Skywest Technical Questions

Question 1

What are holding speed restrictions?

Answer 1

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

Question 2

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

Answer 2

Critical mach is the speed at which some portion of the airflow over the wing first equals Mach 1. the first shockwave will appear at this speed. the resulting shockwaves caused by high speed buffets disrupt the airflow over the wing and interfere with the lifting capabilities of the aircraft. progressively the center of lift moves further aft requiring greater elevator input to maintain altitude

Question 3

When can you proceed down past DA?

Answer 3

1. The aircraft is continuously in a position to land on the intended runway using a normal rate of decent and normal maneuvers. 2. The visibility is at least the visibility prescribed in the approach to be flown. 3. At least one designated visual cue: a. Approach lighting (except a descent below 100’ above the TDZ cannot be made unless the Red Side Row Bars (ALSF-2) or the Red Terminating Bars (ALSF-1) are identifiable. b. Touch Down Zone, Touch Down Zone markings, Touch Down Zone lights c. Threshold, Threshold markings, Threshold lights d. Runway, Runway markings, Runway lights e. VASI f. REIL

Question 4

What is bypass air and what is the benefit?

Answer 4

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 5

What is a yaw dampener?

Answer 5

A system used to reduce (or damp) the undesirable tendencies of an aircraft to oscillate in a repetitive rolling and yawing motion, a phenomenon known as the Dutch roll.

Question 6

Why do airliners all have swept wings?

Answer 6

Swept wings reduce airflow acceleration over the wings and delay critical mach. As airflow acceleration over the wing is reduced, the airplane can go faster before you experience shockwaves and the resultant drag/mach tuck

Question 7

What is dutch roll?

Answer 7

dutch roll is a combination of rolling and yawing oscillations that normally occurs when the dihedral effects of an aircraft are more powerful than the directional stability

Question 8

What is Mach Buffet?

Answer 8

As the air flows over your wing, it accelerates. At some point, the air in front of your wing may be subsonic, but it will accelerate past the speed of sound as it flows over the wing’s upper surface. Once this happens, a shock wave forms. Turbulent flow develops behind the wing, causing a buffet called mach buffet.

Question 9

What do taxiway signs look like?

Answer 9

Destination/direction - yellow background with black inscriptions
Location - black background with yellow inscriptions

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.

Question 11

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

Answer 11

If not assigned by ATC, Vmo or the airspeed of the arrival

Question 12

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

Answer 12

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 13

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

Answer 13

At the wing tips

Question 14

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

Answer 14

Request a lower altitude

Question 15

How long is a TAF valid for?

Answer 15

24 or 30 hours

Question 16

What are the stages of a jet engine?

Answer 16

Specifically for a turbofan (since that’s the type you’ll fly at SkyWest), the front to back stages begin with a giant fan. From there the air splits into the bypass air and the air that will go through the engine core. As the air enters the engine core it will go through a Low Pressure Compressor, then a High Pressure Compressor (this is the stage where bleed air is taken). From the High Compressor stage its directed to the Combustion Stage where the air will expand and mix with fuel for ignition. That energy is captured by the next 2 stages of turbines, the High Pressure and Low Pressure turbine (in that order). These turbines are connected to the compressors up front respectively (high turbine to high compressor N1, and Low Pressure Turbine to Low Pressure Compressor N2). Leaving the turbines, the air is rejoined with the bypass air and blown out the back of the engine. For some engines, up to 80% of the thrust generated can be from this bypass air.

Question 17

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 17

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

Question 18

How would you know which way thunderstorms are moving by looking at cloud formation ?

Answer 18

Moving to the side of anvil

Question 19

What is the ladder symbol on airport diagram?

Answer 19

ILS critical holding short

Question 20

What is used from the engine’s bleed air?

Answer 20

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

Question 21

What is the print and background color of a runway sign?

Answer 21

white letters red background

Question 22

Speeds in and around class B, C, and D

Answer 22

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)