Air carrier first officer reported aircraft deceleration on landing was interrupted when a bump was ...

Attributes
ACN	1343357
Time
Date	201603
Local Time Of Day	0001-0600
Place
Locale Reference	MDW.Airport
State Reference	IL
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Landing
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 253
Events
Anomaly	Ground Event / Encounter Other / Unknown

Narrative:

I am writing to communicate a concern I experienced last night regarding braking performance at mdw. I landed on 31C [in] a fairly heavy [large transport aircraft] in wet good conditions; autobrake max; flaps 40 with a headwind of about 8 knots. I touched down approximately 1200 ft down runway; on speed; smooth; no bounce; auto brakes actuated and reverse thrust was applied; normal maximum braking; decelerated for about three seconds until we hit a 'bump' in runway at 4R intersection.we felt main struts extend (but still on ground) and felt aircraft accelerate for approximately one to two seconds; struts then compressed and normal maximum brake deceleration returned. We exited the runway at taxiway sierra without incident. My concern is the 31C/4R runway intersection elevation difference has become significant and is affecting braking performance.

Original NASA ASRS Text

Title: Air carrier First Officer reported aircraft deceleration on landing was interrupted when a bump was encountered at the intersection of MDW Runways 31C/4R.

Narrative: I am writing to communicate a concern I experienced last night regarding braking performance at MDW. I landed on 31C [in] a fairly heavy [large transport aircraft] in wet good conditions; autobrake max; flaps 40 with a headwind of about 8 knots. I touched down approximately 1200 ft down runway; on speed; smooth; no bounce; auto brakes actuated and reverse thrust was applied; normal maximum braking; decelerated for about three seconds until we hit a 'bump' in runway at 4R intersection.We felt main struts extend (but still on ground) and felt aircraft accelerate for approximately one to two seconds; struts then compressed and normal maximum brake deceleration returned. We exited the runway at taxiway Sierra without incident. My concern is the 31C/4R runway intersection elevation difference has become significant and is affecting braking performance.

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.

Air carrier first officer reported aircraft deceleration on landing was interrupted when a bump was encountered at the intersection of mdw runways 31C/4R.