A flight crew of a beech 1900D reports serious distractions during descent and approach caused by th...

Narrative:

Distractions caused by the activation of the landing gear warning system installed in the beechcraft 1900 C/D airliner. Parameters for activation of the landing gear warning system on the beechcraft 1900D airliner: landing gear up and locked or intransit and power levers in a position that yields approximately 89% to 86% +/-1% N1 gas generator RPM decreasing, and the flaps in up or 17 degree position. Result: red lights in the landing control handle and aural warning which can be canceled with the warning horn silence button adjacent to the landing gear control handle. (Lights remain illuminated.) landing gear up and locked or intransit and flap handle placed beyond the 17 degree position. Results: red lights in the landing gear control handle and aural warning which cannot be canceled. Problem associated with design of beechcraft 1900D landing gear warning system. Distraction -- the landing gear warning system will activate when the power is reduced to initiate descent, control speed during descent, or to decrease indicated airspeed in level flight. System activation will always occur during normal arrival procedures in the terminal area. The use of power ranging from maximum cruise to flight idle is normal and should not result in activation of the warning system. It is therefore my position that power lever position (angle) should not be the only parameter that results in warning system activation. Single parameter system activation should be modified to include an airspeed switch, an altitude switch, (radar altimeter), or both. Callback conversation with reporter revealed the following information: the reporter stated the power lever angle input to the landing gear warning should be improved to eliminate the continuous manual silencing of the warning horn. The reporter said the main problem is the rigging of the throttle switches which are not all uniform and actuate at the same power setting. The reporter states in a stepped approach with frequent power changes this horn is distracting at the worse possible times. The reporter said this system should have an airspeed input like the dash 8 system.

Original NASA ASRS Text

Title: A FLC OF A BEECH 1900D RPTS SERIOUS DISTRACTIONS DURING DSCNT AND APCH CAUSED BY THE LNDG GEAR WARNING HORN SOUNDING WHEN PWR CHANGES OCCUR.

Narrative: DISTRACTIONS CAUSED BY THE ACTIVATION OF THE LNDG GEAR WARNING SYS INSTALLED IN THE BEECHCRAFT 1900 C/D AIRLINER. PARAMETERS FOR ACTIVATION OF THE LNDG GEAR WARNING SYS ON THE BEECHCRAFT 1900D AIRLINER: LNDG GEAR UP AND LOCKED OR INTRANSIT AND PWR LEVERS IN A POS THAT YIELDS APPROX 89% TO 86% +/-1% N1 GAS GENERATOR RPM DECREASING, AND THE FLAPS IN UP OR 17 DEG POS. RESULT: RED LIGHTS IN THE LNDG CTL HANDLE AND AURAL WARNING WHICH CAN BE CANCELED WITH THE WARNING HORN SILENCE BUTTON ADJACENT TO THE LNDG GEAR CTL HANDLE. (LIGHTS REMAIN ILLUMINATED.) LNDG GEAR UP AND LOCKED OR INTRANSIT AND FLAP HANDLE PLACED BEYOND THE 17 DEG POS. RESULTS: RED LIGHTS IN THE LNDG GEAR CTL HANDLE AND AURAL WARNING WHICH CANNOT BE CANCELED. PROB ASSOCIATED WITH DESIGN OF BEECHCRAFT 1900D LNDG GEAR WARNING SYS. DISTR -- THE LNDG GEAR WARNING SYS WILL ACTIVATE WHEN THE PWR IS REDUCED TO INITIATE DSCNT, CTL SPD DURING DSCNT, OR TO DECREASE INDICATED AIRSPD IN LEVEL FLT. SYS ACTIVATION WILL ALWAYS OCCUR DURING NORMAL ARR PROCS IN THE TERMINAL AREA. THE USE OF PWR RANGING FROM MAX CRUISE TO FLT IDLE IS NORMAL AND SHOULD NOT RESULT IN ACTIVATION OF THE WARNING SYS. IT IS THEREFORE MY POS THAT PWR LEVER POS (ANGLE) SHOULD NOT BE THE ONLY PARAMETER THAT RESULTS IN WARNING SYS ACTIVATION. SINGLE PARAMETER SYS ACTIVATION SHOULD BE MODIFIED TO INCLUDE AN AIRSPD SWITCH, AN ALT SWITCH, (RADAR ALTIMETER), OR BOTH. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PWR LEVER ANGLE INPUT TO THE LNDG GEAR WARNING SHOULD BE IMPROVED TO ELIMINATE THE CONTINUOUS MANUAL SILENCING OF THE WARNING HORN. THE RPTR SAID THE MAIN PROB IS THE RIGGING OF THE THROTTLE SWITCHES WHICH ARE NOT ALL UNIFORM AND ACTUATE AT THE SAME PWR SETTING. THE RPTR STATES IN A STEPPED APCH WITH FREQUENT PWR CHANGES THIS HORN IS DISTRACTING AT THE WORSE POSSIBLE TIMES. THE RPTR SAID THIS SYS SHOULD HAVE AN AIRSPD INPUT LIKE THE DASH 8 SYS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	378134
Time
Date	199708
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Beech 1900
Operating Under FAR Part	Part 135
Navigation In Use	Other
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 7000 flight time type : 600
ASRS Report	378134
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

A flight crew of a beech 1900D reports serious distractions during descent and approach caused by the landing gear warning horn sounding when power changes occur.