HP&L Real world Vs JAR world

[lionco]

Does anybody out there know the answer to this question.

An up slope runway will on approach.....

a) Seem to be LONGER and your approach could be too HIGH

b) Seem to be SHORTER and your approach could be too LOW

I've been told, by my very reliable ground school instructor, that JAR want answer a)

BUT I have read feedback notes that quite rightly contradict this.

Please, can I have some feedback!

[VFE]

I'd personally go for answer 'b' as it the more correct answer.

An upsloping runway will look short from an average 3 degree glideslope approach and will also make you feel like you are higher than you should be. The subsequent risk of this is that you could make the approach too low (to give you the usual visual picture of an ideal approach) thus running the risk of landing short (which is also tested I believe). But you knew this anyway.

I don't know why your GS instructor told you anything different. Did he/she explain why you should go for answer 'a'?

If anyone else has any other view (scuse the pun!) on this question I'd be happy to stand corrected. Hopefully I passed HP&L anyway so can do a little jig when the results arrive. ;)

VFE.

[FlyingForFun]

Hmm, I don't have my text books to hand, but I'd have said would seem to be LONGER and your approach could be too LOW.

For the high/low question, draw a side-view of the situation. Draw an up-sloping runway, with an aircraft in the correct position on final approach. Then, holding the runway threshold still, rotate the page so that the runway "appears" flat - this is simulating what your brain sees. Notice that the aircraft moves up - in other words, your brain thinks you are too high (when you're not), and so you fly down, causing you to be too low.

The apparent length of the runway can also be answered with this rotating-page technique. Think about the road-markings that you see painted on the road - they are very long when viewed from above, but from your car they look normal. The flatter the viewing angle, the shorter the image appears. But an up-sloping runway gives you a less-flat viewing angle, so the runway appears longer.

I think.

FFF
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Edit, because the more I think about it, the more I think I'm wrong, and B) is the correct answer. Except I can't explain it.... will come back later once I've thought about it more, unless someone else explains it well first.

[VFE]

Good analysis there FFF.

I now think that the grey area here must come from what perspective the examiner who created this question was taking. Unfortunately perspective varies from person to person and as we all know can be affected by factors such as rain on the DV window, fog and having someone poke you in the eye etc etc.....

I would seriously go for answer 'b' still but write a little note on the plain paper to Bloggs at Aviation House explaining the reasons (as explained by FFF) for your answer...... unless LOW and LONGER appear in answer 'c' or 'd' of course.

VFE.

[Looks like FFF and I are posting at the same time here!]

[mad_jock]

I haven't got my notes but I go with B as well.

For HPL get your hands on the oxford Last minute facts sheet.

It has about 300 1 liners on HPL and its is not unknown for people to pass just reading that sheet.

MJ

[FlyingForFun]

Is definitely B.

For the low bit, see my earlier explaination.

For the short bit, hold a ruler horizontally a foot or two in front of your nose. Then "incline" it upwards, and watch it getting shorter. What I can't explain is why my earlier explaination, using road markings as an example, is wrong - can anyone answer that one for me?

FFF
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[fat and retarded]

I am afraid that your reliable instructor is less than reliable (or has simply confused a & b) as the correct answer is b i.e. an upslope runway gives the illusion of being too high leading to a lower approach.