Military pilot of an light transport descended off assigned altitude due to misunderstanding of ATC ...

Attributes
ACN	267823
Time
Date	199404
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : msy
State Reference	LA
Altitude	msl bound lower : 38000 msl bound upper : 39000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	other
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : other
Flight Phase	cruise other descent other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	government : military
Function	flight crew : captain oversight : pic
Qualification	pilot : military pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 140 flight time total : 6000 flight time type : 140
ASRS Report	267823
Person 2
Affiliation	government : military
Function	flight crew : first officer
Qualification	pilot : military
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : required legal separation non adherence : clearance
Independent Detector	atc equipment other atc equipment : unspecified other controllera other other : unspecified
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	faa : reviewed incident with flight crew Other
Miss Distance	horizontal : 12000 vertical : 1100
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While en route to knbg from kblv at FL390, I heard ZME ask if air carrier X could accept FL410. Air carrier stated 'negative.' I then asked ZME if it would help if I started down early. He stated I would have to turn or begin a descent. I again offered to begin a descent. ZME cleared me to descend to FL370 and advised I could expect lower in 6-7 mins. Passing FL381, ZME asked my altitude. I reported 38100 ft for FL370 as assigned. ZME stated I wasn't cleared to FL370 and to climb back up to FL390. I did so, air carrier X stated that I wasn't cleared to FL370. There was no danger of a midair as we both had each other in sight, but obviously there was a miscom. Upon reaching the ground I contacted ZME (ARTCC supervisor) and asked that an investigation be initiated. I spoke with ARTCC controller who advised me to call back for the results of an investigation.

Original NASA ASRS Text

Title: MIL PLT OF AN LTT DSNDED OFF ASSIGNED ALT DUE TO MISUNDERSTANDING OF ATC INSTRUCTIONS.

Narrative: WHILE ENRTE TO KNBG FROM KBLV AT FL390, I HEARD ZME ASK IF ACR X COULD ACCEPT FL410. ACR STATED 'NEGATIVE.' I THEN ASKED ZME IF IT WOULD HELP IF I STARTED DOWN EARLY. HE STATED I WOULD HAVE TO TURN OR BEGIN A DSCNT. I AGAIN OFFERED TO BEGIN A DSCNT. ZME CLRED ME TO DSND TO FL370 AND ADVISED I COULD EXPECT LOWER IN 6-7 MINS. PASSING FL381, ZME ASKED MY ALT. I RPTED 38100 FT FOR FL370 AS ASSIGNED. ZME STATED I WASN'T CLRED TO FL370 AND TO CLB BACK UP TO FL390. I DID SO, ACR X STATED THAT I WASN'T CLRED TO FL370. THERE WAS NO DANGER OF A MIDAIR AS WE BOTH HAD EACH OTHER IN SIGHT, BUT OBVIOUSLY THERE WAS A MISCOM. UPON REACHING THE GND I CONTACTED ZME (ARTCC SUPVR) AND ASKED THAT AN INVESTIGATION BE INITIATED. I SPOKE WITH ARTCC CTLR WHO ADVISED ME TO CALL BACK FOR THE RESULTS OF AN INVESTIGATION.

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.

Military pilot of an light transport descended off assigned altitude due to misunderstanding of ATC instructions.