Narrative:

This report is being written to address the issues occurring on a night VMC approach when the flaps failed to extend. The focus of the report is on the both the checklists and the crew communication at the time of the failure. TRACON coordination; [dispatch] coordination; flight attendant briefing; and a slats extended; no trailing edge flaps landing were all performed uneventfully. Maintenance coordination was also normal; and after further research; it was discovered that the cause of the issue was an issue with an electrical connector. A corresponding [incident report] was also filed in compliance with FAA and company policy. This was the end of a 4-day trip and the captain's leg. Flap extension was initiated approximately 15 miles on final. There was no flap movement. We noticed the flap indicators were split abnormally; but basically stuck at zero. The slats also did not move and there was no disagree light either. At that point; the captain decided to continue to fly and have the first officer (first officer) run the checklist. The first officer had been having issues with sa (situational awareness) most of the trip; and though he was equipped with a new bose headset; was not effective in his communication on the radio in normal situations. This influenced the captain's decision to have the first officer run the checklist instead of the desired technique of the tasks being delegated the other way around. The ATC environment was low threat; and we basically got a discreet controller and frequency and lots of airspace to work the problem. The captain felt this allowed the most interaction in the issue without sacrificing sa. The controls were exchanged a few times to allow the captain to brief the other players in the issue. The decision seemed to guide the crew to the correct outcome without increasing the potential risks noted above.choosing the correct checklist for a flap issue always presents a great challenge. I recall this being addressed in training; in the way many other things were.yes; the flap checklist series is one which makes you want to advocate public stoning for the author. So; in our case; we did have a trailing edge flaps disagree; in the sense of the handle and lack of movement when it is placed in flaps 1. And yes; there is a conditional on this about the indicator tips being less than one needle width. The assessment for use of this checklist is buried in a complex sentence; and; yes; I prefer rounded river rock for my throwing pleasure. (See; that was just a complex sentence which was disparate; but had relevant connection). Here is the actual condition: the flap position indicators disagree with the flap lever and any difference between the flap indicator needle tips is less than one needle width. If you simply ignore that and just start the checklist because it sounds like it fits; you get to decipher another complex sentence in step 1; which asks the same question backwards with an 'and/or' qualifier. Well; we didn't feel an uncommanded roll upon flap extension; and frankly; it's difficult to assess whether or not the needle split is simply normal for 1960's analog gauges; or there really was a split flap indication that maybe shut the system down. So; we actually held the checklist; looked it over and decided to see if it actually applied. Then; we looked at the trailing edge flaps asymmetry checklist; in case we could decipher the needle with and/or not roll. It seems that either checklist eventually guided us to trailing edge flaps up landing. We assessed that the purpose of these checklists was to see what exactly you could get to move; but not cause an asymmetry or make things worse. Yes; we read the buried caution about that too. Eventually; we went back to the trailing edge flaps disagree checklist and decided to activate the slats using the alternate flap extension system. The slats did come out; and the led lights indicated this. Then; we tried to get the flaps to 15 with alternate extension; monitoring for 'needle movement and/or roll'; but they didn't move. So; the handle didn't work; the alternate system didn't work on the flaps; so we could now move on to trailing edge flaps up landing. Inductive reasoning on this process would now indicate that the flap indicator was perhaps one or more needle widths apart; and this wasn't just like the tiller that had about an inch of play during taxi or many of the other 1960's things we tolerate about this plane that are really out of tolerance. So; we followed the asymmetry pathway on this checklist; and we completed it in its entirety. At this point; I probably should withdraw my public stoning comment as boeing eventually got us to the right place. Had I simply interpreted the 'and/or' in the complex sentence in truly trying to understand that a flap asymmetry is more than just uncommanded roll; but a measurement on analog needle width whose explanation is garnered outside of checklist steps; I would've been set free. Instead we were stuck; after a long day begging for memory of that time 3 and half years ago when my sim instructor explained how these checklists work. It still seems to me as if this entire process and problem definition is quite obtuse.I hope there will be consideration put forth to revise these checklists and their 'obtuse' conditions so that we may have a better chance of success without racking our brains and/or re-taking a systems class simply to understand what process we have to go through to land the airplane.

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Original NASA ASRS Text

Title: B737 flight crew reported that there was no flap movement when the flaps were commanded to flaps 1.

Narrative: This report is being written to address the issues occurring on a night VMC approach when the flaps failed to extend. The focus of the report is on the both the checklists and the crew communication at the time of the failure. TRACON coordination; [Dispatch] coordination; FA briefing; and a slats extended; no trailing edge flaps landing were all performed uneventfully. Maintenance coordination was also normal; and after further research; it was discovered that the cause of the issue was an issue with an electrical connector. A corresponding [incident report] was also filed in compliance with FAA and company policy. This was the end of a 4-day trip and the Captain's leg. Flap extension was initiated approximately 15 miles on final. There was no flap movement. We noticed the flap indicators were split abnormally; but basically stuck at zero. The slats also did not move and there was no disagree light either. At that point; the Captain decided to continue to fly and have the FO (First Officer) run the checklist. The FO had been having issues with SA (Situational Awareness) most of the trip; and though he was equipped with a new Bose headset; was not effective in his communication on the radio in normal situations. This influenced the Captain's decision to have the FO run the checklist instead of the desired technique of the tasks being delegated the other way around. The ATC environment was low threat; and we basically got a discreet controller and frequency and lots of airspace to work the problem. The Captain felt this allowed the most interaction in the issue without sacrificing SA. The controls were exchanged a few times to allow the Captain to brief the other players in the issue. The decision seemed to guide the crew to the correct outcome without increasing the potential risks noted above.Choosing the correct checklist for a flap issue always presents a great challenge. I recall this being addressed in training; in the way many other things were.Yes; the flap checklist series is one which makes you want to advocate public stoning for the author. So; in our case; we did have a TRAILING EDGE FLAPS DISAGREE; in the sense of the handle and lack of movement when it is placed in Flaps 1. And yes; there is a conditional on this about the indicator tips being less than one needle width. The assessment for use of this checklist is buried in a complex sentence; and; yes; I prefer rounded river rock for my throwing pleasure. (See; that was just a complex sentence which was disparate; but had relevant connection). Here is the actual condition: The flap position indicators disagree with the flap lever and any difference between the flap indicator needle tips is less than one needle width. If you simply ignore that and just start the checklist because it sounds like it fits; you get to decipher another complex sentence in step 1; which asks the same question backwards with an 'and/or' qualifier. Well; we didn't feel an uncommanded roll upon flap extension; and frankly; it's difficult to assess whether or not the needle split is simply normal for 1960's analog gauges; or there really was a split flap indication that maybe shut the system down. So; we actually held the checklist; looked it over and decided to see if it actually applied. Then; we looked at the TRAILING EDGE FLAPS ASYMMETRY checklist; in case we could decipher the needle with and/or not roll. It seems that either checklist eventually guided us to TRAILING EDGE FLAPS UP LANDING. We assessed that the purpose of these checklists was to see what exactly you could get to move; but not cause an asymmetry or make things worse. Yes; we read the buried caution about that too. Eventually; we went back to the TRAILING EDGE FLAPS DISAGREE checklist and decided to activate the slats using the alternate flap extension system. The slats did come out; and the LED lights indicated this. Then; we tried to get the flaps to 15 with alternate extension; monitoring for 'needle movement and/or roll'; but they didn't move. So; the handle didn't work; the alternate system didn't work on the flaps; so we could now move on to TRAILING EDGE FLAPS UP LANDING. Inductive reasoning on this process would now indicate that the flap indicator was perhaps one or more needle widths apart; and this wasn't just like the tiller that had about an inch of play during taxi or many of the other 1960's things we tolerate about this plane that are really out of tolerance. So; we followed the asymmetry pathway on this checklist; and we completed it in its entirety. At this point; I probably should withdraw my public stoning comment as Boeing eventually got us to the right place. Had I simply interpreted the 'and/or' in the complex sentence in truly trying to understand that a flap asymmetry is more than just uncommanded roll; but a measurement on analog needle width whose explanation is garnered outside of checklist steps; I would've been set free. Instead we were stuck; after a long day begging for memory of that time 3 and half years ago when my sim instructor explained how these checklists work. It still seems to me as if this entire process and problem definition is quite obtuse.I hope there will be consideration put forth to revise these checklists and their 'obtuse' conditions so that we may have a better chance of success without racking our brains and/or re-taking a systems class simply to understand what process we have to go through to land the airplane.

Data retrieved from NASA's ASRS site 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.