Clearance interpretation, 10000 ft for 11000 ft. Altitude deviation altitude overshot.

Attributes
ACN	233751
Time
Date	199302
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lga
State Reference	NY
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute airway : zny
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 75 flight time total : 10000 flight time type : 2000
ASRS Report	233751
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time total : 16000
ASRS Report	233872
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We had a crossing altitude at jibes, and we had FMS problems that caused confusion on this fix. The controller vectored us off course to avoid this problem. The next clearance was conditional (descend to 10000 ft, out of a certain altitude, turn right, intercept to arrival, contact approach control on frequency XXXX, we were at 10000 ft several mins and approach asked us what altitude we were at. Then he told us to climb to 11000 ft, we did. I do not know if we misunderstood the clearance or not. But we did what we thought our clearance was. I believe the list below would help correct problems like this: 1) stop conditional clrncs. 2) stop extremely complex clrncs. 3) separate frequency changes from clrncs. 4) stop the requirement to wear headsets. They may help to NTSB but they interfere with our job performance. We only have earphones on 1 ear and speakers off, so if you have any hearing loss you may be missing something. When speakers were used you had a stereo effect. Supplemental information from acn 233872: I believe that voice communication is the weakest link in the aviation safety chain. I also believe that a third crew member would reduce communication errors. I don't think that headsets are any improvement over speakers. I also think that headsets can damage hearing due to momentary high volume settings that sometimes occur at frequency changes.

Original NASA ASRS Text

Title: CLRNC INTERP, 10000 FT FOR 11000 FT. ALTDEV ALT OVERSHOT.

Narrative: WE HAD A XING ALT AT JIBES, AND WE HAD FMS PROBS THAT CAUSED CONFUSION ON THIS FIX. THE CTLR VECTORED US OFF COURSE TO AVOID THIS PROB. THE NEXT CLRNC WAS CONDITIONAL (DSND TO 10000 FT, OUT OF A CERTAIN ALT, TURN R, INTERCEPT TO ARR, CONTACT APCH CTL ON FREQ XXXX, WE WERE AT 10000 FT SEVERAL MINS AND APCH ASKED US WHAT ALT WE WERE AT. THEN HE TOLD US TO CLB TO 11000 FT, WE DID. I DO NOT KNOW IF WE MISUNDERSTOOD THE CLRNC OR NOT. BUT WE DID WHAT WE THOUGHT OUR CLRNC WAS. I BELIEVE THE LIST BELOW WOULD HELP CORRECT PROBS LIKE THIS: 1) STOP CONDITIONAL CLRNCS. 2) STOP EXTREMELY COMPLEX CLRNCS. 3) SEPARATE FREQ CHANGES FROM CLRNCS. 4) STOP THE REQUIREMENT TO WEAR HEADSETS. THEY MAY HELP TO NTSB BUT THEY INTERFERE WITH OUR JOB PERFORMANCE. WE ONLY HAVE EARPHONES ON 1 EAR AND SPEAKERS OFF, SO IF YOU HAVE ANY HEARING LOSS YOU MAY BE MISSING SOMETHING. WHEN SPEAKERS WERE USED YOU HAD A STEREO EFFECT. SUPPLEMENTAL INFO FROM ACN 233872: I BELIEVE THAT VOICE COM IS THE WEAKEST LINK IN THE AVIATION SAFETY CHAIN. I ALSO BELIEVE THAT A THIRD CREW MEMBER WOULD REDUCE COM ERRORS. I DON'T THINK THAT HEADSETS ARE ANY IMPROVEMENT OVER SPEAKERS. I ALSO THINK THAT HEADSETS CAN DAMAGE HEARING DUE TO MOMENTARY HIGH VOLUME SETTINGS THAT SOMETIMES OCCUR AT FREQ CHANGES.

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.