Ask Captain Lim

Dear Captain Lim,

Congratulations on flying the Airbus A320! I have heard that it is a very nice plane to fly and the side stick is also very comfortable.

My mum recently bought a new car and it has ultrasonic sensors on the rear bumper so that she doesn't reverse into anything. Could a system like this be incorporated into the tail of a fly-by-wire aircraft (like the A320 or the B777) so that the computers will stop the aircraft from scraping the tail?

Incidentally, my mum found your website very reassuring when I showed it to her before she flew to Italy on an A319. She is (was) terrified of flying because she was on a plane (British Airways or British Caledonian, I don't know which) taking off from Nairobi in the late 1970s/early 1980s (not sure when) back to London when a bird flew into the engine, causing it to catch fire.

I have seen the effects of a bird striking a Rolls Royce Trent (as on a B777) and it was not that dramatic. Were tests not as stringent in the past? Or do they test with smaller birds (chickens?) and this engine ate a vulture?

Does this mean that flying in Africa where there are larger birds is more dangerous than flying in Europe where the birds are much smaller?

Thanks,

Felix

Hi Felix,

I note that you are just as concerned about tail strikes than pilots are! Sure, although a car ultrasonic sensors operation works on a different principle, it would have been nice to develop some form of anti-tail strike device in all airplanes. In reality, very few planes have them. As far as I know, only the latest B777-300ER and B777-200LR have such tail-strike protection. This software feature helps prevent inadvertent scraping of the tail on the runway at takeoff or landing by commanding elevator movement if the airplane*s attitude exceeds preset limits.

Even the Airbus A340-600 (stretched version that is most prone to tail strike) doesn*t have a system similar to the Boeing 773ER*s Tail-Strike Protection. However, it does employ a pitch limit indicator with associated aural warnings - also found on the Airbus A320. This cannot be said to be exactly the same but serves the same purpose to prevent tail strikes.

On a different note - what about bird strikes? Yes, most modern jet engines can handle bird strikes quite well. Very often, small to medium sized birds are ingested into jet engines harmlessly (like a meat grinder eh? :-). Other times, they can do slight damage, like causing some dents on the turbine blades. It happened on the engine of an Airbus A320 I flew recently? yet it was no big deal after the engineer cleared the plane for further flights (as it was within tolerence)! Of course, in the worst-case scenario, large birds may cause more serious damage to the engine of some older planes.

So are African birds larger? Possible. Nevertheless, pilots are alerted frequently of migratory birds in the vicinity most airports. Yes, they are vigilant of such menace and do take note of them, taking avoidance action whenever possible, to ensure your safety!