Gday guys

Just a quick question on the peformance exam I just sat

had two question's like

Vb, is not marked on the ASI face so what would be the closest to this speed Va, Vno Vne in turbulent conditions

and factors affecting landing distance, what would make a landing distance longer? water on runway, less flap then recommended, slope down or tail wind

thanks crew

Hi Flyz

Since an encounter with turbulence can result in sudden increases in angle of attack as the aircraft encounters updrafts, the effect can be similar to a sudden application of back elevator deflection. If turbulence penetration speed, Vb, is not available, a useful substitute would be the maximum control deflection speed, Va'.

As far as I can see, all of the options you have given for the landing distance question would result in an increase in landing distance.

Bob

Thanks Bob

I gathered as much with the second question, they just ask what would increase it the most distance

CASA and their sneaky questions
How is one meant to know this when so many factors can change the outcome.

Hi Flyz,

If the question was pick which answer will increase landing distance the most I would go for less flap than recommended.
This is where CAO 20.7.4 para 10 (Landing distance required) comes into play. In other words, you take the stall speed for that lower flap setting and times it by 1.3 to give you the minimum approach speed to flown at 50'. As you can imagine at the higher speed, you will be further down the runway by the time the aircraft comes to a complete stop.

The other options like wet runway, down slope, tailwind will have too many variables.To give you an example, an aerodrome I used to be based at was 720 metres long, on the coast, hills most the way around it and a 2% slope downhill towards the beach. It was usually a shorter distance to take a 5kt tailwind and land uphill than it was to land into wind and have the runway slipping by beneath you becuase it was falling away at about the same rate you were sinking during the hold off. Eventually, you touched down. If your speed was right, it was no problem. Once the seabreeze kicked in, landing downhill into wind was the better (only) option.

And since we are on the topic of performance. The slope at this runway was capable of handling a landing above 5kts tailwind within reason. However, performance charts only go to 5kts tailwind. After that you cannot calculate LDR, you will then become a test pilot, and you will have to be able to explain why you deemed it safe to operate outside the limits of the P-charts...your Honor!

Hope this helps.

Cheers,
Mister W.

Thanks Mister W

Good help and explanation, less flap it is

Cheers

Flyz