A lear 60 captain reported overshooting assigned altitude departing mdw in windy and turbulent condi...

Attributes
ACN	1299951
Time
Date	201510
Local Time Of Day	1201-1800
Place
Locale Reference	MDW.Airport
State Reference	IL
Aircraft 1
Make Model Name	Learjet 60
Operating Under FAR Part	Part 91
Flight Phase	Initial Climb
Route In Use	SID Midway 1
Flight Plan	IFR
Aircraft 2
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 40 Flight Crew Total 6800 Flight Crew Type 1200
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Altitude Overshoot Deviation - Procedural Clearance Inflight Event / Encounter Wake Vortex Encounter Inflight Event / Encounter Weather / Turbulence

Narrative:

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 as soon as possible.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

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.

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.