Close proximity GA small aircraft straight in on a training flight and an unk in the traffic pattern...

Attributes
ACN	199534
Time
Date	199201
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lns
State Reference	PA
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lns
Operator	general aviation : instructional
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	descent other
Route In Use	approach : straight in
Flight Plan	VFR
Aircraft 2
Make Model Name	Small Aircraft
Flight Phase	other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 300 flight time total : 4000 flight time type : 3000
ASRS Report	199534
Person 2
Affiliation	Other
Function	instruction : trainee
Qualification	pilot : student
Events
Anomaly	conflict : nmac non adherence : far
Independent Detector	other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	Other
Miss Distance	horizontal : 150 vertical : 150
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

After an uneventful flight my student made radio contact with the tower about 10 mi east of the airport. We were at this time cleared for a straight in approach. We were also requested to report a 2 mi final. Our cruising altitude was 4500. Soon after making radio contact my student spotted the field and we started our descent. As we were passing through 3000 ft approximately 5 mi from the field an aircraft passed underneath our aircraft in close proximity. There was no time for evasive action. The time in between sighting the aircraft and our passage was no more than 2-3 seconds. It would appear that the aircraft was hidden by our wing as it approached and by the time the aircraft was large enough to be seen underneath the wing we were already close. Since both my student and myself were both scanning the local approach alert for other aircraft the only other method we could have used to spot him sooner would have been to have used s-turns to give us greater visibility beneath our aircraft. The flight was instructional in nature so the student was flying under my supervision. There was to be great importance placed on navigation and communications. This event however showed how one must always watch for the unexpected. While I do not feel that we were too involved in the cockpit this event is a good example of how one can never spend too much attention to the outside of the aircraft.

Original NASA ASRS Text

Title: CLOSE PROX GA SMA STRAIGHT IN ON A TRAINING FLT AND AN UNK IN THE TFC PATTERN.

Narrative: AFTER AN UNEVENTFUL FLT MY STUDENT MADE RADIO CONTACT WITH THE TWR ABOUT 10 MI E OF THE ARPT. WE WERE AT THIS TIME CLRED FOR A STRAIGHT IN APCH. WE WERE ALSO REQUESTED TO RPT A 2 MI FINAL. OUR CRUISING ALT WAS 4500. SOON AFTER MAKING RADIO CONTACT MY STUDENT SPOTTED THE FIELD AND WE STARTED OUR DSCNT. AS WE WERE PASSING THROUGH 3000 FT APPROX 5 MI FROM THE FIELD AN ACFT PASSED UNDERNEATH OUR ACFT IN CLOSE PROX. THERE WAS NO TIME FOR EVASIVE ACTION. THE TIME IN BTWN SIGHTING THE ACFT AND OUR PASSAGE WAS NO MORE THAN 2-3 SECONDS. IT WOULD APPEAR THAT THE ACFT WAS HIDDEN BY OUR WING AS IT APCHED AND BY THE TIME THE ACFT WAS LARGE ENOUGH TO BE SEEN UNDERNEATH THE WING WE WERE ALREADY CLOSE. SINCE BOTH MY STUDENT AND MYSELF WERE BOTH SCANNING THE LCL APCH ALERT FOR OTHER ACFT THE ONLY OTHER METHOD WE COULD HAVE USED TO SPOT HIM SOONER WOULD HAVE BEEN TO HAVE USED S-TURNS TO GIVE US GREATER VISIBILITY BENEATH OUR ACFT. THE FLT WAS INSTRUCTIONAL IN NATURE SO THE STUDENT WAS FLYING UNDER MY SUPERVISION. THERE WAS TO BE GREAT IMPORTANCE PLACED ON NAV AND COMS. THIS EVENT HOWEVER SHOWED HOW ONE MUST ALWAYS WATCH FOR THE UNEXPECTED. WHILE I DO NOT FEEL THAT WE WERE TOO INVOLVED IN THE COCKPIT THIS EVENT IS A GOOD EXAMPLE OF HOW ONE CAN NEVER SPEND TOO MUCH ATTN TO THE OUTSIDE OF THE ACFT.

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.