C172 and low wing aircraft had near midair collision in myf class D airspace.

Attributes
ACN	529208
Time
Date	200111
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : myf.airport
State Reference	CA
Altitude	msl bound lower : 0 msl bound upper : 1500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : myf.tower tower : mod.tower
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Flight Plan	None
Aircraft 2
Controlling Facilities	tower : myf.tower
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 10 flight time total : 205 flight time type : 19
ASRS Report	529208
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	aircraft equipment problem : critical non adherence : required legal separation other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : separated traffic controller : issued new clearance controller : issued alert flight crew : took evasive action none taken : anomaly accepted none taken : insufficient time
Miss Distance	horizontal : 300
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

On initial call-up to tower control at myf, I was told to squawk XXXX on my transponder and make a straight-in approach to runway 28L. I proceeded as requested. At approximately 5 NM east of the runway, I heard a clearance or some other instruction given to another plane for runway 28L. As a precaution, and not having heard further instruction for me from the tower, I contacted the tower to check on my clearance, and confirmed that I was cleared for runway 28L. The controller mentioned to that he had trouble contacting me on my current radio. I then switched to my #2 radio, and confirmed that the tower could read me. I could read the tower on both radios. Approximately 1/4 NM or less from the runway on final, I heard the tower say that 2 aircraft were attempting to land on the same runway at the same time. The tower then issued a traffic alert. I looked to my left in time to see a low wing airplane turn away from me and head south. He appeared to have been flying a nonstandard approach. He should have been behind me on final, or should have extended his downwind until it was safe to turn base. He should not have been on my left, flying a base approach to the runway. As his plane veered away, I heard him say 'I (meaning him) had clearance.' I proceeded to land safely. On the ground I checked both radios with ground control. The radios worked fine. I believe that tower control lost awareness of the 2 planes in the pattern for runway 28L. I think that if the tower had been more attentive, a simple instruction to either plane could have prevented this close call. Also, the low wing aircraft should not have attempted to land, even with clearance on runway 28L, if there was another plane below it and on final approach. He should have been more vigilant. A contributing factor may have been radio problems, but there was adequate time -- once radio communications were addressed -- to avoid the conflict that occurred.

Original NASA ASRS Text

Title: C172 AND LOW WING ACFT HAD NMAC IN MYF CLASS D AIRSPACE.

Narrative: ON INITIAL CALL-UP TO TWR CTL AT MYF, I WAS TOLD TO SQUAWK XXXX ON MY XPONDER AND MAKE A STRAIGHT-IN APCH TO RWY 28L. I PROCEEDED AS REQUESTED. AT APPROX 5 NM E OF THE RWY, I HEARD A CLRNC OR SOME OTHER INSTRUCTION GIVEN TO ANOTHER PLANE FOR RWY 28L. AS A PRECAUTION, AND NOT HAVING HEARD FURTHER INSTRUCTION FOR ME FROM THE TWR, I CONTACTED THE TWR TO CHK ON MY CLRNC, AND CONFIRMED THAT I WAS CLRED FOR RWY 28L. THE CTLR MENTIONED TO THAT HE HAD TROUBLE CONTACTING ME ON MY CURRENT RADIO. I THEN SWITCHED TO MY #2 RADIO, AND CONFIRMED THAT THE TWR COULD READ ME. I COULD READ THE TWR ON BOTH RADIOS. APPROX 1/4 NM OR LESS FROM THE RWY ON FINAL, I HEARD THE TWR SAY THAT 2 ACFT WERE ATTEMPTING TO LAND ON THE SAME RWY AT THE SAME TIME. THE TWR THEN ISSUED A TFC ALERT. I LOOKED TO MY L IN TIME TO SEE A LOW WING AIRPLANE TURN AWAY FROM ME AND HEAD S. HE APPEARED TO HAVE BEEN FLYING A NONSTANDARD APCH. HE SHOULD HAVE BEEN BEHIND ME ON FINAL, OR SHOULD HAVE EXTENDED HIS DOWNWIND UNTIL IT WAS SAFE TO TURN BASE. HE SHOULD NOT HAVE BEEN ON MY L, FLYING A BASE APCH TO THE RWY. AS HIS PLANE VEERED AWAY, I HEARD HIM SAY 'I (MEANING HIM) HAD CLRNC.' I PROCEEDED TO LAND SAFELY. ON THE GND I CHKED BOTH RADIOS WITH GND CTL. THE RADIOS WORKED FINE. I BELIEVE THAT TWR CTL LOST AWARENESS OF THE 2 PLANES IN THE PATTERN FOR RWY 28L. I THINK THAT IF THE TWR HAD BEEN MORE ATTENTIVE, A SIMPLE INSTRUCTION TO EITHER PLANE COULD HAVE PREVENTED THIS CLOSE CALL. ALSO, THE LOW WING ACFT SHOULD NOT HAVE ATTEMPTED TO LAND, EVEN WITH CLRNC ON RWY 28L, IF THERE WAS ANOTHER PLANE BELOW IT AND ON FINAL APCH. HE SHOULD HAVE BEEN MORE VIGILANT. A CONTRIBUTING FACTOR MAY HAVE BEEN RADIO PROBS, BUT THERE WAS ADEQUATE TIME -- ONCE RADIO COMS WERE ADDRESSED -- TO AVOID THE CONFLICT THAT OCCURRED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.