Narrative:

Power back taxi from gate incident in which left main gear rolled from hard surface taxiway onto soft ground and settled. No damage to aircraft or injury to passenger or crew. However, settling of left main gear precluded aircraft from continuing taxi under its own power. Aircraft was then deplaned, defueled partially and subsequently towed back to hard surface. For the flight crew, a power back is a blind reverse taxi maneuver during which directional guidance comes exclusively from a ground marshaller. This incident resulted from the marshaller's use of confusing and nonstandard signals and the captain's failure to immediately stop aircraft's rearward movement when confusion became apparent. During the pwrback the flight attendants were standing performing the safety demonstration and for this reason the captain would want any directional transition of the aircraft to be very smooth. Were it standard procedure to have the flight attendants seated during power backs the captain might have more expeditiously stopped aircraft's rearward movement allowing aircraft to remain on hard surface. Recommendation: while I would emphatically not favor any FAA prohibition of reverse taxi operations I would recommend to any individual airline operator that this practice be discontinued because of the inherent problems associated with any blind maneuver.

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Original NASA ASRS Text

Title: MLG TAXIES INTO THE MUD DURING A PWRBACK FROM THE GATE.

Narrative: PWR BACK TAXI FROM GATE INCIDENT IN WHICH L MAIN GEAR ROLLED FROM HARD SURFACE TXWY ONTO SOFT GND AND SETTLED. NO DAMAGE TO ACFT OR INJURY TO PAX OR CREW. HOWEVER, SETTLING OF L MAIN GEAR PRECLUDED ACFT FROM CONTINUING TAXI UNDER ITS OWN PWR. ACFT WAS THEN DEPLANED, DEFUELED PARTIALLY AND SUBSEQUENTLY TOWED BACK TO HARD SURFACE. FOR THE FLC, A PWR BACK IS A BLIND REVERSE TAXI MANEUVER DURING WHICH DIRECTIONAL GUIDANCE COMES EXCLUSIVELY FROM A GND MARSHALLER. THIS INCIDENT RESULTED FROM THE MARSHALLER'S USE OF CONFUSING AND NONSTANDARD SIGNALS AND THE CAPT'S FAILURE TO IMMEDIATELY STOP ACFT'S REARWARD MOVEMENT WHEN CONFUSION BECAME APPARENT. DURING THE PWRBACK THE FLT ATTENDANTS WERE STANDING PERFORMING THE SAFETY DEMONSTRATION AND FOR THIS REASON THE CAPT WOULD WANT ANY DIRECTIONAL TRANSITION OF THE ACFT TO BE VERY SMOOTH. WERE IT STANDARD PROC TO HAVE THE FLT ATTENDANTS SEATED DURING PWR BACKS THE CAPT MIGHT HAVE MORE EXPEDITIOUSLY STOPPED ACFT'S REARWARD MOVEMENT ALLOWING ACFT TO REMAIN ON HARD SURFACE. RECOMMENDATION: WHILE I WOULD EMPHATICALLY NOT FAVOR ANY FAA PROHIBITION OF REVERSE TAXI OPS I WOULD RECOMMEND TO ANY INDIVIDUAL AIRLINE OPERATOR THAT THIS PRACTICE BE DISCONTINUED BECAUSE OF THE INHERENT PROBS ASSOCIATED WITH ANY BLIND MANEUVER.

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.