A C172 landed over a C150 pilot that had takeoff clearance on runway 27 at ipt.

Attributes
ACN	544350
Time
Date	200204
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ipt.airport
State Reference	PA
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Cessna 150
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	ground : position and hold
Flight Plan	None
Aircraft 2
Controlling Facilities	tower : ipt.tower
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	landing : roll
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : multi engine pilot : cfi pilot : commercial
Experience	flight time last 90 days : 90 flight time total : 3275 flight time type : 1000
ASRS Report	544350
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Miss Distance	horizontal : 150 vertical : 200
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

I was holding short runway 27 at taxiway D, and believed I had been cleared for a right downwind departure when a non radio airplane made an approach and landing, I inadvertently began to taxi toward the hold line and as I reported my clearance back, I canceled the hold clearance that the controller was giving me. At the point I saw the shadow of an airplane crossing left to right of midpoint of taxiway, I looked to my right and saw the airplane high and in a steep descent for landing. I immediately stepped on the brakes and did hear the hold clearance. I reported back and asked for verification of original departure clearance. As all this happened in a very short, and stressful period of time, I inadvertently taxied beyond the hold line, and to the edge of the runway. I believe a contributing factor could be that the non radio aircraft possibly flew a nonstandard approach. She did say that she was flying from the north. I believe she was inside of the threshold of runway 27 on a high right base and proceeded to land.

Original NASA ASRS Text

Title: A C172 LANDED OVER A C150 PLT THAT HAD TKOF CLRNC ON RWY 27 AT IPT.

Narrative: I WAS HOLDING SHORT RWY 27 AT TXWY D, AND BELIEVED I HAD BEEN CLRED FOR A R DOWNWIND DEP WHEN A NON RADIO AIRPLANE MADE AN APCH AND LNDG, I INADVERTENTLY BEGAN TO TAXI TOWARD THE HOLD LINE AND AS I RPTED MY CLRNC BACK, I CANCELED THE HOLD CLRNC THAT THE CTLR WAS GIVING ME. AT THE POINT I SAW THE SHADOW OF AN AIRPLANE XING L TO R OF MIDPOINT OF TXWY, I LOOKED TO MY R AND SAW THE AIRPLANE HIGH AND IN A STEEP DSCNT FOR LNDG. I IMMEDIATELY STEPPED ON THE BRAKES AND DID HEAR THE HOLD CLRNC. I RPTED BACK AND ASKED FOR VERIFICATION OF ORIGINAL DEP CLRNC. AS ALL THIS HAPPENED IN A VERY SHORT, AND STRESSFUL PERIOD OF TIME, I INADVERTENTLY TAXIED BEYOND THE HOLD LINE, AND TO THE EDGE OF THE RWY. I BELIEVE A CONTRIBUTING FACTOR COULD BE THAT THE NON RADIO ACFT POSSIBLY FLEW A NONSTANDARD APCH. SHE DID SAY THAT SHE WAS FLYING FROM THE N. I BELIEVE SHE WAS INSIDE OF THE THRESHOLD OF RWY 27 ON A HIGH R BASE AND PROCEEDED TO LAND.

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.