The closest kids my older brother and I had to play with growing up during WWII in Winnipeg were the Kruger brothers. They lived two houses and a vacant lot down the street from our house. There was Ron the oldest, Lloyd in the middle, and Bob at the bottom. Their father, Sam, was a vital asset in our war-rationed neighbourhood. Mr. Kruger saved our soles. He was the community shoemaker. With all the shortages, worn clothes and especially shoes were mended not thrown away.
Mr. Kruger demanded and got high scholastic achievement from his boys. As a result, both Ron and Bob became engineers and Lloyd built a successful automotive business. After the war when the huge economic boom powered by the greatest generation that ever lived overtook us, we went our separate ways. Over the years, and many moves later, I lost touch with the Kruger boys even Ron who I learned worked in the same airline as I, although I had no idea where he worked and in what capacity. Our paths never crossed.
It was beautiful clear day in January. We were flying a Boeing 727 from Winnipeg to Toronto with a full load of southbound passengers, most of them connecting in Toronto to escape the bitter Winnipeg winter. The ride was smooth, both terminals CAVU, and a favourable wind favoured a straight out easterly departure from Winnipeg and a straight in easterly arrival to Toronto. Even the usual messed up radar vectors from Toronto Arrival Control would not ruin our early arrival.
A few minutes after reaching TOC at FL330 and setting cruise power, the oil filter bypass/low oil pressure amber light for the number three engine on the front panel came on. A quick check of the second officer’s panel revealed oil pressure and temperature were normal. The QRH (Quick Reference Handbook) mandated reducing power on the affected engine. However, if the front caution light went out and the S/O panel indications remained normal, then the engine could be kept running at reduced power to meet the demands of the electrical and pressurization systems. Buried within the wordy QRH was the need to press to test the bypass warning light on the front panel for brightness. In other words, the light had a dual purpose and dual brightness function.
We discussed our options and agreed to keep the engine running at whatever power kept the light out as long as pressure and temperature remained normal. The alternative meant shutting down the engine and returning to Winnipeg. That meant inconvenience and aggravation for our connecting passengers, not to mention cost considerations for the airline. But something about the complicated QRH procedure left me feeling uncomfortable. We decided to seek further advice and called Maintenance Central in Montreal on the company frequency. We told them our problem, actions and plans and asked them if our actions would cause any damage to the engine. They replied that we had interpreted the procedure correctly.
Feeling good about our decision, we continued with the number three engine just above idle keeping all the a/c systems running normally. We had no trouble maintaining FL330 with only a slight reduction of airspeed. We would still arrive early, all our passengers would be happy and the company would save the cost of the associated delayed connections. For weeks, I wore a smug smile on my face as I told my colleagues what a wonderful job I had done.
Then one day I learned the whereabouts of one of my boyhood pals. I opened my company mailbox to find an envelope containing a curt note from the manager of the company Pratt & Whitney overhaul department. It read:
We found a little problem after tearing down the number three engine on a/c number 413 that you brought in from Winnipeg on flight 190 January 15th. The engine was starved of oil. If the engine had continued running for fifteen minutes longer, it would have catastrophically self-destructed.
Just thought you’d like to know.
Manager PW JT8D Engine Overhaul Montreal
As a career-long Boeing enthusiast, I found the 727 oil filter bypass warning system counter intuitive to the typical uncomplicated engineering of both Pratt and Whitney and Boeing. I lost trust in our airline’s Maintenance Central and Flight Operations Department and the quality of their 727 QRH write up. Buried deep in the procedure – not highlighted in any way – was a statement to use the procedure only if one engine was already shut down as a means to keep electrics and pressurization operating. That statement should have been in a large bold font at the very beginning of the procedure.
Above all was my regret over not exercising proper good judgment by not interpreting the QRH procedure with the due diligence it deserved. The possibility that I might have caused a disaster left me shaken to the core and prompted me to do some serious soul searching about my professionalism.
I thoroughly enjoyed my 13 years flying the 727, thinking that it was completely devoid of any bad habits or engineering flaws. Compared to other airplanes, it seems nit-picky to point out this one small but potentially dangerous flaw in an otherwise great machine. In spite of some interesting management shuffles, our airline is a great airline and I’m proud to have been part of the team. To me it was the range of experience, age and camaraderie of the three-person crew on the 727 that made my time on it so enjoyable.
Explanation of our company’s fix on the original Boeing AOM re: oil filter by-pass W/L:
Insert 192 (Low Oil Pressure Or Filter Bypass Light – Modification) was issued 21 Jan 81 and the technical explanation of the insert was: “A modification will be carried out to make the intensity of the light different for each function. A resistor will be installed in the Low Oil Pressure switch line and it will therefore not provide as bright a light as will the Filter Bypass Switch. To know which brightness you have, press to test. The Filter Bypass will be the same as the test. Low Oil Pressure will be dimmer.”