Narrative:

I was the captain and acting as the PF of an MD11 flight X on nov/tue/04. The first officer was acting as the pilot monitoring for this leg of the trip. A B767 flight Y departed in front of us sdf runway 17R. Louisville tower cleared us into position and hold. By the time I lined up on runway 17R, louisville tower cleared us for takeoff and assigned us a heading of 190 degrees. Shortly after takeoff, louisville departure cleared us to intercept V4 to pxv. We then received the handoff to ZID passing 10000 ft. ZID proceeded to step-climb us due to traffic ahead. I distinctly remember ZID clearing flight Y to proceed direct to bum. I believe it was at that time we received our unrestr climb clearance to FL260. Our flight plan had us at FL260 until pxv. At pxv the flight plan showed a new cruise altitude of FL310. We requested our planned cruise altitude from ZID a few mi before pxv. ZID granted our request for FL310 and we were level at FL310 by pxv. At pxv, our flight plan had a 20 degree to 30 degree right turn to our first waypoint. Approximately 20 NM northwest of pxv, we received a 'traffic, traffic' TCASII alert. I immediately selected the TCASII button on the gcp. The conflicting traffic was at our 4 O'clock position, at the same altitude of FL310 and closing fairly quickly. I then heard ZID try to give an urgent heading clearance to a flight. But the flight number was blocked due to another transmission. I keyed the microphone and stated, 'blocked. Who was that for?' at that point, we received a 'climb, climb' TCASII RA. I immediately disconnected the autoplt and manually complied with the +1000 FPM to +4000 FPM vertical climb guidance on the ivsi. A few seconds later, we received a 'monitor vertical speed' TCASII RA with the green band from +500 FPM to +1000 FPM. We were in IMC WX conditions and did not see the conflicting B767 Y traffic. We did hear ZID give instructions to flight Y. They stated that they were complying with a TCASII RA. I instructed the first officer to tell ZID that we were also complying with a TCASII RA. At that point, I glanced at my navigation display and noticed that we were 1000 ft above the B767 and received the 'clear of conflict' TCASII notification. Our altitude was approximately FL317. I called for the autoplt and descended back down to FL310. We never saw the B767. First of all, let me state 'thank god!' then I would like to add 'thank god for TCASII!' I would also like to add that I believe my previous training prepared me to handle this event. Because it was just like the simulator! But what were the links in this chain of events? The first officer of flight Y called me at the hotel in pdx and we tried to reconstruct the sequence of events between our 2 flts. During that conversation, he stated that had we not had TCASII or had not followed its instructions, it would have been difficult to determine if we would have had any separation between our 2 aircraft. Even though we were in IMC, we were close enough that they had our aircraft in sight. I believe after reconstructing our 2 flts, I would like to offer my hypothesis. The B767 was cruising in front of us at mach .83. We were cruising at mach .855. At this point we were both flying down V4 to pxv. ZID then cleared flight Y to proceed direct to bum. Our flight paths are now diverging. Somewhere along V4 to pxv, we passed the B767 off to our right. As we crossed over pxv and turned right 20 degrees to 30 degrees to our first waypoint, our flight paths were now converging. At approximately 20 NM northwest of pxv at FL310, the TCASII event occurred. Another factor, I believe, was our flight plan. I believe that the ZID controller knew exactly where bum is geographically when he cleared flight Y direct to bum. I am speculating that the controller was not familiar with where, geographically, our first waypoint was. Therefore, the controller might not have been expecting us to make a turn to the right over pxv and into the path of flight Y. This was also my first domestic flight plan. The flight plan waypoints were almost like interping a latitude/longitude position. You have a general idea of where that latitude/longitude is, but are not exactly sure. I have no idea what tools the controllers have to predict our flight paths when we are on a free-flight flight plan. I am not sure if the controllers have the ability to display our flight plans on their radar scope. Software may need to be developed. I also would like to approach this event from a training point-of-view. I am an MD11 simulator instructor and believe that we need to emphasize a few points during TCASII training. Most MD11 pilots that come through the simulator for recurrent training have forgotten about the TCASII button on the gcp and what that button does. We might also need to review the basic TCASII components and TCASII procedures. A common technique during a simulated TCASII RA is to use the vertical speed mode of the autoplt. Pilots believe that using this autoplt mode will aid in the accuracy of the RA target on the ivsi. In our situation (weight, speed and altitude), I believe the aircraft response would have been too slow. A better option we should emphasize is to disconnect the autoplt and fly the TCASII RA manually. The other trend I see in the simulator is when the pilot does respond manually, the pilot will tend to overshoot the TCASII RA green band target. This usually causes a secondary TCASII RA and usually goes unnoticed and not complied with. Another suggestion I have is that ATC clearance delivery transmit a full-route clearance in the pre departure clearance. I would like to be assured that what I am programming in my FMS is what ATC has us cleared for. Our pre departure clearance on that flight read something like: 'cleared V4 pxv as filed.' that did not give me a 'warm-fuzzy' when we got our TCASII RA. Were we where we were supposed to be? I later concluded that we were when the next sector controller gave us a heading change for 40 NM and then cleared us direct to our next waypoint. I can also speculate that we may have safety issues loading flight plans that are not unlike the gross navigation errors that can occur when loading an overwater flight plan. I know this is a current work-in-progress, but we need to have the capability to automatically upload these flight plans into the FMS. Supplemental information from acn 638886: there was frequency congestion and multiple stepped on radio calls which may have prevented an ATC avoidance vector. Additionally, we were on a random routing off of published airways. ATC either did not or could not provide for traffic de-confliction. Supplemental information from acn 639314: near the time of the rejection of our FL350 request (I believe a few mins later), the controller instructed us to proceed direct butler, and subsequently to a point back on our flight plan. The controller made a brief nondescript explanation of why we were being sent on this routing, of which I do not remember replying. As a recommendation, I have learned from this event, that it is helpful for the TCASII display to remain in a low range setting. Thus, when a TA/RA aural warning is overheard, quick reference to an aircraft in close proximity can be attained (if VFR).

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Original NASA ASRS Text

Title: NMAC AT FL310 AVOIDED BY TCASII ALERT BTWN AN MD11 AND A XING B767 AT THE SAME ALT ON FREQ WITH ZID.

Narrative: I WAS THE CAPT AND ACTING AS THE PF OF AN MD11 FLT X ON NOV/TUE/04. THE FO WAS ACTING AS THE PLT MONITORING FOR THIS LEG OF THE TRIP. A B767 FLT Y DEPARTED IN FRONT OF US SDF RWY 17R. LOUISVILLE TWR CLRED US INTO POS AND HOLD. BY THE TIME I LINED UP ON RWY 17R, LOUISVILLE TWR CLRED US FOR TKOF AND ASSIGNED US A HDG OF 190 DEGS. SHORTLY AFTER TKOF, LOUISVILLE DEP CLRED US TO INTERCEPT V4 TO PXV. WE THEN RECEIVED THE HDOF TO ZID PASSING 10000 FT. ZID PROCEEDED TO STEP-CLB US DUE TO TFC AHEAD. I DISTINCTLY REMEMBER ZID CLRING FLT Y TO PROCEED DIRECT TO BUM. I BELIEVE IT WAS AT THAT TIME WE RECEIVED OUR UNRESTR CLB CLRNC TO FL260. OUR FLT PLAN HAD US AT FL260 UNTIL PXV. AT PXV THE FLT PLAN SHOWED A NEW CRUISE ALT OF FL310. WE REQUESTED OUR PLANNED CRUISE ALT FROM ZID A FEW MI BEFORE PXV. ZID GRANTED OUR REQUEST FOR FL310 AND WE WERE LEVEL AT FL310 BY PXV. AT PXV, OUR FLT PLAN HAD A 20 DEG TO 30 DEG R TURN TO OUR FIRST WAYPOINT. APPROX 20 NM NW OF PXV, WE RECEIVED A 'TFC, TFC' TCASII ALERT. I IMMEDIATELY SELECTED THE TCASII BUTTON ON THE GCP. THE CONFLICTING TFC WAS AT OUR 4 O'CLOCK POS, AT THE SAME ALT OF FL310 AND CLOSING FAIRLY QUICKLY. I THEN HEARD ZID TRY TO GIVE AN URGENT HDG CLRNC TO A FLT. BUT THE FLT NUMBER WAS BLOCKED DUE TO ANOTHER XMISSION. I KEYED THE MIKE AND STATED, 'BLOCKED. WHO WAS THAT FOR?' AT THAT POINT, WE RECEIVED A 'CLB, CLB' TCASII RA. I IMMEDIATELY DISCONNECTED THE AUTOPLT AND MANUALLY COMPLIED WITH THE +1000 FPM TO +4000 FPM VERT CLB GUIDANCE ON THE IVSI. A FEW SECONDS LATER, WE RECEIVED A 'MONITOR VERT SPD' TCASII RA WITH THE GREEN BAND FROM +500 FPM TO +1000 FPM. WE WERE IN IMC WX CONDITIONS AND DID NOT SEE THE CONFLICTING B767 Y TFC. WE DID HEAR ZID GIVE INSTRUCTIONS TO FLT Y. THEY STATED THAT THEY WERE COMPLYING WITH A TCASII RA. I INSTRUCTED THE FO TO TELL ZID THAT WE WERE ALSO COMPLYING WITH A TCASII RA. AT THAT POINT, I GLANCED AT MY NAV DISPLAY AND NOTICED THAT WE WERE 1000 FT ABOVE THE B767 AND RECEIVED THE 'CLR OF CONFLICT' TCASII NOTIFICATION. OUR ALT WAS APPROX FL317. I CALLED FOR THE AUTOPLT AND DSNDED BACK DOWN TO FL310. WE NEVER SAW THE B767. FIRST OF ALL, LET ME STATE 'THANK GOD!' THEN I WOULD LIKE TO ADD 'THANK GOD FOR TCASII!' I WOULD ALSO LIKE TO ADD THAT I BELIEVE MY PREVIOUS TRAINING PREPARED ME TO HANDLE THIS EVENT. BECAUSE IT WAS JUST LIKE THE SIMULATOR! BUT WHAT WERE THE LINKS IN THIS CHAIN OF EVENTS? THE FO OF FLT Y CALLED ME AT THE HOTEL IN PDX AND WE TRIED TO RECONSTRUCT THE SEQUENCE OF EVENTS BTWN OUR 2 FLTS. DURING THAT CONVERSATION, HE STATED THAT HAD WE NOT HAD TCASII OR HAD NOT FOLLOWED ITS INSTRUCTIONS, IT WOULD HAVE BEEN DIFFICULT TO DETERMINE IF WE WOULD HAVE HAD ANY SEPARATION BTWN OUR 2 ACFT. EVEN THOUGH WE WERE IN IMC, WE WERE CLOSE ENOUGH THAT THEY HAD OUR ACFT IN SIGHT. I BELIEVE AFTER RECONSTRUCTING OUR 2 FLTS, I WOULD LIKE TO OFFER MY HYPOTHESIS. THE B767 WAS CRUISING IN FRONT OF US AT MACH .83. WE WERE CRUISING AT MACH .855. AT THIS POINT WE WERE BOTH FLYING DOWN V4 TO PXV. ZID THEN CLRED FLT Y TO PROCEED DIRECT TO BUM. OUR FLT PATHS ARE NOW DIVERGING. SOMEWHERE ALONG V4 TO PXV, WE PASSED THE B767 OFF TO OUR R. AS WE CROSSED OVER PXV AND TURNED R 20 DEGS TO 30 DEGS TO OUR FIRST WAYPOINT, OUR FLT PATHS WERE NOW CONVERGING. AT APPROX 20 NM NW OF PXV AT FL310, THE TCASII EVENT OCCURRED. ANOTHER FACTOR, I BELIEVE, WAS OUR FLT PLAN. I BELIEVE THAT THE ZID CTLR KNEW EXACTLY WHERE BUM IS GEOGRAPHICALLY WHEN HE CLRED FLT Y DIRECT TO BUM. I AM SPECULATING THAT THE CTLR WAS NOT FAMILIAR WITH WHERE, GEOGRAPHICALLY, OUR FIRST WAYPOINT WAS. THEREFORE, THE CTLR MIGHT NOT HAVE BEEN EXPECTING US TO MAKE A TURN TO THE R OVER PXV AND INTO THE PATH OF FLT Y. THIS WAS ALSO MY FIRST DOMESTIC FLT PLAN. THE FLT PLAN WAYPOINTS WERE ALMOST LIKE INTERPING A LATITUDE/LONGITUDE POS. YOU HAVE A GENERAL IDEA OF WHERE THAT LATITUDE/LONGITUDE IS, BUT ARE NOT EXACTLY SURE. I HAVE NO IDEA WHAT TOOLS THE CTLRS HAVE TO PREDICT OUR FLT PATHS WHEN WE ARE ON A FREE-FLT FLT PLAN. I AM NOT SURE IF THE CTLRS HAVE THE ABILITY TO DISPLAY OUR FLT PLANS ON THEIR RADAR SCOPE. SOFTWARE MAY NEED TO BE DEVELOPED. I ALSO WOULD LIKE TO APCH THIS EVENT FROM A TRAINING POINT-OF-VIEW. I AM AN MD11 SIMULATOR INSTRUCTOR AND BELIEVE THAT WE NEED TO EMPHASIZE A FEW POINTS DURING TCASII TRAINING. MOST MD11 PLTS THAT COME THROUGH THE SIMULATOR FOR RECURRENT TRAINING HAVE FORGOTTEN ABOUT THE TCASII BUTTON ON THE GCP AND WHAT THAT BUTTON DOES. WE MIGHT ALSO NEED TO REVIEW THE BASIC TCASII COMPONENTS AND TCASII PROCS. A COMMON TECHNIQUE DURING A SIMULATED TCASII RA IS TO USE THE VERT SPD MODE OF THE AUTOPLT. PLTS BELIEVE THAT USING THIS AUTOPLT MODE WILL AID IN THE ACCURACY OF THE RA TARGET ON THE IVSI. IN OUR SIT (WT, SPD AND ALT), I BELIEVE THE ACFT RESPONSE WOULD HAVE BEEN TOO SLOW. A BETTER OPTION WE SHOULD EMPHASIZE IS TO DISCONNECT THE AUTOPLT AND FLY THE TCASII RA MANUALLY. THE OTHER TREND I SEE IN THE SIMULATOR IS WHEN THE PLT DOES RESPOND MANUALLY, THE PLT WILL TEND TO OVERSHOOT THE TCASII RA GREEN BAND TARGET. THIS USUALLY CAUSES A SECONDARY TCASII RA AND USUALLY GOES UNNOTICED AND NOT COMPLIED WITH. ANOTHER SUGGESTION I HAVE IS THAT ATC CLRNC DELIVERY XMIT A FULL-RTE CLRNC IN THE PDC. I WOULD LIKE TO BE ASSURED THAT WHAT I AM PROGRAMMING IN MY FMS IS WHAT ATC HAS US CLRED FOR. OUR PDC ON THAT FLT READ SOMETHING LIKE: 'CLRED V4 PXV AS FILED.' THAT DID NOT GIVE ME A 'WARM-FUZZY' WHEN WE GOT OUR TCASII RA. WERE WE WHERE WE WERE SUPPOSED TO BE? I LATER CONCLUDED THAT WE WERE WHEN THE NEXT SECTOR CTLR GAVE US A HDG CHANGE FOR 40 NM AND THEN CLRED US DIRECT TO OUR NEXT WAYPOINT. I CAN ALSO SPECULATE THAT WE MAY HAVE SAFETY ISSUES LOADING FLT PLANS THAT ARE NOT UNLIKE THE GROSS NAV ERRORS THAT CAN OCCUR WHEN LOADING AN OVERWATER FLT PLAN. I KNOW THIS IS A CURRENT WORK-IN-PROGRESS, BUT WE NEED TO HAVE THE CAPABILITY TO AUTOMATICALLY UPLOAD THESE FLT PLANS INTO THE FMS. SUPPLEMENTAL INFO FROM ACN 638886: THERE WAS FREQ CONGESTION AND MULTIPLE STEPPED ON RADIO CALLS WHICH MAY HAVE PREVENTED AN ATC AVOIDANCE VECTOR. ADDITIONALLY, WE WERE ON A RANDOM ROUTING OFF OF PUBLISHED AIRWAYS. ATC EITHER DID NOT OR COULD NOT PROVIDE FOR TFC DE-CONFLICTION. SUPPLEMENTAL INFO FROM ACN 639314: NEAR THE TIME OF THE REJECTION OF OUR FL350 REQUEST (I BELIEVE A FEW MINS LATER), THE CTLR INSTRUCTED US TO PROCEED DIRECT BUTLER, AND SUBSEQUENTLY TO A POINT BACK ON OUR FLT PLAN. THE CTLR MADE A BRIEF NONDESCRIPT EXPLANATION OF WHY WE WERE BEING SENT ON THIS ROUTING, OF WHICH I DO NOT REMEMBER REPLYING. AS A RECOMMENDATION, I HAVE LEARNED FROM THIS EVENT, THAT IT IS HELPFUL FOR THE TCASII DISPLAY TO REMAIN IN A LOW RANGE SETTING. THUS, WHEN A TA/RA AURAL WARNING IS OVERHEARD, QUICK REF TO AN ACFT IN CLOSE PROX CAN BE ATTAINED (IF VFR).

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.