FLYING LESSONS for November 3, 2016

Transcription

1 FLYING LESSONS for November 3, 2016 FLYING LESSONS uses the past week s mishap reports to consider what might have contributed to accidents, so you can make better decisions if you face similar circumstances. In almost all cases design characteristics of a specific make and model airplane have little direct bearing on the possible causes of aircraft accidents, so apply these FLYING LESSONS to any airplane you fly. Verify all technical information before applying it to your aircraft or operation, with manufacturers data and recommendations taking precedence. You are pilot in command, and are ultimately responsible for the decisions you make. FLYING LESSONS is an independent product of MASTERY FLIGHT TRAINING, INC. This week s LESSONS: Pursue Mastery of Flight The pilot of a Beech Baron came to Wichita to fly with me last week. He has a beautiful 1972 Baron 58 with a great, immediate pre-glass panel update, new paint and new interior an enviable early 58 to be sure. I soon learned that the pilot had accepted his airplane from the avionics shop for some routine work just a few days before, and his flight up to Wichita in spotlessly blue although unseasonably warm October skies was the first flight since the avionics work was complete. Before we began our briefing, the pilot told me he had the FBO s mechanic looking at the CHT (cylinder head temperature) gauge on his right engine. The indicated temperature had been fluctuating during his one-hour trip up. Since it was randomly showing sudden drops, normal indication and unusually hot temperatures, it seemed more likely that it was an electrical gauge problem than a true fluctuation of CHTs. Either way, he needed it fixed, and the good people here at Wichita/Eisenhower National Airport (KICT) were already out looking at his airplane. Some time during our roughly 1.5 hour instructional pre-brief the mechanics stopped by the briefing room and told the owner they appeared to have fixed the gauge. We would check the CHT early in our flight the Kinds of Operations and Equipment List (KOEL)* table in the Limitations section of the Baron 58 Pilot s Operating Handbook (POH) makes proper operation of both engines CHT gauges required for all types of flight VFR or IFR, day or night. If the CHT was still erratic and inoperative, we would abort the training flight and bring it back to the shop. *KOEL requirements are contained in 14 CFR (d)(2)(ii) for pilots operating U.S.-registered aircraft. See Happily the CHT gauges were both working perfectly when the pilot started engines for our training flight. However, another problem raised its head during engine start. Without getting too deep into type-specific systems design, the Baron employs a pair of instrument air pressure pumps, one on each engine, to drive its air-driven instruments (and if so equipped, pneumatic deice boots). The instrument air pressure system is similar to the vacuum system on other types of airplanes, and it performs the same function of spinning gyroscopes to stabilize the flight instruments. The only difference is that where vacuum systems suck, pressure systems blow. The pilot monitors operation of the instrument air system using an Instrument Air Pressure Gauge. The gauge s needle displays system pressure. The gauge also employs two small red bullets called Source Failure Indicators. When the left air pump is working the left bullet is retracted and disappears. When the right pump is working the right bullet disappears. The Baron s owner is very familiar with his airplane s pneumatic system and its 2016 Mastery Flight Training, Inc. All rights reserved. 1

2 common failure modes. He already knew the procedure of starting one engine and checking the system s operation before starting the other engine. Not only does this confirm independent operation of the first pneumatic pump before the second one starts, it also permits detection of a stuck system valve that can render the pneumatic flight instruments (in this case, the primary attitude indicator) inoperative if one air pump fails, even if the other one is still working. Before engine start the Instrument Air Pressure Gauge looked like representation (1) above. The needle indicated no air flow and both red Source Failure Indicator bullets were visible. The pilot started the left engine. During his flow check of the panel immediately after start he noted proper indication in the gauge: the needle showed proper air pressure, the left bullet was retracted and the right bullet was still visible because the right engine, and therefore the right instrument air pressure pump, were not yet working as in representation (2). Unfortunately when the pilot started the right engine the gauge indications did not change. The right bullet remained visible; the right instrument air pressure pump was not working it still looked like representation (2) above. We briefly discussed the possibility the pneumatic system had somehow been disturbed during the check of the CHT. We didn t know whether the mechanics had worked on the engine or under the panel. It was unlikely, but it may have been that the instrument air lines had been jostled or knocked loose inadvertently while the technicians addressed the CHT. It could have been an indicator line or an actual instrument air line; it could have been a Source Failure Indicator sensing failure or actual failure of the right instrument air pump. We did not know and there was no way to find out from the pilots seats. Again happily, our training flight would be conducted entirely under Visual Flight Rules (VFR) in spectacularly clear Visual Meteorological Conditions (VMC). The KOEL requires both instrument air pumps and the monitoring gauge to be operative for all types of flight except Day/VFR. Flying under VFR on a beautifully clear day, we could legally and safely fly with an inoperative pump and/or a broken air pressure gauge. We decided to continue the flight and report the failure later. A Post-It note Right Pump Inop placard next to the gauge was all we could do to make this dispatch legal with the inoperative equipment. Sure enough, the CHT worked fine when we flew. But after about an hour of maneuvers flying the left engine s instrument air pump failed resulting in indications such as representation (3), which look just like the gauge appears before starting. We thought it highly unlikely both pumps quit within an hour of one another, given they tend to last between 500 and 600 operating hours before failure in this type of airplane. In the partial panel simulated IFR ( hood ) practice that followed, taking advantage of the condition while we returned for a practice ILS approach into Wichita, we found the VOR/LOC was not indicating on the Horizontal Situation Indicator (HSI). The localizer and glideslope worked on 2016 Mastery Flight Training, Inc. All rights reserved. 2

3 the #2 VOR head which the pilot used for the practice approach, but neither the localizer nor a nearby VOR was being received by the HSI. Up to that point it had been working properly when referencing the GPS, and it still would we figured an antenna wire had been accidentally disconnected from the HSI during the CHT repairs or while the Baron had been in the avionics shop just before our training day. Since the weather had been so clear the pilot had flown using GPS up for our training flight and had had no reason to switch over to the VLOC mode for an approach. We landed and debriefed the good VFR and serendipitous partial panel experience the pilot had flown to that point. We committed to get together for IFR instruction once the HSI and instrument air pumps were fixed. Because permits it for Day/VFR flight, the pilot chose to fly home under VFR to get the work done at his home airport. As of this writing I ve not heard what has been found to be the cause of these failures. The next day I was on a flight instructor forum on FaceBook. The pilot of a Cessna Citation was asking the group about places to stop on a cross-continent flight; he was picking up the used jet from a repair shop and his departure was delayed because of a circuit breaker issue. He was concerned that his delay would cause him to make his flight after dark. Citing my experience from the day before I wrote: Take a local test flight in day VMC before committing yourself to the trip. Ensure everything works, not just what was directly addressed by the mechanic. I reported a similar experience, and similar FLYING LESSONS, in my August 11, 2016 report. See I don t know if the Citation pilot heeded my advice. I haven t head any follow-up, nor has there been any mishap report, so chances are everything worked out just fine. However, crashes of airplanes on their first flight after inspection, installation, maintenance or repair are not uncommon. In many cases the pilot accepts the airplane from the shop and immediately launches into Instrument Meteorological Conditions (IMC) and/or night sometimes very bad conditions indeed. Mechanics are human, too, subject to the same human errors as are we pilots. Add the complexity and at times frailty of wiring and hoses in an airplane in its fifth decade of use, and you can see the potential for inadvertent outcomes from otherwise outstanding service. No one will know for certain until the airplane is flown. Returning an airplane to service after it s been in the shop is a partnership between the technician that does the work, the inspector who signs it off, and the pilot who conducts the postmaintenance test flight. As we ve said before, but which bears repeating now and then, under the Federal Air Regulations it s the aircraft owner or operator, not the mechanic, who is ultimately responsible for the airworthiness of an airplane. Ancillary LESSONS include: Know how the systems work in each individual airplane you fly. Systems and the way you operate them may differ significantly between two otherwise very similar airplanes, even between close serial numbers of the same make and model. Know what to check on each system immediately after start and as you change from one phase of flight to the next. This is the first corollary to know your systems, because you need to know the design and operation to be able to do a quick, effective flow check backed up by a printed checklist when time permits. Know what normal, abnormal and emergency indications look like. This is the second corollary, because it comes from knowing how the system is designed and operated. Know what to do when you find normal, abnormal or emergency indications. This is 2016 Mastery Flight Training, Inc. All rights reserved. 3

4 the third corollary. Most times what to do means reference the checklist. In the case of true emergencies, you need to know what to do and how to do it from memory so you can immediately do what s necessary and proper before you have time to reference a printed checklist. Know what s required and what is optional. Primarily I m referring to the rules for Minimum Equipment Lists, KOELs, and regulatory-based requirements for VFR, IFR, Night and, if certificated, Flight in Icing Conditions. Tab the KOEL in Section II, Limitations, of your Airplane Flight Manual (AFM) or POH so you can reference the system requirements if you detect a malfunction or failure. Comments? Questions? Let us learn from you, at mastery.flight.training@cox.net See Debrief: Readers write about recent FLYING LESSONS: We ll focus on reader mail in next week s FLYING LESSONS. What do you think? Send your thoughts to mastery.flight.training@cox.net Please help me cover the costs of providing FLYING LESSONS through the secure PayPal donations button at Thank you, generous supporters. Icing season The FAA, NASA and AOPA have updated the presentation Ice-Induced Stall Pilot Training. This free YouTube video is intended to help pilots understand the phenomenon of tailplane and wing stall while flying in icing conditions. The training also explains icing certification rules. And it recommends cockpit procedures to mitigate ice induced stall in order to maintain controlled flight during unexpected icing encounters. At a few seconds under 30 minutes in length the video is longer than we ve become accustomed to. But it s very well done. It goes in depth into the difference between wing and tailplane stalls, including how to know when to apply the proper recovery technique; configurations that will prevent tailplane stalls even during tailplane ice accumulation; minimum ice penetration speeds; and for all situations, suggestions for airplanes that do not have manufactuer s guidance for these situations in their Airplane Flight Manual or Pilot s Operating Handbook. If you ever fly IFR in below-freezing temperatures it s worth the time to review. Watch Ice-Induced Stall Pilot Training. See You can always find the current and two most recent FLYING LESSONS reports at The Little Things So there I was providing flight instruction to a primary student on a dark moonless night with no horizon and no instrument rating and now facing a formidable distraction. Gene Benson 2016 Mastery Flight Training, Inc. All rights reserved. 4

5 Many FLYING LESSONS readers may already also subscribe to Gene Benson s Vectors for Safety at This month s Vectors includes Sometimes it s the Little Things, an excellent essay that s worth your quick read. See Share the skies with master aviators. Forward FLYING LESSONS to a friend Pursue Mastery of Flight. Thomas P. Turner, M.S. Aviation Safety Flight Instructor Hall of Fame 2010 National FAA Safety Team Representative of the Year 2008 FAA Central Region CFI of the Year Three-time Master CFI FLYING LESSONS is 2016 Mastery Flight Training, Inc. For more information see or contact mastery.flight.training@cox.net Mastery Flight Training, Inc. All rights reserved. 5