Narrative:

I departed barnstable municipal airport on an IFR flight plan which would take myself and my instrument student to nantucket, ma, on an instrument training flight. We departed runway 15, we penetrated the overcast at 500-600 ft, and were promptly instructed by hyannis tower to contact cape approach. I changed frequencys and contacted approach control. I briefly took my eyes off of the instruments, as I felt confident in my student's ability to keep the airplane under control by reference to instruments. I returned my eyes back to the instrument panel. I noticed that the attitude indicator was showing the aircraft to be in a fairly steep descending bank to the right. I began to tell my student to correct for this. He said 'something's wrong.' after xchking the instruments, I could see that in fact we were in a climbing left bank. I hesitated for a brief moment, refusing to believe my instruments, then immediately assumed a vacuum failure. Taking control of the airplane I began to level the wings, and decrease our pitch, as I could see our airspeed decreasing. I contacted cape approach and advised them of our situation, requesting vectors for an immediate return to hyannis. They responded and asked if I wished to declare an emergency, to which I answered 'negative,' fearing the possible paperwork and questions to answer if I did so. I leveled off at my assigned altitude of 1700 ft and was so focused on trying to control the airplane with no attitude indicator, that I failed to realize that the airplane had deviated to the north, from our initially assigned heading of 150 degrees. Shortly thereafter, cape approach instructed me to make a climbing right turn to 3000 ft and a heading of 200 degrees. As I began figuring out the amount of time to turn using a timed turn at a standard rate, approach called back again with the same instruction, and a sense of urgency. I did my best to complete an accurate timed turn, while climbing, but the sense of urgency at hand forced me to count too quickly, resulting in an early rollout and failure to comply with the vector in a timely manner. I leveled out at 3000 ft and noticed that the heading indicator and magnetic compass showed the same heading, and the attitude indicator seemed to be working. However, I decided that I would not trust them and would keep them out of my scan, using only my remaining instruments, and using timed turns in order to comply with vector headings. Captain approach called back, and the controller gave me a telephone number to call when I landed, and instructed me to ask for the shift supervisor. I began to feel added tension in an already tense situation, as I believed that this meant I would be in some sort of trouble. I was then given several vectors, with which I tried my best to comply using timed turns, and a magnetic compass, but had limited success, deviating from most of them due to the added tension which I felt. I was then told to descend to 1700 ft and expect an ILS approach to hyannis. Focusing mainly on trying to control the airplane, and maintaining my heading using only a magnetic compass, I descended to approximately 1200 ft before being told by the controller that I was too low and had to climb back up to 1700 ft. Approach control, shortly thereafter, called back and asked if I was receiving the localizer. I looked to see if I was, and all I saw in both windows were 'navigation' flags. I responded that I was not receiving the localizer, and after several exchanges with ATC I realized that they were giving me the ILS 24 approach, and I was expecting the ILS 25 approach, for which I was already set up. I quickly looked up the ILS 24 approach plate, and managed to get the correct frequencys for the approach and get set up. I was vectored back to the 24 localizer, and the needle began to come in shortly thereafter. Cape approach then cleared me for the approach, advising me that I was 2 mi from the OM. Shortly thereafter, the controller called me back and advised me to check my altimeter setting, because he was getting a low altitude alert on me. I looked at my altimeter, and saw that I was at 1000 ft and looking at the approach plate, the procedure mandates maintaining 1700 ft until GS intercept. I began to climb back up, and rapidly intercepted the GS, and began a descent again. I then realized that I had wandered off of the localizer and reintercepted it. After a couple of deviations from the GS and localizer, I broke out of the clouds at approximately 500 ft and landed on runway 24 without any further occurrences. Upon taxiing in and shutting the airplane down, I called approach control on the telephone, as instructed. The controller then asked me what happened, and after my brief description of the events, advised me that I had come within 400 ft of another aircraft. Upon further review of the events as they occurred, I realize that the situation would not have been as severe if I had maintained a constant scan of the instrument panel, and taken control of the aircraft from my student sooner. Further deviations from ATC instructions could have been avoided if I maintained a better scan, not focusing so much on the fact that there was a problem with the gyro instruments. Additionally, the air traffic controller's actions of giving me a telephone number, and instructions to call as soon as I landed, did not help the situation.

Related reports:

Google
 

Original NASA ASRS Text

Title: INSTRUCTOR WITH INST STUDENT HAD VACUUM PUMP FAILURE IN IMC. UNABLE TO COMPLY WITH ALTS AND VECTORS ISSUED.

Narrative: I DEPARTED BARNSTABLE MUNICIPAL ARPT ON AN IFR FLT PLAN WHICH WOULD TAKE MYSELF AND MY INST STUDENT TO NANTUCKET, MA, ON AN INST TRAINING FLT. WE DEPARTED RWY 15, WE PENETRATED THE OVCST AT 500-600 FT, AND WERE PROMPTLY INSTRUCTED BY HYANNIS TWR TO CONTACT CAPE APCH. I CHANGED FREQS AND CONTACTED APCH CTL. I BRIEFLY TOOK MY EYES OFF OF THE INSTS, AS I FELT CONFIDENT IN MY STUDENT'S ABILITY TO KEEP THE AIRPLANE UNDER CTL BY REF TO INSTS. I RETURNED MY EYES BACK TO THE INST PANEL. I NOTICED THAT THE ATTITUDE INDICATOR WAS SHOWING THE ACFT TO BE IN A FAIRLY STEEP DSNDING BANK TO THE R. I BEGAN TO TELL MY STUDENT TO CORRECT FOR THIS. HE SAID 'SOMETHING'S WRONG.' AFTER XCHKING THE INSTS, I COULD SEE THAT IN FACT WE WERE IN A CLBING L BANK. I HESITATED FOR A BRIEF MOMENT, REFUSING TO BELIEVE MY INSTS, THEN IMMEDIATELY ASSUMED A VACUUM FAILURE. TAKING CTL OF THE AIRPLANE I BEGAN TO LEVEL THE WINGS, AND DECREASE OUR PITCH, AS I COULD SEE OUR AIRSPD DECREASING. I CONTACTED CAPE APCH AND ADVISED THEM OF OUR SIT, REQUESTING VECTORS FOR AN IMMEDIATE RETURN TO HYANNIS. THEY RESPONDED AND ASKED IF I WISHED TO DECLARE AN EMER, TO WHICH I ANSWERED 'NEGATIVE,' FEARING THE POSSIBLE PAPERWORK AND QUESTIONS TO ANSWER IF I DID SO. I LEVELED OFF AT MY ASSIGNED ALT OF 1700 FT AND WAS SO FOCUSED ON TRYING TO CTL THE AIRPLANE WITH NO ATTITUDE INDICATOR, THAT I FAILED TO REALIZE THAT THE AIRPLANE HAD DEVIATED TO THE N, FROM OUR INITIALLY ASSIGNED HDG OF 150 DEGS. SHORTLY THEREAFTER, CAPE APCH INSTRUCTED ME TO MAKE A CLBING R TURN TO 3000 FT AND A HDG OF 200 DEGS. AS I BEGAN FIGURING OUT THE AMOUNT OF TIME TO TURN USING A TIMED TURN AT A STANDARD RATE, APCH CALLED BACK AGAIN WITH THE SAME INSTRUCTION, AND A SENSE OF URGENCY. I DID MY BEST TO COMPLETE AN ACCURATE TIMED TURN, WHILE CLBING, BUT THE SENSE OF URGENCY AT HAND FORCED ME TO COUNT TOO QUICKLY, RESULTING IN AN EARLY ROLLOUT AND FAILURE TO COMPLY WITH THE VECTOR IN A TIMELY MANNER. I LEVELED OUT AT 3000 FT AND NOTICED THAT THE HDG INDICATOR AND MAGNETIC COMPASS SHOWED THE SAME HDG, AND THE ATTITUDE INDICATOR SEEMED TO BE WORKING. HOWEVER, I DECIDED THAT I WOULD NOT TRUST THEM AND WOULD KEEP THEM OUT OF MY SCAN, USING ONLY MY REMAINING INSTS, AND USING TIMED TURNS IN ORDER TO COMPLY WITH VECTOR HDGS. CAPT APCH CALLED BACK, AND THE CTLR GAVE ME A TELEPHONE NUMBER TO CALL WHEN I LANDED, AND INSTRUCTED ME TO ASK FOR THE SHIFT SUPVR. I BEGAN TO FEEL ADDED TENSION IN AN ALREADY TENSE SIT, AS I BELIEVED THAT THIS MEANT I WOULD BE IN SOME SORT OF TROUBLE. I WAS THEN GIVEN SEVERAL VECTORS, WITH WHICH I TRIED MY BEST TO COMPLY USING TIMED TURNS, AND A MAGNETIC COMPASS, BUT HAD LIMITED SUCCESS, DEVIATING FROM MOST OF THEM DUE TO THE ADDED TENSION WHICH I FELT. I WAS THEN TOLD TO DSND TO 1700 FT AND EXPECT AN ILS APCH TO HYANNIS. FOCUSING MAINLY ON TRYING TO CTL THE AIRPLANE, AND MAINTAINING MY HDG USING ONLY A MAGNETIC COMPASS, I DSNDED TO APPROX 1200 FT BEFORE BEING TOLD BY THE CTLR THAT I WAS TOO LOW AND HAD TO CLB BACK UP TO 1700 FT. APCH CTL, SHORTLY THEREAFTER, CALLED BACK AND ASKED IF I WAS RECEIVING THE LOC. I LOOKED TO SEE IF I WAS, AND ALL I SAW IN BOTH WINDOWS WERE 'NAV' FLAGS. I RESPONDED THAT I WAS NOT RECEIVING THE LOC, AND AFTER SEVERAL EXCHANGES WITH ATC I REALIZED THAT THEY WERE GIVING ME THE ILS 24 APCH, AND I WAS EXPECTING THE ILS 25 APCH, FOR WHICH I WAS ALREADY SET UP. I QUICKLY LOOKED UP THE ILS 24 APCH PLATE, AND MANAGED TO GET THE CORRECT FREQS FOR THE APCH AND GET SET UP. I WAS VECTORED BACK TO THE 24 LOC, AND THE NEEDLE BEGAN TO COME IN SHORTLY THEREAFTER. CAPE APCH THEN CLRED ME FOR THE APCH, ADVISING ME THAT I WAS 2 MI FROM THE OM. SHORTLY THEREAFTER, THE CTLR CALLED ME BACK AND ADVISED ME TO CHK MY ALTIMETER SETTING, BECAUSE HE WAS GETTING A LOW ALT ALERT ON ME. I LOOKED AT MY ALTIMETER, AND SAW THAT I WAS AT 1000 FT AND LOOKING AT THE APCH PLATE, THE PROC MANDATES MAINTAINING 1700 FT UNTIL GS INTERCEPT. I BEGAN TO CLB BACK UP, AND RAPIDLY INTERCEPTED THE GS, AND BEGAN A DSCNT AGAIN. I THEN REALIZED THAT I HAD WANDERED OFF OF THE LOC AND REINTERCEPTED IT. AFTER A COUPLE OF DEVS FROM THE GS AND LOC, I BROKE OUT OF THE CLOUDS AT APPROX 500 FT AND LANDED ON RWY 24 WITHOUT ANY FURTHER OCCURRENCES. UPON TAXIING IN AND SHUTTING THE AIRPLANE DOWN, I CALLED APCH CTL ON THE TELEPHONE, AS INSTRUCTED. THE CTLR THEN ASKED ME WHAT HAPPENED, AND AFTER MY BRIEF DESCRIPTION OF THE EVENTS, ADVISED ME THAT I HAD COME WITHIN 400 FT OF ANOTHER ACFT. UPON FURTHER REVIEW OF THE EVENTS AS THEY OCCURRED, I REALIZE THAT THE SIT WOULD NOT HAVE BEEN AS SEVERE IF I HAD MAINTAINED A CONSTANT SCAN OF THE INST PANEL, AND TAKEN CTL OF THE ACFT FROM MY STUDENT SOONER. FURTHER DEVS FROM ATC INSTRUCTIONS COULD HAVE BEEN AVOIDED IF I MAINTAINED A BETTER SCAN, NOT FOCUSING SO MUCH ON THE FACT THAT THERE WAS A PROB WITH THE GYRO INSTS. ADDITIONALLY, THE AIR TFC CTLR'S ACTIONS OF GIVING ME A TELEPHONE NUMBER, AND INSTRUCTIONS TO CALL AS SOON AS I LANDED, DID NOT HELP THE SIT.

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.