 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
LJ55 encounter temperature inversion at FL430 in ZNY airspace en route to bermuda, attempt descent clearance with comrdo and ZNY, but descend to FL425 until fuel burnoff allowed climb back to FL430.
| Attributes | |
| ACN | 573552 |
| Time | |
| Date | 200302 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | intersection : retta |
| State Reference | US |
| Altitude | msl bound lower : 43000 msl bound upper : 42500 |
| Environment | |
| Flight Conditions | VMC |
| Weather Elements | Turbulence |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : charter |
| Make Model Name | Learjet 55 |
| Operating Under FAR Part | Part 135 |
| Navigation In Use | other |
| Flight Phase | cruise : level |
| Route In Use | enroute : atlantic |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : charter |
| Function | flight crew : captain |
| Qualification | pilot : atp pilot : cfi |
| Experience | flight time last 90 days : 150 flight time total : 8900 flight time type : 1100 |
| ASRS Report | 573552 |
| Person 2 | |
| Affiliation | company : charter |
| Function | flight crew : first officer |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude inflight encounter : weather inflight encounter other non adherence : clearance other anomaly |
| Independent Detector | other flight crewa |
| Resolutory Action | controller : issued new clearance flight crew : returned to assigned altitude flight crew : exited adverse environment flight crew : regained aircraft control |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance Weather Environmental Factor Aircraft |
| Primary Problem | Weather |
Narrative:
ZNY ATC told us that we had to be leveled off at FL430 by retta intersection, which we did make, but the temperature of the atmosphere was increasing which was noted, and the increase in temperature prevented us from maintaining FL430. So I made the decision to decrease altitude to FL425 which the aircraft was able to do. As time went on and the aircraft became lighter and lighter from the fuel being burned, we went back up to FL430, which was about 25 mins after we initially descended to FL425. We tried to get a call on frequency 8846 kilohertz, but the static was so bad, I am not sure the controller even heard us. We also tried the backup frequency of 11330 kilohertz and VHF 129.90, but nothing. We were in VFR conditions the entire time and were looking for other aircraft. The fact that the temperature was higher than I came up with on the preflight planning was the reason the loss of performance of the aircraft. My options were very limited. I couldn't hold altitude. I didn't want to make any turns, and I did make sure I stayed out of rvsm airspace. My decision was to try 100 ft increments of lower altitude and we held altitude at FL425. The ZNY controllers did inform us they moved aircraft out of our way when they saw us descending later on when we talked to them on 128.50 going into bermuda.
Original NASA ASRS Text
Title: LJ55 ENCOUNTER TEMP INVERSION AT FL430 IN ZNY AIRSPACE ENRTE TO BERMUDA, ATTEMPT DSCNT CLRNC WITH COMRDO AND ZNY, BUT DSND TO FL425 UNTIL FUEL BURNOFF ALLOWED CLB BACK TO FL430.
Narrative: ZNY ATC TOLD US THAT WE HAD TO BE LEVELED OFF AT FL430 BY RETTA INTXN, WHICH WE DID MAKE, BUT THE TEMP OF THE ATMOSPHERE WAS INCREASING WHICH WAS NOTED, AND THE INCREASE IN TEMP PREVENTED US FROM MAINTAINING FL430. SO I MADE THE DECISION TO DECREASE ALT TO FL425 WHICH THE ACFT WAS ABLE TO DO. AS TIME WENT ON AND THE ACFT BECAME LIGHTER AND LIGHTER FROM THE FUEL BEING BURNED, WE WENT BACK UP TO FL430, WHICH WAS ABOUT 25 MINS AFTER WE INITIALLY DSNDED TO FL425. WE TRIED TO GET A CALL ON FREQ 8846 KILOHERTZ, BUT THE STATIC WAS SO BAD, I AM NOT SURE THE CTLR EVEN HEARD US. WE ALSO TRIED THE BACKUP FREQ OF 11330 KILOHERTZ AND VHF 129.90, BUT NOTHING. WE WERE IN VFR CONDITIONS THE ENTIRE TIME AND WERE LOOKING FOR OTHER ACFT. THE FACT THAT THE TEMP WAS HIGHER THAN I CAME UP WITH ON THE PREFLT PLANNING WAS THE REASON THE LOSS OF PERFORMANCE OF THE ACFT. MY OPTIONS WERE VERY LIMITED. I COULDN'T HOLD ALT. I DIDN'T WANT TO MAKE ANY TURNS, AND I DID MAKE SURE I STAYED OUT OF RVSM AIRSPACE. MY DECISION WAS TO TRY 100 FT INCREMENTS OF LOWER ALT AND WE HELD ALT AT FL425. THE ZNY CTLRS DID INFORM US THEY MOVED ACFT OUT OF OUR WAY WHEN THEY SAW US DSNDING LATER ON WHEN WE TALKED TO THEM ON 128.50 GOING INTO BERMUDA.
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.