‘Lightning’ Strikes Nimrod MRA4

Warton, UK - One of the three BAE Systems Nimrod MRA4 development aircraft has taken part in a series of tests to ensure the aircraft’s safety in the event of a lightning strike. During the trials, it has been cocooned in more than four kilometres of specialised aluminium framework and subjected to over 400 high voltage pulses to simulate lightning strikes.

The aircraft being tested is PA03, which is being used to test out the whole of the mission system.

Chris Jones, Lightning Technologist at BAE Systems said: “There are some 90 boxes on the aircraft that are flight safety-critical and we need to prove that all of these would be unaffected in the event of a lightning strike.

“The first task is to fool the aircraft into thinking it is flying in the air, and so we have designed a complex metal frame that is constructed all round the aircraft to act as a return conductor. This acts as a circuit so we can put electrical current into the nose of the aircraft, take it out into the return conductor and bring it back to the generator.

“During the testing we have a pulse generator that is charged to high voltage and simply zap the aircraft with a high current pulse of up to 50,000 amps. We take information from electrical cables inside the aircraft and record this on an oscilloscope. This allows us to measure this information and compare it with qualification data. The information from the trial, together with electromagnetic modelling and further analysis, provides the basis for achieving clearance.”

BAE Systems’ Large Aircraft Business managing director Joe Harland said: “These trials are another significant step in the design and development programme for the Nimrod MRA4 aircraft. Not all our important tests are most effectively completed in flight. These lightning strike trials are a major undertaking, but, in common with the hot and cold weather trails conducted last year, are essential in demonstrating the ability of the aircraft to cope with the harshest of operational environments.”