Turbine FARs

The word on the regs

October 1, 1995

On the typical pilot's fun meter scale, studying the Federal Aviation Regulations lies somewhere between wart removal and IRS audits. Great literature it's not, but keeping up with the FARs is a necessary part of life for aviators. Turbine pilots who would rather scrape bugs off windshields than scrutinize the Fed's legalese should be encouraged, therefore, that the Part 61 and 91 rules unique to turboprops and jets are few in number. Where the FAA has seen fit to pen such regulations, it has done so because of the special characteristics of turbine aircraft — on the whole they fly higher and faster, and are noisier and more complex, than reciprocating aircraft.

One could study FAR Part 61, pertaining to certification of pilots and flight instructors, all day long and never find mention of the words "turbine-powered." FAR 61.31(a) does, however, dictate that a person may not act as pilot in command of a "turbojet- powered aircraft" unless he holds a type rating for that aircraft. The type rating is proof that the PIC has undergone specialized training tailored to the aircraft's unique characteristics and systems. Turbojets aren't the only aircraft that require type ratings, of course. Unless otherwise exempted, operation of any large aircraft — defined in the FARs as having a maximum certificated takeoff weight in excess of 12,500 pounds — demands that the PIC be type- rated.

While this may be common knowledge to most of us, it is probably less well known that operation of a "high altitude aircraft," with certain exceptions spelled out in FAR 61.31(f), means that the pilot in command must complete ground and flight training specific to high-altitude flight. The FAA considers a high-altitude aircraft to be one that is pressurized and has a service ceiling or maximum operating altitude, whichever is lower, above 25,000 feet msl. Although turbine-powered aircraft aren't singled out by name, the regulation obviously applies to various turbine types. Note that the aircraft in question need not be operated above Flight Level 250 for FAR 61.31(f) to apply. The rule merely requires that the aircraft be capable of such flight. The ground training needs to include "instruction on high altitude aerodynamics and meteorology," as well as address various physiological aspects of high-altitude flight. Flight training (in an aircraft or simulator) must cover normal cruise flight operations above 25,000 feet msl, as well as emergency descent and rapid decompression procedures. A logbook or training record endorsement is the PIC's required proof of satisfactory completion of such training.

According to a spokesman for FlightSafety International, a fair number of pilots who come for turbine aircraft training are unaware of the need for the high-altitude endorsement. Neglecting this sign- off could conceivably have serious insurance ramifications (e.g., a voided policy), should the pilot later be involved in an aircraft accident or incident.

That's about it for need-to-know Part 61 turbine FARs. There is a bit more meat to gnaw on the Part 91 bone, and the juiciest parts center around operational considerations of turbine aircraft while in different kinds of airspace areas. FAR 91.129, pertaining to operations in Class B, C, or D airspace, is intended to minimize the effects of noise generated by turbine aircraft. Subsection (e) states that each pilot of "a large or turbine-powered airplane shall, unless otherwise required by the applicable distance from cloud criteria, enter the traffic pattern at an altitude of at least 1,500 feet above the elevation of the airport and maintain at least 1,500 feet until further descent is required for a safe landing." If an ILS is in use for the landing runway, pilots of such aircraft must remain "at or above the glideslope between the outer marker...and the middle marker...." And if a VASI is available, they "shall maintain an altitude at or above the glideslope until a lower altitude is necessary for safe landing."

Similarly for noise reasons, FAR 91.129(g) requires that "each pilot of a turbine-powered airplane and each pilot of a large airplane must climb to an altitude of 1,500 feet above the surface as rapidly as possible." Where a formal runway use program has been established by the FAA, FAR 91.129(h) commands that "each pilot of a large or turbine-powered airplane assigned a noise abatement runway by ATC must use that runway" unless the pilot requests another in the interest of safety.

Noise abatement is also the reasoning behind FAR 91.126(c), which pertains only to turbojets operating in uncontrolled (Class G) airspace. If landing at an airport in Class G airspace, pilots must use the minimum certificated landing flap setting for the conditions. Reduced flap settings for jet aircraft usually translate into quieter noise footprints. The PIC may elect to use a different setting if "it is necessary in the interest of safety."

FAR 91.117, which generally addresses aircraft speed, does not mention turbine-powered aircraft by name. Pilots of jet fuel- burning aircraft need to be aware of it, however, because of the wide range of speeds at which such aircraft are flown. The regulation stipulates that aircraft may not be operated at indicated airspeeds of more than 250 knots when below 10,000 feet msl. It further mandates that aircraft operating at or below 2,500 feet agl, within four nautical miles of the primary airport of a Class C or D airspace area, must be flown at 200 knots or less. An exception is allowed if the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed.

The 200-knot limit also applies in the areas underlying Class B airspace, as well as in VFR corridors passing through it. The speed limits are intended to blur the distinction between high- and low- performance aircraft, making it easier for ATC to control a mix of otherwise incompatible traffic. Limiting the speed of very fast aircraft at lower altitudes also makes "see and avoid" a more viable concept.

FAR 91.131, regarding operations in Class B airspace, instructs that "each person operating a large or turbine-powered airplane to or from a primary airport for which a Class B airspace area is designated, must operate at or above the designated floors of the Class B airspace area while within the limits of that area." Within a Class B area, a 250-knot limit applies. The intent here is to allow the faster-moving aircraft which typically utilize the primary airports in Class B airspace to operate at normal or closer to normal speeds. At the same time, requiring aircraft to operate "at or above the designated floors of the Class B airspace" helps segregate them from the slower-moving types usually found below the floors. This regulation should be remembered if, for example, the pilot of a turbine aircraft operating in Class B airspace is cleared for a visual approach to a primary airport. Such a clearance normally allows the pilot wide discretion to undertake any reasonable maneuvering needed to arrive in position for a normal landing; however, he or she must take care not to penetrate the floor of the Class B airspace while doing so.

Part 91 contains just a smattering of other miscellaneous regulations specific to turbine-powered aircraft. Because jet aircraft are capable of very high climb and descent rates, FAR 91.219 requires that "turbo-jet-powered" civil aircraft be equipped with altitude alerting systems or devices. "Subpart E — Maintenance, Preventative Maintenance, and Alterations" details the kinds of maintenance inspections that multiengine turbine-powered aircraft must have. Generally speaking, 100-hour and annual inspections are out; continuous airworthiness inspection programs are in. The particulars of such programs vary from aircraft to aircraft, and the FARs detail different ways owners or operators may comply.

Otherwise, pilots of turbine-powered aircraft don't have a whole lot more regulatory red tape to deal with than everyone else. Of course, the plot thickens when commercial flights under parts 121 or 135 are conducted. Or, for that matter, when Subpart F of Part 91, covering certain uses of large aircraft and multiengine turbojets, comes into play. This subpart covers operations such as aerial photography, pipeline patrol, sales demonstration flights, carriage of athletic teams, and other non-commercial business use of these aircraft when no charge for "common carriage" is made. But that's another story.