<< >> NASA ASRS Report 540197, March 2002

A DC9 crew at FL350 is assigned FL340 and questions the controller as to the legality of the non standard altitude.

Attributes
ACN	540197
Time
Date	200203
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : alo.vortac
State Reference	IA
Altitude	msl bound lower : 32000 msl bound upper : 34000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zmp.artcc
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 95 flight time total : 6000 flight time type : 25000
ASRS Report	540197
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : published procedure non adherence other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance controller : separated traffic
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance

Narrative:

At XA15Z, we were at cruise (FL350) from ord to msp and under control of ZMP (frequency 134.25). The controller gave us a heading of 330 degrees (or something close to that). So we flew northeast of the alo VOR towards msp. The vectors were for spacing into msp. At approximately XA57Z, the controller told us to descend to FL340. I asked the controller if that was a legal altitude and the response was something like 'expect a lower altitude after you descend' followed by 'you have traffic and you would have to turn 40 degrees to the left.' I responded saying we would take the turn. We turned as assigned then soon after, the controller gave us a descent to FL320. I concluded that we needed to descend to resolve some conflict and did begin to descend. The controller then assigned us FL330 or FL310 which were normal altitudes in the airspace structure. This made us feel a little more comfortable, and the rest of the flight went normally. The focus of this report is more on my reaction to altitude assignments of FL340 and FL320, which, in over 30 yrs of flying, I understood not to be legal or usable altitudes. We were very uncomfortable with the unusual altitude clrncs.

Related reports:

• ARTCC radar controller questions the assigned altitude.
• ZKC controller questions DC9 flight crew about assigned turn...
• Air carrier questions whether they were not at their assigne...
• ZDC controller questions B732 flight crew's assigned altitud...
• ARTCC controller questions descent when awareness of the act...

	Enter your search terms Submit search form
	Web www.37000feet.com

Original NASA ASRS Text

Title: A DC9 CREW AT FL350 IS ASSIGNED FL340 AND QUESTIONS THE CTLR AS TO THE LEGALITY OF THE NON STANDARD ALT.

Narrative: AT XA15Z, WE WERE AT CRUISE (FL350) FROM ORD TO MSP AND UNDER CTL OF ZMP (FREQ 134.25). THE CTLR GAVE US A HEADING OF 330 DEGS (OR SOMETHING CLOSE TO THAT). SO WE FLEW NE OF THE ALO VOR TOWARDS MSP. THE VECTORS WERE FOR SPACING INTO MSP. AT APPROX XA57Z, THE CTLR TOLD US TO DSND TO FL340. I ASKED THE CTLR IF THAT WAS A LEGAL ALT AND THE RESPONSE WAS SOMETHING LIKE 'EXPECT A LOWER ALT AFTER YOU DSND' FOLLOWED BY 'YOU HAVE TFC AND YOU WOULD HAVE TO TURN 40 DEGS TO THE L.' I RESPONDED SAYING WE WOULD TAKE THE TURN. WE TURNED AS ASSIGNED THEN SOON AFTER, THE CTLR GAVE US A DSCNT TO FL320. I CONCLUDED THAT WE NEEDED TO DSND TO RESOLVE SOME CONFLICT AND DID BEGIN TO DSND. THE CTLR THEN ASSIGNED US FL330 OR FL310 WHICH WERE NORMAL ALTS IN THE AIRSPACE STRUCTURE. THIS MADE US FEEL A LITTLE MORE COMFORTABLE, AND THE REST OF THE FLT WENT NORMALLY. THE FOCUS OF THIS RPT IS MORE ON MY REACTION TO ALT ASSIGNMENTS OF FL340 AND FL320, WHICH, IN OVER 30 YRS OF FLYING, I UNDERSTOOD NOT TO BE LEGAL OR USABLE ALTS. WE WERE VERY UNCOMFORTABLE WITH THE UNUSUAL ALT CLRNCS.

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.