Go Back  PPRuNe Forums > PPRuNe Worldwide > The Pacific: General Aviation & Questions
Reload this Page >

Tricky IFR Questions At Interviews

Wikiposts
Search
The Pacific: General Aviation & Questions The place for students, instructors and charter guys in Oz, NZ and the rest of Oceania.

Tricky IFR Questions At Interviews

Thread Tools
 
Search this Thread
 
Old 19th Nov 2005, 23:26
  #1 (permalink)  
Thread Starter
 
Join Date: Jul 2004
Location: South Of Where ever you are sitting
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
Tricky IFR Questions At Interviews

What are some tricky IFR questions that you have been asked in interviews.
It would be nice to hear some questions that people have had trouble with in interviews.

Or on the other hand what are some good questions?
Gateway Customer is offline  
Old 20th Nov 2005, 02:11
  #2 (permalink)  
 
Join Date: Apr 2004
Location: Orstralia
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
What are the rules for descending below LSALT at night from FL140 in an unpressurissed, 5 seat, single engine, day VFR category aircraft, carrying 8 passengers, 2 opened cans of Avgas and 3 active fuses of gelignite?

I'm not sure if it's in the AIP's or CAO's. Let me know if you find it
pistol night is offline  
Old 20th Nov 2005, 03:43
  #3 (permalink)  
 
Join Date: May 2002
Location: New Zealand
Posts: 347
Likes: 0
Received 0 Likes on 0 Posts
Are you looking for OZ or NZ IFR interview questions?
flyby_kiwi is offline  
Old 20th Nov 2005, 09:12
  #4 (permalink)  
Thread Starter
 
Join Date: Jul 2004
Location: South Of Where ever you are sitting
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
maimly looking for Oz questions, anything would be handy
Gateway Customer is offline  
Old 20th Nov 2005, 11:40
  #5 (permalink)  
 
Join Date: Apr 2001
Location: Established.
Age: 53
Posts: 658
Likes: 0
Received 0 Likes on 0 Posts
Reaching the minima on the ILS how do you tell if you have 800m, 1.2k or 1.5k vis?

When calculating ROD req'd for a 3 deg slope why do you add the 50'? ie 5 x GS + 50. eg GS 150kt means 800 fpm req'd.
The Messiah is offline  
Old 20th Nov 2005, 14:57
  #6 (permalink)  
 
Join Date: Aug 2002
Location: no fixed address
Posts: 181
Likes: 0
Received 0 Likes on 0 Posts
Further to the Messiah's first question...

How do you determine you have the published circling visibility for your catagory of aircraft after an arrival, and how was this number calculated in the first place? No HIAL to help you out with this one.

How about Temperature correction for ILS Glidepath/OM check height for say ISA+20 at 1500'?

Requirements for using Special Alternate wx minimas, including instrumentation AND the other stuff?
VH-ABC is offline  
Old 20th Nov 2005, 15:03
  #7 (permalink)  
 
Join Date: Apr 2001
Location: overthere
Posts: 3,040
Received 26 Likes on 10 Posts
I am sorry, but are you going to make a temp correction at ISA+20?

Don
donpizmeov is offline  
Old 21st Nov 2005, 01:42
  #8 (permalink)  
 
Join Date: Apr 2001
Location: Established.
Age: 53
Posts: 658
Likes: 0
Received 0 Likes on 0 Posts
Temperature correction at the outer marker, and for ISA +20? come off it!

It is only a gross error check at best anyway and I wouldn't encourage tying yourself up with mental arithmetic at that point during the approach. I accept making a temp correction to the MSA in extreme cold but ISA +20 is not going to cause a problem is it as your true alt would be higher than your altimeter reading.
The Messiah is offline  
Old 21st Nov 2005, 03:21
  #9 (permalink)  
 
Join Date: Aug 2002
Location: no fixed address
Posts: 181
Likes: 0
Received 0 Likes on 0 Posts
Messiah,

Agree with yourself and donpizmeof... I wouldnt be sparing much brain bandwidth to calculate out ISA+20 at the outer marker either, however the original thread started by Gateway customer was tricky IFR questions asked in INTERVIEWS.

Good topic too.
VH-ABC is offline  
Old 21st Nov 2005, 08:28
  #10 (permalink)  
 
Join Date: Sep 2005
Location: My Suitcase
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
my 2 cents worth...

regarding the 50 ft, i am not too sure but it is either because the ILS glideslope is supposed to bring u 50 ft above the threshold, or since its a precision approach, 50 ft has been added for the PEC.

and from night pistol, if its an IFR flight, then if my memory serves me well, you can only descend below the LSALT within the circling area, which for Cat A, is 1.68 nm from the runway threshold. apart from that, the usual requirements: clear of cloud, in sight of runway, min 5 km vis. ref: AIP ENR 1.5
overmars is offline  
Old 21st Nov 2005, 10:10
  #11 (permalink)  
 
Join Date: Apr 2001
Location: Established.
Age: 53
Posts: 658
Likes: 0
Received 0 Likes on 0 Posts
overmars

It is neither, and furthermore you don't apply PEC in a 747 yet it is still 5x GS + 50'.

It is in fact basic trigonometry, which would take too long to type here but SOHCAHTOA explains it. Remember that?
The Messiah is offline  
Old 21st Nov 2005, 11:14
  #12 (permalink)  
 
Join Date: May 2003
Location: PH 298/7.4DME
Posts: 554
Likes: 0
Received 0 Likes on 0 Posts
PEC

Overmars,

I reckon PEC is a "one off" 50' amendment.

If we are talking about ROD calculations on a 3deg slope, and if you're adding 50' to the result after 5GS, it would result in a 50 foot per minute increase to your ROD during the approach rather than increasing MDA's, which have no bearing to your ROD calculation.

Me think that the 50' addition to the ROD calculation allows for a more exact profile, i.e. 3.3 degrees.

This of course assuming a fairly typical range of approach ground speeds, for example 120 - 170kts, so CAT B & C, perhaps. If your APP GS is any greater, you may find you have to add more than 50fpm to your ROD calculation to achieve the 3.3 degree slope.

Does this sound feasible or have I had too many jellycups??

520.
Continental-520 is offline  
Old 23rd Nov 2005, 02:05
  #13 (permalink)  
 
Join Date: Sep 2003
Location: The Back Paddock
Posts: 139
Likes: 0
Received 0 Likes on 0 Posts
TCH...............
Capt. On Heat is offline  
Old 23rd Nov 2005, 03:12
  #14 (permalink)  
 
Join Date: Aug 2002
Location: no fixed address
Posts: 181
Likes: 0
Received 0 Likes on 0 Posts
The maths...

Example 1. G/S 150 kts = 912000 ft/hr (roughly) = 15200 ft/min. That is your horizontal speed.

To achieve 3 degree profile... which is 5 percent... which is 1 in 20, you need 760 ft/min vertical speed.

Or done the quick way, 150 * 5 = 750 fpm.

Example 2. G/S 100 kts = 608000 ft/hr (roughly) = 10133 ft/min.
Again, to achieve 3 degree profile, 5 percent, 1 in 20..., you need 506 ft/min vertical speed.

Or in your head quickly... 100 * 5 = 500 fpm.

Never heard of applying an extra 50 fpm to the calculation, so that's my answer in an interview scenario... and I couldnt fly that accurately if I tried anyway. Gotta use this one as a rough guide for a ballpark figure... I got other things I got to look at in my scan!



Now surely there must be more useful questions that people have been asked in interviews during their careers???
VH-ABC is offline  
Old 23rd Nov 2005, 05:21
  #15 (permalink)  
 
Join Date: Jun 2003
Location: oz
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
I'm not an IFR driver heres my view of things for those who care

The Maths:
TOA
tan(3)=ROD/GS
tan(3)*GS=ROD (knots)

Theres 1852 m in a nm, and 3.281 ft in a m so nm > ft is *6076.412 and of course hours to minutes is *60.

So converting knots to fpm is 6076/60 = 101.2735

tan(3)*101.2735*GS=ROD
tan(3)*101.2735 = 5.307
So all that crap means that for a 3 degree approach GS*5.307 gives required ROD, so why is 50 ft added? possibly to account for the .307 but then again could be wrong.

My 2c
Pilot steve is offline  
Old 23rd Nov 2005, 08:21
  #16 (permalink)  
 
Join Date: Jun 2001
Location: Australia
Posts: 889
Likes: 0
Received 0 Likes on 0 Posts
DME gives slant range speed as GS, not 'true' ground speed. So you'd have to use sin not tan if using DME. Not that it makes much difference - I get the same answer as you Pilot steve.

So tell us Messiah - is we right?
Oktas8 is offline  
Old 23rd Nov 2005, 09:02
  #17 (permalink)  
 
Join Date: Jul 2002
Location: australia
Posts: 358
Likes: 0
Received 0 Likes on 0 Posts
I reckon it's probably to make it a tad more accurate. My brain finds it easier to halve my groundspeed then add a zero rather than multiplying by five. Isn't that what most people do? Same result....just seems easier.
cjam is offline  
Old 23rd Nov 2005, 11:10
  #18 (permalink)  
 
Join Date: Apr 2005
Location: Townsville
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
"Keep it simple stupid"

Some good fellow tought me that many moons ago, I still live by it today. I'm with you cjam
littletruck is offline  
Old 25th Nov 2005, 14:28
  #19 (permalink)  
 
Join Date: Sep 2005
Location: My Suitcase
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
I am planning an IFR flight to a destination with an instrument approach chart with the minima titles shaded gray. A colleague of mine told me that if I use the QNH on the aerodrome TAF, I do not have to increase the minima altitudes by 50 ft. Sounds good. But if en route, ATS informs me of the Area QNH, do I use the Area QNH for the approach and increase the minimas by 50 ft, or do I stick to the TAF QNH and leave the minimas as it is?

Hope someone could help me out here.

Thanks.
overmars is offline  
Old 25th Nov 2005, 20:23
  #20 (permalink)  
 
Join Date: Apr 2004
Location: Sydney
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
If you have a local NH you follow the altimeter setting rules and set local NH at the top of descent and leave the minimas as they are. You're only reuired to add 50ft to the minimas if you use the area NH, which you wouldn't do if you have one from the TAF.

The shaded box means nothing unless you have an actual NH - which must be obtained from an ATIS, AWS or AWIS.

...and for those who haven't noticed, a certain key on my keyboard is broken dammit!!
ovum is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.