Landing Gear Flashcards
What are the conditions for the anti-skid system
The anti-skid system is electrically controlled and is operational with the following conditions
- Switch in ARM position
- Gear handle down or alt gear handle pulled
- Parking brakes released
- Wheel speed greater than 10 kn
When is the anti skid not available
If the left and right D.C. Busses are unpowered
Where are the break temperatures displayed and describe what’s displayed
- first officers instrument panel
- The BRAKE TEMP gauge indicates hottest or selected break temperature depending on the position of the break temp selector
When does the BRAKE OVHT light illuminate
88
90
1 when it exceeds 305*C on 88
2. Or 540*C on 90
When will the fuse plugs blow
On the 88 if the brake temp is above 305*C for proximately five minutes
What is the minimum hydraulic pressure necessary to set the parking break
88
90
1400 psi on 88
1700 psi on 90
On the BRAKE PRESS gauges
What does an Amber ABS light mean
When the landing gear handle is down, AUTO BRAKE selector is moved out of the OFF position and AUTO BRAKE ARM/DISARM switch is in DISARM
When are auto breaks available in the normal brake system, ABS, and when should you not use it and when will it be unavailable
- Anti-skid system armed and operational
- With left and/or right hydraulic system failure do not use auto brakes
- ABS is unavailable if the flaps are less than 26° for landing or the accumulators are the only source of hydraulics
What are the conditions required for the autobrake rejected take off system operation
And if initiated what speeds and modes are controlling
- Automatic or manual extension of the spoiler handle extension
- If a rejected take off is initiated below 70 kn on the 88 or 90 kts on theMD90, the ABS reverts to landing mode operation in MIN Breaking is provided
- At speeds greater than 70 kts(88) or 90 kts (90), maximum dual system automatic braking is applied immediately without any time delay
Which is only limited by antiskid operation
What’s the conditions for ABS operation during landing.
Explain the delay function
- spoiler handle is deployed either automatically or manually with throttles retarded and brake pedals released
- Automatic braking is delayed after spoiler deployment for approximately one second in MAX position at 1 sec, three seconds(88) or 1 sec(90) in MIN or MED positions.
ABS landing mode is inhibited if the throttles or not retarded towards idle - With MED selected, brake pressure is modulated to the brakes by the land manifold to maintain a fixed level of the deceleration however with MAX selected, full right brake system pressure is applied to the brakes and the maximum deceleration is limited only by anti-skid operation
What brake pedal deflection will disengage automatic braking(auto brakes)
88
90
MD88 -
Auto brakes are disarmed at any speed by depressing brake pedals beyond 25% travel
MD90 -
- Below 90 kn, 25% pedal deflection is required to disengage
- Above 90 kn, 90% pedal deflection is required to disengage
Describe the secondary indicator for nose gear extension
Nose gear verification is provided by an indicator on the forward pedestal. The indicator appears when the nose gear is fully extended and nose gear links are locked over center
During what aircraft condition will the GEAR HORN OFF button not silence the gear warning
When gear is not down and flaps are extended beyond approximately 26°, gear must then be down and locked to silence warning system
What’s the maximum break temperatures for take off and to set the parking break
88
90
MD88 -
- No takeoff in excess of 205*C, OVHT light extinguished
- Max temp for setting is 300*C
MD90 -
- Max for setting parking brake is 500 degrees C
- Before take off, OVHT light extinguished and BRAKE TEMP gauge does not exceed 250°C for airport elevations up to 2200 feet MSL.
- For higher airport elevations refer to guidance in volume one, NP and ODM
Corrections to brake temp limits
- when outside air temperature exceeds 32°C, subtract 5° for each 1° above 32°C
- for each 1 kts of tailwind subtract 15*C
