Narrative:

I was the pilot flying (PF) and we were given a descent to FL290 out of FL390. At FL300 the pilot monitoring (pm) asked if he wanted me to re-cruise us at FL290. I said yes. He re-cruised us to FL290 as we continued the descent. Shortly thereafter; washington center gave us a crossing restriction to be at FL240 35 miles south of riccs. I reached up to set 240 in the MCP window; but since we had not reached FL290; I changed my mind and reprogrammed the FMC.while trying to reprogram the FMC; I could not get it to accept FL240 at 35S of riccs. It kept giving me a constraint error. I asked the pm why that was going on and we both focused on the FMC. Once the plane leveled at FL290; the FMC would accept the FL240 entry. I verbalized and confirmed that we were in LNAV and VNAV and that 35 south of riccs was loaded in the FMS at FL240. However; I never went back and verified that I had selected FL240 in the MCP window. There were only a couple of miles before the descent was to begin. I noticed we had received a message on the FMC to reset the altitude and realized my mistake. By this time; we were high; and I initiated a vertical speed (vs) descent with speedbrakes at a faster airspeed. Just as we were beginning the descent; washington center called and asked if we were given a crossing restriction. We leveled at FL240 at approximately 32 miles south of riccs.I should have immediately set the altitude in the MCP window; which would have protected us. My reaching up to set the window probably threw off the pm and then my confusion on why the FMC would not except my inputs lead me down a rabbit hole that distracted me. I failed to properly follow the input and verify procedures and had I; I would have caught my mistake.

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Original NASA ASRS Text

Title: An air carrier crew was cleared to cross a point at FL240 and after programming the FMC became distracted in conversation. Consequently; they failed to set the MCP altitude and crossed the fix high.

Narrative: I was the pilot flying (PF) and we were given a descent to FL290 out of FL390. At FL300 the pilot monitoring (PM) asked if he wanted me to re-cruise us at FL290. I said yes. He re-cruised us to FL290 as we continued the descent. Shortly thereafter; Washington Center gave us a crossing restriction to be at FL240 35 miles south of RICCS. I reached up to set 240 in the MCP window; but since we had not reached FL290; I changed my mind and reprogrammed the FMC.While trying to reprogram the FMC; I could not get it to accept FL240 at 35S of RICCS. It kept giving me a constraint error. I asked the PM why that was going on and we both focused on the FMC. Once the plane leveled at FL290; the FMC would accept the FL240 entry. I verbalized and confirmed that we were in LNAV and VNAV and that 35 south of RICCS was loaded in the FMS at FL240. However; I never went back and verified that I had selected FL240 in the MCP window. There were only a couple of miles before the descent was to begin. I noticed we had received a message on the FMC to reset the altitude and realized my mistake. By this time; we were high; and I initiated a vertical speed (VS) descent with speedbrakes at a faster airspeed. Just as we were beginning the descent; Washington Center called and asked if we were given a crossing restriction. We leveled at FL240 at approximately 32 miles south of RICCS.I should have immediately set the altitude in the MCP window; which would have protected us. My reaching up to set the window probably threw off the PM and then my confusion on why the FMC would not except my inputs lead me down a rabbit hole that distracted me. I failed to properly follow the input and verify procedures and had I; I would have caught my mistake.

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.