Question: Capt. Cox, I just saw a program about the Kegworth crash in 1989 where the British Midland pilots, struggling to fly a distressed aircraft, shut down the wrong engine in their 737-400. Several passengers were aware of the apparent mistake but were too timid to say anything. As the pilot, what exactly would you want a passenger to do in a situation like that — if he thinks the crew may have made a mistake or has important information that the flight crew needs?  A pilot brushes snow off a wing during a safety check of a plane in Windsor Locks, Conn. Captain Cox recommends ringing the flight attendant call bell if, and only if, you are convinced that there is a safety risk and taking action is essential.  A pilot brushes snow off a wing during a safety check of a plane in Windsor Locks, Conn. Captain Cox recommends ringing the flight attendant call bell if, and only if, you are convinced that there is a safety risk and taking action is essential.  — submitted by reader md65000  Answer: The best way to get information to the pilots is through the flight attendants. It is very important that you explain to him/her exactly what you believe the issue is and why you believe it is important that the pilots are made aware of your concern. The more detail provided in the explanation, the better chance the flight attendant will advise the pilots.  This is a very difficult issue. You cite an example of a case where the wrong engine was shut down. However, consider the case of a compressor stall when flames can briefly (usually under 1 second) pop out of the front of an engine accompanied by a loud boom. The pilots know that a compressor stall has occurred and that they will return for a landing. Passengers are, understandably, shaken and startled by the event, even more so when the thrust is significantly reduced as the airplane stops climbing and levels off to return to the airport. Is this something a passenger should tell flight attendants and ask him/her to tell the pilots? Probably not. The pilots are busy coordinating the return to the airport; they will usually make an announcement when they have time. Having a flight attendant make an "emergency" call to the flight deck would create additional workload to the pilot during a very busy time.  Question: Supposing you, Capt. Cox, are on an airplane (say an MD80) as a passenger, and after entering the runway and hearing the engines spool up for takeoff, you realize either of the following:  1) flaps are 0 degrees, or 2) the wings are covered with snow, enough to change the aerodynamics of the wings and adversely affect lift.  Knowing that either of these two conditions have high potential to cause a crash, what would you do at this point as a passenger? I don't know how the cabin crew would react to someone notifying them of such condition, especially during this phase of "flight."  Answer: This is a tough question. Some airplanes (e.g. Fokker F-100 and F-28) are certified for takeoff with 0 flap. Airplanes with slats (devices on the front of the wing which extend for takeoff and landing) usually have the flaps extend with the slats. There have been a few cases where the wing was not properly configured prior to takeoff resulting in an accident (e.g. Northwest in Detroit and Spanair in Madrid). To determine if there is an actual risk, some knowledge of the airplane is required. Modern airplanes have warning systems to alert the crew if the wing is not properly configured. In the accident cases cited, the crew and the warning system failed, a very rare occurrence.  In case of a contaminated wing it is easier to determine that there could be a risk.  If you are convinced that there is a risk and taking action is essential, rapidly ringing the flight attendant call bell should cause a response. Tell the flight attendant, "I am a pilot, it is critical that you tell the captain: The wing has ice on it or the slats/flaps are not set for takeoff." If you are not a pilot with training to make the determinations, please consider carefully before taking such a step.  If you wait until the engines are spooling up for takeoff, there is nothing you can do.  Readers, please leave your questions for John Cox here, and only leave comments about this week's column below.  John Cox is a retired airline captain with U.S. Airways and runs his own aviation safety consulting company, Safety Operating Systems.  , visit our FAQ's. To report corrections and clarifications, contact Standards Editor  . For publication consideration in the newspaper, send comments to  . Include name, phone number, city and state for verification. To view our corrections, go to
Captain Cox gives cautious advice to passengers about speaking up in moments when safety is on the line.