Letters
26th August 2006
The following was published in The Times:
Sensible cabin baggage limits
Sir, As the security risk has recently been downgraded and the travelling public is adapting to a far more stringent security regime than ever before, now would seem to be an appropriate time to reconsider the whole subject of what is allowed to be carried into the aircraft cabin.
For many years the Air Safety Group has been concerned at the increasing amount of carry-on baggage, including large numbers of duty-free bottles, that seem to have become the norm. Recent actions of charging for checked in baggage by at least one low-cost carrier have made the situation even worse.
We suggest two courses of action that should now be introduced as permanent measures. First, all future carry-on cabin baggage should be strictly limited to one item per person, the maximum size being that currently allowed (0.16m x 0.35m x 0.45m) and secondly, intended purchases ordered at the airport of departure and/or on the aircraft, in particular of duty-free bottles, should be collected at the final destination airport.
These practical measures to reduce carry-on baggage would involve no change to airport facilities. Insisting that "duty-free" be purchased or collected on arrival would maintain the airlines’ sales with the bonus of them not having to carry a large number of bottles and other items throughout the flight. The reduced amount of cabin clutter would improve both the comfort and overall safety of the passengers, especially during an emergency evacuation.
CAPTAIN R. WILLIAMS
Chairman, Air Safety Group
Taunton
30th September 2008
Mr David King, Chief Inspector,
Air Accident Investigation Branch,
Farnborough House,
Berkshire Copse Road,
Aldershot, Hants,
GU11 2HH
Dear Mr King
B777 Accident at Heathrow – 17th January 2008
Following an increasing number of reports of interference problems in the mid 1990's caused by the use of mobile telephones onboard aircraft, I was instrumental, as Head of Flight Operations (Policy and Regulations) of the Safety Regulation Group, in banning their use. Since that time there have been numerous other reports where their unauthorised use has posed interference to onboard navigation equipment and other systems. On February 5th of this year I noted an MOR (Number 200801349) filed relating to a B747 of British Airways that on 3 occasions exceeded the set airspeed on autopilot by an uncommanded increase in power on all four engines and it then turned the wrong way following a direct track to the next waypoint. This was established as being caused by an unauthorised use of a mobile telephone in Business Class leading the Captain to have to intervene to insist it be switched off, whereupon the aircraft behaved normally.
After the B777 accident at Heathrow, I wrote to Flight International (letter published on 4th March 2008 issue) posing the question of possible interference by one or more mobile telephones to the fuel control units and/or software on the accident B777, which, in the light of the above B747 incident, did seem to us to be a distinct possibility.
The Air Safety Group has serious concerns at the apparent headlong rush currently evident to satisfy the demand for almost unlimited use of mobile telephones onboard commercial aircraft and we hope sincerely that the certification processes will ensure their safe introduction and utilisation. We recently presented our concerns to the Parliamentary Advisory Council for Transport Safety (PACTS) – we currently advise them on Aviation Safety issues - and by way of follow up would like to receive the AAIB views on this matter.
I am sure the AAIB Investigation would have established whether or not any mobile telephones were actually operating during the final stages of the accident flight. Could you possibly advise if there were any Mobiles or other PEDs switched on inside the B777 at the time immediately leading up to the accident? If there were, then I assume it would be almost impossible to establish where, precisely, on the aircraft they were positioned, bearing in mind that the passengers may not always stay in their originally allocated seats throughout the flight.
From the AAIB Interim Report it is noted that HIRF and EMI possible interference has been discounted following tests 'well in excess' of published maximum emissions. From my recollection of the mid 1990’s we were very concerned at the random nature of the interference being experienced, which depended largely upon which source of emission was being generated and precisely where that source was positioned within the aeroplane, together with the potential for emissions being combined to produce anything up to a tenfold increase on occasion. This random nature was almost impossible to replicate during testing inside an aircraft on the ground.
To help us understand a little more, and going back to the aforementioned B747 incident, would the FDR and QAR on that aircraft, for example, have registered the increased, and uncommanded, fuel flow resulting in the increased airspeed on the three occasions? I assume that they would, but would the cause have been evident as being due to HIRF/EMI or simply all four throttles being moved forward, for whatever reason, and exceeding the autopilot set airspeed? How could that exceedance have been generated and what piece of equipment could have been interfered with to cause that specific problem? Whilst satellite navigation equipment does appear to be more readily prone to interference from mobile telephones (causing the aircraft to turn the wrong way), the fact that engine fuel controls also appear to be susceptible is of great concern.
I would very much welcome your comments and assurances that the AAIB Investigation has complete confidence that no such HIRF/EMI interference could possibly have contributed in any way to this accident. One cannot help but wonder whether it might now perhaps be prudent to initiate further research into this phenomena?
Yours sincerely
Captain Russ Williams FRAeS
Chairman, Air Safety Group
PACTS (Aviation Working Group)
Cc Group Director, Safety Regulation
Chief Executive, PACTS
