D had exclusive right to provide aviation equipment to P. Governed by ASF agreement. P needed new runway. D said needed new system. P said they weren’t bound to pay, but would do it under protest to get the runway working. P refused to pay
Did the parties enter into an enforceable agreement when the P promised to pay D?
Post-contractual modification, unsupported by consideration, may be enforceable so long as it is established that the variation was not procured under economic duress (variation w/o consideration is enforceable so long as no economic duress – modification of Stilk)
Consideration must move from promisee (N) – promisee must suffer a detriment in return for the promise of the promisor (G).
D had to pay, because there was economic duress