Narrative:

At approximately XA30 pm mar/xx/95 I was with a student practicing takeoffs and lndgs on runway 10L at port columbus, columbus, oh. We were cleared for touch and go, #2 behind a 737. He cleared the runway while we were on short final. We maintained an approach angle somewhat above his approach and aimed for a landing flare about 1000 ft beyond his touchdown point. At about 50-70 ft above the runway we encountered brief but extremely violent turbulence. It felt like an extremely violent thermal and there was momentary loss of control. There did not seem to be any roll inducing forces and it was over in a second or so. The winds were light and the air was smooth. My evaluation of this incident is that, due to the fact that the jet was landing on a 6000 ft runway, with light winds, that he probably used considerable reverser thrust. It is my guess that this is what generated the turbulence we encountered. An experienced or student pilot might lose complete control under these circumstances. My reason for submitting this report is with the hope that the people who wrote the wake avoidance procedures would consider this as a problem that should be addressed and possibly be added to the procedure. Callback conversation with reporter revealed the following: the reporter was an instructor with almost 10000 hours total time. All of his experience has been in the small single engine type. His student was from a foreign country and had about 4 hours total time. The student did not have a good grasp of english, and perhaps were he by himself, would have frozen at the controls were he to encounter such turbulence and be by himself. Usually the air carrier turbo jets use the long runway. The reporter is concerned by the aircraft turbulence generated by heavy reversing and how long it lasts on the runway in still air. He feels the industry should study the patterns and publish the results.

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Original NASA ASRS Text

Title: FLT INSTRUCTOR RPTR ENCOUNTERS UNEXPECTED TURB ON LNDG BEHIND A BOEING 737.

Narrative: AT APPROX XA30 PM MAR/XX/95 I WAS WITH A STUDENT PRACTICING TKOFS AND LNDGS ON RWY 10L AT PORT COLUMBUS, COLUMBUS, OH. WE WERE CLRED FOR TOUCH AND GO, #2 BEHIND A 737. HE CLRED THE RWY WHILE WE WERE ON SHORT FINAL. WE MAINTAINED AN APCH ANGLE SOMEWHAT ABOVE HIS APCH AND AIMED FOR A LNDG FLARE ABOUT 1000 FT BEYOND HIS TOUCHDOWN POINT. AT ABOUT 50-70 FT ABOVE THE RWY WE ENCOUNTERED BRIEF BUT EXTREMELY VIOLENT TURB. IT FELT LIKE AN EXTREMELY VIOLENT THERMAL AND THERE WAS MOMENTARY LOSS OF CTL. THERE DID NOT SEEM TO BE ANY ROLL INDUCING FORCES AND IT WAS OVER IN A SECOND OR SO. THE WINDS WERE LIGHT AND THE AIR WAS SMOOTH. MY EVALUATION OF THIS INCIDENT IS THAT, DUE TO THE FACT THAT THE JET WAS LNDG ON A 6000 FT RWY, WITH LIGHT WINDS, THAT HE PROBABLY USED CONSIDERABLE REVERSER THRUST. IT IS MY GUESS THAT THIS IS WHAT GENERATED THE TURB WE ENCOUNTERED. AN EXPERIENCED OR STUDENT PLT MIGHT LOSE COMPLETE CTL UNDER THESE CIRCUMSTANCES. MY REASON FOR SUBMITTING THIS RPT IS WITH THE HOPE THAT THE PEOPLE WHO WROTE THE WAKE AVOIDANCE PROCS WOULD CONSIDER THIS AS A PROB THAT SHOULD BE ADDRESSED AND POSSIBLY BE ADDED TO THE PROC. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: THE RPTR WAS AN INSTRUCTOR WITH ALMOST 10000 HRS TOTAL TIME. ALL OF HIS EXPERIENCE HAS BEEN IN THE SMALL SINGLE ENG TYPE. HIS STUDENT WAS FROM A FOREIGN COUNTRY AND HAD ABOUT 4 HRS TOTAL TIME. THE STUDENT DID NOT HAVE A GOOD GRASP OF ENGLISH, AND PERHAPS WERE HE BY HIMSELF, WOULD HAVE FROZEN AT THE CTLS WERE HE TO ENCOUNTER SUCH TURB AND BE BY HIMSELF. USUALLY THE ACR TURBO JETS USE THE LONG RWY. THE RPTR IS CONCERNED BY THE ACFT TURB GENERATED BY HVY REVERSING AND HOW LONG IT LASTS ON THE RWY IN STILL AIR. HE FEELS THE INDUSTRY SHOULD STUDY THE PATTERNS AND PUBLISH THE RESULTS.

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.