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|
Attributes | |
ACN | 1685988 |
Time | |
Date | 201909 |
Local Time Of Day | 1801-2400 |
Place | |
Locale Reference | RNO.Airport |
State Reference | NV |
Environment | |
Light | Night |
Aircraft 1 | |
Make Model Name | B737-800 |
Operating Under FAR Part | Part 121 |
Flight Phase | Initial Approach |
Flight Plan | IFR |
Person 1 | |
Function | Captain Pilot Flying |
Qualification | Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) |
Experience | Flight Crew Last 90 Days 431 Flight Crew Type 17560 |
Events | |
Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT Inflight Event / Encounter Weather / Turbulence |
Narrative:
I was the captain and pilot flying. We were flying the keeno 2 arrival; runway 16 transition; into rno. Contacting approach; we requested; and were given; the RNAV yankee to 16R. Initial winds reported by tower were calm. As our approach progressed; the controller next reported winds out of the north at nine knots. On final; he then reported gusting winds in excess of our tailwind limits. So we informed him we were initiating a go-around.we then received vectors for the ILS to runway 34L. We were on final with autopilot a coupled; localizer/GS captured; flaps 5 and airspeed approximately 170 kts. Suddenly (I believe at approximately 2;000 feet AGL) we received a terrain warning. This was somewhat surprising and confusing since we were visually aligned and; as mentioned; on the localizer/GS. Nonetheless; I initiated the terrain avoidance maneuver to ensure terrain separation; we informed ATC of the event and got vectors around for another approach to 34L. In discussing the situation with my first officer; the only plausible explanation I could imagine was the warning had been triggered based on our speed (and increased vvi) in the descent due to a 30 knot (or so) tailwind at altitude. Therefore; I explained I would slow and configure early on the next approach to hopefully preclude any additional GPWS warnings.we slowed and configured early; and again visual with the autopilot coupled and localizer/GS captured; we subsequently received a second terrain caution. Our fuel state at that time I believe was about 5.8.this gave us basically three options:1) go-around again and divert: in my mind; there would be at least two additive conditions resulting from such a decision. The first was; with a 2.2 burn to our alternate; in a best-case scenario we would be landing close to emergency fuel. In addition; there was significant weather between us and the divert station.2) go-around and attempt another approach: this scenario would have its own set of potential threats. What if the weather deteriorated further (e.g. Windshear; winds again out of limits; or any other unanticipated issue.)? Now we would be in a situation where divert was likely impossible and again approaching a critical fuel state.3) land. A timely decision was obviously required. And; in assessing and balancing the current risks; I believed the safest course of action was to land. We were properly using our automation resources; the approach was stable; our terrain situational awareness was high; and we both had a clear visual of the terrain and runway (including vasis). Said another way; it was my judgement (if another go-around was performed) there was a very real risk (based on current fuel state and unpredictability of the weather) of finding ourselves in an undesirable emergency fuel situation. And; with other potential threats coupled with increasingly limited options. I simply stated my desired intentions (without all the cerebral explanation) to my first officer and he expressed agreement. We continued to an uneventful landing.one final note for clarification: both myself and the first officer were unquestionably aware of company procedure to initiate a go-around any time a GPWS caution is received on approach at night or in IMC. I am personally aware as well; the only justification for deviating from any such procedure or other regulations would be under the purview of captain's emergency authority. That is exactly; in a sense; what I felt I was doing by electing to continue the approach under these circumstances. What made this for me a considerably precarious dilemma was the fact we had not declared an emergency and indeed were not (at least as yet) in an emergency situation.I realize to postulate that I was exercising emergency authority to preclude a reasonably high chance of becoming an emergency may indeed raise some legitimate questions. Nevertheless; this seemed to be a more tenable position than to intentionally continue down this risk-fraught pathto an emergency merely to be able to justify such a decision in the end. Certainly there may be others who could share some additional thoughts and considerations here. I am absolutely open to any recommendations which can enhance my capabilities to safely operate our aircraft. For now; however; I cannot personally think of what we should have done differently with respect to this decision. As delineated in the text; I believe we had three basic options. As best I was able; I tried to assess the risks and then balance those risks to achieve a safe outcome. In that regard; l honestly thought continuation to landing was the best option at that time and under those specific circumstances.
Original NASA ASRS Text
Title: B737 Captain reported an erroneous GPWS warning; resulting in a missed approach.
Narrative: I was the Captain and Pilot Flying. We were flying the KEENO 2 Arrival; Runway 16 transition; into RNO. Contacting Approach; we requested; and were given; the RNAV Yankee to 16R. Initial winds reported by Tower were calm. As our approach progressed; the Controller next reported winds out of the north at nine knots. On final; he then reported gusting winds in excess of our tailwind limits. So we informed him we were initiating a go-around.We then received vectors for the ILS to Runway 34L. We were on final with Autopilot A coupled; LOC/GS captured; Flaps 5 and airspeed approximately 170 kts. Suddenly (I believe at approximately 2;000 feet AGL) we received a terrain warning. This was somewhat surprising and confusing since we were visually aligned and; as mentioned; on the LOC/GS. Nonetheless; I initiated the terrain avoidance maneuver to ensure terrain separation; we informed ATC of the event and got vectors around for another approach to 34L. In discussing the situation with my F/O; the only plausible explanation I could imagine was the warning had been triggered based on our speed (and increased VVI) in the descent due to a 30 knot (or so) tailwind at altitude. Therefore; I explained I would slow and configure early on the next approach to hopefully preclude any additional GPWS warnings.We slowed and configured early; and again visual with the autopilot coupled and LOC/GS captured; we subsequently received a second terrain caution. Our fuel state at that time I believe was about 5.8.This gave us basically three options:1) Go-around again and divert: In my mind; there would be at least two additive conditions resulting from such a decision. The first was; with a 2.2 burn to our alternate; in a best-case scenario we would be landing close to emergency fuel. In addition; there was significant weather between us and the divert station.2) Go-around and attempt another approach: This scenario would have its own set of potential threats. What if the weather deteriorated further (e.g. windshear; winds again out of limits; or any other unanticipated issue.)? Now we would be in a situation where divert was likely impossible and again approaching a critical fuel state.3) Land. A timely decision was obviously required. And; in assessing and balancing the current risks; I believed the safest course of action was to land. We were properly using our automation resources; the approach was stable; our terrain situational awareness was high; and we both had a clear visual of the terrain and runway (including VASIs). Said another way; it was my judgement (if another go-around was performed) there was a very real risk (based on current fuel state and unpredictability of the weather) of finding ourselves in an undesirable emergency fuel situation. And; with other potential threats coupled with increasingly limited options. I simply stated my desired intentions (without all the cerebral explanation) to my First Officer and he expressed agreement. We continued to an uneventful landing.One final note for clarification: both myself and the First Officer were unquestionably aware of company procedure to initiate a go-around any time a GPWS Caution is received on approach at night or in IMC. I am personally aware as well; the only justification for deviating from any such procedure or other regulations would be under the purview of Captain's Emergency authority. That is exactly; in a sense; what I felt I was doing by electing to continue the approach under these circumstances. What made this for me a considerably precarious dilemma was the fact we had not declared an emergency and indeed were not (at least as yet) in an emergency situation.I realize to postulate that I was exercising emergency authority to preclude a reasonably high chance of becoming an emergency may indeed raise some legitimate questions. Nevertheless; this seemed to be a more tenable position than to intentionally continue down this risk-fraught pathto an emergency merely to be able to justify such a decision in the end. Certainly there may be others who could share some additional thoughts and considerations here. I am absolutely open to any recommendations which can enhance my capabilities to safely operate our aircraft. For now; however; I cannot personally think of what we should have done differently with respect to this decision. As delineated in the text; I believe we had three basic options. As best I was able; I tried to assess the risks and then balance those risks to achieve a safe outcome. In that regard; l honestly thought continuation to landing was the best option at that time and under those specific circumstances.
Data retrieved from NASA's ASRS site 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.