A pilot reported climbing 700 feet to reach assigned altitude after being issued a faulty altimeter ...

Attributes
ACN	976037
Time
Date	201110
Local Time Of Day	0601-1200
Place
Locale Reference	SSC.Airport
State Reference	SC
Aircraft 1
Make Model Name	Small Aircraft Low Wing 2 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Pilot Flying
Qualification	Flight Crew Commercial Flight Crew Instrument
Experience	Flight Crew Last 90 Days 25 Flight Crew Total 1300 Flight Crew Type 125
Events
Anomaly	ATC Issue All Types Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Other / Unknown

Narrative:

The barometric pressure reporting system for shaw AFB approach control failed. The controller was repeatedly issuing an altimeter setting of 29.41; which was subsequently corrected to 30.11 consistent with myr and flo approaches. Upon hand off; this placed me 700 feet below of my assigned altitude of 6000 feet. After requesting clarification of the altimeter setting; I informed the controller that I was forced to climb the 700 feet to regain assigned altitude; which he acknowledged. Shortly thereafter; and once back at 6000 MSL indicated based upon the altimeter setting of 29.41; shaw approach announced that their barometric system had failed and asked all aircraft to 'standby'. After issuing the new altimeter setting; the controller asked me to 'say altitude' as I was descending; presumably because of the altitude error my transponder was creating. While I am unaware of any conflicts; this failure had obviously serious consequences for aircraft separation.

Original NASA ASRS Text

Title: A pilot reported climbing 700 feet to reach assigned altitude after being issued a faulty altimeter setting by Approach Control. Shortly thereafter the correct altimeter setting was issued and a 700 foot descent is required to return to the correct altitude.

Narrative: The barometric pressure reporting system for Shaw AFB Approach Control failed. The controller was repeatedly issuing an altimeter setting of 29.41; which was subsequently corrected to 30.11 consistent with MYR and FLO approaches. Upon hand off; this placed me 700 feet below of my assigned altitude of 6000 feet. After requesting clarification of the altimeter setting; I informed the controller that I was forced to climb the 700 feet to regain assigned altitude; which he acknowledged. Shortly thereafter; and once back at 6000 MSL indicated based upon the altimeter setting of 29.41; Shaw approach announced that their barometric system had failed and asked all aircraft to 'standby'. After issuing the new altimeter setting; the controller asked me to 'say altitude' as I was descending; presumably because of the altitude error my transponder was creating. While I am unaware of any conflicts; this failure had obviously serious consequences for aircraft separation.

Data retrieved from NASA's ASRS site as of April 2012 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.

A pilot reported climbing 700 feet to reach assigned altitude after being issued a faulty altimeter setting by approach control. Shortly thereafter the correct altimeter setting was issued and a 700 foot descent is required to return to the correct altitude.