The language used and amount of information given in publications such as manuals and service bulletins have been affected by the product liability environment. The "failure to warn" doctrine has resulted in a proliferation of warnings for both expected and conceivable uses or hazards. This not only consumes excessive amounts of valuable engineering time in crafting the content and language of each warning, but also generates so many warnings that they lose their impact. Also, the concern for being held accountable for encouraging possible misuse of the airplane has resulted in deleting some worthwhile information from at least one manufacturer's manuals.

Two examples of this are procedures for getting through clouds for VFR (visual flight rules)-rated pilots—those not rated for instrument flight—and soft field takeoff procedures. Instrument-rated pilots have been taught and tested to be able to control an airplane's flight path without visual reference to the ground or the horizon. VFR pilots are not licensed to fly in weather conditions that require instruments for maintaining attitude control. Some manufacturers' manuals have provided information on how to control the airplane in clouds as an aid to VFR pilots should they inadvertently be caught in clouds. Unfortunately, some lawyers have contended that such information could cause a VFR pilot to fly under conditions that, in some cases, could result in a crash. The same is argued for description of soft field landing and takeoff procedures. Thus, information that would be helpful to many pilots has been removed from the manuals.

The current product liability environment has added cost to the aircraft certification process. FAA engineers have been, and continue to be, influenced by this environment. In many cases, the certification criteria for showing compliance are now excessively conservative. This is especially true when a well-developed, rational database does not exist, and "what if" studies are required to an excess. Although undocumented, experience shows that it has become difficult to get certification approvals from FAA engineers who have been personally involved in product liability lawsuits in which a prior approval was questioned.

New regulations are being developed for questionable safety issues, those for which there is no absolute proof that a problem would ever exist, even though aircraft have been operating safely for years without allocating