Fly by Light

Well it looks like the science fiction is being overtaken by reality. Recently a Gulfstream 550 jet was controlled by a light signal from the cockpit to one of the flying controls. The controls of an aircraft are traditionally moved by the pilots commands being transmitted to the control via a stainless steel cable or aluminum rods. This also involves pulleys and bellcranks to move the cable in the correct direction. Then 'fly by wire' was developed which relies on electrical signals to move the control surfaces. This saved weight and allowed computers to control the aircraft without the traditional cables.
Now we have a signal from the pilots controls changed into a light pulse which is transmitted via fiber optics to a receiver where it is converted back to an electrical signal to move the control. This saves even more weight and is a lot more reliable than an electrical wire which can short or break. There is no danger of losing the signal if even a fraction of the fiber optic cable is left intact after it has been damaged.
If you think this is ground breaking then you will be amazed to learn that in the same experimental aircraft there was a 'fly by wireless' system operating as a back up which as the name suggests has no connection from the cockpit to the control except a radio signal. This has to be the ultimate in weight saving and reliability. When it is fully tested and approved it will be almost unheard of to lose control of the aircraft due to mechanical or hydraulic failure as the systems will not rely on them.

Qantas Airliner Plunges Out of Control.



A terrifying headline to all who fly in aircraft and it is a very real risk in the age of modern air travel. The infrequency of this occurrence is thankfully rare and the majority are weather related and avoidable.



So, what went wrong with the Qantas Airbus A330-300 aircraft? During the flight the aircraft had several departures from its assigned altitude, the result of these changes were injuries and panic in the cabin as people who were not wearing their seat belts were thrown around.



The majority of modern aircraft are flown by a fly by wire system; this is in response to the development of flight control computers which control the aircraft's altitude and direction of the flight. These computers are designed to keep the aircraft within its design limits. If the aircraft is going too slow, too fast, or approaching the design limits it will take action to correct the situation.



So, how does the computer know whats going on? There are sensors on the aircraft which measure the outside air temperature, air speed, altitude and angle of attack, (the amount of nose up or nose down), all these inputs, and many others, are sent to an Air Data Inertial Reference Unit (ADIRU) which converts them to signals for the Flight Computer so they can operate the flight controls the way the pilots require.



On the Qantas aircraft the ADIRU gave incorrect data to the Flight Computers which made the aircraft climb to reduce an incorrect overspeed and then dive to avoid a non existent stall due to low airspeed. The aircraft autopilot was engaged until the unexpected climb when it disconnected and the crew flew the aircraft themselves. Even though the crew was flying the aircraft the inputs from the ADIRU still continued to affect the aircraft. The design of the system is to keep the aircraft within its limits and the ADIRU was giving erroneous information to the Flight Control Computer that these limits were being approached. The effects were minimised by the crew but they were still bad enough to cause inuries to people who were in the cabin.



This is the first known occurrence of this type of failure with the ADIRU. Airbus have issued a Telex to all the operators of this type of aircraft to provide operational actions to minimise the effects in the event of this happening again. There are 3 ADIRU’s and 3 Primary Flight Computers on the aircraft control system and the investigation will now concentrate on how a failure with one had such an effect on the aircraft.

The US Federal Aviation Authority have now issued an Airworthiness Directive (AD) concerning the problems with ice in the fuel system of Boeing 777-200 and 300 airplanes fitted with Rolls Royce Trent 800 engines. The AD requires the crew to monitor the fuel temperature within 3 hours of top of descent and if it is below a certain temperature they must increase the engine power to prevent the formation of ice in the main tank fuel supply system. They can do this by stepping up to a higher altitude or increase the airspeed. There is no requirement to carry out this procedure if the aircraft is not fitted with Trent 800 engines.

There is also a procedure for the circulation of the fuel on the ground by a certified mechanic to prevent the formation of ice.

This AD is a result of the problems encountered in January 2008 by a British Airways Boeing 777 which failed to respond to a command for increased thrust while the aircraft was on approach to London Heathrow airport and landed short of the runway. the interim report suggested ice formed in the main fuel tank supply system during low fuel flow conditions in cruise flight. This ice then dislodged and caused a restriction in fuel supply during high flow conditions during approach.

No doubt there will be more measures to prevent the formation of ice from the engine and aircraft manufacturers but in the mean time the FAA are counting on this procedure to prevent the recurrence of the fuel restriction and loss of engine power.

British Airways Boeing 777 Crash at Heathrow

Ice has always been the enemy of aircraft, it builds up on the wings and reduces lift and it lies on the runway and reduces braking and directional control when landing, but now there is a new hazard. After nine months of investigation the Air Accidents Investigation Branch (AAIB) have decided the cause of the British Airways Boeing 777 landing short at Heathrow and crashing was due to ice in the fuel. All the passengers and crew escaped the aircraft with only minor injuries apart from one man who broke his leg.

It has been known for years that there is water in aviation fuel and when the temperature drops, due to the aircraft operating at altitude, ice crystals form in the fuel. There have been chemical and mechanical solutions to this problem and it is a largely unknown problem in large commercial aircraft.

The fuel passing through a Trent 800 engine like the one that was powering the BA aircraft goes to an oil/fuel heater in the engine fuel system. This takes hot oil from the engine to a matrix of small pipes and passes fuel around the pipes on its way to the fuel control unit and the burners. This is normally sufficient to melt any ice that may be in the fuel so it will not interfere with the operation of the engine. The theory of the investigators is that ice formed before the engine oil/fuel heater and reduced the amount available for the engines to use.

The High Pressure fuel pumps that are downstream of the oil/fuel heater showed evidence of cavitation. This is a condition that happens when the impellor of the pump has an insufficient fuel supply to boost to a higher pressure and mechanical damage is caused to the pumps. Clearly there was low fuel supply to the engines but where was the restriction? Because of filters, low-pressure pumps and valves that are all in the fuel supply system it has not yet been determined as to where the problem lies.

Why it occurred is also a mystery as there has never been a case of fuel starvation due to icing in the fuel system of a commercial airliner. The Flight Data Recorder has shown that within 6 seconds both engines reduced power to a value below that needed to maintain flight and the automatic systems and the pilots took the required actions to supply more fuel but to no avail as it could not get to the High Pressure Pump.

The low fuel flow at cruise power settings on an especially cold, long flight may have caused a build up of ice in an area in the fuel system which, with the high fuel demand in the landing phase of flight, detached from its location and caused the restriction. This theory has not yet been proven despite extensive and imaginative testing. The reason it is being put forward is every other scenario has been eliminated. As this is a preliminary report we will have to wait some time, maybe years, before the final report is issued and the cause is known. In the mean time the FAA and the manufacturers of the engine and aircraft are going to look at ways to mitigate the effects of long, cold flights on the fuel system.

Qantas Airlines Maintenance Problems

A Qantas 747 en-route from Singapore to London which had to land at Frankfurt with an engine shut down due to a vibration warning is the latest incident to plague the airline.

The recent explosion that resulted in a large hole in the side of a Qantas Airlines Boeing 747-400 has been confirmed to have been caused by a failed emergency oxygen cylinder. This is believed to be the first occurrence of a cylinder failure on board an aircraft. The manufacturer of the cylinders requires the cylinders to be removed from the aircraft and undergo hydrostatic testing every 3 or 5 years depending on the model. Providing Qantas have kept to the schedule they cannot be blamed for the failure.

There have been several more incidents with Qantas aircraft in the last two weeks which has brought the harsh light of public scrutiny to the airline. A Boeing 767 had to return to the airport when fluid was spotted coming from the aircraft on take off by Air Traffic Control. This turned out to be an hydraulic leak. The other was a Boeing 737-800 which had an open undercarriage door after the landing gear was selected up after take off. Another hydraulic leak from the nose wheel steering system closed the runway at Sydney for40 minutes while the oil was cleaned up.

Was this a series of coincidental faults or an indication of an underlying problem with the maintenance of the aircraft? To my mind an airline with a safety record second to none and unrelated incident on different types of aircraft would suggest the former. Qantas and the Australian Aviation Authority have a Safety Management System in place which other countries, including the US and Canada, are still aiming to achieve. It consists of a program of self assessment, risk analysis and investigations into incidents which ensure lessons are learnt and the probability of a repetition of the events is minimised.

However, the Qantas airlines flight attendants have requested assurances from Qantas management that there is nothing wrong with the aircraft and these incidents are coincidental. Also, the Australian Aviation Authority has begun a two week assessment of Qantas to ensure the safety systems are at work in the company. The mechanics spokesman has said they have always done the best work possible but are now doing it while subject to budget restraints.

Third party maintenance is a sticking point with the mechanics that fear the standards they are aiming for will not be achieved by sending the aircraft to Hong Kong and Malaysia for heavy maintenance checks. A 767 had to be grounded on return from Malaysia recently with over 90 snags. The aircraft that suffered the explosion is expected to be back in service in November 2008 at a cost of $10 million.

Zoom Airlines Financial Woes

News today about Zoom Airlines which operates flights between Canada and the United Kingdom (UK) has run into financial problems. An aircraft was taken back from Zoom by the owner who leased the aircraft to them. This was after the Calgary Airport refused to refuel them as the bill owed to the airport authority was in excess of $400,000.

A little while later the airport authority in Glasgow, Scotland refused to allow a Zoom aircraft to leave because the Civil Aviation Authority in UK had outstanding bills from the European Air Traffic Control agency (Eurocontrol) that had to be paid.

Zoom Airlines has now filed for creditor protection in the UK and Canada as they have a financial plan in place to sort their cash flow out which 95% completed. If the protection is granted by the courts the airline will continue to operate and the passengers will not be left holding worthless ticket.

Many of the airlines in the world have been in Protection from the courts in the last few years and have managed to survive. This is now part of the business plan of airlines in the world of rising fuel prices and competition for passengers. We can only hope the airline survives and all the jobs with it are not lost.

Update

Zoom Airlines has now stopped operations. The airline management say that the actions of the creditors prevented them from continuing to fly and therefore the decision has been made to stop all further operations. The company apologises to all the passengers and more than 600 employees who are now out of work.

Memorable Trip

A couple of days ago I came across a program on Discovery about the first commercial jetliner in the world. It was the De Havilland Comet and they had a lot of problems with it. There were a number of mysterious crashes where the aircraft just broke up in the air with no warning and plummeted from the sky with no survivors. Not the best of starts to the jet age.

After exhaustive testing, including submerging a full size aircraft in a specially built water tank and forcing water in and out of the cabin to simulate pressurization, the problem was discovered. The skin was to thin and the windows and doors square shapes caused stress to build in the corners and cracks to form. These cracks gradually grew until the fuselage failed and the aircraft broke up in flight. This was the first documented aircraft failure from metal fatigue and the start of the balancing act between strength and weight which is still being played out today.

Another reason I watched the show was a sentimental one. The Comet was the first aircraft I flew overseas on when I was in the RAF. That is dating me but I don’t think I mind anymore. We were on our way to Peru from England and I had expected to go in a Britannia which was a four engine turbo prop but to be going in one of the five Comets that the RAF had was a real treat.

When we had boarded the ‘treat’ turned into a slog with a fuel stop in Shannon, Ireland and another in Gander, Newfoundland before the overnight stop in Washington DC. The next morning suffering from an underestimate of the strength of the American beer we boarded and headed for the island of Jamaica.

The airport staff also was surprised by the Comet and we spent fifteen minutes dying from the heat, trapped on board as they ‘rushed’ Jamaica style to find a set of steps to get us off the aircraft. After a couple of hours we were on board again for the final leg to Lima in time for the evening meal, if only we had learned Spanish. Still for a nineteen year old the trip was memorable and ten weeks in South America and the return in the Britannia were even more so. But that is another story.

What if I Can't Swim?

Air Canada Jazz, the regional feeder airline for Air Canada, has just announced that the Life Preservers will be removed from all flights as a weight saving move. This is, of course, another way of saving precious fuel. But what about the customer’s reaction? Well, an airline always treats their customers like non voting shareholders who pick up the tab for anything the airlines do. This is just another example of an airline doing something without due regard to how it will be received by the travelling public. The announcement was not thought out in regard to the reaction from the rule ignorant public being whipped into a frenzy by the headline hungry press!

It is now common knowledge from the on going press coverage that Life Preservers are not required on the Jazz flights due to the fact they are not over water for the required distance.

This is not the only savings in weight that is being carried out throughout the industry. There are changes in cutlery, magazines and even the amount of water on board to flush the toilets. One airline has changed the size of the wine bottles to save weight.

With the price of fuel, bad economy and the shrinking of people’s real wealth, the reductions in everything but the actual ticket price will continue.

Internet in The Air.

American Airlines have broken new ground with the introduction of WI-FI computer access on selected flights over the US. It will be available above 10,000 feet and will cost $12.95 on flights of more than 3 hours. So instead of the movie we will all be tapping away at the laptop and surfing the Web. Cell phone and Voice over Internet Protocol (VOIP) is still not allowed.


“Today, U.S. air travel changes forever. With Aircell’s unique ATG inflight Internet service, airlines finally have an economically viable option for providing the broadband connectivity passengers are demanding,” says Aircell President and CEO Jack Blumenstein.

Thielert Engine

The aircraft engine I always thought needed more development was the diesel engine. It was used in the past by large aircraft and even airships but they were always considered to be big and complicated for small single or twin engined aircraft. But a company from Liechtenstein called Thielert changed all that.

They developed an engine from the Mercedes A-class automotive power unit, which has been certified for use in aircraft by the FAA and is in use in several hundred aircraft around the world. The only problem is that Thielert have gone into liquidation. This leaves several hundred owners and companies with no support for the engine in their aircraft. Spares are becoming scarce and expensive and there is no other company authorized to do the work on them. Furthermore the gearbox and clutch between the engine and the propeller has to be inspected every 300 hours. This is a very expensive exercise, as it had to be removed and shipped to the factory for the inspection.

Cessna, with all their business experience find themselves in the same boat with 160 Thielert powered 172’s to be delivered this year and no engines to put into them. An Austrian company called Diamond are the other manufacturer who have many hundreds of aircraft powered by Thielert’s diesel engines. There are other engines being developed which will hopefully take the place of the Theilert but they are not certified yet.

Why all this sudden interest in diesel engines? Well you get a lot more bang for your buck as the specific fuel consumption is a lot better in a diesel therefore reducing fuel costs. The USA had no motivation for diesels’ with the supply of cheap gasoline but that has all changed now. An additional advantage is there is no ignition to worry about and the engines have been developed to be a single lever control. This means the end to the prop and fuel mixture levers with the FADEC doing all the adjustments automatically.

The diesel powered single engine trainer will give the pilot more time to fly the plane instead of all the engine related monitoring tasks therefore gaining more flying skills faster and reducing the amount of time spent in the air consuming that expensive fuel. The weekend flyer will also have more time to fly the aircraft instead of being preoccupied with controlling the engine, an added safety feature.

Another advantage is the fuel it will run on. Jet A1 is going to be the fuel of choice with diesel as an alterative, this is readily available anywhere the planes fly to. Aviation Gasoline (AV Gas) is becoming a rare commodity as not all FBO’s carry it and refineries are reluctant to produce it given the small customer base. Transportation of the fuel is also a headache due to the lead content which means it normally has to be trucked everywhere to prevent lead build up in pipelines and valves. This all adds to the cost and you know whom that will be passed onto.

So the diesel engine has a lot going for it now that it can be fitted into the small aircraft and still produce the required power. I would expect to see more being the power plant of choice when the new ones are certified. It is just a pity that Thielert went the way they did and left a whole lot of people in a whole lot of mess.

UPDATE

There maybe a future for the Thielert engine after all. There are reports of several letters of interest detailing development and financing from interested parties. The insolvency administrator will evaluate the offers and reduce them to a few which will be given due diligence and a decision will be made for the engine production to be taken over.

American Eagle Versus the TSA

Security at airports has always been a controversial issue. People need the assurance of security checks and searches but don’t want to be personally involved. Having a stranger poke and prod your personal belongings, or worse still your person, is something that nobody enjoys. Most people recognise the need for these intrusions and there is normally no harm done during these inspections.

When it comes to aircraft security things can be a lot different. There was the recently reported case of a TSA inspector at Chicago O’Hare airport who grounded 9 American Eagle aircraft while he was doing his job of testing the security of the aircraft parked on the airport. This is a common exercise at all North American Airports where aircraft park overnight and are supposed to be secured to prevent intruders gaining access to them. This inspector went a little over the top, literally, by climbing on the aircraft to see if he could gain entry. In doing so he damaged external probes which are on the side of the fuselage by using them as steps and handholds. Using this method he was able to gain access to the bridge which links the aircraft to the airport.

In my opinion he should be looking to see if it is possible to gain access to the area where the aircraft are parked as this restricted area has a lot more potential for bad guys than gaining access to the interior of an aircraft.

I guess he crossed the line between aircraft security and aircraft safety which is a grey area for the security inspector who could benefit from an education in the hazards associated with aircraft to himself and the crew and passengers. There is now the possibility of action being taken by the TSA against the airline as he gained entry to 7 of the 9 aircraft. There is, of course, the other possibility of the airline taking action against the TSA for potentially damaging the aircraft in gaining access to them. Another win win situation for the lawyers.

Electra Flyer-C, Green Flying?

One of the biggest expenses in operating an aircraft is the fuel bill. This is really high at the moment with the price of aviation gasoline the same as the fuel for your car. The other repetitive expense is the cost of maintenance for the engine. So what if you do without an engine and buy a glider? Well, you still have to get it into the air by towing or winching and there is a lot of dependence on the wind for the timing and length of your flight.

But, the answer may have been found to these problems with the aircraft that made its debut at the Air Venture show at Oshkosh, Wisconsin last week. It is the Electra Flyer-C which has the flying attributes of a glider combined with the power of an electric motor to launch and power the flight. The motor runs from a Lithium Battery which then drives a 45 inch diameter propeller. With a top speed of 90 MPH and a cruise of 75 MPH this compares well with other small single engined aircraft. The duration of up to 2 hours is low but as this is a new technology the battery and motor efficiency will no doubt be improved and better endurance will result.

A full charge can be done in as little as 2 hours and the manufacturer thinks it will cost of 60 cents on your power bill. The other saving is there is little maintenance compared to the traditional piston engine. So, if you are interested in being on the cutting edge of ‘green’ flying visit their site at electraflyer.com and learn more about this innovative technology

Can We Have Our Plane Back Please?

Just when you think everything is going well it all goes wrong. It is literally one of a kind and it is now a prisoner of war. What is it? The new Epic Elite Very Light Jet (VLJ) out of the Bend, Oregon facility is now in Tbilisi in Georgia.

The problems Georgia and Russia are having has trapped the aircraft in a hangar with no hope of an early exit as there are now too many holes in the runway for a successful take off. Why Tbilisi? Well Epic and the Tbilisi Aerospace Manufacturing Company (TAM) are partners in the production of the Elite which is to be certified first in Russia. The aircraft was coming to the end of a tour of Europe when it arrived in Tbilisi.

The chance of it making the proposed visits to Farnborough and Oshkosh are not likely considering the position it finds itself in at the moment. But on the other side of the coin the people who have the aircraft are very keen to keep it in good condition, so all are hoping for a happy outcome to the problem.

Antonov 225

There was a moment not to forget when I visited my sister in Manchester, England in 2006. As we stood in the garden, which is under the approach to the airport, the skies darkened and the sense that something big was in the air grew with the passing seconds. Then there it was, right above us, the Antonov 225 the biggest aircraft in the world, surprisingly quite for a six engined Goliath.

My nephew had the chance to take a tour of the aircraft and the scale was huge. There was a fully laden transport truck in the cavernous hold and still plenty of space to move around. Well supported by twenty eight main wheels and four nose wheels this aircraft is in a league of its own.

Originally designed to support the Russian Space industry the cargo deck is capable of holding booster rockets and the top of the aircraft can also hold a space shuttle.

With a payload of 250 tons this aircraft is all business. The only aircraft of its type flying it was a privilege and a thrill to see it in person.

American Airlines

Is it just me or is the FAA out to close down the industry in the USA? American Airlines have just been slapped with a penalty of $7,500,000 for a paperwork snafu.

Now we all know there are rules in place and they are there for good reasons but when there is no safety issue but merely a wrong selection in the MEL I am at a loss to see how the huge penalty can be justified. For those of you who are unsure of how an MEL works let me explain.

The manufacturer of the aircraft provides each aircraft with a list of the equipment which, given the right controls and circumstances, the aircraft can still be safely operated when this equipment is not working. It could be something as simple as a landing light or as complicated as the auto pilot. Normally, on an airliner, the MEL book can be a few inches thick. The pilots and the maintenance personnel are trained in the operation of the MEL and without it a lot of flights would not be on time.

Because American has used the wrong entry in the MEL to defer the fixing of the equipment the FAA have imposed a huge fine. The equipment was allowed to be broken while the aircraft operated and the only thing wrong was a paperwork entry. No lives were at risk and the equipment was fixed within the limits of the MEL. So why the size of the fine? The FAA are not saying but American's lawyers are asking and the whole thing is going to be a long drawn out legal battle. The likes of which neither American Airlines or the cash strapped FAA can afford!