Altitude bust. - NASA ASRS

Attributes
ACN	262033
Time
Date	199401
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : l15
State Reference	NV
Altitude	msl bound lower : 3500 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : las artcc : zma
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 11 flight time total : 201 flight time type : 46
ASRS Report	262033
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : became reoriented other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After clearance to transition las vegas class B airspace, I was cleared to maintain 4000 MSL while crossing the approach end of mccarran runway 25. A combination of events caused me to descend to 3500 MSL. I noticed the error just as I was notified by the alert controller that I was too low. I was able to initiate a climb and return to my assigned altitude before effecting other traffic. This incident was caused by 2 factors with another contributing factor. 1ST, the pilot's push-to-talk switch had been inoperative for several weeks. This necessitated using the hand microphone. After leveling off at 4000 MSL (I thought) I dropped the microphone. At that moment, the electric trim slipped and the pitch did not respond. Because I was reaching for the microphone, I missed the continued descent. The contributing factor is the part 135 requirement that only the operator is responsible for maintenance. My operator's mechanic and avionics shop will not even talk to me, the owner. I had mentioned to the operator several times about the push-to-talk switch, and had thought it was corrected. He had been too busy, however, and had not taken care of the problem. This is not the 1ST time I have had to literally hound the operator to correct something his experienced, professional pilots find only a minor annoyance, but that I, a low-time private pilot flying for my own enjoyment, consider a hazard.

Original NASA ASRS Text

Title: ALT BUST.

Narrative: AFTER CLRNC TO TRANSITION LAS VEGAS CLASS B AIRSPACE, I WAS CLRED TO MAINTAIN 4000 MSL WHILE XING THE APCH END OF MCCARRAN RWY 25. A COMBINATION OF EVENTS CAUSED ME TO DSND TO 3500 MSL. I NOTICED THE ERROR JUST AS I WAS NOTIFIED BY THE ALERT CTLR THAT I WAS TOO LOW. I WAS ABLE TO INITIATE A CLB AND RETURN TO MY ASSIGNED ALT BEFORE EFFECTING OTHER TFC. THIS INCIDENT WAS CAUSED BY 2 FACTORS WITH ANOTHER CONTRIBUTING FACTOR. 1ST, THE PLT'S PUSH-TO-TALK SWITCH HAD BEEN INOP FOR SEVERAL WKS. THIS NECESSITATED USING THE HAND MIKE. AFTER LEVELING OFF AT 4000 MSL (I THOUGHT) I DROPPED THE MIKE. AT THAT MOMENT, THE ELECTRIC TRIM SLIPPED AND THE PITCH DID NOT RESPOND. BECAUSE I WAS REACHING FOR THE MIKE, I MISSED THE CONTINUED DSCNT. THE CONTRIBUTING FACTOR IS THE PART 135 REQUIREMENT THAT ONLY THE OPERATOR IS RESPONSIBLE FOR MAINT. MY OPERATOR'S MECH AND AVIONICS SHOP WILL NOT EVEN TALK TO ME, THE OWNER. I HAD MENTIONED TO THE OPERATOR SEVERAL TIMES ABOUT THE PUSH-TO-TALK SWITCH, AND HAD THOUGHT IT WAS CORRECTED. HE HAD BEEN TOO BUSY, HOWEVER, AND HAD NOT TAKEN CARE OF THE PROB. THIS IS NOT THE 1ST TIME I HAVE HAD TO LITERALLY HOUND THE OPERATOR TO CORRECT SOMETHING HIS EXPERIENCED, PROFESSIONAL PLTS FIND ONLY A MINOR ANNOYANCE, BUT THAT I, A LOW-TIME PVT PLT FLYING FOR MY OWN ENJOYMENT, CONSIDER A HAZARD.

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.