Ont tower controllers reported of a miscommunication relating to a clearance. Aircraft departing was...

Attributes
ACN	1353366
Time
Date	201605
Local Time Of Day	0001-0600
Place
Locale Reference	ONT.Airport
State Reference	CA
Aircraft 1
Make Model Name	Medium Transport
Flight Phase	Taxi
Flight Plan	IFR
Person 1
Function	Other / Unknown
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 23
Person 2
Function	Other / Unknown
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 1
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter Weather / Turbulence

Narrative:

At the time of the event we were experiencing thunderstorms; lightning; hail; flooding in the cab; delays and flight plan timeouts. We were also short staffed as a result of a sickout and a controller performing an extra duty. We also had a tech ops employee in the cab patching multiple leaks in the ceiling during the incident.the ground controller verified coordination on a departure with sct who coordinated a time and reiterated the altitude (maintain 4;000). The ground controller relayed this to the tower controller; who misheard the 4;000 and thought he heard 5;000.the environmental factors were an overwhelming factor in this scenario (weather; cab flooding; staffing; confusion); but the one thing that might have prevented the mis-issued altitude was the reiterated altitude assignment. Since 4;000 is part of the LOA there could be (and was) potential confusion.

Original NASA ASRS Text

Title: ONT Tower controllers reported of a miscommunication relating to a clearance. Aircraft departing was restricted to 4;000 feet; the Controller mistakenly heard then issued 5;000. Distractions were reportedly involved.

Narrative: At the time of the event we were experiencing thunderstorms; lightning; hail; flooding in the cab; delays and flight plan timeouts. We were also short staffed as a result of a sickout and a controller performing an extra duty. We also had a tech ops employee in the cab patching multiple leaks in the ceiling during the incident.The Ground Controller verified coordination on a departure with SCT who coordinated a time and reiterated the altitude (maintain 4;000). The ground controller relayed this to the Tower Controller; who misheard the 4;000 and thought he heard 5;000.The environmental factors were an overwhelming factor in this scenario (weather; cab flooding; staffing; confusion); but the one thing that might have prevented the mis-issued altitude was the reiterated altitude assignment. Since 4;000 is part of the LOA there could be (and was) potential confusion.

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.

Ont tower controllers reported of a miscommunication relating to a clearance. Aircraft departing was restricted to 4;000 feet; the controller mistakenly heard then issued 5;000. Distractions were reportedly involved.