B737 flight crew apparently lands without clearance due to heavy turbulence.

Attributes
ACN	336040
Time
Date	199605
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : den
State Reference	CO
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	Marginal
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	landing other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 30000 flight time type : 7000
ASRS Report	336040
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	incursion : landing without clearance
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Cos-den heavy moderate CAT at 9000 ft MSL, hard to keep in control but not loss of control. Copilot very uncomfortable, worried about landing, lost checklist on floor during turbulence. The best route of flight, toward den and den land runway 35L. Other aircraft inbound from east also landing runway 35L/right. We were cleared straight-in for runway 35L. Very, very, very busy flying due turbulence. Copilot says we did not get landing clearance. I don't know, too busy flying.

Original NASA ASRS Text

Title: B737 FLC APPARENTLY LANDS WITHOUT CLRNC DUE TO HVY TURB.

Narrative: COS-DEN HVY MODERATE CAT AT 9000 FT MSL, HARD TO KEEP IN CTL BUT NOT LOSS OF CTL. COPLT VERY UNCOMFORTABLE, WORRIED ABOUT LNDG, LOST CHKLIST ON FLOOR DURING TURB. THE BEST RTE OF FLT, TOWARD DEN AND DEN LAND RWY 35L. OTHER ACFT INBOUND FROM E ALSO LNDG RWY 35L/R. WE WERE CLRED STRAIGHT-IN FOR RWY 35L. VERY, VERY, VERY BUSY FLYING DUE TURB. COPLT SAYS WE DID NOT GET LNDG CLRNC. I DON'T KNOW, TOO BUSY FLYING.

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.