Altitude crossing restriction not complied with.

Attributes
ACN	176470
Time
Date	199104
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pmo
State Reference	CA
Altitude	msl bound lower : 13600 msl bound upper : 14000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	other
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Navigation In Use	Other
Flight Phase	descent other
Route In Use	departure sid : sid enroute airway : v137
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 40 flight time total : 3500 flight time type : 5
ASRS Report	176470
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	altitude deviation : crossing restriction not met non adherence : clearance
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During a sales demonstration flight with one prospective customer occupying the coplts seat and operating in VMC conditions on an IFR flight plan, center cleared our flight to destination airport via a published SID routing with a later clearance to descend to 14000' by fix 'X'. Our flight was later handed off to another controller who apparently cleared us to cross fix 'X' at 14000' and then to descend further to 13000'. The clearance was understood as a clearance to descend to 13000' but to be at or below 14000' at fix 'X'. About 5 NM short of fix 'X' and at approximately 13600' and descending the controller informed us that we should be at 14000' until fix 'X'. An immediate climb was initiated to 14000' until passing fix 'X'. During this time the potential customer was asking numerous detail questions which added to pilot workload and possible confusion. Also the practice of clearing an aircraft to an altitude with a hard altitude (intermediate) should be reviewed. A separate and unique lower altitude clearance once the aircraft had passed the subject fix would eliminate the possibility of this type of confusion. The responsibility of safely and accurately flying the aircraft is more important than any other distraction or duty. Fly first!

Original NASA ASRS Text

Title: ALT CROSSING RESTRICTION NOT COMPLIED WITH.

Narrative: DURING A SALES DEMONSTRATION FLT WITH ONE PROSPECTIVE CUSTOMER OCCUPYING THE COPLTS SEAT AND OPERATING IN VMC CONDITIONS ON AN IFR FLT PLAN, CTR CLRED OUR FLT TO DEST ARPT VIA A PUBLISHED SID RTING WITH A LATER CLRNC TO DSND TO 14000' BY FIX 'X'. OUR FLT WAS LATER HANDED OFF TO ANOTHER CTLR WHO APPARENTLY CLRED US TO CROSS FIX 'X' AT 14000' AND THEN TO DSND FURTHER TO 13000'. THE CLRNC WAS UNDERSTOOD AS A CLRNC TO DSND TO 13000' BUT TO BE AT OR BELOW 14000' AT FIX 'X'. ABOUT 5 NM SHORT OF FIX 'X' AND AT APPROX 13600' AND DSNDING THE CTLR INFORMED US THAT WE SHOULD BE AT 14000' UNTIL FIX 'X'. AN IMMEDIATE CLB WAS INITIATED TO 14000' UNTIL PASSING FIX 'X'. DURING THIS TIME THE POTENTIAL CUSTOMER WAS ASKING NUMEROUS DETAIL QUESTIONS WHICH ADDED TO PLT WORKLOAD AND POSSIBLE CONFUSION. ALSO THE PRACTICE OF CLRING AN ACFT TO AN ALT WITH A HARD ALT (INTERMEDIATE) SHOULD BE REVIEWED. A SEPARATE AND UNIQUE LOWER ALT CLRNC ONCE THE ACFT HAD PASSED THE SUBJECT FIX WOULD ELIMINATE THE POSSIBILITY OF THIS TYPE OF CONFUSION. THE RESPONSIBILITY OF SAFELY AND ACCURATELY FLYING THE ACFT IS MORE IMPORTANT THAN ANY OTHER DISTR OR DUTY. FLY FIRST!

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.