User Interfaces and Iran Air Flight 655


In March I purchased a flight from Amsterdam to Nottingham from BMI baby. During entry of my data there was one section that had several paragraphs on how they strongly encouraged me to purchase travel insurance. Since such travel insurance is a ridiculous idea, particularly for such a short flight, I was strongly determined not to get travel insurance. I unticked the travel insurance box, and refused to enter my name in that area. However, I couldn’t continue without entering a name in this travel insurance section. So I entered Lord X X as the name so that I could continue.

Unfortunately, this was actually the passenger name area. I didn’t read the part where it stated that I should Enter the details of each person travelling, remembering to enter the name(s) exactly as it’s written on each passport. Unfortunately I didn’t read this carefully because between this paragraph and the text box is four paragraphs about travel insurance and immediately after this section I filled in my personal detail including my name and address.

An unfortunate user interface leading to an unfortunate user mistake. But hope is not lost. There is still the confirmation page before I purchase the ticket. Surely I can catch my mistake there. Well this page under passenger and payment final confirmation has a section called your details which correctly lists my name and address. And another section lists 1 passenger: Adult 1: X X. Who knows what those X’s mean. My name is correctly listed under my details, so everything seems fine to me, and I agree to the purchase.

It cost me €50 to change my name on my ticket today, because of my carelessness and mostly because of a bad user interface. If the passenger name had been better labelled in either the original page, or, more importantly, the confirmation page, I would have not made this mistake.

But I am only out €50. In 1988 the USS Vincennes pursued Iranian gunboats into Iranian waters and, as it happened, directly under the path of Iran air flight 655. During the battle, the commercial Airbus A300B2 took off from Bandar Abbas heading to Dubai. The USS Vincennes immediately began tracking this unidentified aircraft. The operator, using the Aegis combat system, tracked the selection cursor over the unidentified aircraft to mark it. The commercial aircraft IFF identification system automatically identified itself to the USS Vincennes as mode 3, civilian aircraft. Of course, it is possible for a hostile plane to fake the IFF mode 3.

USS Vincennes continued to track the aircraft as it approached the ship. On radar it was still marked. Then something funny happened, it appeared to also identify itself as mode 2, military aircraft, specifically an F-14. At this point the Airbus was labelled as an F-14 on the USS Vincennes radar. The problem was that the selection cursor (as opposed to the marked aircraft) was still sitting on the airport in Bandar Abbas, where an F-14 was on the runway. Because of the user interface design, it was unclear which aircraft was identifying itself as an F-14.

The aircraft was asked ten times to identify itself, seven times on a military distress frequency that the Airbus cannot receive, and three times on a commercial distress frequency. The aircraft was named in the request by course and speed. The USS Vincennes gave the ground speed of the aircraft, while the pilots were probably comparing the request to their air speed and figured the request was for some other plane. The USS Vincennes had no radio for receiving commercial air traffic control information.

Ultimately the poor user interface of the Aegis combat system led to the USS Vincennes firing SM-2ER antiaircraft missiles and destroying the Airbus A300B2, and killing over two hundred passengers.

I am only out €50.



Russell O’Connor: contact me