EMERGENCY LANDING OF MILITARY AIRCRAFT IN WOODLANDS

EMERGENCY LANDING OF MILITARY AIRCRAFT IN WOODLANDS: 3.

Mr Michael Palmer asked the Deputy Prime Minister and Minister for Defence

Column: 1325

(a) what is the outcome of the investigation on the emergency landing of an RSAF Apache AH-64 on the vacant field along Woodlands Avenue 12; (b) what measures will the RSAF take to prevent such incidents from occurring again; (c) given the proximity to civilian populated areas which aircraft must fly in Singapore, what procedures does the RSAF have in place when an emergency such as this arises; and (d) if the RSAF will review its policy on aircraft flying in close proximity to housing estates to reduce the risk to public safety.

4.

Mr Low Thia Khiang asked the Deputy Prime Minister and Minister for Defence what safeguards are in place to protect civilians from safety risks arising from SAF air training accidents.

5.

Er Lee Bee Wah asked the Deputy Prime Minister and Minister for Defence (a) what is the root cause of the recent emergency landing by an RSAF helicopter in an open field in Woodlands; (b) what is the standard procedure for pilots who have to make an emergency landing; (c) what is the guideline on public safety when a pilot has to make an emergency landing; and (d) whether it is safe to conduct flight training in Singapore which is densely populated.

6.

Assoc. Prof. Paulin Tay Straughan asked the Deputy Prime Minister and Minister for Defence whether the Ministry can make public the list of emergency landing sites for military aircraft and whether notices can be placed at these sites to help users stay alert should an emergency arise.

The Deputy Prime Minister and Minister for Defence (Mr Teo Chee Hean): Mr Speaker, Sir, may I have your permission to take Question Nos. 3, 4, 5 and 6 together?

Column: 1326

Mr Speaker: Yes.

Mr Teo Chee Hean: Mr Speaker, Sir, MINDEF has carried out investigations with the aircraft and engine manufacturers into the cause of the loss of power in both engines which led to the incident of the Apache landing in the open field. Following the incident, both engines from the aircraft were sent to the manufacturers for a full tear-down and inspection. The manufacturers have identified a defective component which is present in both engines of the aircraft, which led to the loss of power and shut-down of both engines during flight.

The defective component is called the Anti-Ice Start Bleed Valve (AISBV). A corroded valve would lead to malfunctioning of the guide vanes that channel air to the aircraft engine. The disruption of airflow to the engine will lead to the loss of engine power. The Anti-Ice Start Bleed Valves in both engines were found internally corroded when opened up by the manufacturer. The defect was caused by corrosion in the valve which occurred over time. The investigation then looked into why the AISBV was corroded and why the corrosion went undetected. We looked into whether there was a manufacturing defect or a maintenance error.

Sir, the valves used in the RSAF Apache fleet are the same as those used by other Apache operators around the world. We have no evidence that there were manufacturing defects in these valves. We have also ascertained that the RSAF maintenance crews adhered to the required maintenance procedures specified by the manufacturer for the aircraft, including the AISBV. Prior to this, there were no reported incidents of the same nature. Currently, there are also no stipulated maintenance checks that would allow such internal corrosion in the AISBV to be detected by the maintainers. The maintenance procedure does not call for

Column: 1327

the RSAF to open up the AISBV for inspection. This can only be done by the manufacturer. The aircraft operator, in our case the RSAF, needs to replace the AISBV only after a fault code appears in the aircraft computer during flight, or when running the engine on the ground for tests. The nature of the malfunction arising from the corrosion was not detected by the aircraft computer and therefore no fault code was generated. We are now studying, together with the aircraft manufacturer, the maintenance procedures to see whether the maintenance procedures mandated by the manufacturer need to be modified so that corrosion which occurs inside this valve can be prevented, or can be detected and corrected should it occur.

To ensure that our helicopters are fitted only with valves that operate properly, the RSAF will replace all existing valves with new ones, or valves that are re-certified by the manufacturer, and test the engines thoroughly before we clear each helicopter for flying. Having also reviewed and established that the RSAF’s maintenance, flight and training safety procedures are sound, the Apache and the SeaHawk helicopters will progressively resume flying this week.

Mr Speaker, Sir, the RSAF maintains the highest standards of maintenance and flight safety. Let me now turn from the cause of the power loss in the engines to how the RSAF's pilots are trained to handle emergencies. Training in emergencies is a key part of the training of all our pilots. In the event of an emergency, where possible, the aircraft will be flown back to the nearest airbase immediately. If this is not feasible, the pilots will attempt a safe landing at the nearest open space.

In doing so, the key priority is always to avoid populated areas. Safety to the populace has the highest priority. This is what the two pilots did in this incident. When they determined that they were not able to land at an airbase, they

Column: 1328

considered their options, and found an open space away from buildings and populated areas, verified and confirmed that the field was clear of people, and then executed an emergency landing.

Any open unused plots of land or open fields are potential emergency landing sites for helicopters. Depending on the flight route of the helicopter, various open spaces are identified and briefed as part of pre-flight procedures for that flight. This is carried out for all RSAF helicopter flights. Hence, it is not possible to identify any specific open spaces as designated emergency landing sites as emergency landing sites depend on the flight routes being taken and where the emergency occurs. Our pilots are trained to ensure the safety of the public before making a decision to land in any of these open spaces, and they will forego such a landing even at risk to themselves if there is a danger to the population.

Let me now turn to the issue of flight training in Singapore and the safety of our population. Mr Speaker, Sir, Singapore is densely populated and has limited airspace. The RSAF also has to share the tight airspace with civilian aircraft. Given these constraints, in addition to local training, the RSAF conducts training in overseas training areas as well as on simulators. The RSAF strikes an appropriate balance amongst these three forms of training. Local training is essential to maintain the proficiency of our Singapore-based aircrew, and to ensure that all our pilots are familiar with the local operating environment. Overseas training is more costly but it helps address the airspace constraints our pilots face at home. Simulator training is a useful and effective component of pilot training to improve piloting and operational skills. It allows pilots of varying experience to be trained on aircraft handling under different operational scenarios and this includes, in particular, training all our pilots on

Column: 1329

handling the various types of aircraft emergencies.

Mr Speaker, Sir, the safety of our populace is a top priority of MINDEF and the RSAF. We have thus taken steps to ensure that training flights over residential areas are minimised whenever possible, that they are conducted safely and that they are in accordance to norms prescribed by international aviation bodies, such as the International Civil Aviation Organisation and the Federal Aviation Authority of the United States. These norms govern the minimum flying altitudes designed to ensure the safety of residents living in close proximity to airbases, airports or air fields. They are similar to those adopted in airports which operate in densely-populated cities as well as where civilian helicopters are used for transportation in major cities and land on helipads on high-rise buildings in densely populated areas. So it is not uncommon for aircraft and helicopters, even civilian ones, to operate over densely populated areas.

While we cannot totally prevent machine failures from occurring, we will do our best to minimise the risk of such failures. The RSAF has in place a comprehensive maintenance programme to ensure the air worthiness of our aircraft. In addition, all our pilots undergo regular emergency aircraft training; and discussions on emergency procedures are carried out as part of every pre-flight preparation. This is to ensure that the pilots are able to respond quickly and professionally in order to minimise any risk posed to the public in the event of an aircraft emergency.

Mr Michael Palmer (Pasir Ris-Punggol): I thank the Minister for his comprehensive reply. Given that detection of corrosion in the AISB valve did not happen this time round, are the RSAF and all the

Column: 1330

manufacturers working on a means to detect corrosion or any other faults in the AISB valve for future engines?

Mr Teo Chee Hean: Yes, certainly. Mr Speaker, Sir, the airforce as an operator of the aircraft follows strictly the maintenance and inspection procedures that are mandated by the aircraft manufacturer based on its experience garnered from many years of producing aircraft and also, in the case of the Apache, many years of operating the aircraft. As I said, this is the first time such a failure due to corrosion of this valve has occurred. So this is a new occurrence. We are discussing, together with the manufacturers, what procedures – maintenance procedures, replacement procedures and lifting procedures – which will be able to prevent the recurrence of such an event.

Mr Low Thia Khiang: I would like to ask about safety emergency procedures for a fighter aircraft and pilot training aircraft flying over Singapore.

Mr Teo Chee Hean: Mr Speaker, Sir, broadly speaking, the same procedures apply. In the case of a training aircraft, there is always an experienced instructor pilot together with the trainee. So he will be able to handle all the emergencies that arise. In fact, training aircraft are, in general, quite safe compared to other aircraft. They are designed that way for extra safety. Perhaps, I should cite one example. Members will recall that on 15th January 2009 in the United States, the US Airways Flight 1549 which was a scheduled commercial passenger flight, an Airbus A320, was on its way from New York to North Carolina when it encountered a bird strike during its initial climb out from LaGuardia Airport in New York. This resulted in a complete loss of power in both engines. The pilots determined that they were unable to reliably reach any air field safely and elected to glide the aircraft towards the

Column: 1331

Hudson River before executing an emergency landing on the river. The river is in the middle of New York city. I do not think it was pre-designated as an emergency landing site by the Civil Aviation Authority. But these things do happen. Pilots are trained to deal with them and, in this case, quite clearly, the pilot did an excellent job and the incident had been described by some as the most successful ditching in aviation history and the pilot and aircrew were lauded for their heroism in bringing the aircraft down safely on the river.

Er Lee Bee Wah (Ang Mo Kio): Mr Speaker, the Deputy Prime Minister mentioned that the corrosion has never happened before, according to the manufacturer, and the probability of having more corrosion is even rarer. I would like to ask the Deputy Prime Minister what is the age of this helicopter.

Mr Teo Chee Hean: Before this incident, the RSAF had flown some 28,000 accident-free Apache hours since operating the aircraft eight years ago. So, this is a relatively new aircraft and the aircraft is maintained regularly according to the procedures specified by the manufacturer. Our maintenance standards are very high.

Mr Cedric Foo Chee Keng (West Coast): Sir, I would like to ask the Deputy Prime Minister if he would recommend to the manufacturer to look into the redundancy issue. The Apache has two engines and, as I understand it, it can fly with one. But if both engines can fail at the same time, then the issue of redundancy has not been properly addressed. My follow-up question is: would the Minister comment on how our pilots perform when both engines failed on them?

Mr Teo Chee Hean: Certainly, we were very surprised by this incident because, as the Member has said, the Apache is designed as a highly redundant aircraft

Column: 1332

meant to take combat hits, carry out its mission and bring the crew home. So we were very surprised by this incident because the Apache is a very robust aircraft. In fact, we did not have any accident with it for over 28,000 flying hours over eight years. So this was a very unique case. The valve that was installed was corroded. It did not happen before. So we are examining, together with the manufacturer, why such a thing occurred in the first place and also whether there are maintenance procedures which can be taken to prevent it from occurring. It could be, for example, replacing a valve more frequently or sending the valve for tear-down and re-certification more frequently. These are currently not in the maintenance procedures, and we will certainly do so.

As regards the performance of the pilots, this was carefully evaluated by the airforce and the conclusion is that the pilots did very well under the circumstances. In an emergency like this, they typically have a minute or two like in the LaGuardia case, they had three minutes. So the pilots must have great presence of mind and must take the right decisions. In the case of these pilots, they did have another option and that would have been to carry on and try to land the aircraft in a forested area which was adjacent to where they had landed. If they had done so, I think they would have been at higher risk themselves. They saw the open field, checked that it was clear and decided to make a landing there. The airforce's conclusion is that they made the right call and did well.

Mr Speaker: Last question, Assoc. Prof. Tay.

Assoc. Prof. Paulin Tay Straughan (Nominated Member): Sir, first, I would like to apologise for my ignorance because I do not quite understand these things. But, typically, Sir, in an incident like this, how much response time will the ground

Column: 1333

staff have? I am thinking if there was sufficient time for the nearest Police post, or whatever, to go to the area that is designated for the emergency landing to try to clear the area. In this instance, if the school had been dismissed at that time and kids were spewing out from the school, I think we could not have avoided fatalities.

Mr Teo Chee Hean: I would like to make a few points. Firstly, as I said, in answer to previous supplementary questions, if there had been any risk to the population, the pilots would not have landed, even at great risks to themselves. They would not have done so. Pilots are trained to do that, and that is what they would do. Secondly, the area in which they landed was about 400 metres or more from the nearest building – 400 metres is a considerable distance. I had a look at the place myself on the evening of the incident. It was about 400 to 500 metres away from the school and any other building. So the pilots, in my assessment, chose the place well, given the limited time that they had.

So the issue of whether or not there are people who can respond within the two or three minutes to clear the place, that does not really arise because if it is a place with people, and the pilots can avoid landing there and land somewhere else even at risk to themselves, they would have done so. But I must say also that the Police were very quick on the scene. They arrived on the scene within minutes and cordoned off the area.