Airbus Challenges Passenger Recovery Plan Proposal

For long-range flights, it is better to avoid diversions by improving aircraft design than by developing and implementing costly passenger recovery plans, according to an Airbus memorandum obtained by ASW.

The Feb. 11 document was written in response to a U.S. Aviation Rulemaking Advisory Committee (ARAC) report on extended operations (ETOPS). That report essentially applies the same ETOPS standards to three- and four-engine aircraft as are applied to twinjets (see ASW, Jan. 13). One of the precedent-setting aspects of the report was its call for operators to develop passenger recovery plans should their aircraft have to divert to a remote airfield. Under present guidelines, U.S. carriers are not required to have recovery plans.

According to the Airbus discussion of the ARAC report, the potentially costly recovery plans could penalize operators of three- and four-engine jets, which would not necessarily be forced to divert in the event of a one-engine shutdown, or the loss of two engines on a four-engine aircraft.

Sources say the absence of contingency plans could cost more, as a result of negative media coverage, loss of future business from a botched diversion, reductions in allowed flights and suspension of code sharing agreements, not to mention the legal consequences of such unpreparedness.

Of interest, the ARAC report was submitted as a consensus document, without any dissenting views, as all participants determined that they could live with the recommendations. The participants in the almost three years of monthly meetings included representatives from aircraft manufacturers, including Airbus, engine manufacturers, airlines and their associations, various trade unions and the flying public.

Airbus officials declined to comment on the company memorandum.

According to the Airbus paper, the ARAC proposal “has been influenced by economic pressure to cut down the cost of ETOPS flights and increase [the] ETOPS upper limit, but not enough effort was spent on developing compensating safety factors to maintain the level of operational safety.” The working rules of the group charter were drafted such that it was difficult to propose new standards on ETOPS of less than 180 minutes.

Defenders of the ARAC report counter that its recommendations concerning the safety of ETOPS were made on a conservative basis.

The whole ETOPS issue is playing out against the move by manufacturer Boeing [BA] to increase the operational flexibility of its popular B777 twinjet for ETOPS. A source who participated in the ARAC deliberations said the B777 was envisioned as so dominating the Pacific Ocean routes that its watery expanse would come to be known as a “B777 lake.” The ARAC looked at whether ETOPS restrictions could be expanded beyond the 180-minute limit for diversions on one engine (hence Boeing’s application for a 207-minute exemption for the B777, which started the whole ARAC process of updating ETOPS regulations). While the Airbus A330 twinjet is an ETOPS competitor, its four-engine A340 and the coming A380 also are formidable competitors, where increasingly long routes over the poles, across oceans and over vast expanses of undeveloped land masses are envisioned. The rules for ETOPS beyond 180 minutes were written such that the B777 could qualify, while some thought the A330 could qualify with slight modifications, according to the source.

The source said, “It is fair to say that all the decisions made by the ARAC reflected the economic interests of the participants as much as an objective assessment of the safety factors.”

The Airbus analysis posits two approaches. “To maintain the intended level of safety when operating the new routes,” it argues, “one may either design to avoid diversions or adopt operational procedures to protect the safe conduct of diversions.”

The conceptual schism may be significant. If one may generalize, the draft ARAC report supports aircraft reliability backed up by an emergency diversion plan, while the Airbus analysis stresses redundancy and avoiding the necessity of a diversion.

Boeing argues that its B777 twinjet has demonstrated exceptional reliability. Of the miniscule 29 in-flight shutdowns out of some 314,000 B777 ETOPS flights, more than 60 percent involved flight times of less than 30 minutes. Some are considerably more. In January a British Airways B777 posted a one hour and 41 minute single engine divert, and this record for the B777 was bested last week with a single engine divert in the Pacific of more than three hours.

Some individuals familiar with the debate maintain that it is not prudent to discount the need, however unlikely, of contingency planning for a diversion. Even the best technical redundancy will not prevent diversions for non-technical reasons (which account for most diversions). Another source said the absence of such plans could cost a carrier and its insurers, as well as the manufacturers as possible third parties, considerable sums of money. Indeed, it is in the operators’ own interest to prepare contingency plans for diversions.

Other sources, who have reviewed the Airbus memorandum, say some of the safety concerns it raises should stimulate discussion at the very least. The memorandum uses the acronym LROPS (long-range operations), thereby making a distinction between ETOPS as traditionally meant to stand for twinjet operations and LROPS for aircraft with more than two engines.

This point alone may generate comment, as the nomenclature issue was discussed in great detail during the ARAC meetings. Some participants in the ARAC discussion sought to apply the term LROPS to all operations beyond 180 minutes, which would have made a clear distinction between these and other operations. Ultimately it was decided to alter the acronym ETOPS from “extended-range twin-engine operations” to “extended operations” for better international understanding and operational harmonization. The Airbus use of the term LROPS is consistent with Joint Aviation Authorities (JAA) usage.

Need to divert. The Airbus case: “Operators of three- and four-engine airplanes do not need to divert to the nearest airport in case of engine failure. Other causes of diversion may be eliminated by appropriate technology, or their effect may be minimized so that the crew can safely fly to a safer and more distant airport.”

Comment: This statement appears to be the crux of the Airbus stance in opposition to the ARAC report. Nonetheless, incidents occur that do not allow the luxury of diverting to the most suitable airport, and the nearest airport may need to be used within the shortest possible flying time. Recall the 1998 case of Swissair Flight 111. The pilots originally considered diverting their New York-Geneva flight to Boston, but as the situation worsened they opted for an emergency landing at Halifax. The airplane crashed before the pilots could land safely. In a case last week involving a United Airlines [UAL] B777 twinjet on a flight from Auckland, New Zealand, to Los Angeles, the crew lost an engine 1,100 nautical miles from Hawaii, elected to divert to Honolulu, then subsequently decided to land at Kona, Hawaii, which was closer, after considering extant NOTAMs (notices to airmen) and the weather. Sources point out that many diversions are unrelated to the number of engines and can involve other system failures, passenger medical emergencies (e.g., heart attacks, injuries from turbulence), cabin smoke emitting from materials left in galley ovens, and so forth. Nor should the potential for human error be discounted. Despite the redundancies built into Boeing and Airbus aircraft, an A330 twinjet lost all fuel Aug. 24, 2001, and had to glide to a deadstick landing in the Azores.

Airbus: “The two approaches of protecting diversions (recovery plan) and precluding diversions (LROPS design) are well recognized in JAA and ICAO [International Civil Aviation Organization] drafts.”

Comment: The important point here is that the captain of a three or four-engine aircraft has the option (but not the necessity) of diverting in the event of an engine failure, and he also has the option of continuing on to the planned destination, or to a more hospitable alternate airfield. With this option, Airbus seems to be questioning the need for all this diversion and passenger recovery planning – although most diversions occur for other reasons. Recall that the ARAC report maintains that in an engine-out situation, the captain must land at the nearest suitable airport, even if there is enough fuel to continue to another aerodrome (see ASW, Jan. 13).) Airbus: “The result of the ARAC draft would not only be an economic penalty, but also an increase in risk, preventing the crew [from using] the safest airport.”

Comment: Consider the ETOPS guidance issued by Transport Canada, which appears to offer a prudent yet flexible policy perspective.

Fuel reserves. Airbus: “Fuel reserves would no longer be calculated with any safety margin. This proposal … is linked with a design requirement introducing sophisticated fuel alerts to warn the crew ahead of time in case [of] a potentially unsafe fuel situation. [The] ARAC proposal to allow the operational reduction of fuel reserves without retroactive incorporation of the fuel alerts is clearly unsafe.”

Comment: A European supplier of airplane performance monitoring (APM) equipment observes in its marketing literature, “For ETOPS carriers the additional 5 percent fuel carriage (critical fuel scenario) can only be deferred when APM is carried out.” (See http://www.lido.net) However, APM equipment is not designed as an in-flight aid. It is intended to track fuel consumption so that deteriorating performance can be identified and corrected by maintenance. In-flight alerting is something else.

For a big airplane, relief from that 5 percent “fiddle factor” can translate into a significant weight saving, which in turn equals more payload. For a B747-400 freighter, for example, eliminating the 5 percent variable reserve of trip fuel can mean an extra seven tons of payload. That is a lot of revenue-generating parcels.

It should be noted that credit for APM does not appear to be part of the ETOPS guidance issued Oct. 11, 2002, by the UK’s Civil Aviation Authority (CAA), which, under “Fuel Planning Considerations,” Para. 4.4c, says, “A contingency figure of 5 percent should be added to calculated fuel burn from the critical point.”

Airbus: “Furthermore the fuel reserves necessary to ensure a safe diversion at low altitudes in case of engine failure would make such routes uneconomical for two engine airplanes.”

Comment: This is not necessarily so, sources say. The highest fuel consumption is generated by a loss of pressurization. In this case, the aircraft must descend to 10,000 feet and operate with all engines running. This scenario consumes more fuel than operating a twinjet on one engine at 17,000-19,000 feet.

Airbus has a point, sources say, inasmuch as greater icing loads might be encountered at lower altitude.

The fuel planning called for in the ARAC report seems consistent with requirements put forward by the UK’s CAA and Transport Canada, but with a notable exception. Fuel for winds is based on a five percent prediction error, which is significantly different than current practice to add five percent to the total for errors in predicted winds.

Apart from the increased fuel consumption with one engine inoperative, wing and engine anti-ice systems would place a greater strain on a single engine also carrying the electrical and pressurization/air conditioning loads. Some sources are skeptical that a backup auxiliary power unit (APU) could remain running in severe icing conditions. There is another under-appreciated twist. The radius for, say, a 180-minute divert in still air is based on the airplane’s speed at maximum continuous thrust (MCT) of the one remaining engine. That biases the case to a wider radius than would be the situation with a lower thrust level. At lower thrust, the chance of losing the remaining engine also might be reduced. At least in this one respect, the ETOPS criteria are optimized to provide twinjet operators with the greatest flexibility in planning their flights. Reportedly, some pilots do not plan to conduct a diversion at MCT, and it should not be surprising that diversions from near the 180 minute limit may take longer because wind is not considered in the time planning – although it is accounted for in the fuel planning. The loss of an engine on a three- or four-engine airplane would not require the remaining powerplants to be jacked up to maximum continuous thrust.

Indeed, pilots say that loss of one engine on a three- or four-engine airplane does not present the same challenge. According to this school of thought, the loss of one engine on a twinjet imports a significant degradation in the remaining level of safety. As retired Capt. Tim Gallagher, one of the architects of the ARAC report, observed, when one engine on a twinjet is lost, the crew has no propulsive redundancy left. Another pilot added, “Accidentally closing down the wrong engine is not the same problem in a three- or four-holer. It can happen, but do it in a twin and you’ll be lucky to ever regain your mental equilibrium, let alone composure.”

With respect to Airbus’ larger point about reducing fuel margins, a source who participated in the ARAC discussions said the criteria were adjusted for the critical fuel scenario. “Icing penalties were reduced from arbitrary percentages to realistic estimates of the additional fuel actually required,” he explained. With respect to wind conditions, he said, “Diversion fuel requirements are to be based on forecast wind, with a pad, rather than fixed percentages of the ‘no wind’ fuel requirements that could easily be inadequate or excessive,” he explained. The planning criteria, he asserted, are now “far better than adding an arbitrary penalty.” He noted that operators of three- and four- engine aircraft, under the ARAC fuel requirements, must also now plan for a loss of pressurization diversion.

There is another subtle aspect of the ARAC report that bears mention. In the event of a belly hold fire, operators must provide enough capability to suppress the fire for the 180-minute divert time on one engine plus an additional 15 minutes – in still air. However, for operations beyond 180 minutes, operators are allowed to assume that, in the event of a belly hold fire, all engines are running, and therefore they can fly faster – although for flights beyond 180-minute diversion winds aloft must be considered.

The implicit assumption in the belly hold fire scenario is that it will not burn through the skin, at which point all bets are off regarding fire suppression, as the inferno then would be stoked by oxygen from the ambient air. The May 13, 2002, water line heater fire in the belly hold of an Air Canada B767 showed the potential for an electrical fire to penetrate the hull (see ASW, June 10, 2002). Static port heater fires fueled by thermal acoustic insulation blanketing MD-82 twinjets also have shown the potential to breach the hull.

Designated divert airfields. Airbus: “This proposal would force operators of three- and four-engine airplanes to designate and use alternate airports in the polar regions and implement a costly passengers’ recovery plan.”

Comment: Planning is predicated on being able to suppress a fire in the belly hold, which may make it possible to continue to a more suitable airfield. According to Gerard Bruggink, when a fire in an inaccessible space is not suppressed, the situation “should be treated as an emergency of the first order.” According to Bruggink, the crew should prepare to land and evacuate “instead of delaying … by continuing towards a distant airport.” (See ASW, May 24, 1999) Bruggink’s assessment argues in favor of planning to use alternate airports in the face of such an emergency.

The ARAC report is potentially years away from becoming a regulatory proposal by the U.S. Federal Aviation Administration (FAA). Furthermore, it is just one of three ETOPS documents in ongoing development: 1) the ARAC consensus recommendations, 2) the JAA ETOPS/LROPS recommendations still in development and, 3) ICAO international ETOPS recommendations. There is an urgent need to harmonize these efforts into one regulatory document to avoid chaos in extended-range international flights, whatever the number of engines on the airplanes, sources assert. Unambiguous rules in clear, easily understandable language are of greatest importance, especially for pilots whose first language is not English.

‘Promptly Initiate a Diversion’

Transport Canada on Standard Maximum Diversion Time (extracts):

Operators shall ensure that:

1. Company procedures require that upon occurrence of an in-flight shutdown of an engine, the pilot shall, subject to PIC’s Authority [pilot in command, italics in original], promptly initiate a diversion and fly to and land at the nearest suitable airport in terms of flying time, at which a safe landing can be made; and

2. A procedure shall be established such that in the event of a single or multiple critical system failure, the pilot shall, subject to PIC’s Authority, initiate the diversion procedure and fly to and land at the nearest suitable airport, unless it can be established that no substantial degradation of safety results from continuation of the planned flight.

Source: Transport Canada, ETOPS Operational Approval Criteria, see http://www.tc.gc.ca/CivilAviation/Commerce/manuals/manuals_word/tp6327/chapter3.rtf

‘Be Prepared’

For contingency and passenger recovery plans, operators would have to be prepared in their own interest to know:

• How to evacuate passengers from a plane at diversionary airports, i.e., over polar routes (Canada, Russia, China, etc.)
• The availability of ramps or air stairs to evacuate (experience has shown that suitable ramps did not exist at some airports and they had to be crudely constructed).
• Availability of clothing for crews and passengers before evacuation in inclement and freezing weather.
• Availability of suitable transportation to airport buildings.
• Availability of suitable accommodations (hotels, food, etc.).
• Availability of medical facilities.
• Availability of airport rescue and fire fighting (ARFF).
• Availability of sufficient runway/ramp space to handle a recovery aircraft in addition to the diverted aircraft.
• Capability to refuel and take off.
• Suitability of financial resources. If credit cards not accepted, do pilots have funds to pay for fuel, services, etc., and in which currency?
• Political stability – danger that plane and occupants [could] become hostages for monetary or political reasons.
• Availability of suitable communications.

Sources: FAA Guidance for Polar Operations; Air Crash Victims Family Group