obsolescence reserves of $3.0 million. Gross profit in the Asset Management Solutions segment increased $48.8 million to $81.5 million, or 149.4%, for the six months ended June 30, 2022, compared to the six months ended June 30, 2021. The gross profit increase is mainly attributable to higher revenues generated for the six months ended June 30, 2022, as noted above.
Aircraft gross profit margins increased to 38.0% for the six months ended June 30, 2022, from 27.8% for the six months ended June 30, 2021 due to higher margin on Flight Equipment sales, and lower inventory obsolescence reserves of $3.8 million. Engine gross profit margin was 46.3% for the six months ended June 30, 2022, an increase from 42.0% for the six months ended June 30, 2021, which was primarily the result of higher margins on Flight Equipment sales and engine leasing activity, offset by higher inventory obsolescence reserves of $0.8 million and impairment of Flight Equipment of $0.9 million.
TechOps
Our revenue from TechOps increased by $12.5 million or 20.6%, to $73.3 million for the six months ended June 30, 2022, compared to the prior year period. The increase was primarily driven by the sale of Flight Equipment, which was purchased and controlled by the TechOps segment prior to its ultimate sale; offset by lower revenues from services as a result of a shift in resources to support our cargo conversion projects on the B757 product line, as well as lower storage and related maintenance activities in our Roswell facility as operators continue to return aircraft into active status.
Cost of sales in TechOps increased $10.3 million or 23.9%, to $53.2 million for the six months ended June 30, 2022 compared to the prior year period, driven by costs generated from the sale of Flight Equipment of $16.1 million; offset by lower cost of sales on MRO Services due to lower revenues as noted above. Gross profit in TechOps increased $2.3 million, or 12.7% for the six months ended June 30, 2022 compared to the six months ended June 30, 2021, driven by the profit generated from the sale of Flight Equipment of $7.5 million, offset by lower gross profit of $5.3 million on MRO Services. Gross profit margin decreased to 27.5% for the six months ended June 30, 2022 compared to 29.4% for the six months ended June 30, 2021, and was largely attributable to lower margin generated on MRO Services of 23.6% for the six months ended June 30, 2022 compared to 28.5% during the six month ended June 30, 2021, driven by lower margin maintenance work at our Roswell facility.
Selling, General and Administrative Expenses
Selling, general and administrative expenses increased $17.0 million, or 56.1% to $47.3 million for the six months ended June 30, 2022, compared to the prior year period. The increase was mostly related to share-based compensation expense of $7.0 million for performance restricted stock units not deemed probable of achieving performance targets as of the second quarter of 2021. The remaining increase relates to higher payroll expenses associated with market adjustments and additional headcount, as well as higher cost incurred on information technology and cybersecurity.
Payroll Support Program Proceeds
We recognized CARES Act proceeds of $14.8 million during the six months ended June 30, 2021. No such proceeds have been received or recognized during the six months ended June 30, 2022.
As of June 30, 2022, we were in compliance with the applicable provisions of the CARES Act, Payroll Support Extension Law, and American Rescue Plan Act of 2021.
Change in Fair Value of Warrant Liability
We account for our private warrants as a liability at their fair value, with changes in fair value recognized in our results from operations for the period. The fair value of our private warrants is determined using a Black Scholes option pricing model. For the six months ended June 30, 2022, we recorded a $0.1 million benefit in fair value of the warrant liability income, compared to a $0.6 million expense in the prior year period.