|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||airport : bwi.airport|
|Altitude||msl single value : 16000|
|Controlling Facilities||artcc : zdc.artcc|
|Operator||common carrier : air carrier|
|Make Model Name||MD-80 Series (DC-9-80) Undifferentiated or Other Model|
|Operating Under FAR Part||Part 121|
|Navigation In Use||other|
|Route In Use||arrival star : ravnn|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Independent Detector||other flight crewa|
|Resolutory Action||none taken : anomaly accepted|
|Problem Areas||Flight Crew Human Performance|
Chart Or Publication
|Chart||star : ravnn|
This month (may 2007); I flew the ravnn one arrival into baltimore a total of 5 times on various trips. According to the chart; this arrival became effective on mar/xa/07. In my opinion; it is a poorly designed arrival. Normally; the instructions from the controller are to; 'descend via the ravnn one arrival;' at approximately csn. Here's why I believe it is poorly designed. Generally; the MD80 descends at about a 3 degree angle; at idle power with no wind. In other words; we descend about 300 ft per mi. The distances between the various intxns on the arrival barely allow this type of descent to make the altitude restrs. It has been working ok so far because summer winds are fairly light; and anti-icing equipment is not required; which allows idle thrust to be used. This winter; when tailwinds on the arrival are much stronger; and extra thrust is required to maintain sufficient heating for anti-icing system; there is no way the arrival will work. This is possibly the case even in the summer; if the controller needs a drastic speed reduction during one of the tight descent segments. The simplest way to fix the arrival would be to change all of the altitude restrs to 'at or above;' instead of just 'at;' as they are now. This 'at or above' logic is in use at many airports; and works very well. If traffic does not permit this kind of a change; then I would suggest spreading out the intxns so as to allow more space for the descent. For example; a pilot being asked to descend 2000 ft for hard altitude restrs; as in the case between fimbo and udude on this arrival; should be given a minimum of 8 mi to ensure compliance. 9 or 10 mi would be even better. Again; the current 6.5 mi barely works with summer WX and no speed restrs. I am making these suggestions now in the hopes of preventing my fellow pilots from having to file reports this winter. I am also hoping to prevent the inevitable headaches that ATC will have to endure when pilots start telling them; 'unable;' when asked to fly this arrival this winter.
Original NASA ASRS Text
Title: MD80 CAPTAIN REPORTS POTENTIAL PROBLEMS WITH THE NEW RAVNN 1 RNAV ARRIVAL TO BWI DURING WINTER OPERATIONS.
Narrative: THIS MONTH (MAY 2007); I FLEW THE RAVNN ONE ARR INTO BALTIMORE A TOTAL OF 5 TIMES ON VARIOUS TRIPS. ACCORDING TO THE CHART; THIS ARR BECAME EFFECTIVE ON MAR/XA/07. IN MY OPINION; IT IS A POORLY DESIGNED ARR. NORMALLY; THE INSTRUCTIONS FROM THE CTLR ARE TO; 'DSND VIA THE RAVNN ONE ARR;' AT APPROX CSN. HERE'S WHY I BELIEVE IT IS POORLY DESIGNED. GENERALLY; THE MD80 DSNDS AT ABOUT A 3 DEG ANGLE; AT IDLE PWR WITH NO WIND. IN OTHER WORDS; WE DSND ABOUT 300 FT PER MI. THE DISTANCES BTWN THE VARIOUS INTXNS ON THE ARR BARELY ALLOW THIS TYPE OF DSCNT TO MAKE THE ALT RESTRS. IT HAS BEEN WORKING OK SO FAR BECAUSE SUMMER WINDS ARE FAIRLY LIGHT; AND ANTI-ICING EQUIP IS NOT REQUIRED; WHICH ALLOWS IDLE THRUST TO BE USED. THIS WINTER; WHEN TAILWINDS ON THE ARR ARE MUCH STRONGER; AND EXTRA THRUST IS REQUIRED TO MAINTAIN SUFFICIENT HEATING FOR ANTI-ICING SYS; THERE IS NO WAY THE ARR WILL WORK. THIS IS POSSIBLY THE CASE EVEN IN THE SUMMER; IF THE CTLR NEEDS A DRASTIC SPD REDUCTION DURING ONE OF THE TIGHT DSCNT SEGMENTS. THE SIMPLEST WAY TO FIX THE ARR WOULD BE TO CHANGE ALL OF THE ALT RESTRS TO 'AT OR ABOVE;' INSTEAD OF JUST 'AT;' AS THEY ARE NOW. THIS 'AT OR ABOVE' LOGIC IS IN USE AT MANY ARPTS; AND WORKS VERY WELL. IF TFC DOES NOT PERMIT THIS KIND OF A CHANGE; THEN I WOULD SUGGEST SPREADING OUT THE INTXNS SO AS TO ALLOW MORE SPACE FOR THE DSCNT. FOR EXAMPLE; A PLT BEING ASKED TO DSND 2000 FT FOR HARD ALT RESTRS; AS IN THE CASE BTWN FIMBO AND UDUDE ON THIS ARR; SHOULD BE GIVEN A MINIMUM OF 8 MI TO ENSURE COMPLIANCE. 9 OR 10 MI WOULD BE EVEN BETTER. AGAIN; THE CURRENT 6.5 MI BARELY WORKS WITH SUMMER WX AND NO SPD RESTRS. I AM MAKING THESE SUGGESTIONS NOW IN THE HOPES OF PREVENTING MY FELLOW PLTS FROM HAVING TO FILE REPORTS THIS WINTER. I AM ALSO HOPING TO PREVENT THE INEVITABLE HEADACHES THAT ATC WILL HAVE TO ENDURE WHEN PLTS START TELLING THEM; 'UNABLE;' WHEN ASKED TO FLY THIS ARR THIS WINTER.
Data retrieved from NASA's ASRS site as of January 2009 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.