Air carrier lost navigational capability on a portion of overwater flight due to thunderstorm activi...

Attributes
ACN	118219
Time
Date	198907
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gls
State Reference	TX
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	instruction : instructor
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 9500 flight time type : 4200
ASRS Report	118219
Person 2
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 165 flight time total : 4200 flight time type : 1200
ASRS Report	118038
Events
Anomaly	inflight encounter : weather other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

En route between cancun, mexico and houston intercontinental on A-766, an ADF airway, we had to deviate to the west of course for a significant portion of our travel in the merida fir. We attempted to return to course the cozumel ADF, which is normally weak became unusable as did any other ADF due to thunderstorm activity behind us. Unable to receive any us NAVAID, we had to turn back to course and use flight plan winds to attempt to maintain that course. The first us navaids had not become usable when we reported barrow intersection to houston center. Within a few minutes, houston advised that we were nearly 55 mi west of barrow intersection and gave us vectors to avoid entering military airspace K-602, and to return toward course. Within minutes of the vectors, galveston ADF, scholes and beaumont vors were within range and for the first time we were able to confirm our position via NAVAID.

Original NASA ASRS Text

Title: ACR LOST NAVIGATIONAL CAPABILITY ON A PORTION OF OVERWATER FLT DUE TO TSTM ACTIVITY.

Narrative: ENRTE BETWEEN CANCUN, MEXICO AND HOUSTON INTERCONTINENTAL ON A-766, AN ADF AIRWAY, WE HAD TO DEVIATE TO THE WEST OF COURSE FOR A SIGNIFICANT PORTION OF OUR TRAVEL IN THE MERIDA FIR. WE ATTEMPTED TO RETURN TO COURSE THE COZUMEL ADF, WHICH IS NORMALLY WEAK BECAME UNUSABLE AS DID ANY OTHER ADF DUE TO TSTM ACTIVITY BEHIND US. UNABLE TO RECEIVE ANY U.S. NAVAID, WE HAD TO TURN BACK TO COURSE AND USE FLT PLAN WINDS TO ATTEMPT TO MAINTAIN THAT COURSE. THE FIRST U.S. NAVAIDS HAD NOT BECOME USABLE WHEN WE REPORTED BARROW INTXN TO HOUSTON CENTER. WITHIN A FEW MINUTES, HOUSTON ADVISED THAT WE WERE NEARLY 55 MI WEST OF BARROW INTXN AND GAVE US VECTORS TO AVOID ENTERING MIL AIRSPACE K-602, AND TO RETURN TOWARD COURSE. WITHIN MINUTES OF THE VECTORS, GALVESTON ADF, SCHOLES AND BEAUMONT VORS WERE WITHIN RANGE AND FOR THE FIRST TIME WE WERE ABLE TO CONFIRM OUR POSITION VIA NAVAID.

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.

Air carrier lost navigational capability on a portion of overwater flight due to thunderstorm activity.