( CNN ) -- Just weeks before a Continental Connection commuter plane crashed near Buffalo , another airline had reminded its pilots about safety issues with instrument approaches at the airport . Only a few pieces of the Continental Connection Dash 8 turboprop were recognizable after the crash . However , a spokeswoman for the Federal Aviation Administration on Thursday said it was extremely unlikely the February 12 crash and the warning were related . Instrument approaches are those in which pilots use cockpit displays to line up their aircraft with the runway when visibility is low . The alert , initially issued by Southwest Airlines and reissued Wednesday by the airline 's pilot association , warned there was a `` potentially significant hazard '' concerning the instrument landing system 's glide slope guidance signal for runway 23 . The airline advised , `` Pilots who are preparing to configure and land have the potential to experience abrupt pitch up , slow airspeed , and approach to stall if conditions present themselves in a certain manner . '' Southwest Airlines spokesperson Linda Rutherford said an earthen dam at the end of the runway was interfering with the signal being sent to inbound flights . Rutherford would not confirm if any of Southwest 's recent flights into Buffalo experienced problems on approach . `` We often put out alerts on obstructions to a navigation aid , '' Rutherford told CNN . She also pointed out , though landing on the same runway , Southwest Airlines flights approach runway 23 from the north , turning right , while the Colgan Air flight that crashed was approaching from the south turning left . Rutherford called that distinction important . View a Google Earth image of runway 23 » . The National Transportation Safety Board told CNN the agency was `` aware '' of the Southwest Airlines alert , but would not comment further . The issue is caused by a geographic feature at the airport , a valley , `` something we ca n't do anything about , '' said FAA spokeswoman Laura Brown . She said the `` altitude reading makes it look like you 're a lot higher than you are , because there is a valley there . '' The feature has been noted on FAA charts for years , she said . `` As far as we can tell , there is no way this had any role in the accident , '' Brown told CNN . `` It 's not a navigation aid that would have applied to the approach . '' The alert from Southwest Airlines advises pilots that the problem could cause the planes navigational system to interpret data `` in such a way as to result in a nose-up pitch and loss of airspeed . '' Flight data recorders obtained by the NTSB of the crashed Colgan air Flight 3407 show during its approach to runway 23 , the twin turbo prop Dash-8 pitched up 31 degrees before going into a stall due to lack of airspeed . Southwest Airlines Pilot Association told its pilots the `` issue is being addressed on several levels in an attempt to address procedures , facilities , and communication regarding this matter . '' The alert advises any pilots experience trouble to contact the association 's safety office .
NEW : FAA spokeswoman says it does n't appear issue was related to crash . Warning concerned runway 23 , the same one the crashed plane was lined up to use . Airline advised possibility of `` abrupt pitch up , slow airspeed , and approach to stall '' Southwest Airlines spokeswoman said earthen dam was interfering with signals .