May 2, 1974
Location: En route from Guerrero state to Mexico City,
Antonio de los Santos Montiel was flying en route from
Guerrero state to Mexico city in his Piper Aztec 24, he
became aware of three objects positioned extremely close
around the plane. He heard a noise from below, as if one
of the objects had collided with his plane. He then noticed
that the aircraft controls and landing gear were frozen.
Artist Robert Gonzales' rendition of UFOs 'escorting'
The size of each UFO was 3 meters diameter by 1.2 meters
Ignacio la Mora (Carlos' uncle), pilot/witness Carlos
and APRO Field Investigator F.I. Fernando Pareja.
Controller Julio Diaz and Pilot Carlos Montiel.
APRO Bulletin, Vol. 24 No. 2 (Aug 1975)
May 2, 1974, Carlos Antonio de los Santos Montiel, 23,
left Mexico City in his Piper Aztec 24, registered as
XB-XAU, for Zihuatenajo, state of Guerrero. He arrived
there in the afternoon and although he had originally
planned to return that day, he decided to stay over and
return on the 3rd. He had dinner at 8 p.m. and retired.
morning of the third was cloudy with considerable smog,
mist and very poor visibility. Carlos took off, nevertheless,
at 10:30, without having his breakfast. He climbed his
little plane to 13,500 feet but conditions were still
bad, so he climbed to 14,500 where he found a clear blue
sky and continued on his return trip to Mexico City.
in the area of Tequesquitengo, Carlos decided to lose
altitude in order to make visual contact with Lake Tequesquitengo
and verify his position, instead of depending on his instruments.
When he got down underneath the cloud cover, ground mist
and fog blocked his view of the Lake. Then things began
he looked from the left (he had been gazing through his
left side window) to the front, he became aware of something
on his right and glanced in that direction and was shocked
to see an object with the appearance of two plates joined
together at the rim with a cupola which had what seemed
to be a little window and an antenna on top. It was positioned
20 centimeters above the surface of the wing and about
1½ meters from the Piper's cabin. (See drawing
by Staff Artist Robert Gonzales.) A glance back to the
left revealed another object of the same description in
the same position above the left wing.
was petrified," Carlos told officials later,
"after I saw a third object which seemed about
to collide head-on with the windshield. But it went beneath
the aircraft and I heard a strange noise from below as
though it had collided with the underside of the plane."
then noted that his airspeed had decreased from 140 nautical
miles per hour to 120. He tried to bank to the left, in
an attempt to "bump" the object away from his
plane but the controls were frozen and would not move.
He then tried to let down the landing gear, hoping to
get rid of the object under him, but with no results.
Field Investigator, Fernando J. Tellez Pareja, listened
to the tape-recorded conversation between Santos and the
Mexico City International Airport Control Tower, which
Carlos initiated after he found his controls were frozen:
Center Mexico from extra bravo extra alfa union. Mayday!
Mayday! (Ed. Note: "Mayday!" is an international
City: Come in, extra bravo extra alfa union. (Here
the pilot repeated his call twice apparently he
did not hear Mexico City answer.) Center Mexico here,
come in extra alfa union.
Extra alfa union to Center Mexico. My aircraft is out
of control I have no control over it I have
three unidentified objects flying around me. I have three
unidentified objects flying around me, one came under
my aircraft and hit it. The landing gear is locked in
and the controls won't release them. My position
I am on the Radial 004 from the VOR Tequesquitengo
I am not controlling the plane Center Mexico, can
you hear me?
Mexico: Take note extra alfa union, give me your position
and your situation. We are contacting competent authorities
(here interrupted by Carlos again)
The aircraft is out of control.
this point, Mexico City International Airport closed its
runways to traffic and prepared for the expected emergency
landing. The objects continued maintaining position on
XB-XAU, exerting complete control over the aircraft.
"Mayday" or emergency call was received at 12:15
p.m. on Saturday, May 3. The control tower contacted Ignacio
Silva la Mora (Carlo's uncle), an authority on aircraft,
who was put in touch with Carlos via radio to analyze
the problem and help with landing preparations.
Carlos had reached the Ajusco navigational fix, the UFOs
had elevated the aircraft from 15,000 feet (the altitude
while over Tequesquitengo) to 15,800 and then, one by
one, they left. First, the object over his left wing elevated
until it was over the cabin, then above the object on
the right wing, and then these two flew off and were lost
to view in the direction of the Popocatepetl and Iztaccihuatal
volcanoes. The controls of the aircraft were immediately
normal and Carlos regained control.
then attempted to lower the landing gear, circling Mexico
City International Airport eight times, in radio contact
to ascertain if he was successful. Finally, after 40 minutes
of circling while he worked on the control column with
a screw driver, he managed to lower the wheels and landed
at 1:34 p.m. on the grassy area between runway 5 right
and 5 left where emergency vehicles, including firemen
and ambulance, were waiting.
landing, Carlos was taken to the Airport Clinic where
he was thoroughly examined and found to be normal and
fit. Some individuals had hinted that he might have been
under the influence of drugs or alcohol but the medical
examination laid that speculation to rest.
days after the incident, Captain Augusto Ramirez Altamirano
(Chief of Inspectors for the region from the Aeronautical
Civil Direction) said that Carlos would have to undergo
a series of tests to determine if he had really seen the
UFOs or if they were an illusion from flying too high
May 7, Dr. Luis Amezcua, Chief of the Aviation Medicine
Department of Mexico City International Airport, completed
a series of medical tests (neurological, physical and
psychiatric, etc.) and gave his opinion that Carlos had
been suffering from low blood sugar because he had not
eaten from 8 p.m. the night before until after the incident
the next day and inferred that Carlos had hallucinated.
Investigator Telles interviewed the witness and gives
us the following insight: Carlos de los Santos is 23,
has been a pilot for two years, has 370 flying hours to
his credit, has a private and commercial pilot's license.
He is employed by Pelletier, S. A., a company which specializes
in analysis and study of water. His father is Chief Mechanic
of the Mexicana de Aviacion Airlines. Carlos neither smokes
nor drinks, is not interested in science fiction and has
never read a UFO book.
far as radar confirmation was concerned, Mr. Julio Cesar
Interian Diaz, the Mexico City International Airport Terminal
Radar Controller, said that the distance from Tequesquitengo
to Mexico City is 48 nautical miles and that the blip
of Carlos' plane was picked up on radar when 43 miles
out of Mexico City. Carlos' aircraft was the only one
in that sector at that time. The radar registered the
separation of another blip which went in another direction
from Carlos' plane, executing a 270-degree turn in a radius
of 3 or 4 miles at a speed of 450-500 nautical miles per
hour. Mr. Interian Diaz said that he did not know of any
aircraft which could execute such a maneuver.
in-depth investigation is being conducted by an aeronautical
engineer with the help of Field Investigator Fernando
Telles. We should note here that this is Mr. Telles' first
important case and he has done an outstanding job of investigating
Note: Regarding the theorizing concerning the low blood
sugar reaction: Carlos exhibits none of the symptoms of
hypoglycemia (low blood sugar): sluggishness, irritability,
overweight. Had he actually been a diagnosed hypoglycemic
and suffered such a fearful hallucination, the fear would
have triggered a release of adrenalin into his blood which
would have, in turn, triggered a high flow of insulin,
resulting in shock, in which case he would not have been
able to land the airplane.)