Jun 21 2019

Know Your Aircraft Posted 5 years 190 days ago ago by Randy Mains

I gave a CRM class at a helicopter air medical flight program recently and something occurred that reminded me why it’s imperative that pilots know their aircraft.  

The incident happened when I was given a tour of the hospital’s aircraft by the program director and one of the pilots on duty who was a former Black Hawk pilot in the Army.  The aircraft looked brand new and I could see it had everything a pilot could ask for to help them while flying in VMC or IMC conditions. 

Blanks 
Because it was quite a new-generation aircraft, and because I didn’t know much about this model, I asked the pilot, “What make of engines does it have?” He got this dull look on his face as he tried to recall, finally admitting sheepishly, “I don’t know?” Trying to get him off the hook as a way to keep from embarrassing himself further in front of his boss I asked, “How many shaft horsepower do you have per engine?” Again, I got that blank look accompanied by a now very red face.  He said apologetically, “I don’t know.” In an effort to ask a question he may know I asked, “What’s your endurance?” Fully embarrassed now, he admitted that he didn’t know. I stopped asking questions because I could tell he was flustered and looking foolish in front his boss. 

To say I was shocked at his lack of familiarity with his aircraft would be a colossal understatement because his lack of knowledge to these very basic questions caused me to wonder what other technical questions this pilot might not know. Admittedly, not knowing these relatively trivial questions wouldn’t kill him (however, it would be nice to know how long you could fly on a tank of gas) but donning my flight examiner’s hat I thought if I were giving this young man a checkride I would have dug deeper to find the depth of his lack of knowledge. 

Even a layman knows why a pilot needs to know their aircraft and its systems.  One only has to look at the recent Lion Air and Ethiopian Airlines Boeing 737 Max 8 crashes that recently filled the headlines. 

Infamous  Incidents
There have been earlier accidents, quite infamous ones in fact, where lack of knowledge of an aircraft’s differences between models of the same type of aircraft caused loss of life. To the point, one aviation disaster stands out in my memory:

On January 8th, 1989, British Midland Flight 92, a Boeing 737- 400, crashed on the embankment of the M1 motorway near Kegworth, Leicestershire, England, while attempting to make an emergency landing at East Midlands Airport.  Several links in the error chain contributed to the accident, but the root cause of the crash wasn’t the engine failure and subsequent engine fire. The root cause was the crew misdiagnosing the emergency and shutting down the good engine because they didn’t know the new 737-400’s systems; instead of the Number One engine driving a single air conditioning system, the Number Two engine also drove a second air conditioning system.  Who would ever imagine not knowing something so seemingly trivial would cause a fatal crash?

They were on a flight from London Heathrow Airport to Belfast Airport, when a fan-blade fractured in the left engine; this filled the flight deck with smoke by disrupting the air conditioning system. The pilots wrongly believed that the smoke indicated a fault in the right engine, since earlier models of the 737 they flew ventilated the flight-deck from the right engine.  Their mistake would prove fatal for 47 people of the 127 on board and seriously injure 74 others. The two pilot’s misdiagnosis became fatal because the newer model 737–400 that they were flying used a different system that ventilated the flight deck from the right-hand and left-hand engines. Wedded to their perception that the problem had to be the right engine when smoke entered the cockpit, as it would have been in earlier models, they took their misperception to the next step and shut down the functioning engine causing more fuel to be pumped into the malfunctioning engine that resulted in it bursting into flames. 

As a Level-D flight simulator instructor and examiner at CAE in Dubai, I have witnessed numerous mistakes made by pilots who did not understand their aircraft:  wrong fuel switches turned off, misuse of the autopilot, and emergencies misdiagnosed with predictable results, that sometimes become catastrophic.  

An example in our world of helicopers occurred when pilots of AS350 series helicopters took off with their yaw servo hydraulic switches in the “off” position.  After two accidents occurred (one fatal), Airbus Helicopters issued a safety information notice for pilots flying aircraft equipped with dual hydraulic systems to remind them of the procedures and indications for the run-up hydraulic checks and the importance of strict compliance with the pre-takeoff checklist.

What if?

May I suggest in your quiet moments, maybe when on standby for a flight, ask yourself: what would I do if (fill in the blank) happened?  Then turn to the flight manual, or your SOPs, to see how the problem should be remedied.

Emulate my Australian friend, a fellow nicknamed “Trackless,” by his ‘mates’ because his legs were so short his bottom rubbed out his footprints.  Whenever Trackless did not have passengers on board, he was known for suddenly saying to the other pilot, “Now, for exercise…” then he’d announce some sort of emergency like falling engine oil pressure.  We would pull out the checklist and go through the touch drills as a way to familiarize ourselves with that particular emergency or malfunction; it’s an excellent way to bring up one’s game.

Don’t allow yourself to fall into the complacency trap like that air medical pilot did at the beginning of this column.  Know your aircraft intimately by staying familiar with the books. Keep abreast of airworthiness directives. Know the differences between the similar aircraft models you fly. Is there a hidden ‘gotcha’ between models that could ruin your day? And use the checklist…always.

Knowing your aircraft is not just a mere convenience; it is your professional responsibility and might one day save your life and the lives of those who entrust you with theirs.

Randy Mains is an author, public speaker, and a CRM/AMRM consultant who works in the helicopter industry after a long career of aviation adventure. He currently serves as chief CRM/AMRM instructor for Oregon Aero. He may be contacted at [email protected].