What is in this article?:
- How Much Runway Is Enough?
- Faith in Factory Numbers — With Qualifiers
- Smaller Flight Departments, Shorter Runways
- Mitigating Risk — Airline Approach; Business Aircraft Approach
Faith in Factory Numbers — With Qualifiers
Plenty of corporate flight departments are comfortable operating from runways that meet minimum approved AFM requirements for takeoff, one-engine inoperative climb and landing, assuming that they're using runways longer than a specified minimum length. If they'll be using shorter runways, then they undertake a comprehensive review of a close look at runway performance
Burbank, Calif.-based Avjet, for instance, uses a 6,000-ft. minimum length as the trigger for undertaking a detailed runway analysis for its large-cabin business aircraft, explains director of operations Gregory Wilcox. “Our operational control staff uses a number of flight planning tools, including Universal Weather, ARINC and UltraNav, to assure we have safe margins.”
Part of the detailed airport analysis includes looking at actual obstacle clearance requirements for each runway. Many landing facilities have close-in obstructions that require more than the regulatory 200 ft./nm climb (3.3%) gradient for IFR departures.
Avjet, among other operators, imposes several restrictions on operating out of certain airports in mountainous terrain, including Aspen, Eagle, Telluride and Rifle, along with Sun Valley, Jackson Hole, Lake Tahoe and Tahoe-Truckee. Authorization to use such “special-use” landing facilities only is allowed during daylight conditions with VFR weather from the final approach fix to the runway and a reported visibility of at least 5 mi. Use of certain runways may be prohibited for landing and others may be off limits for takeoffs.
Many larger flight departments require more than one level of approval for operating out of such special-use airports. The validation process, including compliance with specific operating limitations for special-use airports, also gives the flight department manager the confidence to back up decisions made by flight crews to divert rather than land and delay or cancel a departure if warranted by winds, weather, runway contamination or warm temperatures, among other unfavorable conditions.
Airlines have similar procedures for challenging airports, ones with comparatively short runways, close-in obstacles, frequent hot-and-high conditions or nearby terrain hazards, says Don Gunther, former vice president of safety for Continental Airlines.
Flight crews must be specially trained and qualified for operations at certain airports, such as Tegucigalpa, Honduras' Toncontin Airport (MHTG). “It's all about how to mitigate risks for particular airplanes,” he says. “Tegucigalpa, for instance, is a special qualification airport, one that requires the crew to train to proficiency in the simulator and then fly with a [Tegucigalpa] qualified check airman aboard.”
Gunther also says that airlines use FOQA (Flight Operations Quality Assurance) data, collected from a quick-access flight data recorder or stand-alone recording device, to monitor overall crew performance. Based upon FOQA data, Continental developed an RNP procedure for Toncontin Airport that enables pilots to fly more-precise approaches and touch down at the desired point on the runway with more consistency.