aerodynamic Centre (AC) ?

2) At 0* angle of attack, what will be the pressure differential around the wings i.e. will it be no pressure diff OR will it be lower pressure above the wings??

3) Minimum no. of satellites for GPS position and RAIM ??
Is it 4/5 ?

[neels0908]

The Aerodynamic Centre is that point around which the net result of the different pitching moments ( Thrust-Drag moment and Lift-Weight moment) will act.

at zero degrees, the pressure on top of the wing will still be lower than the pressure below on a normal aerofoil(well chambered thick aerofoil).....

The pressure will be the same on the top and the bottom at zero degrees if it is a symetrical aerofoil....

and Min. No of satellites for a GPS reading is 4. U need 5 for RAIM.





and wrt to the question regarding stall speed,


guys....
with regard to the question on stall speed,

the formula for lift is : LIFT= (C.L) * {(0.5) * (rho) * (TAS) * (TAS)}
where {(0.5) * (rho) * (TAS) * (TAS)} is the dynamic pressure, which gives the indicated airspeed.

So, from the above equation, when we equate for {(0.5) * (rho) * (TAS) * (TAS)} , it will be : (dynamic pressure) = LIFT/(C.L)

and stall occurs when the coefficient of lift is maximum.
Hence, during stall, (dynamic pressure) =LIFT / (C.L max)

and since C.L max is constant for an aerofoil and the load factor is directly proportional to the Lift produced during straight and level flight, if the load factor acting on an A/c is the same, it will always stall at the same IAS.

Also, when (C.L) = (C.L max) , that is the AoA at which the A/c will always stall irrespective of the Altitude or the speed. { Please note that whenever most of the books say speed, they mean the TAS (v) }

Now , from the very first equation , if we equate for the speed {i.e TAS (v)}, we get

(TAS) * (TAS) {or (v squared)} = [{LIFT}/ {(C.L max) * (0.5) * (rho)}]



hence TAS {or (v)} will be equal to the square root of the expression on the right hand side of the above equation.

From the derived equations for the TAS {or (v)} and the IAS , we see that density (rho) is involved only in the equation,

So.... Under constant load factor, the IAS at which an A/c will stall will always remain constant, but the TAS will vary inversely with density

i.e , the A/c will stall at a higher TAS at higher altitudes, since density is lower.


Hope this helps .
Best o Luck to all u guys....

[antigravity61]

???
1) What is Aerodynamic Centre (AC) ?

2) At 0* angle of attack, what will be the pressure differential around the wings i.e. will it be no pressure diff OR will it be lower pressure above the wings??

3) Minimum no. of satellites for GPS position and RAIM ??
Is it 4/5 ?

@mike_sierra

Any book on principles of aerodynamics will have the answer if you are looking for the answer.

let me try:

1. The torques or moments acting on an airfoil moving through a fluid can be accounted for by the net lift applied at some point on the foil, and a separate net pitching moment about that point whose magnitude varies with the choice of where the lift is chosen to be applied. The aerodynamic center is the point at which the pitching moment coefficient for the airfoil does not vary with lift coefficient i.e. angle of attack, so this choice makes analysis simpler. Aerodynamic center - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Aerodynamic_center)

Whats more important is where is it located?
AC is located approximately 25% of the chord from the leading edge of the aerofoil.

2. at 0 AOA symmetric aerofoils doesnt produce any lift as there is nil pressure difference. But in non symmetric aerofoils, lift is being produced as the wings are cambered.

3. for 2D - 3 satellites and 3D - 4

[carl_ton]

hi ..just wanted to know that for the Jet Airways exam....can spatial reasoning...cubes view in 3 dimension have multiple answers....or only one answer ?

[Maverick2167]

yes they can have multiple answers.... especially in cubes/folding type reasoning

[azax]

regarding the stall speed discussion ...

by how much will the stall speed increase if the a/c banks at 45deg??
since the load factor will increase - but how do we calc. this?

Also,

questions regarding 1:60 Rule ...
will they be asked as there are no calculators allowed?
guys with prior IndiGo and Jet exam experience please shed some light?



could someone please explain turning errors of the compass -
Q) the compass will overread as it is turning thru
E W N or S???

Also,
where can i read DGCA standard Basic Navigation online ?
-earth, departure, relative motion, payload, time, 1n60, maps n charts??

thanks

[Pulkdahulk]

Q) What is the lift-weight relation in an unaccelerated climb ?

[azax]

weight is greater than lift and the CoG moves forward in a unaccelerated climb

[Uniform.]

if m not wrong some basic electricity que. were also asked.....

is there any1 who appeared last time and can tell smth abt electricity part??:confused:

also, how much human factors is given importance..!

[mike_sierra]

by how much will the stall speed increase if the a/c banks at 45deg??
-At 45* bank, the load factor is 1.41, so the IAS will be sq root of the load factor X IAS..

questions regarding 1:60 Rule ...
will they be asked as there are no calculators allowed?
-The formulas and calculations are relatively simple since they do not involve much calculator work..

could someone please explain turning errors of the compass -
Turning errors are caused because of the magnetic dip phenomena.They affect the readings on N and S headings. In the NH, while turning through north from the equator, the compass trends to under-read, so you need to roll out early. Similarly in NH, while turning through south, it tends to over-read
Remember:
Undershoot North Overshoot South

[cvchetan]

At 0 AOA, lift is produced, which is equivalent to the weight of the a/c... else a/c would sink.. since lift is produced, the upper surface will hv lower preassure than the lower..

[neels0908]

@ azax

The formula for variation of stall speed with bank angle is :
Vs (new) = Vs(old) * root of [ 1/ cos{phi}] ,

where {phi} is the bank angle....
in your case... it will be 45 degrees.

so

Vs(new) = Vs(old) * root of [ 1/ cos (45 dergees)]
=> Vs(new)=Vs(old)* root of [1/ 0.707]

=> Vs(new) = VS(old) * 1.19

=> Vs(new) / Vs(old) = 1.19

so the stall speed increases by 19% for a bank angle of 45 degrees.


And the compass errors, remember UNOS for the northern hemisphere turning error.

So to attain u're required heading in the northern hemisphere, you will have to undershoot any heading on the northern part of the compass, (you can also say the compass will over-read, but i'm not sure if that is correct. People generally refer to it as over-shooting) (i.e 271 to 089) and u will have to undershoot (again... u can call it under-reading) any heading that is on the southern part of the compass (i.e 091 to 269).

but there is no turning on easterly (090) or westerly (270) headings on both hemispheres.

n i hv no idea abt 1:60 rule questions, but since calculators are not allowed, i think u can expect a couple questions from that topic.

Good Luck :ok:

[neels0908]

nopes... generally lift produced is equal to weight at small positive angles of attack ( ideally about + 4 dergees)... Thats y most commercial aircrafts cruise at a small positive AoA, which will be the most efficient angle of attack as well. Angles of attack... at 0 degrees AoA, the lift produced will be less than the weight and the A/c will sink.

[PP351]

At steady climb all forces should be same and balanced so lift and weight will act same in an unaccelerated climb.

[neels0908]

i agree.... in an un-accelerated climb, the lift will be equal to the weight.

[azax]

no the lift is marginally less than the weight in a steady climb ...
the flight is definitely in equilibrium but thats because a vertical component of the thrust vector balances out the excess weight component

[neels0908]

i'm sorry... i stand corrected... the sum of the lift and the vertical component of thrust put together will be equal to the weight.

[kiitos.patole]

Hello..

First of all I must say that, the Explainations done in this thread till now are very well done! Applaud to all of you'll!

Now coming to the question that our friend asked here,
'The Stall Speed at 8000feet is 45kts, what would it be at 20000feet?'

At such high altitudes there is one important effect that acts on the wing, which is the very well known Mach No. compressibility effect. At such altitudes, the actual equivalent airspeed(EAS) increases because this effect disturbs the pressure pattern and increases the 'effective weight' on the wing, resulting in a higher EAS stall speed.
Hence, it is the EAS(which is IAS corrected for compressibility and position /instrument error) which increases.


Cheers!

[PP351]

no the lift is marginally less than the weight in a steady climb ...
the flight is definitely in equilibrium but thats because a vertical component of the thrust vector balances out the excess weight component

So in a descent, is lift more than weight?

Also it could be also said that the TOTAL (if you can capitalize, so can I) lifting component (lift and excess thrust vectors acting together) is equal to weight. If you want to get technical about it, then aren't we both correct?

Anyway, if you and your aerodynamicist friends want to look at it that way, that's fine with me But i'll stick to what the book says and let the scientist worry about the accuracy of it. When I'm crossing the FAF, I'm not worried about whether lift is more or less than weight.

Anyway i don't wanna offend you and don't want to go really that deep into the matter but just FYI i think that you're little confused about the components of the force vectors. The magnitude of the vertical component of the lift vector is less than the magnitude of the vertical component of the weight vector, because the weight vector is at an angle to the lift vector. The magnitude of lift and weight are the same.

The magnitude of the vertical component of thrust plus the magnitude of the vertical component of lift is equal to the magnitude of the vertical component of weight plus the magnitude of the vertical component of drag.

[tmbpilot]

@kiitos.patole thats what i have been saying.....

[PP351]

the indicated stall speed in the airspeed indiactor should remain same regardless of the altitude but i suppose the TAS for that stall speed will increse with altitude.

[kiitos.patole]

@tmbpilot : Sorry dude... my bad... Your post wasnt flashy enough to be noticed.. ;)
My bad man...

[SuperflyTNT]

Anyone know which airspace require transponder to fly in and which don't ?

[azax]

could someone please explain how to get the convergence angle from rhumb line and great circles???

thanks

[Shabez]

an aircraft on hdg 124(T) measures qdr of VOR to be 303.If deviation on this hdg is 2 degree E and Variation is 1 degree W.What is QUJ?


a radio station on ground bears 312(relative) at aircraft flying on heading 058 (M).If var is 1 deg E and dev is 2 deg W, calculate QDM and QTE
:ugh:

also is someone could please explain the answers.

[azax]

an aircraft on hdg 124(T) measures qdr of VOR to be 303.If deviation on this hdg is 2 degree E and Variation is 1 degree W.What is QUJ?


a radio station on ground bears 312(relative) at aircraft flying on heading 058 (M).If var is 1 deg E and dev is 2 deg W, calculate QDM and QTE


also is someone could please explain the answers.

LEts see
QDR is magnetic from the station
a/c heading 122(T) after deviation
and 123(M)

303
(M) from station vor

QUJ true track to the station 122 !?!?!


temme if this one is right???

[Sierra2467]

yup, correct

[Aviator_Prat]

AC 058(M)
RB 312
QDM 010/
QDR 190 QTE 191
CD(2W)MV(1E)T

Correct me if i am wrong.

Lets see what Jet has in store for us tomorrow!!!:ugh:

Cheers