Looking at some safety authority numbers leaves few questions as to why we seldom see a safety investigation or accident report involving ground-handling incidents. It’s not because they don’t occur (as anyone with a modicum of operating experience well knows), but so many fall short of the level of damage that clears the reporting threshold for "incidents" and "accidents" befalling operating aircraft. By "operating" we mean any phase of flight operation, from takeoff to touchdown. And yet, with some frequency, ground mishaps do happen.
Once clear of the runway, aircraft typically travel at speeds which (instinctively, at least), impact operators’ actions in such a way that reduce the potential for serious aircraft damage, injury or fatality. But those instincts often fail to account for the potential energy of large mass impacts even when moving at low velocity… Such dissipations of energy can render aircraft unfit to fly.
A National Transportation Safety Board examination of airline and General Aviation safety noted ground handling and ground incidents to be among its top four, over several reports. In a majority of cases the transport category aircraft needed repair before returning to service. It’s well worth noting the amount of training, practice, qualification and experience levels required to tug airliners on an airport ramp, yet in some instances it’s the flight crews – not the tug drivers – who precipitate the event.
In General Aviation, of course, the fleet size dwarfs that of the airlines. The same applies to airport variety, and consequently the indigenous conditions and the experience of pilots and ramp staff.
When the repair costs of taxi and tug accidents fall short of the NTSB’s reporting threshold, the event is not counted among others as accidents or incidents. But taxi accidents, both fatal and (overwhelmingly) non-fatal, ranked around seventh on a list of the 10 defined causes. The tab for ground mishaps amounts to millions in insurance claims, as well as the expense of replacement lift while repairs are made.
GROUND-BASED RISKS
There’s no question: No two objects may occupy the same space at the same time. In reality, over most of the planet the combination of millions of square miles of open sky and positive control practices of various air-traffic-management agencies render such a likelihood "minuscule" – yet even then, the higher risks of aerial encounters exist in the crowded skies of the world’s major airports.
When on the ground, aircraft face far more risks from the various other participants sharing that airport real estate – and not only other airplanes: Fuel trucks, tugs, support vehicles, catering trucks, buildings, obstacles – the ground area of an airport is a very busy place indeed…
Ground events occur during the seemingly simple act of towing an aircraft out of its hangar; they happen to aircraft parked on ramps; at the tips of other aircraft’s wings. They occur when ramp staff works a crowded corporate hangar to remove the one way in the back of said hangar.
One single-engine propjet operator of our acquaintance suffered the errant indignity of sitting in the cockpit for a tow out to the ramp, a move designed to protect the occupants from the sub-freezing conditions outside. But a confused signal and a tight turn brought the tow to an abrupt end when the tug dragged the aircraft to a spot where a prop blade impacted a low obstacle.
The bend in the blade barely showed – until a friendly journalist suggested taping a piece of wire coat hanger to a parking cone and checking all four blades for any run-out… and there it was – all of an eighth of an inch – 0.125! The mechanic who was called to assess the damage offered, “You probably would feel it more than see it, but feel it you certainly would.”
The prop blade also showed damage at the hub – a strain crack of tiny proportions but huge implications. That strain crack might well have led to a blade failure. “Now that would have shaken us to death,” my acquaintance noted, “if the vibration didn’t break the engine completely off its mount!”
So something as simple as moving into a hangar with a shorter door span puts an aircraft at risk – particularly at home where crew tend to adapt to each customer’s specific airplane. Likewise, taxiing from runway to ramp without minding the taxi guidelines painted on the pavement catches radomes and wing-tips, tail cones, gear doors and winglets. And the catering truck driver accustomed to dragging luggage trains under the wing may need added training to remember how much higher that rig stands.
Vehicles driving on ramps frequently show up in volunteered reports to various safety organizations. Complementary to the multiple risks aircraft face on airport ramps and in hangars is the variability in what airports demand and enforce on the businesses they allow on the field.
Varying training requirements, differing operational standards, and wildly divergent insurance requirements all help add up to a challenge: identifying best practices for ground handling, then creating a system encouraging their use, creating a program, training and auditing of participants for adherence to standards, and repeating the process often enough to assure its use.
That’s the work IBAC and NATA accomplished and announced in July 2014 in the form of IS-BAH following several years of work with domestic and international Business Aviation groups – efforts to promote the use of industry best practices blended through a progressive Safety Management System (SMS) for FBOs and Business Aircraft Handling Agencies (BAHA).
Although national requirements for FBOs and BAHA operations to adhere to the standard may take time, aircraft operators’ recognition of adherence to IS-BAH standards will grow quickly as implementation takes hold and spreads. That may well turn into a change in visiting habits by some operators anxious to improve the odds of falling victim to "ramp rash" or "hangar chaffing." And those operators may also realize some opportunities to save on their insurance if underwriters recognize the value in their clients limiting their FBO use to IS-BAH adherents.
If IS-BAH catches on as well as IS-BAO standards have, expect that point to soon be showing up in FBO ads and promotions. In the meantime, remember – let’s be careful down here.
About the author:Dave Higdon writes about aviation from his base in Wichita, Kan. During three decades in aviation journalism, Higdon has covered every aspect of civil aviation from sport flying to the airline industry. He spent several years covering the aviation regulatory and political affairs in Washington- D.C.- including all the relevant agencies and interest groups. An active instrument-rated pilot with more than 5-000 flight hours in everything from foot-launched wings to business and combat jets- he currently writes for Avionics News- Plane & Pilot- Aviation Safety- World Aircraft Sales Magazine- and on his podcast- Uncontrolled Airspace.
