Connect with us


The cold, hard facts about Flight BA38



In my many years of flying, I have noticed that in the western hemisphere, winter weather is usually worse after the New Year than before. Perhaps the sting is in the tail.

On January 16, 2008, I was operating a Boeing 747-400 flight from Singapore to London-Heathrow. Our night-time departure from Singapore gave us an expected arrival time (ETA) of a few minutes before 6 am on the 17th. The flight was uneventful except for when, somewhere over Austria, we encountered a spell of cold weather at high altitude which made our fuel temperatures drop well below acceptable levels. In my 30-something years as a pilot, this was the first time I experienced such a phenomenon, in this part of the world. Our indication of fuel temperature in the wing tanks (where fuel is mostly carried) turned from the colour green to amber, prompting us to exercise caution. The very low temperatures persisted all the way to London.

When this happens, pilots have two options: either descend to lower altitudes where there is warmer air; or increase the cruising speed, which in turn will increase air compressibility because of a phenomenon called the ‘ram effect’, thereby warming the surrounding air and, as a consequence, the fuel in the wings.

A few months before that incident, while flying a 747-400 cargo (freighter) aircraft from O’Hare Airport, Chicago, USA to Shanghai, China, on a route close to the North Pole, we experienced low fuel temperatures and decided to take the second option of increasing our cruising speed. It took a long time to raise our fuel temperatures to an acceptable level. So, in this latest instance, en route to London, I decided to descend to warmer air. It should be noted that both methods consume more fuel. Being winter, the tail winds were strong and we had made up some time and consumed less fuel than expected, so we could afford to burn extra fuel on the descent to a ‘warmer’ altitude. Apart from that, the flight was uneventful, and we touched down at London Heathrow only about a minute before our 6 am ETA.

After entry formalities were completed, followed by a short ride to our London hotel, I was in bed soon after 8.30 am. I slept soundly until approximately 1 pm. After waking up, as usual I switched on the TV and discovered that there had been a crash of a British Airways Boeing 777 at around midday, near the approach end of Heathrow’s Runway 27L (Left). The aircraft had undershot the runway badly and landed ‘short’, narrowly missing the Hatton Cross Tube Station. It was the first major accident at Heathrow Airport in 30 years.

What could have gone wrong? Were the pilots at fault? I suspected that the unusual low temperatures we experienced that morning may have been a contributory factor in the crash. Anyway, it was too early to tell, and one had to wait until the preliminary report of the Aircraft Accidents Investigation Branch (AAIB) of the UK’s Department of Transport to be published. This is their story.

The British Airways (BA) Boeing 777-263 ER (Extended Range), Registration G-YMMM, departed Beijing, China about 6 hours behind our flight. The BA Flight Dispatchers had known that there was a forecast of unusually cold air masses that morning and therefore planned the flight at lower than normal heights to prevent the fuel from being affected by low temperatures. Being not too heavy, for the sake of passenger comfort, throughout the flight high power settings were not used even for climb to intermediate levels. The descent to London had also involved minimum power for a long period. Then, at the last moment of the landing approach (at a height of 720 feet), the two engines which were on automatic thrust lost power (ran down),but did not totally quit. When the First Officer, who was the ‘pilot flying’ (PF) on that sector, opened the throttles to increase power to the required setting, the engines didn’t respond. As a result, the aircraft could not remain on the required glide path and went into a high rate of descent to maintain flying speed, consequently undershooting and touching down heavily on the grass, 330 metres short of the runway’s paved area.

For the more technically minded, the landing approach of an aircraft involves a balance of Potential Energy, Kinetic Energy, and Chemical (Fuel) Energy. While the total of Potential Energy and Kinetic Energy is a constant, Chemical Energy in variable amounts has to be used to overcome the drag created by wheels and flaps when they are extended to maintain safe flight at slow speeds (e.g. on descent and approach before landing). In fact, when it became apparent that the situation was hopeless and the aircraft was undershooting, the captain, watching helplessly in horror, quickly reduced the flap setting to reduce the drag.

On touching down with a high sink rate, the undercarriage collapsed, and the aircraft slid forward a short distance before stopping. After it stopped there was considerable leakage of fuel from both engines, but fortunately no fire. The 16 crew members and nearly all 135 passengers suffered either minor injuries or none at all. However, one passenger did incur serious injuries when a wheel mounting pierced the cabin floor as a result of the heavy ground impact. One minute and 42 seconds after the crash alarm was sounded by the control tower, emergency crews were at the crash site. (See picture 2)

Subsequently, the Air Accidents Investigation Branch (AAIB) UK took over the accident investigation. With the use of the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) (collectively called, inaccurately, the ‘black box’ – they are actually contained in Day-Glo orange casings to facilitate location and retrieval amongst the wreckage) they were able to reconstruct the flight, including the last few moments before the crash. As engine power was not available when demanded by the throttle inputs, it was suspected that there was some obstruction to the fuel flow into the engines. The AAIB had to simulate low temperatures and fuel flows while conducting the research.

Research done on both sides of the Atlantic more than 50 years ago showed that jet fuel (a form of kerosene), when subjected to temperatures below freezing, becomes waxy and sticky. Furthermore, it is near impossible to drain all the naturally occurring water in the fuel tanks. After flying for a while in sub-zero temperatures, the fuel becomes ‘cold soaked’. Then, upon landing at the next airport, warm, humid air enters the relatively empty tanks through the air vents, and because of the presence of cold fuel, condensation occurs inside the fuel tanks, forming water droplets. Being of higher density, water will then drip and pool at the bottom of the tanks, where most of it could be physically drained by the ground engineers. However, some of the water inevitably remains and turns into ice crystals at low temperature on the next flight. It was determined by the AAIB that these were the two most likely ‘culprits’.

During the Board’s extensive investigation, it was observed that all aircraft fuel systems were designed based on this outdated research. Today’s aircraft engines, such as the Rolls-Royce Trent 800 series, which power the Boeing 777, are much larger and expected to operate for longer hours in sub-zero temperatures.

In its final report the AAIB made 18 safety-related recommendations. After which, the main component whose design was changed was the Fuel Oil Heat Exchanger (FOHE). Before entering the engine, cold fuel was heated with hot engine oil in the FOHE. (See picture 3)

In the FOHE, cold fuel was sent through tubes with hot oil from the engine circulating around them. The design of the tubes was such that they were protruding by about 4mm, not flush with face of the FOHE. When tested in the lab, it was found that this trapped and accumulated the waxy fuel, along with ice crystals in the fuel, on top of the tubes, thereby effectively blocking them. (See picture 4)

The AAIB investigation identified the following probable causal factors that led to the fuel flow restrictions:

1) Accreted ice from within the fuel system was released, causing a restriction to the engine fuel flow at the face of the FOHE on both engines.

2) Ice had formed within the fuel system, from water that occurred naturally in the fuel, whilst the aircraft operated with low fuel flows over a long period and the localised fuel temperatures were in an area described as the ‘sticky range’.

3) The FOHE, although compliant with the applicable certification requirements, was shown to be susceptible to restriction when presented with soft ice in a high concentration, with a fuel temperature that is below -10°C and a fuel flow above flight idle.

4) Certification requirements, with which the aircraft and engine fuel systems had to comply, did not take account of this phenomenon as the risk was unrecognised at that time.

“A chain is as strong as its weakest link.” The FOHE certainly was a weak link, which was accepted by Boeing and Rolls-Royce.

An intercontinental jet aircraft has thousands of components certified by the USA’s Federal Aviation Administration (FAA) or European Union Aviation Safety Agency (EASA), and must be proved to be fail-safe: a practically impossible task. Therefore, a given component is introduced to service when the authorities feel it is basically safe, and carry out rectification/modification of components when problems occur during service.

Many years ago Ralph Nader highlighted in his book ‘Collision Course’ the truth about air safety, that human life is quantified at $1,000,000/- each by the aircraft manufacturers. If a modification costs more in dollar terms than the amount of people it is meant to save, then such a modification is considered not viable. But that’s another story!

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *


Why Small Farms will be the backbone of food security



The ecological axiom that: ‘Energy flow through a system tends to organise and simplify that system’, is abundantly clear in agriculture. As farms moved from small interdependent units, bounded by fences and hedgerows, to large cropping fields to accommodate machine management, we lose the biodiversity that once existed on that landscape and the biomass that provided the Ecosystem Services. This sacrifice was rationalised through the invocation of economic profit. The economic ‘profit’ gained by subsidies on fossil fuel and uncontrolled extraction from the Global Commons. The ‘development’ of agriculture has become a race to control the commodity market. The farmer ceased to be a feature of the farm. In a telling statement, the farmers of Sri Lanka sent the following statement to the CGIAR in 1998 :

‘We, the farmers of Sri Lanka would like to further thank the CGIAR, for taking an interest in us. We believe that we speak for all of our brothers and sisters the world over when we identify ourselves as a community who are integrally tied to the success of ensuring global food security. In fact it is our community who have contributed to the possibility of food security in every country since mankind evolved from a hunter-gather existence. We have watched for many years, as the progression of experts, scientists and development agents passed through our communities with some or another facet of the modern scientific world. We confess that at the start we were unsophisticated in matters of the outside world and welcomed this input. We followed advice and we planted as we were instructed. The result was a loss of the varieties of seeds that we carried with us through history, often spanning three or more millennia. The result was the complete dependence of high input crops that robbed us of crop independence. In addition, we farmers producers of food, respected for our ability to feed populations, were turned into the poisoners of land and living things, including fellow human beings. The result in Sri Lanka is that we suffer from social and cultural dislocation and suffer the highest pesticide- related death toll on the planet. Was this the legacy that you the agricultural scientists wanted to bring to us ? We think not. We think that you had good motives and intentions, but left things in the hands of narrowly educated, insensitive people.’

The diverse farm had to yield to production monoculture, which was made possible through the burning of fossil fuels. Ironically the burning of fossil fuels is the major reason for the current destabilised climate and threat to agriculture. One consequence of climate change is the predicted rise in global temperatures. If ambient temperatures exceed 40 degrees , which has become the reality in many places even today, food production will be compromised. All the food we eat originates with plants and plants produce using photosynthesis. Photosynthesis, or the capture of solar energy by plants, is done with chlorophyll, the thing that makes plants green and chlorophyll begins to break down after 40 degrees. Landscapes whose summer temperatures go beyond this limit will have smaller and smaller crops as the temperatures increase. The only solution to this oncoming crisis, is to begin introducing trees at strategic points on the landscape.

Trees and all other forms of vegetation cool the environment around them through the transpiration process, which takes place in the leaves. The water absorbed by the roots is sent up to the leaves which release it as vapor, cooling the air around it. Measurements on trees done by research institutions worldwide, indicate that an average large tree produces the cooling equivalent of eight room sized air conditioners running for 10 hours, a cooling yield 0f 1,250,000 Bthu per day. Plantations of trees have been recoded to have daytime temperatures at least 3 degrees below the ambient. This is an important aspect of Ecosystem Services that needs to be considered for adaptive agriculture.

Small farms which produce food with low external energy and maintain high biomass and biodiversity, are the models of food production that can face the climate compromised future before us. Capital, resource and energy expensive agricultural systems could fail in a high temperature future and threaten global food security, we need options. One would be to encourage a consumption and distribution system that facilitates small farmers to enter the market. Another would be to realise the value of the ecosystem services of a farm and develop systems to measure and reward. We are all aware of the future before us. Now is not the time to stand blinking like a deer facing the headlights.

But placing trees in and around cropping areas becomes a problem in large cropping fields designed to accommodate machine management. The management of such trees and hedgerows requires needs that cannot be provided without human management. Agricultural landscapes will need management that will be adaptive to the changing climate. An example would be; small interdependent units bounded by fences and that increase biodiversity and the biomass while providing Ecosystem Services.

Investment in food security, should take climate change seriously. All new agricultural projects should address the heat thresholds of the planned crops. The Sri Lankan country statement at COP 21 stated that :

“We are aware that the optimum operating temperature of chlorophyll is at 37 deg C. In a warming world where temperatures will soar well above that, food production will be severely impacted.”

And that :

“We are aware that the critical Ecosystem services such as; production of Oxygen, sequestering of Carbon, water cycling and ambient cooling is carried out by the photosynthetic component of biomass. This is being lost at an exponential rate, due to the fact that these Ecosystem Services have not been valued, nor economically recognised.”

These statements cry out for the recognition of the role that small farms will have to play in the future. In a temperature compromised future, small farms with high standing biomass, through their cooler temperatures will continue to produce food in heat stressed periods. If such Ecosystem Services can be given a value, it will strengthen the economy of small farms and ensure local, sustainable food production into the future.

Small farms which produce food with low external energy and maintain high biomass and biodiversity, are the models of food production that can face the climate compromised future before us. Capital, resource and energy expensive agricultural systems could fail in a high temperature future and threaten global food security, we need options. One would be to encourage a consumption and distribution system that facilitates small farmers to enter the market. Another would be to realize the value of the ecosystem services of a farm and develop systems to measure and reward. We are all aware of the future before us. Now is not the time to stand blinking like a deer in sheadlights.

Continue Reading


Encouraging signs, indeed!



Derek and Manilal

Local entertainers can now breathe a sigh of relief…as the showbiz scene is showing signs of improving

Yes, it’s good to see Manilal Perera, the legendary singer, and Derek Wikramanayake, teaming up, as a duo, to oblige music lovers…during this pandemic era.

They will be seen in action, every Friday, at the Irish Pub, and on Sundays at the Cinnamon Grand Lobby.

The Irish Pub scene will be from 7.00 pm onwards, while at the Cinnamon Grand Lobby, action will also be from 7.00 pm onwards.

On November 1st, they are scheduled to do the roof top (25th floor) of the Movenpik hotel, in Colpetty, and, thereafter, at the same venue, every Saturday evening.

Continue Reading


Constructive dialogue beyond international community



by Jehan Perera

Even as the country appears to be getting embroiled in more and more conflict, internally, where dialogue has broken down or not taken place at all, there has been the appearance of success, internationally. President Gotabaya Rajapaksa will be leading a delegation this week to Scotland to attend the UN Climate Change Conference (COP26). Both the President, at the UN General Assembly in New York, and Foreign Minister Prof G L Peiris, at the UN Human Rights Council, in Geneva seem to have made positive impacts on their audiences and, especially amongst the diplomatic community, with speeches that gave importance to national reconciliation, based on dialogue and international norms.

In a recent interview to the media Prof Peiris affirmed the value of dialogue in rebuilding international relations that have soured. He said, “The core message is that we believe in engagement at all times. There may be areas of disagreement from time to time. That is natural in bilateral relations, but our effort should always be to ascertain the areas of consensus and agreement. There are always areas where we could collaborate to the mutual advantage of both countries. And even if there are reservations with regard to particular methods, there are still abundant opportunities that are available for the enhancement of trade relations for investment opportunities, tourism, all of this. And I think this is succeeding because we are establishing a rapport and there is reciprocity. Countries are reaching out to us.”

Prof Peiris also said that upon his return from London, the President would engage in talks locally with opposition parties, the TNA and NGOs. He spoke positively about this dialogue, saying “The NGOs can certainly make a contribution. We like to benefit from their ideas. We will speak to opposition political parties. President Gotabaya Rajapaksa is going to meet the Tamil National Alliance on his return from COP26, which we will attend at the invitation of the British Prime Minister. So be it the NGO community or the foreign diaspora or the parliamentary opposition in Sri Lanka. We want to engage with all of them and that is very much the way forward”


The concept of a whole-of-government approach is indicative of a more cohesive approach to governance by government ministries, the public administration and state apparatus in general to deal with problems. It suggests that the government should not be acting in one way with the international community and another way with the national community when it seeks to resolve problems. It is consistency that builds trust and the international community will trust the government to the extent that the national community trusts it. Dialogue may slow down decision making at a time when the country is facing major problems and is in a hurry to overcome them. However, the failure to engage in dialogue can cause further delays due to misunderstanding and a refusal to cooperate by those who are being sidelined.

There are signs of fragmentation within the government as a result of failure to dialogue within it. A senior minister, Susil Premajayantha, has been openly critical of the ongoing constitutional reform process. He has compared it to the past process undertaken by the previous government in which there was consultations at multiple levels. There is a need to change the present constitutional framework which is overly centralised and unsuitable to a multi ethnic, multi religious and plural society. More than four decades have passed since the present constitution was enacted. But the two major attempts that were made in the period 1997-2000 and again in 2016-2019 failed.

President Rajapaksa, who has confidence in his ability to stick to his goals despite all obstacles, has announced that a new constitution will be in place next year. The President is well situated to obtain success in his endeavours but he needs to be take the rest of his government along with him. Apart from being determined to achieve his goals, the President has won the trust of most people, and continues to have it, though it is getting eroded by the multiple problems that are facing the country and not seeing a resolution. The teachers’ strike, which is affecting hundreds of thousands of schoolchildren, is now in its fourth month, with no sign of resolution. The crisis over the halting of the import of chemical fertiliser is undermining the position of farmers and consumers at the present time.


An immediate cause for the complaints against the government is the lack of dialogue and consultation on all the burning issues that confront the country. This problem is accentuated by the appointment of persons with military experience to decision-making positions. The ethos of the military is to take decisions fast and to issue orders which have to be carried out by subordinates. The President’s early assertion that his spoken words should be taken as written circulars reflects this ethos. However, democratic governance is about getting the views of the people who are not subordinates but equals. When Minister Premajayantha lamented that he did not know about the direction of constitutional change, he was not alone as neither does the general public or academicians which is evidenced by the complete absence of discussion on the subject in the mass media.

The past two attempts at constitutional reform focused on the resolution of the ethnic conflict and assuaging the discontent of the ethnic and religious minorities. The constitutional change of 1997-2000 was for the purpose of providing a political solution that could end the war. The constitutional change of 2016-19 was to ensure that a war should not happen again. Constitutional reform is important to people as they believe that it will impact on how they are governed, their place within society and their equality as citizens. The ethnic and religious minorities will tend to prefer decentralised government as it will give them more power in those parts of the country in which they are predominant. On the other hand, that very fact can cause apprehension in the minds of the ethnic and religious majority that their place in the country will be undermined.

Unless the general public is brought aboard on the issue of constitutional change, it is unlikely they will support it. We all need to know what the main purpose of the proposed constitutional reform is. If the confidence of the different ethnic and religious communities is not obtained, the political support for constitutional change will also not be forthcoming as politicians tend to stand for causes that win them votes. Minister Premajayantha has usefully lit an early warning light when he said that politicians are not like lamp posts to agree to anything that the government puts before them. Even though the government has a 2/3 majority, this cannot be taken for granted. There needs to be buy in for constitutional reform from elected politicians and the general public, both from the majority community and minorities, if President Rajapaksa is to succeed where previous leaders failed.

Continue Reading