This excerpt taken from the MAIR 10-Q filed Nov 15, 2005.
SECTION 7. Maintenance and Operation; Possession; Insignia. (a)(I) Maintenance. Lessee, at its own cost and expense, shall: (i) continuously operate, maintain, service, repair and overhaul (or cause to be maintained, serviced, repaired and overhauled) the Engine (including, without limitation, all Parts thereof, including the QEC) in compliance with the Maintenance Program and in compliance with all FAA requirements for FAR Part 121 operation and the Manufacturers recommended maintenance program so as to keep the Engine in as good an operating condition as when delivered by the Manufacturer to Lessor, ordinary wear and tear excepted, so as to maintain in effect all material Manufacturers warranties and guaranties and as may be necessary to enable the airworthiness and serviceability certification for the Engine and airworthiness certification for any Airframe or airframe on which the Engine may be installed from time to time to be maintained in good standing at all times under the Federal Aviation Act, except when all Bombardier Inc. Canadair Regional Jet Model Series  aircraft powered by engines of the same type as the Engine and registered in the United States have been grounded by the FAA, and utilizing the same manner and standard of maintenance, service, repair and overhaul used by Lessee with respect to similar engines used by Lessee in similar circumstances and without in any case discriminating against the Engine by reason of its leased status; provided, however, that in all circumstances the Engine shall be maintained by Lessee in accordance with maintenance standards required by the FAA for FAR Part 121 operation; (ii) maintain or cause to be maintained in English all Aircraft Documentation relating to the Engine and all other records, logs and other materials maintained in respect of the Engine; and (iii) promptly furnish or cause to be furnished to Lessor such information as may be required to enable Lessor to monitor the maintenance status and condition of the Engine and to file any reports required to be filed by Lessor with any governmental authority because of Lessors ownership of the Engine or any Aircraft on which the Engine is installed.
(II) Operation. While installed on an Airframe or airframe and while being operated in
any static testing configuration not on an Airframe or airframe, Lessee will continuously operate the Engine in accordance with its FAA approved flight manual (which shall comply with all Manufacturer recommendations and requirements for the Engine type) and the Manufacturers maintenance manual. Lessee will not maintain, use, service, repair, overhaul or operate the Engine in violation of any law or any rule, regulation, order or certificate of any government or governmental authority (domestic or foreign) having jurisdiction, or in violation of any airworthiness certificate, license or registration relating to the Airframe or airframe on which the Engine is installed issued by any such authority, except to the extent Lessee is contesting in good faith the validity or application of any such law, rule, regulation or order in any reasonable manner which does not adversely affect Lessor or Lessors right, title or interest in the Engine and does not involve any risk of sale, forfeiture or loss of the Engine or the Airframe or airframe on which the Engine is installed or any risk of civil liability or criminal liability being imposed on Lessor. Lessee will not store or operate the Engine or any Airframe or airframe on which the Engine is installed (a) in any area excluded from coverage by any insurance required by the terms of Section 11; provided, however, that the failure of Lessee to comply with the provisions of this clause (a) shall not give rise to an Event of Default hereunder where such failure is attributable to causes beyond the reasonable control of Lessee or to Lessees response to extraordinary circumstances involving an isolated occurrence or isolated series of incidents not in the ordinary course of the regular operations of Lessee and in each such case Lessee is taking all reasonable steps to remedy such failure as soon as is reasonably practicable or (b) other than in operations in accordance with the Airline Services Agreement. Lessee further agrees not to store or operate the Engine, or any Airframe or airframe on which the Engine is installed, outside the United States in any taxable year in a manner that would cause more than 20% of the Basic Rent payable under the Lease to be treated as derived from sources outside the United States.
(b) Possession. Lessee will not, without the prior written consent of Lessor, in any manner deliver, transfer or relinquish possession of the Engine or any Airframe or airframe on which the Engine is installed, or install or permit any Engine to be installed on any airframe other than an Airframe; provided that, so long as no Default or Event of Default shall have occurred and be continuing at the time of such delivery, transfer or relinquishment of possession or installation and so long as Lessee shall comply with the provisions of Sections 7(a) and 11 hereof, Lessee may, without the prior written consent of Lessor:
(i) deliver possession of the Engine, or an Airframe on which it is then installed, to the manufacturer of either thereof (or for delivery thereto) or to any FAA approved organization (or for delivery thereto) for testing, service, repair, maintenance or overhaul work on the Engine or any part of any thereof or such Airframe or for alterations or modifications in or additions to the Engine or such Airframe to the extent required or permitted by the terms of Section 8(c) hereof; or
(ii) to the extent permitted by Section 8(b) hereof, subject any appliances, Parts or other equipment owned by Lessor and removed from the Engine to any pooling arrangement referred to in Section 8(b) hereof.
The rights of any transferee who receives possession by reason of a transfer permitted by this paragraph (b) shall be effectively subject and subordinate to all the terms of this
Lease, including, without limitation, the covenants contained in Section 7(a) hereof and Lessors rights to repossession pursuant to Section 15 hereof, and Lessee shall remain primarily liable hereunder for the performance of all of the terms of this Lease to the same extent as if such transfer had not occurred. No pooling agreement or other relinquishment of possession of the Engine or any Airframe or airframe on which it is installed shall in any way discharge or diminish any of Lessees obligations to Lessor hereunder or constitute a waiver of Lessors rights or remedies hereunder. Notwithstanding anything to the contrary contained herein, Lessee under any and all circumstances may not sublease or sub-sublease, and is prohibited from entering into any sublease or sub-sublease with respect to, the Engine (whether by itself or installed on an Airframe or airframe).
(c) Insignia. On or prior to the Commencement Date, or as soon as practicable thereafter (but in no event later than ten (10) days thereafter), Lessee agrees to affix and maintain (or cause to be affixed and maintained), at its expense, on the Engine a nameplate bearing the inscription:
Northwest Airlines Inc.,
(such nameplate to be replaced, if necessary, with a nameplate reflecting the name of any successor Lessor). Except as above provided, Lessee will not allow the name of any Person to be placed on the Engine, or on any Airframe or airframe on which the Engine is installed, as a designation that might be interpreted as a claim of ownership; provided that nothing contained in this paragraph shall prohibit Lessee from placing its customary colors and insignia on the Engine or such Airframe or airframe.
(d) Engine Records. No later than the 10th day of each calendar month during the Term, Lessee shall deliver to Lessor a written report setting forth the following information for the previous calendar month:
(i) the manufacturers serial number and the registration number of each Airframe or airframe on which the Engine was installed or, if not installed on an Airframe or airframe during any portion of such reporting period, the location of the Engine and a description of steps taken for its preservation and storage;
(ii) the Flight Hours and cycles performed by the Aircraft on which the Engine was then installed;
(iii) the maintenance inspections and repairs performed on the Engine in accordance with the Maintenance Program;
(iv) any airworthiness directives accomplished on the Engine; and
(v) any Engine malfunctions or performance discrepancies requiring shop-level repair or special- or reduced-interval inspections, including the flight log or technical log entries against the Engine relating thereto together with full details of the corrective maintenance and repair actions taken.
The form of such report shall be acceptable to Lessor, and Lessor and Lessee shall promptly develop the form thereof following execution and delivery of this Lease.