UK Crash Investigation Has Implications for U.S. Helicopter Ambulance Operations

A foreign accident report provides at least three ways helicopter operations could be made safer in the United States. The inquiry of the UK’s Air Accidents Investigation Branch (AAIB) into the fatal 2006 crash of a helicopter flying at night and in bad weather to an offshore gas platform comes as the U.S. National Transportation Safety Board (NTSB) is about to hold a public hearing on the safety of helicopter ambulance operations. The hearing is slated for 3-6 February 2009 in Washington DC.

Whether to an offshore oil/gas platform or to a hospital landing deck, the flying is roughly the same, involving a landing on a small patch that may be difficult to pick out amidst a sea of lights and presenting obstacles to be avoided in landing. For example, the pilot of the Air Angels helicopter that crashed 15 October 2008 transporting a patient to Children’s Memorial Hospital in Chicago had never flown to the roof-mounted hospital landing pad before and was concerned about a nearby church steeple. The pilot was assisted by a paramedic with pulling the helicopter out of the hanger for the flight. The paramedic later told investigators, “He tried to liven up the pilot’s mood a bit by joking but the pilot remained anxious.”

In the case of the North Morecombe gas platform crash, the helicopter overshot the landing platform and struck the sea surface, killing the five passengers and two crewmen. The AAIB explored many aspects of the crash and subsequent rescue attempts, but three elements stand out.

First, the helicopter, under the control of the first officer, was approaching the gas platform at too shallow an angle. One result of this error was that the circle of lights surrounding – and marking – the helipad did not appear as a ring, but rather more like a continuous line of lights. The helipad lights were difficult to distinguish from other lights on the target gas rig and other platforms in the area.

The AAIB noted:

“Flight trials and research … showed that changing the color of the helideck perimeter lighting from yellow to green significantly increased the range at which the pilot could visually differentiate the helideck from other platform lighting. Furthermore, this color change enhanced the pilots’ situational awareness and promoted greater confidence in the conduct of an approach. The … improved perimeter lighting will be mandated by ICAO [International Civil Aviation Organization] from January 2009. This investigation re-affirms this advice to UK helideck operators and encourages them to make this change at the earliest practical opportunity.”

Not only is green a different color from the panoply of background lights, green can be seen at night from a greater distance. Since the U.S. is a member of ICAO, the new lighting standard should apply to helipads – both offshore and landward – on this side of the Atlantic Ocean as well.

One wonders why it took until 2009 to put in place a lighting standard more attuned to the eye’s natural light-gathering power at night, but I quibble. Better now than never.

Two other considerations bear on operations inside the helicopter. One deals with placement on the instrument panel of key instruments. The investigation determined that two instruments, the radio altimeter and the torquemeter, were not placed optimally. Regarding the radio altimeter, the investigation report said:

“Although positioned appropriately to assist the pilot with a visually conducted task such as a helipad landing or aborted take off the location did not lend itself well to be incorporated easily into a normal radial instrument flying scan.”

With regard to the torquemeter, the investigation report said:

“The small torquemeter was difficult to read and was positioned well outside the LHS [left hand seat] occupant’s normal FOR [field of regard]. The higher power figures required to hover or go-around [the situation at the time of the accident] were situated in the arc from 6 o’clock to 10 o’clock and were partially obscured by the instrument bevel when viewed cross cockpit. It was not possible to conduct a normal scan on the LHS instruments while setting torque.”

Thus, when the captain (in the left seat) was asked by the first officer to take control of the go-around – right when the helicopter was pitching down towards the sea – key instruments were not ideally placed for viewing. The AAIB recommended that the European Aviation Safety Agency evaluate “without delay” instrument landing systems that would assist helicopter crews in their approaches to oil and gas platforms in poor visual flying conditions at night. We can add to offshore oil platforms the approaches to hospital helipads and other landing pads ashore where certain cockpit instruments need to be located where they can be readily monitored.

What is most interesting in the AAIB report, from the standpoint of single-pilot operations among U.S. helicopter ambulance operators, is its extensive documentation of the duties of both pilots when landing at an offshore platform:

“PNS [pilot not flying] confirms that deck clearance has been obtained and both pilots confirm the identity of the helideck. HANDLING PILOT then carries out a normal decelerative descending approach to the Commital Point. PNF is to carefully monitor the approach, especially at night or in poor visibility … and announce any excessive rate of descent or closing speed. He is to call ’55 KNOTS’ and power above 90% torque until HANDLING PILOT announces that he no longer requires such call … He should call ‘COMMITTED’ when he considers that, in the event of an engine failure, the safest option is to continue to the deck.”

Similar close coordination is required during a go-around.

The point is that it takes two pilots working in close coordination to safely land the helicopter, especially at night and in poor visibility.

How helicopter ambulance flights came to be authorized for single-pilot operation is a mystery. A recent request to the Federal Aviation Administration (FAA) for records of the decision to allow single pilot operation of helicopters designed to be flown by two pilots generated this bafflegarb from the FAA:

“A search … revealed no records responsive to your specific request. As a matter of interest, EMS [Emergency Medical Services] helicopters are authorized to conduct single pilot operations because the aircraft is certificated for one pilot.”

That’s interesting, because every EMS helicopter in U.S. operation features two cockpit seats reflective of a PNF and HANDLING PILOT philosophy. As indicated by the AAIB report, coordination between the two is detailed and real-time. What flight tests and other factors did the FAA use to decide that single-pilot EMS flights were okey-dokey? And, given the rash of EMS crashes in 2008, is the decision approving single-pilot operations under reconsideration?

The FAA isn’t saying. What’s clear, though, from the AAIB report of the helicopter crash at the gas platform, is that landing pad lighting, instrument placement in the cockpit, and one versus two pilots should be high on the list of subjects discussed at the forthcoming NTSB safety hearing.