Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 40; Flight Crew Total 6800; Flight Crew Type 1200
Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Weather / Turbulence
Flight Crew Returned To Clearance
Aircraft; Weather; Environment - Non Weather Related
On departure from MDW; assigned runway 4L. Upper altitude 3;000; we experienced moderate to severe turbulence. It was extremely windy; gusting 30 plus kts. We departed within moments of a B737; and were assigned the same departure and altitude. The autopilot was engaged at 1;000 feet AGL; a normal procedure; it failed to capture the assigned altitude; and may have exceeded altitude by as much as 400 feet. The auto pilot was deselected; and flown manually back to 3;000 feet. At some point it was also found that the number 1 FMS had gone to 'Maneuver' mode; from the previously selected 'Nav' and would not reset. This was only noticed after the aircraft was being manually flown. The copilot side auto pilot and the number2 FMS was then selected; and appeared normal.I am not sure how or if the FMS failure might have contributed to the incursion; but it was very coincidental; that the 2 events happened together. The incursion may of only been caused by the 'general' turbulence; or by the wake from the departing B737. There were several attempts to reset the FMS; such as pressing Nav; Fltplan; Fuel buttons; etc. The unit was eventually powered down; and then seemed normal.There was no ATC exchange about this; only prior to take off 'caution wake turbulence'.I discussed the situation with my copilot; no other corrective action could have been taken in the circumstance. I will discuss the FMS failure with the manufacturer ASAP.
A Lear 60 Captain reported overshooting assigned altitude departing MDW in windy and turbulent conditions. Wake turbulence from preceding B737 may have also been a factor.