The GAO sustained a bid protest because the U.S. Army, in a procurement for aerial wildland fire suppression services, unreasonably determined that the awardee’s proposed helicopter met the solicitation’s water payload requirements.Carson Helicopter Servs., Inc., Comp. Gen. Dec. B-299720 et al., Jul. 30, 2007. While the awardee’s proposal indicated compliance with a requirement that the proposed aircraft have a capacity to deliver 1,000 gallons of water in a single trip, its calculations were inappropriately based on the helicopter manufacturer’s “in ground effect” performance chart, which only applies when the distance from the bottom of the helicopter tires to the ground is 10 feet or less. When the applicable “out of ground effect” chart was used, the awardee’s proposed helicopter did not satisfy the solicitation’s payload requirements. The Army therefore should have awarded the contract to the protester, whose proposal was the only technically acceptable submission. The GAO acknowledged that the Army’s evaluators apparently lacked helicopter expertise and, as a result, did not recognize the payload calculation issue during the evaluation or during their investigation of an earlier agency-level protest regarding this issue. The GAO nonetheless sustained the protest because “a reasonable evaluation of the technical proposals by an evaluator familiar with helicopters reasonably would have created doubt” as to whether the awardee’s proposed helicopter in fact satisfied the payload requirements.