NASA nap · cockpit rest · Ames
A 26-minute NASA nap improved cockpit alertness.
You wanted the last hour to stay awake.
A NASA nap is a planned rest in the cockpit seat. The cockpit is the front of the plane where the pilots sit. Alertness is staying awake enough to fly. Mark Rosekind ran this work at NASA Ames, and volunteer airline pilots flew Boeing 747s over the Pacific. Keep the NASA nap name.
What is a NASA nap?
A NASA nap is a planned rest in the cockpit seat. NASA gave one pilot that rest while the other two people flew the plane. NASA scheduled 40 minutes in that seat and wanted the rest to end one hour before the plane started down.
You wanted the last hour to stay awake. Keep the rest seat.
What is a cockpit?
The cockpit is the front of the plane where the pilots sit. On these flights, three people sat up front. One person got the rest seat, and the other two kept the plane.
They flew Boeing 747s across the Pacific, a long trip over water, and the last hour was still ahead.
What is alertness?
Alertness is staying awake enough to fly. The last hour is when the plane comes down toward the airport. You wanted that hour to stay awake.
Did a NASA nap improve cockpit alertness?
Mark Rosekind and the Ames team published this memorandum in September 1994. NASA Ames Research Center in Moffett Field ran the work. The FAA, the United States aviation office, co-sponsored it. Northwest and United let the team ride with volunteer airline pilots. Those were regular pilots who already flew the long trips.
The title of the memorandum is “Crew Factors in Flight Operations IX: Effects of Planned Cockpit Rest on Crew Performance and Alertness in Long-Haul Operations.” It is NASA Technical Memorandum 108839. It also carries the number DOT/FAA/92/24. You can read the file at ntrs.nasa.gov/citations/19950006379.
Twenty-one pilots joined. Twelve got the rest seat, and nine kept working with no rest seat. They flew three-person Boeing 747s across the Pacific.
How long did the pilots sleep?
NASA scheduled 40 minutes in the rest seat. The sleep that landed was about 26 minutes. The team printed 25.78 minutes, with a spread of 9.58.
Pilots slept on 42 of 45 rest periods the team could read, which is 93 percent. A rest period is one scheduled rest. They took about 5.55 minutes to fall asleep, with a spread of 5.04. Sleep efficiency is the share of the rest seat that was actual sleep, and that share was 64.47 percent.
What is a long blink?
A long blink is when the eyes stay closed longer than five seconds, and the team also called that a microevent. They watched the last 90 minutes of the flight and counted those long blinks, because that window holds the last hour.
How many long blinks did rest pilots have?
Pilots in the rest seats had 34 long blinks in that last 90 minutes. Pilots in the no-rest seats had 120. Fifty percent of the rest pilots had at least one long blink, and 78 percent of the no-rest pilots had at least one.
The mean count was 2.90 for the rest seats and 6.37 for the no-rest seats. The team printed F(1,19)=6.44 and p=.02. A p value tells you how often a gap this big would show up if the groups were the same.
What is top of descent?
Top of descent is when the plane starts down toward the airport. The team counted all 34 rest-seat long blinks before top of descent.
What is a PVT?
A PVT is a reaction-time test that counts lapses. A lapse is a slow tap. In flight, the no-rest pilots had 124 lapses, and the rest pilots had 81. The nap did not move how sleepy the pilots said they felt.
What is REM?
REM is the dream stage of sleep, and pilots in the rest seat did not reach it on any rest period the team could read.
Did the nap erase the trip sleep debt?
By day nine, 18 of 21 pilots owed at least four hours of sleep. The worst debt was 22 hours, and the mean was about nine hours. The nap did not erase the trip debt.
You can still want a short rest to keep that hour awake, even when the pilots still owed sleep from the trip.
Is 26 minutes the ideal nap?
Sleep Foundation still sells 26 minutes as the ideal nap. That page is a neighbor from 6 July 2026. NASA scheduled 40 minutes, and the sleep that landed was about 26 minutes.
Rosekind also wrote a 1995 paper in the Journal of Sleep Research. That paper is a neighbor too.
If you feel unusual distress or you owe a lot of sleep, talk to a clinician, because this page is educational.
If you want the ASMR page, open the ASMR page.
Can you still want the last hour to stay awake?
You wanted the last hour to stay awake. Keep the NASA nap name.
NASA gave a 40-minute rest seat and the sleep that landed was about 26 minutes. Pilots in the rest seats had 34 long blinks in the last hour, and pilots who kept working had 120. You can still want the last hour to stay awake.
Sources
Rosekind M.R., Graeber R.C., Dinges D.F., Connell L.J., Rountree M.S., Spinweber C.L., Gillen K.A. “Crew Factors in Flight Operations IX: Effects of Planned Cockpit Rest on Crew Performance and Alertness in Long-Haul Operations.” NASA Technical Memorandum 108839, DOT/FAA/92/24, September 1994, NASA Ames Research Center, Moffett Field, FAA co-sponsored, Northwest and United field access, volunteer line pilots, n=21, rest 12, no-rest 9, B-747 three-person transpacific. Rest: 3 min prepare, 40 min seat, 20 min recovery, end 1 hr before descent. Slept on 42 of 45 readable rest doors (93 percent). Total sleep 25.78 min SD 9.58, sleep latency 5.55 SD 5.04, efficiency 64.47 percent, no REM on any rest door. Two-way last-90-min microevents greater than 5 sec: no-rest 120, rest 34, at least one event 78 percent no-rest, 50 percent rest, mean 6.37 vs 2.90, F(1,19)=6.44, p=.02, rest 34 all before top of descent, no-rest 98 before TOD, 22 through landing. Four of nine no-rest: slept on five control episodes, two over 10 min. PVT: in-flight no-rest 124 lapses vs rest 81. Subjective: nap did not move self-rated sleepiness. Day-nine: 18 of 21 owed at least 4 hours by day 9, worst 22, mean about 9, and the nap did not erase the trip debt. ntrs.nasa.gov/citations/19950006379 · NASA TM 108839 PDF
Rosekind 1995 Journal of Sleep Research neighbor. Compact 34 percent / 54 percent caption, and the memorandum itself does not print that pair. DOI 10.1111/j.1365-2869.1995.tb00229.x. doi.org/10.1111/j.1365-2869.1995.tb00229.x
Sleep Foundation 6 July 2026 neighbor still sells 26 minutes as the ideal nap. NASA scheduled 40. The 25.78 was what the rest seat produced. sleepfoundation.org/napping