|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||atc facility : den|
|Altitude||msl bound lower : 7500|
msl bound upper : 17500
|Controlling Facilities||tracon : den|
tower : apa
|Operator||general aviation : personal|
|Make Model Name||Small Transport, Low Wing, 2 Recip Eng|
|Flight Phase||descent other|
|Function||flight crew : single pilot|
oversight : pic
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 100|
flight time total : 2000
flight time type : 350
|Anomaly||inflight encounter : weather|
non adherence : far
other anomaly other
|Independent Detector||other controllera|
|Resolutory Action||none taken : detected after the fact|
|Consequence||faa : investigated|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||Pilot Deviation|
A VFR flight, being conducted under far part 91, was approaching denver centennial airport (apa) from the southwest. ATIS indicated visual approach to runway 35L/right in use. Descent was commenced from 17500' MSL, 50 southwest of apa, planning a final approach altitude of 7500 MSL with a target altitude of 8000 MSL 20 southwest of den. At approximately 13000' MSL, 30 southwest of den, heading 060 degree magnetic, IAS of 200 KTS, severe turbulence was encountered (SIGMET for such was current). The aircraft was slowed to design maneuvering speed (155 KTS), temporarily stopping descent. To avoid TCA conflict a 30 degree right turn (to 090 degree magnetic) was made. DME information from den VORTAC indicated position outside TCA. Severe turbulence and cockpit workload prevented retuning navigation receiver to 110.3 MHZ (den 26L ILS and navigation facility upon which TCA is predicated, approximately 1 1/2 NM ssw of den VORTAC), however, visual information indicated position to continue to be outside of TCA until 10000' MSL reached when heading 080 degree magnetic assumed for 'wide left base, outside power lines to 35R' as advised by apa tower. (These power lines are noted to be at 16 DME TCA arc on den TCA chart.) at 8500' MSL, crossing I25 (road) and south of power lines, contact with apa tower was made as requested and turn to final commenced. The aircraft was slowed to vle speed (140 KT) slowing descent until turn to final completed. VASI indicated pink/white, necessitating slightly increased descent rate, until red/white obtained and the landing completed. Request was received from apa tower to contact den TRACON by telephone. Request complied with and supervisor of den approach advised that an aircraft approximately our approach profile encroached den TCA in 2 areas (southwest corner and south of apa). Den was advised that our aircraft was clear of TCA at all times to the best of PIC's knowledge, even given limitations presented by severe turbulence and increased flight deck workload. Two points of safety are noted by this PIC: 1) den TCA would be better predicated on den VORTAC to avoid necessity of continuous retuning of navigation equipment at times when the flight deck workload is highest. Less sophisticated aircraft and those not utilizing the den ILS are the most likely to require TCA avoidance. 2) in this PIC's judgement, TCA avoidance (or approach control contact) can be considered secondary to aircraft control and passenger safety in conditions of severe turbulence, though obviously such cannot be completely ignored.
Original NASA ASRS Text
Title: SMT PLT DESCENDED TO ARPT UNDERLYING TCA, ACCUSED OF PENETRATING TCA.
Narrative: A VFR FLT, BEING CONDUCTED UNDER FAR PART 91, WAS APCHING DENVER CENTENNIAL ARPT (APA) FROM THE SW. ATIS INDICATED VISUAL APCH TO RWY 35L/R IN USE. DSCNT WAS COMMENCED FROM 17500' MSL, 50 SW OF APA, PLANNING A FINAL APCH ALT OF 7500 MSL WITH A TARGET ALT OF 8000 MSL 20 SW OF DEN. AT APPROX 13000' MSL, 30 SW OF DEN, HDG 060 DEG MAGNETIC, IAS OF 200 KTS, SEVERE TURB WAS ENCOUNTERED (SIGMET FOR SUCH WAS CURRENT). THE ACFT WAS SLOWED TO DESIGN MANEUVERING SPD (155 KTS), TEMPORARILY STOPPING DSCNT. TO AVOID TCA CONFLICT A 30 DEG RIGHT TURN (TO 090 DEG MAGNETIC) WAS MADE. DME INFO FROM DEN VORTAC INDICATED POSITION OUTSIDE TCA. SEVERE TURB AND COCKPIT WORKLOAD PREVENTED RETUNING NAV RECEIVER TO 110.3 MHZ (DEN 26L ILS AND NAV FAC UPON WHICH TCA IS PREDICATED, APPROX 1 1/2 NM SSW OF DEN VORTAC), HOWEVER, VISUAL INFO INDICATED POSITION TO CONTINUE TO BE OUTSIDE OF TCA UNTIL 10000' MSL REACHED WHEN HDG 080 DEG MAGNETIC ASSUMED FOR 'WIDE LEFT BASE, OUTSIDE POWER LINES TO 35R' AS ADVISED BY APA TWR. (THESE POWER LINES ARE NOTED TO BE AT 16 DME TCA ARC ON DEN TCA CHART.) AT 8500' MSL, XING I25 (ROAD) AND S OF POWER LINES, CONTACT WITH APA TWR WAS MADE AS REQUESTED AND TURN TO FINAL COMMENCED. THE ACFT WAS SLOWED TO VLE SPD (140 KT) SLOWING DSCNT UNTIL TURN TO FINAL COMPLETED. VASI INDICATED PINK/WHITE, NECESSITATING SLIGHTLY INCREASED DSCNT RATE, UNTIL RED/WHITE OBTAINED AND THE LNDG COMPLETED. REQUEST WAS RECEIVED FROM APA TWR TO CONTACT DEN TRACON BY TELEPHONE. REQUEST COMPLIED WITH AND SUPVR OF DEN APCH ADVISED THAT AN ACFT APPROX OUR APCH PROFILE ENCROACHED DEN TCA IN 2 AREAS (SW CORNER AND S OF APA). DEN WAS ADVISED THAT OUR ACFT WAS CLEAR OF TCA AT ALL TIMES TO THE BEST OF PIC'S KNOWLEDGE, EVEN GIVEN LIMITATIONS PRESENTED BY SEVERE TURB AND INCREASED FLT DECK WORKLOAD. TWO POINTS OF SAFETY ARE NOTED BY THIS PIC: 1) DEN TCA WOULD BE BETTER PREDICATED ON DEN VORTAC TO AVOID NECESSITY OF CONTINUOUS RETUNING OF NAV EQUIPMENT AT TIMES WHEN THE FLT DECK WORKLOAD IS HIGHEST. LESS SOPHISTICATED ACFT AND THOSE NOT UTILIZING THE DEN ILS ARE THE MOST LIKELY TO REQUIRE TCA AVOIDANCE. 2) IN THIS PIC'S JUDGEMENT, TCA AVOIDANCE (OR APCH CTL CONTACT) CAN BE CONSIDERED SECONDARY TO ACFT CTL AND PAX SAFETY IN CONDITIONS OF SEVERE TURB, THOUGH OBVIOUSLY SUCH CANNOT BE COMPLETELY IGNORED.
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.