You are flying along in IMC and have a total instrument failure. Vacuum pump, electric, and a bird hit the pitot tube. Part of it went into both static ports. Fortunately you are flying to a child's birthday party and have a mylar helium filled balloon with you. Keeping the balloon centered on the cabin ceiling you should be able to maintain level flight and also determine if your attitude changes correct? Ascend, it moves forward. Pitch down, it moves back etc... Would it work like that?