Greetings to the OC and AH aficionados. I figured it would be easier to digest this post July 4 rather then during – so here goes.
LINK TO PHOTOS:
http://s145.photobucket.com/albums/r207/wolfala/Engine%20Destruction%20and%20CHT%20EGT%20Evidence/To recap – my aircraft is used in a very high utilization environment (north of 500 hours per year) mostly in a cross country capacity, but also as an IFR trainer for the few and the proud. Needing increased utility and mechanical SA, I chronicled the installation of a JPI-700 in my legacy SR-20 this past December.
http://www.cirruspilots.org/cgi-bin/wwwthreads/showthreaded.pl?Cat=&Board=Hangartalk&Number=300599&page=&view=&sb=&o=&vc=1#Post300599This effectively brought me into the age of having more information then I really wanted to know about. I had been judicious about oil analysis at every oil change and had a very good set of data which was useful for spotting trends and problems. Now I had 1 more tool – an engine monitor to look at CHT, EGT and Flow.
Now there is an old chestnut of wisdom that was passed down by someone before my time that these tools pay for themselves. At least JPI would make that claim – but even if they did it happened to be true.
One winters day on Jan 28th I was finishing up a 50 hour inspection, did the oil change and took my oil sample as before. This particular run had 51 hours on the oil by the air tach. The aircraft had normally gone 45 hours between changes, so this was no different in many respects especially with the high utilization rate it had seen over the winter months.
On the fateful day of Jan 30th, a renter who I had given a checkout to decided to take the aircraft out for 2 hours. Apparently unaware to the equipment changes in the aircraft (principally the JPI) and unsure of its use, he took the aircraft anyway. Since the JPI replaced the analog EGT/CHT gauge, he gave no thought as to its purpose in the cockpit and continued blissfully unaware – while the device recorded his every action.
Everything indicated normally between the run-up and temperatures while on the ground. Temperatures and fuel flow seemed to indicate his adherence to the checklists. But, as fate would have it, on the beginning of his takeoff roll – the fuel flow maxed out at 16.6 instead of 18: He had not activated the Boost Pump as per the POH and Checklists inside of the aircraft. The data ticked away second by second – his takeoff roll continuing, and the cylinder head temperatures onward to thermal runaway with no fuel to keep them cool. 45 seconds into his application of take-off power, the first alarms went off at 380*, and continued unabated. The fuel flow indications remained at takeoff power, and the data then showed that no climb power setting was set, another checklist item skipped. The CHT alarms were now at 425* and rising rapidly – the engine still at takeoff power.
The engine remained at this power setting for 4 agonizing minutes, having reached a temperature of 447*. Only after 4 minutes, was the power finally reduced. The CHT warnings continued for another 2 minutes until they silenced themselves. The pilot continued on, blissfully unaware and landed at Half Moon Bay.
2 days later I go out to the aircraft for an evening IFR lesson with a student – and we settle into a routine for the next 6 hours at 55% power doing approaches in the central valley until about 3am. We land, and I download the data on my Trimble Ranger to take home that evening for a little analysis.
Arriving home bleary eyed – I transfer the data from the Trimble onto my USB thumb drive and access the engine logs; nothing out of the ordinary for the previous 25 hours. The flight after the oil change indicated no problems with the GAMI spread, CHT or EGT excursions or jitters on the EGT indicating valve problems.
I then scrolled down to the flight on Jan 30th. Just a cursory examination at 4am, I thought nothing of it – just a lot of text in a table.
http://www.cirruspilots.org/uploaded_images/3-308983-Flt104.pdfSo I figured I would look at the graph just to have a better visual picture.
http://www.cirruspilots.org/uploaded_images/3-308858-Graph.pdfWhat I saw was nothing short of horrifying – it was Mount Everest. I looked at it again to make sure my eyes were not lying. Yes, it was there – the engine really was being redlined.
The next morning was one of mild disgust. I had been planning to take the plane out of service to have the Magnetos serviced and remove the propeller to have a repaint and propeller guard applied. I reasoned then, with a week of downtime ahead of me – do both of those tasks as well as an “Over temp” inspection. Additionally, Blackstone labs was contacted to expedite the report on the sample taken January 28th – and was informed of the current episode on the 30th and to expect a rushed sample in the coming days.
The flight school owner naturally thought nothing would be wrong. I hoped he was right, but my intuition and A&P classes over at Palo Alto told me there was no way – but it helped a bit to hold out hope for an ok bill of health. We wheeled the bird into the cavernous hanger of Bud Field Aviation at Hayward, underneath the DC-3 which was going through an engine change at the time.
I brought up the data on my laptop from the flight – showing both mechanics Mike Wyant and Hernand Galvan the temperature profiles and fuel flows. Both had not previously seen data driven analysis tools used like this, and they quickly became converts and wanted to know how to use it diagnostically – to which I showed then later on.
Mike Wyant, the mechanic doing the work said the following of the inspection:
“I preformed a cylinder compression check in accordance with Teledyne Continental Motors (TCM) Service Bulletin (SB) SB03-3. During the test I found that all six (6) cylinders showed a reduction in pressure of 10–20 psi, and ring damage on 2 cylinders. This, compared to his annual inspection which been preformed 50 hours and 1 month prior this incident with no indication of compression, ring, or valve problems. The SB also calls for an internal bore scope inspection of the cylinders and valves. During this phase of engine inspection I found several exhaust valves faces dis-colored which is stated in Table 2 of the SB to repair or replace the cylinder in question. With a combination of the two problems (low compressions & dis-colored exhaust valves) I recommended all six (6) cylinders be removed for further evaluation.”
OIL REPORT JAN 28th prior to his flight:
http://www.cirruspilots.org/uploaded_images/28-338476-D30821.pdfOIL REPORT Feb 6:
http://www.cirruspilots.org/uploaded_images/28-338477-D30940.pdfThe oil analysis from Jan 28th and our inspection on Feb 6th came back the next day. The oil change on the 28th went 51 hours with no indications of distress inside the engine. The sample taken on Feb 6th had 9 hours on it – and showed elevated levels of chromium and other metals of cylinder metallurgy many times above the levels of the previously mentioned sample, yet having 1/5th the time in service. With this information in hand from the inspection and oil analysis, we brought the renter pilot in for interrogation under the auspices of him needing to be re-trained. The initial letter sent out indicated to him said that he exceeded our published redline (IN the checklist and on the JPI) on 5 out of 6 cylinders – and that the aircraft was taken out of service to check for damage internally, and for him to meet with myself and 2 of the senior instructions to review his procedures. In that meeting, we showed him the data from his flights – the temperature profiles, and the most recent oil analysis before and after his flights – and the results of the over temperature inspection and recorded damage. The initial reaction was the usual disbelief with him saying “I fly all aircraft the same way – full throttle all the time.” The end result of the meeting was in asking him to repair the damage – to which at that moment he agreed. That was my first mistake.
