20000306002169I

Incident · Minor damage

FAA incident report · Beech A36 · Canadian, TX · March 6, 2000

Date
March 6, 2000 · 16:00 local
Place
Canadian, TX
Airport
Hemphill County Airport
Phase of flight
Level Off Touchdown
Operating rules
General operating rules (Part 91)
Damage
Minor damage
Aircraft
N1143T
Reported as
Beech A36
People aboard
1
Fatal injuries
0
Pilot’s flight hours
350 total100 in this make and model12 in the last 90 days

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

(-23) On final approach to his destination in VFR conditions this private pilot selected gear down. The gear sounded normal but he did not get three green lights. Two additional attempts got the same results, sounded normal but no green lights. The pilot then cranked the gear down manually. He was only able to get the gear down half way approximately 25 turn of the crank instead of the required 50. He claims the gear mechanism bound up at 25 turns. He landed with the gear half way extended. Post incident investigation revealed that the reason he did not get the green lights was because the navigation lights were on which automatically dims the lights making them hard to see in certain lighting conditions. It was discovered that the gear manual system operated normally and that at the half way down point it is normal for the cranking to get hard due to the overcenter motion of the downlock mechanism and the additional air loads in flight. The newer model bonanzas have added a light sensing dimmer circuit to avoid this problem. Investigation closed. (Amended -23) on final approach to his destination in VFR conditions this private pilot selected gear down. The gear sounded normal but he did not get three green lights. Two additional attempts got the same results, sounded normal but no green lights. The pilot then cranked the gear down manually. He was only able to get gear down half way, approximately 25 turns of the crank instead of the required 50 turns. The pilot claimed the gear mechanism bound up at 25 turns and was not able to crank it any further. The aircraft landed with the gear half way extended. During the aircraft recovery effort the mechanic reported that the landing gear was partially deployed and that he manually cranked the gear down until it locked and he got three green lights. The investigation is closed.

As the FAA filed it

(-23) ON FINAL APPROACH TO HIS DESTINATION IN VFR CONDITIONS THIS PRIVATE PILOT SELECTED GEAR DOWN. THE GEAR SOUNDED NORMAL BUT HE DID NOT GET THREE GREEN LIGHTS. TWO ADDITIONAL ATTEMPTS GOT THE SAME RESULTS, SOUNDED NORMAL BUT NO GREEN LIGHTS. THE PILOT THEN CRANKED THE GEAR DOWN MANUALLY. HE WAS ONLY ABLE TO GET THE GEAR DOWN HALF WAY APPROXIMATELY 25 TURN OF THE CRANK INSTEAD OF THE REQUIRED 50. HE CLAIMS THE GEAR MECHANISM BOUND UP AT 25 TURNS. HE LANDED WITH THE GEAR HALF WAY EXTENDED. POST INCIDENT INVESTIGATION REVEALED THAT THE REASON HE DID NOT GET THE GREEN LIGHTS WAS BECAUSE THE NAVIGATION LIGHTS WERE ON WHICH AUTOMATICALLY DIMS THE LIGHTS MAKING THEM HARD TO SEE IN CERTAIN LIGHTING CONDITIONS. IT WAS DISCOVERED THAT THE GEAR MANUAL SYSTEM OPERATED NORMALLY AND THAT AT THE HALF WAY DOWN POINT IT IS NORMAL FOR THE CRANKING TO GET HARD DUE TO THE OVERCENTER MOTION OF THE DOWNLOCK MECHANISM AND THE ADDITIONAL AIR LOADS IN FLIGHT. THE NEWER MODEL BONANZAS HAVE ADDED A LIGHT SENSING DIMMER CIRCUIT TO AVOID THIS PROBLEM. INVESTIGATION CLOSED. (AMENDED -23) ON FINAL APPROACH TO HIS DESTINATION IN VFR CONDITIONS THIS PRIVATE PILOT SELECTED GEAR DOWN. THE GEAR SOUNDED NORMAL BUT HE DID NOT GET THREE GREEN LIGHTS. TWO ADDITIONAL ATTEMPTS GOT THE SAME RESULTS, SOUNDED NORMAL BUT NO GREEN LIGHTS. THE PILOT THEN CRANKED THE GEAR DOWN MANUALLY. HE WAS ONLY ABLE TO GET GEAR DOWN HALF WAY, APPROXIMATELY 25 TURNS OF THE CRANK INSTEAD OF THE REQUIRED 50 TURNS. THE PILOT CLAIMED THE GEAR MECHANISM BOUND UP AT 25 TURNS AND WAS NOT ABLE TO CRANK IT ANY FURTHER. THE AIRCRAFT LANDED WITH THE GEAR HALF WAY EXTENDED. DURING THE AIRCRAFT RECOVERY EFFORT THE MECHANIC REPORTED THAT THE LANDING GEAR WAS PARTIALLY DEPLOYED AND THAT HE MANUALLY CRANKED THE GEAR DOWN UNTIL IT LOCKED AND HE GOT THREE GREEN LIGHTS. THE INVESTIGATION IS CLOSED.