Technical

Question 1

What is critical mach? What happens to the center of pressure/lift as we enter mach tuck?

Answer 1

Mach tuck is an aerodynamic effect, whereby the nose of an aircraft tends to pitch downwards as the airflow around the wing reaches supersonic speeds. The aircraft will be subsonic, and traveling significantly below Mach 1.0, when it first experiences this effect. As the wing becomes more affected by the shock wave the center of pressure will continue to travel aft, thereby causing a significantly higher nose-down force and requiring a nose-up input or trim to maintain level flight. Although Mach tuck develops gradually, if it is allowed to progress significantly, the center of pressure can move so far rearward that there is no longer enough elevator authority available to counteract it, and the airplane enters a steep, sometimes unrecoverable dive

Question 2

What are holding speed restrictions?

Answer 2

0-6000: 200kts 6001-14000: 230kts 14,001 and above 265kts

Question 3

Why do airliners all have swept wings?

Answer 3

Swept wings reduce airflow acceleration over the wings and delay crit mac. The airflow is divided into span-wise flow and chord-wise flow. As airflow acceleration is now reduced over the wing, the airplane can now go faster before you experience shockwave and the resultant drag.

Swept wings delay airflow separation due to the shockwave from approaching the speed of sound thus increasing the aircrafts critical mach number ( you can fly faster)

Question 4

Decode a METAR and TAF

Answer 4

Know the “began” “end” times for rain/snow.
Know the abreviations for: TCU, DSNT SW… Towering Cumulus distant southwest.

Question 5

What is Mach Buffet?

Answer 5

This is a flow separation of airflow over the wing. This can be from to high of an airspeed (flow desperation at crit. mach), or can be from to high of an AOA.

Question 6

What is bypass air and what is the benefit?

Answer 6

Typically bypass air makes up 80% of the air that is sucked into the engine (turbofan). Bypass air flows between the core of the engine and the outside casing. The benefit of using so much bypass air is both fuel efficiency and it’s quieter than a full-on jet engine.

Question 7

What is a Yaw Dampener?

Answer 7

A gyro operated stability augmentation auto control system installed to automatically provide immediate rudder input when necessary to aid in canceling out yaw tendencies such as those of Dutch roll. Basically an autopilot for the rudder.

Question 8

What is Dutch Roll?

Answer 8

A Dutch Roll is a combination of rolling and yawing (coupled lateral/directional) oscillations that normally occurs when the dihedral effects of an aircraft are more powerful than the directional stability

Question 9

Where does the stall occur first on a swept wing aircraft?

Answer 9

At the wingtips

Question 10

What are some things inside a turbine engine to provide positive air flow?

Answer 10

A variable geometry(VG)system regulates airflow through the compressor by changing the position of the compressor inlet guide vane and the variable geometry stator vanes on the first five stages of the compressor. This is done to prevent compressor stall and surge by optimizing the angle of attack of the vanes. TheVG system is controlled by the fuel control unit (FCU) which uses high-pressure fuel to hydraulically move two actuators which are mechanically linked to the VG system. CRJ-200

Question 11

When you can proceed down past the DA(H)

Answer 11

91.175

Question 12

What is the maximum airspeed permitted in a hold between 0-6,000ft , 6,001ft-14,000ft, and 14001ft and above?

Answer 12

Holding Speeds 0-6000’ = 200 knots 6,001’ - 14,000’ = 230 knots 14,001 and above= 265 knots

Question 13

If you’re flying at exactly 10,000ft what is your speed restriction?

Answer 13

Mach 1
91.117 states BELOW 10,000’ no greater than 250 knots. Not AT.

Question 14

How long is a TAF valid for?

Answer 14

24 or 30 hours.

Question 15

What is an ILS hold short line? What’s it protecting? Glide slope or localizer? (Ladder symbol)

Answer 15

Critical area when conditions are below 800/2 where you may be asked to hold short. It protects either the LOC signal, GS signal, or both, depending on the airfield and location of taxiway

Question 16

Speeds in and around class B, C, and D.

Answer 16

Beneath Class B or in VFR corridor through Class B — 200 kias. Class C or D airspace (at or below 2,500 feet agl within 4 nm of the primary airport) — 200 kias (unless a higher speed is specifically approved by ATC) Class E or G airport traffic pattern — 200 kias (recommended)

Question 17

What to do if you find yourself getting closer to coffin corner?

Answer 17

Request lower altitude.

Question 18

What if you were coming in on an approach , past the FAF, you have the runway in sight and the tower tells you visibility is below the required minimums, can you continue?

Answer 18

Yes. Prior the FAF, you can’t continue the approach. Past the FAF, you may descend until DA/MDA

Question 19

What is used from the engine’s bleed air?

Answer 19

Engine and wing thermal anti-ice, also used for pressurization, environmental heating and cooling.

Question 20

What is the difference between A/C and D/C electricity and which is better ?

Answer 20

Alternating current vs. direct current. A/C is lighter weight and more stable.

Question 21

What is the FAF for the ILS?

Answer 21

GS intercept

Question 22

What is the purpose of the turbine? (not a turbine engine)

Answer 22

High Pressure Turbine has one purpose. To turn the High Pressure Compressor Low Pressure Turbine has two purposes. Turn the Low Pressure Compressor and turn the Fan at the front of the engine.

Question 23

You’re in the lateral boundaries of LAX Class B airspace, but under the actual airspace. What is the max airspeed you can fly?

Answer 23

200 knots

Question 24

What happens to speed of sound with decrease in temp or pressure?

Answer 24

Book “Illustrated Guide to Aerodynamics” page 190 states “Because molecules move about faster at a higher rate of speed in warmer air they…transmit sound faster.” As pressure and temperature decreases, the speed of sound also decreases.

Question 25

Where to look for notam affecting change of an app minimum?

Answer 25

FDC (Flight Data Center) Notams

Question 26

What does a diode do?

Answer 26

directs electrical power in one direction, does not allow electrical power to flow in the wrong direction

Question 27

What does the jet stream do in the winter?

Answer 27

Moves south in the northern hemisphere and increases in intensity

Question 28

What is the function of packs in the pneumatic system on a jet?

Answer 28

In large aircraft, the whole environmental heating/cooling system is bundled together, including air cycle machine (ACM), bleed heat source, vapor cycle machine (VCM) (if installed), and mixing valves. This package is normally referred to as a “PACK.” Normally two are installed for redundancy

Question 29

What is a Kelvin-Helmholtz cloud formation?

Answer 29

Though it looks like someone painted the sky with breaking ocean waves, there’s a very good atmospheric explanation for what is really happening. The rolling, wave-like cloud formations are called Kelvin-Helmoltz clouds. Sometimes they are also called billows. They are named for scientists Lord Kelvin and Hermann von Helmholtz, who discovered the process by which they form. Severe Weather Expert Dr. Greg Forbes of The Weather Channel says, “They are the atmospheric equivalent of those great breaking waves that you sometimes see on the ocean.” These breaking atmospheric waves occur in an environment with a large amount of vertical wind shear and stable air. Wind shear is a change in the speed and direction of winds as you go higher in the atmosphere. In this case, winds at the top of the cloud layer are moving faster than the base of that same layer. This causes the top to crash downwards in a curling manner after it hits the stable layer above. The rolling motion created by this type of wind shear also causes turbulence for aircraft. However, the rolling clouds motions are often masked by a large amount of cloud cover. Other times, there are no clouds around to illustrate the wave pattern.

Question 30

What are class c cloud clearance requirements?

Answer 30

3sm, 500 feet below. 1,000 feet above. 2,000 feet horizontal

Question 31

What is virga?

Answer 31

Virga is the phenomenon when rain starts from a cloud and evaporates before it touches the ground. Usually associated with downdrafts and turbulence. Very common in dry western states