Nav Instrument question stumping some of us!

[Ronnie]

Anyone out there who can help a poor soul on countdown to Radio Aids exam tomorrow regarding a question from the Belgrano ....something in the order of:
What is the wavelenght of an ILS frequency?
The answers being offered are in the order of
1: Centimetric
2: Heptimetric
3: Decimetric
Probably easy to work out if quick off the mark and not under great pressure!!!! Nothing in the books. Any help greatly appreciated by those who know and I will pass on the answers to the poor guy concerned

[little red train]

3Khz 100Km
VLF Myriametric
30Khz 10Km
LF Kilometric
300Khz 1Km
MF Hectometric
3Mhz 100m
HF Decametric
30Mhz 10m
VHF Metric
300Mhz 1m
UHF Decimetric
3Ghz 10cm
SHF Centimetric
30Ghz 1cm
EHF Millimetric
300Ghz 1mm

Its easyer to right it length ways across the page.

First thing to do in the exam is remeber

Very Lovely Madens Have Very Usefull Sex Equipment. (First letter of each Freq Band)

Start on top 3 30 300, 3 30 300 inbetween each letter. check start with a 3 end with a 300, then put in the Khz, Mhz & Ghz as apllicable

Below this start at the Right with 1 millimeter, then times by ten
10mm = 1cm
10 x 1cm = 10cm
10 x 10cm = 1m
ect ect

Check theres 2 1's at the start, and ends on 100 without any dody maths inbetween

you can just about figure out the wavelenght bands Right to left again.

Milimetric after the milimetrs
10 * 1mm = Centemeter - Centimetric
10 * 1cm = Deciameter - Decimal like the decimal point (fractions of a tenth ect)
10 * 10 = 100cm - meter - Metric
10 meters - DecaMeter Deca - oposite of Deci, oposite side of the Metric
then its just H, K, M.

It's a pretty easy table to replicate in the exam with practice, & in both RNav & A/C Gen its a good 2 questions quickly in the Bank.

Good luck with the Exams

[twistedenginestarter]

There's no such word as Heptimetric.

I make it approx 3 metres but that's neither centimetric nor decimetric. So I must be wrong.

If I'd have to take a stab it would be centimetric as -again - I don't think you use the term decimetric in practice.

[little red train]

Sorry, Second & Third Exam Tips

RTFQ - Read the Fugging Question

&

ATFQ - Answer the Fugging Question

All ILS (A8W) freqs are between 108m - 112 MHz, they frequenchy share with VORs, ILS uses ODD Khz & 150Khz spacing too Avoid Confusion eg 109.3, 108.15 Mhz - ILS. 108.25 - Not ILS, must be VOR!

Looking @ the Table we instantly see it falls in the VHF Band, 30 - 300Mhz, has wavelenghts between 10 - 1 meter And is Metric.

If you can draw the table out quickly, It is more effective than memory if two or more questions are asked, It also removes the removes the Pressure.

Twisted - Close, C(3*10^8ms) = Freq(Hz)*Lambda(M) -> 300/108 for example = 2.777Meters, 300/112 = 2.679M (confirms Falls between 10 - 1 meters).

Should have used my wonderfull Table!

[This message has been edited by little red train (edited 06 November 2000).]

[Ronnie]

Thanks for your help folks, geatly appreciated.

[BoxProf]

Holy Crap!!! And somehow, knowing this, makes you fly an airplane with greater skill?I'll take the guy that can just dial the number in correctly.

[Alex Whittingham]

Uh, fellows, ILS localisers are VHF or metric and glidepaths are UHF or centimetric. Did the question specify?

[Tinstaafl]

Never mind, BoxProf,

Think how much greater our skills are since it also seems that it is vital we know the colour of the laser in a ring laser gyro. :)

Dial? Numbers? Correctly? That wasn't in the syllabus from the authority. Mustn't be too important then... :)
------------
If I don't like the RLG laser colour can I get a different one? Say... a nice shade of duck egg blue?

[This message has been edited by Tinstaafl (edited 08 November 2000).]

[poisson rouge]

Ronnie old boy, thanks for posting the message for me.... it didn't come up, however some important and vital knowledge required for todays pilots did though! Monkey's bo*ll**ks.

[Oktas8]

Too late for the exam, but if you're like me and hate remembering reams of facts, try the old velocity = freq x wavelength (or vel / freq = wavelength).

freq ILS = about 100MHz or 100,000,000 Hz
vel of light = 300,000,000 m/s

Thus wavelength of ILS
= 300million / 100million
= about 3m

O8