A C-172 encountered a period of severe turbulence along an eastern us mountain range near his destin...

Narrative:

Going IFR with long time student and friend; we began descending from 6;000 to 5;000 approaching br beacon. It was a cold december day for southeast USA. A cold front (very dry) had passed about 10 hours before. It was dry cold allowing no signature cloud formation. First I noticed a very rapid descend (about 500 a minute) then very turbulent pressures trying to turn airplane upside down. Then with full power pitch up at 70 KTS -200 ft vsi! I struggled to climb while turning away from the mountains.I requested change of destination to an airport situated at a less rugged terrain environment. I moved southwest climbed to 6;000 ft. Now southeast [we were] trying to head towards the airport. I could hear others reporting 'severe turbulence and not able to maintain altitude.' we were given 5;000 turn toward our destination but once I got to 5;600 ft again we were exposed to turbulence and rapid loss of altitude and upset attitude. I again requested a retreat to a heading 200 degrees away from the mountains. Tower ATC was quick; accommodating and very polite. I never deviated [in] altitude or heading but I wanted to share this for others to be aware of what happens in winter after a very dry cold front passage. I requested to go to another divert airport. We were given 180 degrees; then direct. We landed without any problems. I borrowed the courtesy car and drove my friend to our original destination.

Original NASA ASRS Text

Title: A C-172 encountered a period of severe turbulence along an Eastern U.S. mountain range near his destination following passage of a dry cold front. Struggling to control the aircraft; the pilot diverted to calmer air for landing.

Narrative: Going IFR with long time student and friend; we began descending from 6;000 to 5;000 approaching BR beacon. It was a cold December day for SE USA. A cold Front (very dry) had passed about 10 hours before. It was dry cold allowing no signature cloud formation. First I noticed a very rapid descend (about 500 a minute) then very turbulent pressures trying to turn airplane upside down. Then with full power pitch up at 70 KTS -200 FT VSI! I struggled to climb while turning away from the mountains.I requested change of destination to an airport situated at a less rugged terrain environment. I moved southwest climbed to 6;000 FT. Now southeast [we were] trying to head towards the airport. I could hear others reporting 'Severe turbulence and not able to maintain altitude.' We were given 5;000 turn toward our destination but once I got to 5;600 FT again we were exposed to turbulence and rapid loss of altitude and upset attitude. I again requested a retreat to a heading 200 degrees away from the mountains. Tower ATC was quick; accommodating and very polite. I never deviated [in] altitude or heading but I wanted to share this for others to be aware of what happens in winter after a very dry cold front passage. I requested to go to another divert airport. We were given 180 degrees; then direct. We landed without any problems. I borrowed the courtesy car and drove my friend to our original destination.

Data retrieved from NASA's ASRS site as of July 2013 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	1136722
Time
Date	201312
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Direct Visual Approach
Flight Plan	IFR
Person 1
Function	Pilot Flying Instructor
Qualification	Flight Crew Multiengine Flight Crew Flight Instructor Flight Crew Instrument
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 21000 Flight Crew Type 3000
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Track / Heading All Types Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Weather / Turbulence

A C-172 encountered a period of severe turbulence along an eastern us mountain range near his destination following passage of a dry cold front. Struggling to control the aircraft; the pilot diverted to calmer air for landing.