AOPA has strongly criticized an FAA plan that reneges on an agreement with aircraft owners over mandatory equipage.
The agency has issued a supplemental notice of proposed rulemaking (SNPRM) requiring two highly accurate and very expensive altimeters for turboprops to operate in a domestic reduced vertical separation minima (DRVSM) environment. The original proposed rule, agreed to by industry, required only one. (Using RVSM allows aircraft operating above 29,000 feet (FL290) to fly with less vertical separation by using much more accurate altitude-sensing equipment.)
In formal comments on the proposal, AOPA stated, "Most U.S.-based turboprops are used for domestic travel, not international, and it is AOPA's position that operators should retain the ability to decide how their aircraft will be equipped, not the federal government."
The FAA says the change in the proposed rule will align the rule with international civil aviation regulations.
Turboprop owners are faced with two expensive alternatives. They can spend, by the FAA's own estimate, $140,000 to upgrade to dual RVSM-compliant altimeters, or they can fly at lower altitudes and pay more for each flight because of a six percent greater fuel burn at those lower altitudes.