A dhc-8 flight crew took evasive action to avoid an encounter with what appeared to be a towplane an...

Narrative:

While on a short flight to den we got a TCAS alert 'traffic traffic' and the TCAS screen showed a target directly ahead with no altitude information. The traffic was barely a mile ahead of us; so I quickly began to scan for him. I saw a small; private field below; and thought it was likely that there was traffic in the pattern; but to play it safe I first scanned straight ahead. Immediately ahead and slightly ahead I saw a light single engine airplane; white and red; headed from left to right. The traffic appeared to be at our altitude so I warned the first officer and he said that he could see them. I asked the first officer to turn off the autopilot; and he responded that it was already off. The other aircraft; though very close started a very steep right turn; I assumed to get out of our way; and within seconds was clearly headed away from us. Just then I noticed a second aircraft; a glider; that was still on a course that would be a collision hazard within 10 seconds. I called for the first officer to climb; but he responded that he could see him; and remained straight and level. Without time to explain myself I grabbed the yoke and pulled the airplane into an abrupt and steep climb. I said aloud that there was a second aircraft; at which time the first officer also saw the glider. I'm not aware if the glider ever saw us; or took evasive action. We leveled off about 11;600 ft; and I called approach to explain our deviation. Approach acknowledged my transmission; but offered no more. I feel that a midair collision; or at least a very near miss would have occurred had we not taken immediate and aggressive measures within 4 or 5 seconds for the second aircraft. After later looking at a sectional chart I think it is possible maybe even likely that the aircraft were a tow-plane and a glider as the chart warns of intensive glider activity.

Original NASA ASRS Text

Title: A DHC-8 flight crew took evasive action to avoid an encounter with what appeared to be a towplane and glider near an area charted for sailplane activity.

Narrative: While on a short flight to DEN we got a TCAS alert 'Traffic Traffic' and the TCAS screen showed a target directly ahead with no altitude information. The traffic was barely a mile ahead of us; so I quickly began to scan for him. I saw a small; private field below; and thought it was likely that there was traffic in the pattern; but to play it safe I first scanned straight ahead. Immediately ahead and slightly ahead I saw a light single engine airplane; white and red; headed from left to right. The traffic appeared to be at our altitude so I warned the First Officer and he said that he could see them. I asked the First Officer to turn off the autopilot; and he responded that it was already off. The other aircraft; though very close started a very steep right turn; I assumed to get out of our way; and within seconds was clearly headed away from us. Just then I noticed a second aircraft; a glider; that was still on a course that would be a collision hazard within 10 seconds. I called for the First Officer to climb; but he responded that he could see him; and remained straight and level. Without time to explain myself I grabbed the yoke and pulled the airplane into an abrupt and steep climb. I said aloud that there was a second aircraft; at which time the First Officer also saw the glider. I'm not aware if the glider ever saw us; or took evasive action. We leveled off about 11;600 FT; and I called approach to explain our deviation. Approach acknowledged my transmission; but offered no more. I feel that a midair collision; or at least a VERY near miss would have occurred had we not taken immediate and aggressive measures within 4 or 5 seconds for the second aircraft. After later looking at a sectional chart I think it is possible maybe even likely that the aircraft were a tow-plane and a glider as the chart warns of intensive glider activity.

Data retrieved from NASA's ASRS site as of April 2012 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	868637
Time
Date	201001
Local Time Of Day	1201-1800
Place
Locale Reference	DEN.Airport
State Reference	CO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Dash 8-200
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Aircraft 2
Make Model Name	Sail Plane
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 240 Flight Crew Total 4855 Flight Crew Type 305
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 300 Vertical 400

A dhc-8 flight crew took evasive action to avoid an encounter with what appeared to be a towplane and glider near an area charted for sailplane activity.