Cessna R172E N7879N accident near Loveland, Colorado

Probable cause

An inflight loss of control on landing approach due to encountering a down-draft, and the pilot's failure to take timely action to abandon the approach and perform a go-around.

NTSB analysis

As the pilot approached the airport, another pilot heard him on the radio and advised him of "significant down drafts" on the approach to runway 15. The pilot acknowledged the transmission and continued his approach. When he turned onto the base leg, he encountered the "severe down-draft/microburst" the other pilot had mentioned. He applied full power in an attempt to climb out, but the airplane continued to descend striking a power-line and tree, and subsequently impacted terrain.

A review of the weather showed that a complex wind pattern existed over the area during the period with a wind shift occurring immediately after the time of the accident. No support for convective microburst activity was noted over the area; however, a large area of light intensity precipitation with some potential for some outflow was noted, which could have been resulted in the different winds occurring over the accident site during the period. In addition, the High Resolution Rapid Refresh model sounding and satellite imagery and pilot reports noted support for mountain wave activity over the area, which supported downslope winds and downdraft activity in the area at the time of the accident. The National Weather Service had AIRMET advisories for turbulence and IFR and mountain obscuration conditions over the area, but no advisory for low-level wind shear.

It is likely the pilot encountered shifting winds due to weather system in the area. With his reduced engine power on the base leg of the traffic pattern, the pilot most likely got into a downdraft that produced a sink rate that he could not recover from.

Text from the NTSB. Open the NTSB docket for CEN19LA107 for the full record.