Sir - In the article "New members join in-trail-climb club" (Flight International, 6-12 December, 1995, P16), Ken Peppard of the US Federal Aviation Administration is quoted as saying that "...pilots, controller and ARINC operators feel comfortable with the procedure". The US Airline Pilots' Association (ALPA) believes this to be an overstatement.

The in-trail-climb (ITC) procedure is an orphaned one. While 14 crews for which Mr Peppard has data felt that the procedure is safe, the fact that hundreds of potential ITCs have not been tested is interesting. Pilots are not performing them, which tells us that something is not right with the procedure, equipment, or training, or all three, for example:

The ITC procedure is unnecessarily flawed. ALPA is concerned about the requirement for the climbing aircraft to go off-route and execute the emergency oceanic contingency procedure if the climb cannot be continued because air-traffic-control refuses to keep the original altitude available for a few more minutes;

The most serious problem with the use of traffic-alert and collision-avoidance equipment lies within the lead-aircraft identification process, which, as the transponder is toggled off and one, does not provide positive radar identification. Targets disappear and reappear and there is no certainty that the target, which disappeared 30s ago and now reappears is the intended one;

The ITC procedure is complex, but the only training available to flight crews is a lengthy handbook bulletin. It is possible that a pilot's first exposure to the bulletin (ie, training) is during his first ITC.

As for the in-trail-descent (ITD) procedure, ALPA believes that ITC problems must be addressed, before any consideration of ITD can begin.


Air Traffic Control Committee Chairman

Airline Pilots Association

Herndon, Virginia, USA


Source: Flight International