Cessna Stationair/Turbo Stationair 6
Flight Crew Flight Instructor; Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 60; Flight Crew Total 1600; Flight Crew Type 900
Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Airport; Human Factors; Procedure
During a holiday weekend; the Tower at Yuma (NYL) was closed.  We were conducting aerial mapping operations around Yuma on that weekend; and during this time observed how chaotic this airport can be when the Tower is not operational. With many different types of flight ops being conducted to Yuma's 8 different runways; all attempting to coordinate over CTAF.  The problem was compounded by the lack of wind; which caused pilots to plan landings on the runway that was simply the most convenient for them.  There was one 10 minute period; as we were taxiing to Runway 8 to conduct our runup; when 4 AV-8B Harriers conducted an overhead break to landing on Runway 21L; followed by 2 C130s landing in the opposite direction on Runway 3R; an unknown GA aircraft departing 'Runway 17/35' (whether it was 17 or 35 is unknown); a CRJ approaching for a landing on Runway 8; and a foreign student pilot with a thick accent and a very fragile grasp of the whole situation announcing intentions to land on Runway 26 (as the CRJ was on approach from the opposite direction).  The military aircrafts' overhead pattern is unfamiliar to most GA pilots; and cuts across the standard GA/non-military traffic patterns.  Additionally; several of the military aircraft never announced clear of the runway; heightening the confusion of who was where.  I suggested over the radio to the foreign student that he enter downwind for Runway 8; and to watch out for the CRJ on a left base for the same runway.  After observing similar chaos over the weekend; it's my strong suggestion that the Tower at Yuma not be closed during normal daytime hours; as it is simply too large and busy of an airport with a very diverse array of flight ops being conducted to it.
C206 pilot describes a holiday weekend at NYL when the Tower is closed and a diverse mix of aircraft are using all eight runways for takeoffs and landings; in calm winds; using The CTAF to coordinate.