Ground de-icing, contaminated runways

Question 1

Holdover time is:

Answer 1

estimated time period that de-icing/anti-icing is effective in preventing ice accretion.

Question 2

The most commonly used de-icing/anti-icing fluid -

Answer 2

Glycol

Question 3

A runway is referred to as contaminated when more than __ % of the required runway surface is covered with the one of the following elements:

Answer 3

A runway is referred to as contaminated when more than 25 % of the required runway surface is covered with the one of the following elements:

(a) surface water more than three millimeters deep;
(B) slush or loose snow, equivalent to more than three millimeters of water;
(c) snow which has been compressed into a solid mass which resists further compression and will hold together or break into lumps if picked up; or
(d) ice, including wet ice

Question 4

Definition of a damp runway:

Answer 4

means a runway of which the surface is not dry and on which the moisture does not give the runway a shiny appearance

Question 5

dry runway definition:

Answer 5

means a dry runway which is neither wet nor contaminated, and includes those paved runways which have been specially prepared with grooves or porous pavement and maintained to retain effectively dry braking action even when moisture is present

Question 6

Wet runway definition:

Answer 6

means a runway of which less than 25% of the surface is covered with water, slush or loose snow when there is sufficient moisture on the runway surface to cause it to appear reflective, but without significant areas of standing water

Question 7

Braking coefficients:

Uncontaminated runway - normal dry surface:
Normal wet surface:
Icy surface:

Answer 7

0. 3
1. 15
2. 05

Question 8

Regarding icy surfaces, friction reduction is most pronounced at low or high speeds?

Answer 8

low speeds

Question 9

The critical hydroplaning speed formula:

Answer 9

V = 9 x square root of P

V = hydroplaning GS
P = tire pressure

bar to psi = bar x 14.5

Question 10

Viscous hydroplaning:

Definition -

type of runway conditions -

Answer 10

The normal lubricating effect of water

All wet runways damp or heavy rain. Runways that lack microtexture

Question 11

Dynamic hydroplaning:

definition -

Conditions -

Answer 11

when a tire is actually lifted of the runway and rides on a wedge of water

runways that lack macrotexture, standing water and high speeds

Question 12

the most common type of hydroplaning?

Answer 12

Viscous hydroplaning

Question 13

the most common type of hydroplaning?

Answer 13

Viscous hydroplaning

Question 14

Reverted rubber hydroplaning:

Definition -

Conditions -

Answer 14

When heavy braking on a wet surface creates a steam barrier between the tyro and runway.

Heavy braking at low speeds

Question 15

How to convert BAR to PSI:

Answer 15

bar x 14.5

Question 16

Reducing the effects of hydroplaning(4):

Answer 16

1. Reducing approach speeds
2. make a firm landing
3. Full weight of the aircraft on the runway(remove spoilers, flaps and lower nose gear unto runway)
4. Tire cornering force, maximus is five degrees of yaw.