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Traversing Oceans on 2 Engines
Be reminded that the primary purpose of this web site is not to decry the shortcomings of airline safety, but to pass on information that will help airline passengers make informed and intelligent choices regarding their own safety. Everything else is secondary. And it is in this light that we now approach an aspect of airline safety that is seldom discussed in public, and not often considered by air travelers as they plan their travels.
Let's begin by noting that over the past couple of decades the trend within the airline industry worldwide has been away from large three and four-engine aircraft toward long-range, mid-sized, two-engine types. Though the considerations prompting this change were varied, the primary impetus was economics of operations. To put it simply, two-engine airplanes cost less, are cheaper to operate, cheaper to maintain, and required but two pilots on the flight deck. The downside, of course, was that such airplanes had less seating capacity and less range. These factors were soon overcome, however, with development of more powerful engines that led to a significant increase in gross weight. This, in turn, made possible larger airplanes with increased seating capacity, plus greater fuel loads that made possible the ability to fly longer non-stop distances.
But there was one restriction that more powerful engines could not overcome, and that was the restriction placed on overwater operations of two-engine airplanes by the FAA's ETOPs (Extended Twin OPerationS) regulation. First enacted in 1953 and aimed at airlines operating between the U.S. and Europe over the North Atlantic, ETOPs began with a "60 minute rule." In effect, this rule stipulated that such overwater flights had to follow routes that kept them always within one hour of a suitable landing site in the event that one of the two engines should fail. Thus, a New York to London or Paris flight had to fly routes that took them closer to Greenland and Iceland rather than the more direct route across the open Atlantic. The greater distance, of course, meant greater fuel consumption and higher operating costs. The safety aspects of such a rule were so obvious, however, that there was little industry opposition. After all, what passenger, or even pilot, aboard a DC-3 flying on one engine over the frigid North Atlantic wouldn't take comfort in knowing that Reykjavik was but an hour away rather than two or three . . . especially when the failure rate of piston engines was calculated as one in every 4000 hours of operation.
As piston-driven twins gave way to jet-powered twins, the FAA in 1985 rationally did away with the 60-minute rule and instituted a 120-minute rule because jet turbine engines were far more reliable than the piston variety . . . only one failure every 40,000 hours of operations. During the first six months under this new rule only four in-flight engine shutdowns occurred over the North Atlantic. And, during a 115,000 subsequent crossings only 13 in-flight shutdowns occurred. By any yardstick, this would seem to be a very acceptable rate. However, there were other airline routes being flown over other parts of the world that could not meet the restriction imposed by the "120 minute rule," effectively mandating the use of three and four-engine airplanes. Among these routes is the heavily traveled routes between US West Coast cities and the Hawaiian Islands.
For some years, airlines operating between the mainland and Hawaii had tried unsuccessfully to get the two-hour restriction lifted so they could operate twin-engine instead of the larger DC-10s, L-1011s, B-747, etc. Experts at knowing what passenger load to expect on any given flight, it didn't make economic sense to use a larger 300 or 400 seat airplane to carry just 200 passengers. How much better it would be to match the airplane with their passenger loads. But the FAA held fast. After all, with 2600 miles of open ocean an engine failure at midpoint would mean 1300 miles of single-engine flight remained. Even given the remarkable reliability of jet engines, the FAA apparently deemed any further loosening of the ETOPs restriction as too risky. If for no other reason than the psychological impact that such an occurrence might have upon passengers who for three or more hours had to fret about that one remaining engine.
Concerned as it always is about airline economics, and under pressure from their political boss at the DOT (Federico Pena), the FAA underwent a change of heart. Did it specifically abolish the "120 minute rule" in favor of a "180 minute rule?" No, it put a bit of political spin on their action and agreed that airlines could file for a specific waiver that would permit them to operate under a "180 minute rule." The door to operate twin-engine airplanes over any airline route in the world, assuming the range to do so, was finally opened. The first to apply for such a waiver was United Airlines who wanted to operate its brand new twin-engine B-777 from the East Coast to Europe over the shortest and most direct route. Permission was granted, and before we knew it twin-engine airplanes were operating between the West Coast and Hawaii as well. Then, effective March 21, 2000, the FAA increased the ETOPs limit for all B-777s to 207 minutes.
With that background information in hand, let's look at what one might expect should a worse case scenario develop on a flight, let's say, between Los Angeles and Honolulu where precisely at mid-point one of the two engines fail. To simplify our scenario, we will assume that neither in-flight wind nor weather are factors to be considered, and the entire flight will be in daylight.
We're at mid-point and cruising at 39,000 feet westbound to Honolulu when the pilots take note of falling oil pressure and increasing temperatures on the #2 (right) engine. Then they take note of a fluctuation in the EPR gauge, or perhaps a developing vibration. Watching carefully while considering not only the engine's condition but also its multi-million dollar pricetag should it destroy itself, the captain decides to shut the engine down. While one pilots start a descent to an altitude where single-engine flight can be sustained (about 20,000 feet), the other pilot issued a radio "Mayday" in order to establish an uninterrupted communications channel with appropriate ground facilities. He reports his current position and the nature of his problem. In turn, he receives information regarding the location of surface ships in his vicinity and along his remaining route of flight, as well as other airliners who might be close by. He will be asked if he wants an Air-Sea Rescue aircraft dispatched to intercept his flight and provide a covering escort. He will get reports on the status of the ocean surface along his route. How rough is the ocean? How high are the swells and in what direction are those swells moving? These and numerous other considerations will enter every pilot's mind whenever confronted by such a situation, for it is part and parcel of their procedures training. But, why you might ask, "If jet engine are so reliable and the odds of losing both engines is so extremely remote, why is it necessary to take such precautions as these? The simple answer is: Murphy's Law. By expecting the worse and preparing for it, pilots are ensuring the best possible outcome.
But then comes the point in our scenario where hard and fast procedures stop and pilots are left to their own judgments in deciding what is the best course to follow thereafter. Sure of what I would do under the same set of circumstances, I queried ten other pilots to determine how their judgments matched up against my own. So I asked the question: What about your passengers . . . will you proceed on the assumption that nothing further will go wrong, or will you assume the worst and deal with your passengers accordingly? True to the airline philosophy of not saying anything that might scare hell out of passengers, four of the ten said they would say nothing to their passengers. They would, however, alert the flight attendants as to the nature of their situation so as to prepare them in the event something worse developed. Three pilots indicated that with reassuring words they would inform their passengers, order a quick briefing on ditching procedures, and then resume normal activity in the cabin. Only three felt as I did, and indicated they would bring a halt to all cabin activity, conduct a full and complete briefing on ditching procedures, including reseating of passengers and instructions on opening exits, donning of life jackets, stowing of passenger articles, handling of life rafts, etc. Having done that, then limited activity could be resumed in the cabin, but all food-service carts would be securely stored and none permitted in the aisles.
Now it's no surprise that when it comes to exercising one's judgment, pilots will often disagree as to the best course of action to follow in any given situation. Whether that judgment is good or bad will never be determined short of a resulting accident where the NTSB list the probable cause as "pilot error." But more than anything else it is errors in pilot judgment that cause many accidents. Given a second shot at handling the exact same situation all over again, almost every pilot would do things differently in arriving at the best and safest course of action. A pilot executes a takeoff with snow or ice adhering to the wings and ends up in the Potomac River. Another takes a shortcut and ends up running into the side of a mountain. Another adheres to a dangerous noise-abatement-procedure and loses an engine at precisely the wrong moment. Another disregards the input of his fellow crewmembers and ends up landing atop a residential neighborhood. The list is painfully extensive, and the resulting toll of injury and death a commentary of sad regrets.
As to the four pilots who would opt to tell their passengers nothing regarding our scenario, I strongly questioned their judgment. So I had to ask: "Cruising at 20,000 feet on a single engine, and that engine suddenly quits, how long will it take your 'glider' to reach the ocean surface?" All four could only approximate the time element. Then came the next question, one whose answer every pilot should know: "How long will it take to conduct a full and complete emergency briefing that will best ensure your passengers' survival upon ditching, assuming a full airplane with a food service in progress?" The answers correctly ranged from 20 to 25 minutes to do the job right. Then I directed the final question to these four otherwise very competent pilots: "Can you possibly conduct that kind of thorough briefing before your glider hits the water?" Their answers were "probably not." I could tell by the sound of their voice and the look in their eyes that they were already rethinking their actions. At that point I reminded them that rather than confronting their passengers with such a possibility and preparing them for it, they were choosing instead to compromise their very safety. I had gotten from them the information I wanted, so I didn't push any further on the subject, but I hoped that we had exchanged some food for thought.
But what about passengers? How might they feel given such a scenario. Well, I queried roughly two dozen occasional and frequent fliers. One-third preferred to remain in the dark given the odds of the other engine quitting. The remainder wanted to be told and given the fullest briefing possible. Almost all inquired as to how often had both engines ceased functioning on an airliner? I could only recall two instances: One, a DC-9 that crashed in Georgia with the loss of 72 lives, and then a B-767 over Colorado that averted disaster by getting one of the engines restarted. Still, I couldn't help but pass on the incident in which a four-engine Boeing Stratocruiser lost two of its four engines and ended up ditching in the Pacific without any loss of life. But Captain Ogg had several hours to brief his crew and passengers before landing in a calm ocean aside Ocean Station November at daybreak. OSN was the designation for a Coast Guard cutter that for years patrolled a 200 mile square area along the 140th meridian between Hawaii and the West Coast for just such a purpose. Primarily because of jet engine reliability and high tech navigational equipment, OSN is no longer in service.
So there you have it. If you're wondering if three and four engine airplanes are safer on overwater flights than the two-engine variety, the answer is yes. But so also would eight engines be safer than four, etc. etc. In any case, however, you have a better idea of what to expect from your crew, and the opportunity to think about your own reactions should you ever find yourself in a similar situation. In closing, let me pass on some very wise words from an elderly female passenger on one of my flights. Faced with the possibility of having to execute a gear-up belly landing due to a hydraulic failure, I waited as long as possible before telling the passengers of the problem. I ended my PA announcement by saying that I would walk through the cabin and answer any concerns they might have. Apparently the PA announcement worked to ease most concerns, for only five of 136 passengers stop me to ask questions. Heading back to the cockpit, I chanced to look at a little old lady who beckoned me to stop. As I leaned over, she grabbed my tie and pulled my face close to her own. Staring into my eyes for a few seconds, she said nothing. Then, releasing my tie, she looked up with a smile on her face and in a soft but confident voice said: "Captain, you don't look worried, so I won't be either." For those who trust their instincts that may be a bit of good advice, provided you get the chance to look your pilots in the eyes. In any event, decide for yourself if you'd like to know or not know.
