Landing Gear & Brakes

Question 1

On the nose landing gear tires, the tire chines are mounted outboard or inboard?

Answer 1

Outboard.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 2

When using the emergency brakes, do you have the anti-skid, locked wheel and touchdown protections?

Answer 2

No.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes.

Question 3

Describe the anti-skid braking function.

Answer 3

Anti-skid provides the maximum allowable braking effort for the runway surface in use. It minimizes tire wear, optimizes braking distance, and prevents skidding. The BCU computes the wheel speed signals from the four wheel speed transducers. If one signal/wheel falls below the wheel speed average, a skid is probably occurring, and braking pressure is relieved on that side. After that wheel speed has returned to the average wheel speed, normal braking operation is restored. The anti-skid protection is available above 10 knots wheel speed to allow the pilot to lock and pivot a wheel.
Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 4

Describe the locked wheel protection.

Answer 4

If one wheel speed is 30% lower than that of another as calculated by the wheel speed transducers and computed by the BCU, a full brake pressure relief is commanded to the associated wheel, allowing wheel speed recovery. The 30% tolerance between the wheel speeds is provided to permit an amount of differential braking, for steering purposes. The locked wheel protection is active above 30 knots wheel speed.
Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 5

In essential power mode, is nose wheel steering available?

Answer 5

No.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 6

When operating the emergency brakes, hydraulic pressure is applied to which brakes?

Answer 6

All main gear brakes.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 7

What does the Free-Fall actuator do?

Answer 7

It requires no electrical or hydraulic power to extend the landing gear. It extends the gear by mechanically actuating the Free-Fall Selector Valve, thus removing hydraulic pressure and unlocking the three landing gear leg uplocks via cable linkage. All three gear then gravity fall to their downlock devices.
Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 8

With a total loss of hydraulic system #1, will the landing gear deploy/operate normally?

Answer 8

No.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 9

When in essential power mode would you have normal braking?

Answer 9

Yes.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 10

The nose wheel air/ground (WOW) sensor provides a signal for?

Answer 10

Nose wheels steering activation and thrust reverser logic.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 11

Nose wheel tire rotation is stopped on retraction by a ________.

Answer 11

Mechanical snubber.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 12

The landing gear is normally help up ___ and extended ___

Answer 12

Mechanically/Hydraulically.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 13

What is the purpose of the landing gear over-center brace?

Answer 13

The over-center brace keeps the landing gear down and locked.
Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 14

In essential power, how is the landing gear extended?

Answer 14

Normally.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 15

Does the emergency brake provide anti-skid protection?

Answer 15

No, it has no anti-skid protection, touchdown protection, or wheel lock protection.
Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 16

The emergency brake lines supply how many brakes?

Answer 16

4 brakes.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 17

If emergency brakes are all that remain due to system malfunction the hydraulic accumulator 2 can provide how many applications of the emergency brakes?

Answer 17

6 applications of the emergency brakes or 24 hours.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 18

If engine 1 is shutdown in flight, how is the landing gear extended?

Answer 18

Normally with the gear handle.

Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 19

Will the landing gear deploy normally with a total loss of hydraulic system 1?

Answer 19

No, the gear will not deploy/operate normally. It must be deployed by using the freefall actuator as directed by the QRH. Once the gear is deployed and extended it cannot be retracted.
Reference: OM Vol.2, Section 2-12, Landing Gear and Brakes

Question 20

What is the maximum landing gear retraction speed?

Answer 20

200 KIAS.

Reference: OM Vol.1, Section 1, Limitations