Gear up landing. - NASA ASRS

Attributes
ACN	219890
Time
Date	199208
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mkt
State Reference	MN
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	landing other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 87 flight time total : 4996 flight time type : 1909
ASRS Report	219890
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 85 flight time total : 3300 flight time type : 1480
ASRS Report	219742
Events
Anomaly	aircraft equipment problem : less severe non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was PIC of an light transport which landed with its gear in the up position in mankato, mn. Contributing factors which led to this incident include erratic operation of the copilot's air data computer which set off the overspd warning alarm, even though there was not an overspd condition. Due to the noise level of this alarm, I pulled the aural warning circuit breaker -- the only method available to silence the alarm -- so the copilot and I could concentrate on flying the aircraft. The approved airplane flight manual does not provide any checklist for failure of the copilot's air data computer. The checklist does allow air data reversion from the copilot's to the pilot's side, but does not mention transfer of data from the pilot's to the copilot's side. I was unaware that the landing gear warning system was now disabled, and it gave no indication to the flight crew of a gear up confign. With the above detractions and ATC giving numerous heading and altitude changes, the gear was overlooked, which led to the gear up landing. Corrective actions should be taken in the confign of the aural warning system. I recommend that if an air data computer is to fail and consequently set off the overspd warning, the pilot or copilot should have the ability to cancel their respective alarm without jeopardizing a completely different system, in this case the landing gear warning system. In addition, there should be a checklist for the failure of the copilot's air data computer and a footnote explaining the serious consequence of silencing the overspd warning by pulling the circuit breaker. Supplemental information from acn 219742: upon final descent for landing the captain did not call for the gear to be put down or for the before landing checklist. However, the captain did call for flaps to 10 degrees, and full flaps. On short final I looked at the before landing checklist, and since there was no gear warning horn and flaps were already full, I assumed the gear was down.

Original NASA ASRS Text

Title: GEAR UP LNDG.

Narrative: I WAS PIC OF AN LTT WHICH LANDED WITH ITS GEAR IN THE UP POS IN MANKATO, MN. CONTRIBUTING FACTORS WHICH LED TO THIS INCIDENT INCLUDE ERRATIC OP OF THE COPLT'S AIR DATA COMPUTER WHICH SET OFF THE OVERSPD WARNING ALARM, EVEN THOUGH THERE WAS NOT AN OVERSPD CONDITION. DUE TO THE NOISE LEVEL OF THIS ALARM, I PULLED THE AURAL WARNING CIRCUIT BREAKER -- THE ONLY METHOD AVAILABLE TO SILENCE THE ALARM -- SO THE COPLT AND I COULD CONCENTRATE ON FLYING THE ACFT. THE APPROVED AIRPLANE FLT MANUAL DOES NOT PROVIDE ANY CHKLIST FOR FAILURE OF THE COPLT'S AIR DATA COMPUTER. THE CHKLIST DOES ALLOW AIR DATA REVERSION FROM THE COPLT'S TO THE PLT'S SIDE, BUT DOES NOT MENTION TRANSFER OF DATA FROM THE PLT'S TO THE COPLT'S SIDE. I WAS UNAWARE THAT THE LNDG GEAR WARNING SYS WAS NOW DISABLED, AND IT GAVE NO INDICATION TO THE FLC OF A GEAR UP CONFIGN. WITH THE ABOVE DETRACTIONS AND ATC GIVING NUMEROUS HDG AND ALT CHANGES, THE GEAR WAS OVERLOOKED, WHICH LED TO THE GEAR UP LNDG. CORRECTIVE ACTIONS SHOULD BE TAKEN IN THE CONFIGN OF THE AURAL WARNING SYS. I RECOMMEND THAT IF AN AIR DATA COMPUTER IS TO FAIL AND CONSEQUENTLY SET OFF THE OVERSPD WARNING, THE PLT OR COPLT SHOULD HAVE THE ABILITY TO CANCEL THEIR RESPECTIVE ALARM WITHOUT JEOPARDIZING A COMPLETELY DIFFERENT SYS, IN THIS CASE THE LNDG GEAR WARNING SYS. IN ADDITION, THERE SHOULD BE A CHKLIST FOR THE FAILURE OF THE COPLT'S AIR DATA COMPUTER AND A FOOTNOTE EXPLAINING THE SERIOUS CONSEQUENCE OF SILENCING THE OVERSPD WARNING BY PULLING THE CIRCUIT BREAKER. SUPPLEMENTAL INFO FROM ACN 219742: UPON FINAL DSCNT FOR LNDG THE CAPT DID NOT CALL FOR THE GEAR TO BE PUT DOWN OR FOR THE BEFORE LNDG CHKLIST. HOWEVER, THE CAPT DID CALL FOR FLAPS TO 10 DEGS, AND FULL FLAPS. ON SHORT FINAL I LOOKED AT THE BEFORE LNDG CHKLIST, AND SINCE THERE WAS NO GEAR WARNING HORN AND FLAPS WERE ALREADY FULL, I ASSUMED THE GEAR WAS DOWN.

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.