Narrative:

While still in the low-speed regime during takeoff on runway xx at ZZZZ; I suddenly smelled a strong acrid odor that I perceived to be associated with an electrical short or fire. Because there was no annunciation of an electrical fault or fire; I continued the takeoff roll for approximately 2-3 additional seconds. The odor did not abate and grew stronger; but I did not hear warning chimes or see any EICAS annunciations. Nonetheless; I elected to abort the takeoff well before reaching 80 kts. Because the abort was initiated in the low-speed regime; we were easily able to stop and exit the runway at taxiway xx.at no time was there a fire annunciation. Accordingly; I did not declare an emergency. By the time we exited the runway; however; we were below minimum fuel. I communicated the issue to ATC; confirmed that I was not declaring an emergency; and received instructions to return to the gate.upon our return to the gate; I communicated the status of our flight to the passengers; conferred with the station personnel regarding possible options for accommodating the passengers; and then initiated contact with dispatch; maintenance control; and [operations control].when I received guidance from [operations control] that the flight was cancelled/delayed until the following day; I coordinated with station personnel to get the passengers off the aircraft. I then met with contract maintenance personnel and confirmed that the required aircraft inspection would have to wait until the following morning. Upon delivering this information to [operations control]; I shut down the aircraft; and the crew went to the assigned hotel for rest in accordance with instructions from [operations control] and crew scheduling. Because I was ultimately released from duty the next morning; I have had no further interaction with the aircraft or any further discussion with any company personnel regarding this matter.the potentially relevant events before the aborted takeoff are worthy of discussion and consideration in reviewing this event. A winter storm had begun on ZZZZ earlier in the afternoon. By the time we blocked out; the visibility was 1-1/2 SM and forecast to drop. There were several inches of snow covering all runways and taxiways. Pilot reports were calling the braking action on runway xx fair to moderate.during our turn; the snow immediately began adhering to the aircraft. By the time we blocked out; there was a substantial amount of snow on all critical surfaces. Accordingly; deicing - type I - and anti-ice - type iv - applications were necessary.because the entire operation of the flight; including taxi; was conducted in icing conditions; a two-engine taxi was required. The queue for deicing was quite long and the time from deice to takeoff was approximately 15 minutes. As a result; we were within a couple hundred lbs. Of minimum fuel when we commenced the takeoff roll. Accordingly; once the abort was complete; return to the gate was required because of the fuel state.like all aborted takeoff decisions; my decision to abort this takeoff had to be made quickly; which; by definition; is without time to make a full and detailed evaluation of all the possibly relevant facts. I think that in this instance; I made the correct and safest decision.because we were performing a 'T/O' power takeoff; I stood up the power while holding the brakes. The acrid smell did not become evident until 2-3 seconds into the takeoff roll. I hesitated an additional 2-3 seconds after first perceiving the smell to determine whether I was certain in my perception that it smelled like an electrical short or fire before initiating the abort. During that period; the smell not only did not abate; it grew stronger.during the moment I had to make the abort decision; I weighed my perception of something burning; the lack of an annunciated problem; the overall weather conditions and how they may impact an emergency return; and the runway/brakingconditions. I concluded that any further delay in aborting the takeoff waiting for an annunciated confirmation of what I was smelling may well put us in the position of a high-speed abort on a snow-covered runway with fair to moderate braking action. Further; because the weather was bad and worsening; I thought about the challenge/possibility of having to make an emergency return to ZZZZ and the risk that would pose. I elected to abort the takeoff and investigate the matter on the ground.I was aware at the time of the possibility of odors in the cockpit and cabin from deicing. However; I waited longer than the required period before turning the bleeds and packs back on after the last de-icing application. Further; more than ten minutes elapsed after turning the bleeds and packs back on and commencing the takeoff. During that time; there were no odors in the cockpit or cabin associated with restoring the bleeds and packs. During my career; I have smelled the results of early restoration of bleeds and packs after de-icing. I would describe the smell as 'sweet or syrupy.' the odor that led to my decision to abort was decidedly acrid like an electrical short/fire. The difference in this odor was why I did not attribute the smell to ingested de-ice fluid. Moreover; the first officer and the flight attendant smelled the same thing and characterized the smell similarly. Because of the combination of these considerations; I elected to abort the takeoff before continued acceleration on the takeoff roll constrained the safe responses to what I perceived to be a potentially growing threat.an additional item to note in the review of this incident is to note what the first officer saw and perceived. Upon debriefing the incident with the first officer; not only did he confirm that he perceived the same odor that I did; but that simultaneously with hearing me call for the 'abort;' he saw the master warning flash and instantly pushed the button to cancel it thinking that it was the annunciation flash that caused me to call for the abort. However; upon scrolling through the mfd (multi-function flight display) maintenance page; there was no electronic record of a fault annunciation.finally; the first officer and flight attendant carried out their duties in commendable fashion and in accordance with SOP. The crew coordination was excellent and led to a safe and orderly resolution of the incident and the conclusion of the flight.accordingly; although ambiguity remains regarding the factual premise for making the decision to abort the takeoff; absent some objective forensic data that would not only resolve that ambiguity but would be ascertainable in the moment of decision; I would make the same decision again if presented with the same scenario.

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Original NASA ASRS Text

Title: EMB-145 Captain reported smelling a burning odor during the takeoff roll; resulting in a rejected takeoff.

Narrative: While still in the low-speed regime during takeoff on Runway XX at ZZZZ; I suddenly smelled a strong acrid odor that I perceived to be associated with an electrical short or fire. Because there was no annunciation of an electrical fault or fire; I continued the takeoff roll for approximately 2-3 additional seconds. The odor did not abate and grew stronger; but I did not hear warning chimes or see any EICAS annunciations. Nonetheless; I elected to abort the takeoff well before reaching 80 kts. Because the abort was initiated in the low-speed regime; we were easily able to stop and exit the runway at Taxiway XX.At no time was there a fire annunciation. Accordingly; I did not declare an emergency. By the time we exited the runway; however; we were below minimum fuel. I communicated the issue to ATC; confirmed that I was not declaring an emergency; and received instructions to return to the gate.Upon our return to the gate; I communicated the status of our flight to the passengers; conferred with the station personnel regarding possible options for accommodating the passengers; and then initiated contact with Dispatch; Maintenance Control; and [Operations Control].When I received guidance from [Operations Control] that the flight was cancelled/delayed until the following day; I coordinated with Station Personnel to get the passengers off the aircraft. I then met with Contract Maintenance Personnel and confirmed that the required aircraft inspection would have to wait until the following morning. Upon delivering this information to [Operations Control]; I shut down the aircraft; and the crew went to the assigned hotel for rest in accordance with instructions from [Operations Control] and Crew Scheduling. Because I was ultimately released from duty the next morning; I have had no further interaction with the aircraft or any further discussion with any company personnel regarding this matter.The potentially relevant events before the aborted takeoff are worthy of discussion and consideration in reviewing this event. A winter storm had begun on ZZZZ earlier in the afternoon. By the time we blocked out; the visibility was 1-1/2 SM and forecast to drop. There were several inches of snow covering all runways and taxiways. Pilot reports were calling the braking action on Runway XX fair to moderate.During our turn; the snow immediately began adhering to the aircraft. By the time we blocked out; there was a substantial amount of snow on all critical surfaces. Accordingly; deicing - Type I - and anti-ice - Type IV - applications were necessary.Because the entire operation of the flight; including taxi; was conducted in icing conditions; a two-engine taxi was required. The queue for deicing was quite long and the time from deice to takeoff was approximately 15 minutes. As a result; we were within a couple hundred lbs. of minimum fuel when we commenced the takeoff roll. Accordingly; once the abort was complete; return to the gate was required because of the fuel state.Like all aborted takeoff decisions; my decision to abort this takeoff had to be made quickly; which; by definition; is without time to make a full and detailed evaluation of all the possibly relevant facts. I think that in this instance; I made the correct and safest decision.Because we were performing a 'T/O' power takeoff; I stood up the power while holding the brakes. The acrid smell did not become evident until 2-3 seconds into the takeoff roll. I hesitated an additional 2-3 seconds after first perceiving the smell to determine whether I was certain in my perception that it smelled like an electrical short or fire before initiating the abort. During that period; the smell not only did not abate; it grew stronger.During the moment I had to make the abort decision; I weighed my perception of something burning; the lack of an annunciated problem; the overall weather conditions and how they may impact an emergency return; and the runway/brakingconditions. I concluded that any further delay in aborting the takeoff waiting for an annunciated confirmation of what I was smelling may well put us in the position of a high-speed abort on a snow-covered runway with fair to moderate braking action. Further; because the weather was bad and worsening; I thought about the challenge/possibility of having to make an emergency return to ZZZZ and the risk that would pose. I elected to abort the takeoff and investigate the matter on the ground.I was aware at the time of the possibility of odors in the cockpit and cabin from deicing. However; I waited longer than the required period before turning the bleeds and packs back on after the last de-icing application. Further; more than ten minutes elapsed after turning the bleeds and packs back on and commencing the takeoff. During that time; there were no odors in the cockpit or cabin associated with restoring the bleeds and packs. During my career; I have smelled the results of early restoration of bleeds and packs after de-icing. I would describe the smell as 'sweet or syrupy.' The odor that led to my decision to abort was decidedly acrid like an electrical short/fire. The difference in this odor was why I did not attribute the smell to ingested de-ice fluid. Moreover; the First Officer and the Flight Attendant smelled the same thing and characterized the smell similarly. Because of the combination of these considerations; I elected to abort the takeoff before continued acceleration on the takeoff roll constrained the safe responses to what I perceived to be a potentially growing threat.An additional item to note in the review of this incident is to note what the First Officer saw and perceived. Upon debriefing the incident with the First Officer; not only did he confirm that he perceived the same odor that I did; but that simultaneously with hearing me call for the 'Abort;' he saw the Master Warning flash and instantly pushed the button to cancel it thinking that it was the annunciation flash that caused me to call for the abort. However; upon scrolling through the MFD (Multi-function Flight Display) Maintenance page; there was no electronic record of a fault annunciation.Finally; the First Officer and Flight Attendant carried out their duties in commendable fashion and in accordance with SOP. The crew coordination was excellent and led to a safe and orderly resolution of the incident and the conclusion of the flight.Accordingly; although ambiguity remains regarding the factual premise for making the decision to abort the takeoff; absent some objective forensic data that would not only resolve that ambiguity but would be ascertainable in the moment of decision; I would make the same decision again if presented with the same scenario.

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.