|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||atc facility : bil|
|Altitude||msl bound lower : 400|
msl bound upper : 1000
|Operator||general aviation : corporate|
|Make Model Name||Small Transport, Low Wing, 2 Recip Eng|
|Flight Phase||cruise other|
|Function||flight crew : single pilot|
|Qualification||pilot : cfi|
pilot : commercial
pilot : instrument
|Experience||flight time last 90 days : 50|
flight time total : 4408
flight time type : 1700
|Anomaly||inflight encounter : weather|
|Independent Detector||other flight crewa|
|Resolutory Action||flight crew : regained aircraft control|
|Air Traffic Incident||other|
I was returning to great falls, mt, from billings, mt, VFR in our company small transport. I was holding about 800 to 1000' above ground level. I was staying low to avoid the much higher winds at altitude. I hit a wind shear and clear air turbulence with no warning, causing a loss of 400-500'. I was hand flying the aircraft and recovered about 300-400' above the ground and continued with no further problem to my destination. A cold front was about 75 mi north of the incident location. This might have been associated with it or it might have been some type of mountain wave coming from a nearby mountain range. Callback conversation with reporter revealed the following: reporter states terrain was almost level, just a bit rolling with mountains 10-15 mi on either side. Flight was below mountain tops. No injury or aircraft stress occurred. Pilot and passenger really scared because no matter what they did nothing helped. Turbulence was light chop.
Original NASA ASRS Text
Title: FLT IN MOUNTAIN WAVE, WIND SHEAR.
Narrative: I WAS RETURNING TO GREAT FALLS, MT, FROM BILLINGS, MT, VFR IN OUR COMPANY SMT. I WAS HOLDING ABOUT 800 TO 1000' ABOVE GND LEVEL. I WAS STAYING LOW TO AVOID THE MUCH HIGHER WINDS AT ALT. I HIT A WIND SHEAR AND CLEAR AIR TURB WITH NO WARNING, CAUSING A LOSS OF 400-500'. I WAS HAND FLYING THE ACFT AND RECOVERED ABOUT 300-400' ABOVE THE GND AND CONTINUED WITH NO FURTHER PROB TO MY DEST. A COLD FRONT WAS ABOUT 75 MI N OF THE INCIDENT LOCATION. THIS MIGHT HAVE BEEN ASSOCIATED WITH IT OR IT MIGHT HAVE BEEN SOME TYPE OF MOUNTAIN WAVE COMING FROM A NEARBY MOUNTAIN RANGE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATES TERRAIN WAS ALMOST LEVEL, JUST A BIT ROLLING WITH MOUNTAINS 10-15 MI ON EITHER SIDE. FLT WAS BELOW MOUNTAIN TOPS. NO INJURY OR ACFT STRESS OCCURRED. PLT AND PAX REALLY SCARED BECAUSE NO MATTER WHAT THEY DID NOTHING HELPED. TURB WAS LIGHT CHOP.
Data retrieved from NASA's ASRS site as of August 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.