Bugrad Lenkung??

[ichnewmoon]

Ich hab eine frage wo mir heute aufgefallen ist:

 

Bis zu welcher Geschwindigkeit kann man das Bugrad lenken??

 

Beim starten ??

 

Nach dem Landen ab welcher Rollgeschw. kann man wieder lenken ??

 

Danke für die Antworten.

 

MfG Roli

[Quax37]

B-737: Bugradlenkung funktioniert immer, unabhängig von der Geschwindigkeit.

[Hägar]

A-330 : Steuerung via Pedale > Beim Start steht der Maximalausschlag von +/- 6° bis 100kts zur Verfügung, danach verringert er sich linear bis 0° bei 150 kts.

Bei der Landung kann das Bugrad erst unter 100 kts wieder gesteuert werden, bei Erreichen von 40kts kann wieder bis +/- 6° ausgeschlagen werden.

 

Steuerung via Handrad > Der Maximalauschlag von +/- 72° kann bis 14 kts ausgenutzt werden, bei höheren Geschwindigkeiten verringert sich dieser nichtlinear und erreicht bei 100kts 0°, kein Unterschied ob Start oder Landung.

 

A-320 : Pedale maximal +/- 6° bis 40kts, dann linear runter bis 0° bei 130kts.

Handrad +/- 75° bis 20kts, linear abnehmend bis 0° bei 70Kts, bei beiden Lenkmöglichkeiten wird nicht zwischen Start und Landung unterschieden.

 

 

Gruss

 

Ruedi

[Sgt. Hartman]

B-737: Bugradlenkung funktioniert immer, unabhängig von der Geschwindigkeit.

 

Hmmmm, das möchte ich aber bezweifeln, denn funktionieren bedeutet für mich auch lenken und nicht das sog. "radieren". Mag sein, daß das Bugrad sich über den Steering Tiller bewegen läßt aber bei hohen Geschwindigkeiten wohl eher uneffektiv.

[Robert Grünig]

funktionieren bedeutet für mich auch lenken und nicht das sog. "radieren".

 

Das ist schwer Ansichtssache. Für mich als Konstrukteur ist die Bugradlenkung funktionstüchtig, solange das System so arbeitet wie es geplant und gewollt ist. Die Reaktion des Fliegers auf die Steuerimpulse ist wieder ein anderes Thema.

 

Gruess

Robert

 

PS: Kann es sein, dass du auch im mtb-news.de-Forum schreibst?

[Quax37]

Hmmmm, das möchte ich aber bezweifeln, denn funktionieren bedeutet für mich auch lenken und nicht das sog. "radieren". Mag sein, daß das Bugrad sich über den Steering Tiller bewegen läßt aber bei hohen Geschwindigkeiten wohl eher uneffektiv.

 

Hmmmm, ich möchte aber bezweifeln, daß du die ursprüngliche Frage noch in Erinnerung hast. :rolleyes:

 

Meine Antwort bleibt daher uneingeschränkt richtig. Es ist auch keineswegs Ansichtssache... :p

.

[iceman007]

Hallo zusammen,

 

hier einmal ein paar Infos aus unseren Schulungsunterlagen. :008: :008:

 

1. B737 Classic

 

Purpose

Nose wheel steering is provided for airplane directional control during ground

maneuvers and taxiing.

System Description

Normal steering is accomplished by using a steering wheel in the flight

compartment. The steering wheel is located on the left sidewall forward of the

captain’s position. Rudder pedal steering is available during takeoff, landing,

and taxiing when small directional changes are required. A full steering wheel

movement of 95 degrees will give 78 degrees of nose wheel turning. Full

deflection of the rudder pedals produces about 7 degrees of nose wheel steer-

ing.

The rudder pedal steering mechanism is engaged for steering by a rotary

actuator when the nose gear is compressed and disengaged when the nose

gear is extended.

Hydraulic power from system A is used to turn the nose wheels to either side

from zero to 78 degrees. In addition, on some airplanes system B may also be

used to turn the nose wheels. An alternate nose wheel steering system, acti-

vated by a switch on the captain’s forward panel, allows power from hydraulic

system B to turn the nose wheels if power from hydraulic system A is lost.

Movement of the steering wheel or the rudder pedals in either direction is trans-

mitted by cables to a steering metering valve which directs 3000 psi hydraulic

pressure to the nose wheel steering actuators to turn the steerable portion of

the nose gear.

The steering system is spring-loaded to the center position. The airplane can

be towed through turns up to 78 degrees without disconnecting the torsion links

or depressurizing the hydraulic system. Internal cams in the shock strut center

the nose gear when the nose gear shock strut is fully extended, therefore turn-

ing the wheels or towing should not be attempted unless the shock strut is

compressed more than two inches.

 

 

OPERATION

Nose wheel steering is available when the nose gear is in the down position

and compressed by weight of the airplane. Positioning the landing gear control

lever to down makes system A hydraulic pressure availabe from the landing

gear down line to the steering metering valve for steering. On some airplanes,

in the event of loss of system A pressure, the alternate nose wheel steering

system can be activated to provide system B pressure to the nose wheels. A

select switch on the captain’s forward panel allows the flight crew to activate

the alternate steering system. The nose gear must be compressed more than

two inches before steering is attempted to avoid damage to the centering

cams.

When the steering wheel is rotated for a turn, the steering cables move and

displace the steering metering valve piston. Hydraulic fluid is directed by the

metering valve through the swivel valves to the steering actuators. The steering

actuators produce a turning moment on the steering collar which is transmitted

by the torsion links to the lower steerable portion of the nose gear. Continued

displacement of the metering valve piston combined with the steering actuator

swivel valves produces 78 degrees of wheel turn for 95 degrees of steering

wheel rotation. During a turn, the metering valve piston is displaced until the

required degree of nose wheel turning is reached and then returned to the cen-

ter position by the follow-up action of the cable.

Nose wheel steering is also available through the rudder pedals. The rudder

pedal steering mechanism is actuated by the squat switch/rotary actuator

system when the nose gear is compressed. The compression movement is

transmitted electrically to move the eccentric and repositon the clutch crank

and allow the clutch arm to contact the stops mounted on the steering crank.

In this position, any movement of the rudder pedals is transmitted from the

steering arm to the quadrant. The quadrant moves the nose wheel steering

cables displacing the steering metering valve piston for the required turn.

 

2. A320 Fam.

 

NOSE WHEEL STEERING

General

Nose wheel steering is possible from the cockpit as follows:

(1) During taxi, and more generally at low speed, through action on a

handwheel.

There are two identical handwheels: one for the Captain, one for the First

Officer.

In the event of simultaneous operation, the orders that the handwheels give are

algebraically added.

The maximum travel of the wheels is plus or minus 74 deg.

The maximum corresponding travel of the handwheel is plus or minus 75 deg.

However, the law between these two travels is not linear.

The servoing is active with the aircraft on ground upon impact of the main land-

ing gear. The steering angle is limited as a function of the aircraft speed.

(2) During takeoff or landing, and more generally at high speed

- either through action of the Captain (or First Officer) on the rudder pedals,

- or automatically through the autopilot (yaw control).

In both cases, the steering angle is limited as a function of the aircraft speed

and the origin of the orders.

When the aircraft speed is above 130 knots, the steering is not available.

The pilot can disconnect the control through the pedals from the steering

control.

To obtain this, the pilot presses and holds a pushbutton switch located on each

handwheel.

(3) After takeoff, the nose wheels are automatically centered under the action

of cams in the shock absorber.

(4) Before the aircraft is towed, the hydraulic system must be depressurized

through action on a lever which can be locked in its two positions.

This lever is located on an electrical box easily accessible from the ground.

The maximum towing angle is plus or minus 95 deg.

The control is electrohydraulic with position feedback of the nose wheel as-

sembly. The Brake and Steering Control Unit (BSCU) controls the nose wheel

steering system.

Control Components

A Captain handwheel which actuates a transmitter unit.

In addition, it includes a pushbutton switch for the disconnection of the steering

control through the rudder pedals.

A First Officer handwheel, designed in a similar way.

Rudder pedals Steering by pedals.

This is limited to 6 deg. depending on A/C speed.

Steering orders from the pedals are sent to the BSCU via the ELAC.

 

Ich hoffe das diese Informationen halbwegs verständlich sind.

 

so long

 

Frank