AusFlightSim - Introduction to Instrument Flying - The Aussie Flight Simulation Site for Enthusiasts Around the World!

I have been asked to put fingers to keyboard and have a brief informative chat about a few things from the real aviation world and how we can apply them to Flight Sim. Here is a brief intro to Instrument Flight. In the following weeks I will talk about approach scenarios, SIDS, STARS among other things, and some techniques and ways to implement them into flight sim situations.

For the purpose of this article, as we go through, questions are posed in red, answers in blue at the end of the article

Flight conducted under Instrument Flight Rules... what is it..??

Flight with total reference to the Instrument Panel. It allows a pilot to complete a flight without visual reference to a horizon. It’s really basic stuff and really brings into play primary and secondary functions and effects of controls, and control inputs include what you do with the pole as well as the throttles. Thought needs to be given to the very basics of what makes an aircraft fly, flight school day one lessons one two and three.

Question 1
WHAT ARE THE PRIMARY FLIGHT CONTROLS AND WHAT ARE THEIR INDIVIDUAL PRIMARY AND SECONDARY EFFECTS?

When people talk of Instrument flight, most think of landing approaches in the muck, but instrument flight is really basic straight and level, calculated turns, climb and decent and navigation. An instrument approach at the end is just the end of the day. Some days in some places, taxiing the aircraft is almost and instrument situation as well, and with modern GPS systems and INS we can see the airport taxiways on the panel and assist in getting us to the threshold or the terminal. All airline flights and the vast majority of charter operations are conducted under Instrument Flight Rules.

The Panel

The Panel

Okay, the first thing we need to understand is that the panel;

THE PANEL TELLS US WHAT HAS OCCURRED... NOT WHAT IS HAPPENING RIGHT NOW.

So, as soon as we see something on the panel, it has already occurred and you are already behind the eight ball as far as reaction and response time. No matter what aircraft, Cessna or Boeing, the same principles apply. There are six primary flight instruments and they MUST be scanned in a regular pattern and control inputs made to correct MINOR deviations BEFORE they become major. On the panel we have three basic pressure instruments deriving information from Pitot and static ports (REMEMBER TO TURN ON PITOT HEAT) and a collection of Gyroscopic and Electronic instruments and indicators. The information we get from the six primary Flight Instruments is all we really need to conduct an instrument flight.

Question 2
WHAT ARE THE 6 PRIMARY FLIGHT INSTRUMENTS?

SO... HOW DO WE FLY ON ISTRUMENTS

First and most important, RELAX, there is no place in this for sweaty palms or racing pulse.

We then set up a constant scan of the instruments and maintain this scan until visual, the scan is always a constant.

The most important and informative instrument is the Artificial Horizon (AH); it is the primary control and performance instrument and the one we refer to constantly. The scan starts there and is called Selective Radial Scan. This is a logical process which ensures high priority is given to the AH. We scan from there to the Airspeed Indicator (ASI), back to AH etc so the scan is actually constant and information is fed to the pilot in logical order.

Selective Radial Scan

Scan From
AH to ASI
Back To AH
To Altimeter
Back to AH
To VSI
Back to AH
To DG
Back to AH
To T and B
Back to AH

Start again...

Technique

Scan by moving your eyes... not the head... adopt a relaxed posture and make control inputs gentle and DO NOT over control. Make sure aircraft is trimmed to reduce your workload. Keep it as simple as possible, but use controls and throttle with a caressing style rather than aggressive movements. Scan slowly but scan regularly. Spend a couple of seconds on each instrument. Before moving on and always maintain the same momentum and technique.

OK... So let's go flying in Flight Sim and see what we can do.

Load a simple aircraft, one of the Single Engine Cessna range or the Baron. The 182 is a great instrument platform and the Baron is wonderful for twin IFR training... she feels a little heavier but still has great response and is stable.

Get yourself some height and trim the aircraft for cruise. NO AUTOPILOTS... forget about outside and then just fly her for a while on a straight and level basis... when comfortable, try some 90 degree turns left and right, use the heading bug to show you the angles. Use only the panel and maintain your scan through out. Remember the primary and secondary effects... we want constant angle of bank turns at a constant height and airspeed and we need to meet the heading so we pull out going the right way. This becomes very important later when we do some NDB and VOR approaches ...overshoot the heading or miss time and there is no runway... terribly embarrassing.

OK we are all happy now... Let’s get serious, dial in some weather, make it dark and add turbulence.

The only way to get good at this is to practice... that's why we use procedural simulators to train in this segment.

Instrument flying is boring, but so so necessary, and the only way to develop the technique is constant practice. Yes, in real life we use an autopilot but this does not diminish the need for scanning and keeping your hands close and ready. Autopilots as with all things electric and electronic... FAIL, and as with all the cute gizmos in the sharp end are an AID... they are not a primary flight control.

Many years ago, I was VFR in a Baron from Perth to Geraldton and return, a beautiful day... up the coast and straight line to Geraldton, same on the trip home, smooth as silk, passengers were happy campers and all was good. When I landed I reported to the engineers that the heading select feature needed some attention as it wandered either side of the bug setting and did not make turns. They asked if she held altitude. I said yes, that works well. The response was, "at least we know you can trim an airplane, the servos for the entire autopilot were disconnected a day before, we just forgot to put it in the maintenance release that the aircraft was without auto pilot and there for VFR only". But all the lights and enunciator panel showed it was working!

We had words...&^%$#*@**

That’s about all for now ...have some fun get it mucky and practice!

Next time we will talk about departure and arrival procedures and see if we can induce some real life into your flying.

And remember, always be aware of what is happening around you

Watch Out

Question 1
WHAT ARE THE PRIMARY FLIGHT CONTROLS AND WHAT ARE THEIR INDIVIDUAL PRIMAMRY AND SECONDAY EFFECTS?

The effects below are based on applying control input at straight and level flight at a constant airspeed. i.e. aircraft is in balance and lift equals weight and thrust equals drag

THROTTLES

Primary Effect	Increase or decrease speed of airframe through a parcel of air
Secondary Effect	Increase or decrease angle of attack therefore causes aircraft to climb or descend

RUDDERS

Primary Effect	Turns aircraft left or right
Secondary Effect	Rolls aircraft and causes loss of altitude and increase in airspeed

ELEVATORS

Primary Effect	Changes angle of attack of the wing thereby causing aircraft to climb or descend
Secondary Effect	In climb, causes airspeed to drop. In descent, the opposite

AILERONS

Primary Effect	Rolls the aircraft around a point by way of a bank.
Secondary Effect	Will start a diving turn and increase airspeed

Question 2
WHAT ARE THE 6 PRIMARY FLIGHT INSTRUMENTS?

ARTIFICIAL HORIZON (AH)
AIR SPEED INDICATOR (ASI)
ALTIMETER (ALT)
TURN AND BANK INDICATOR (T and B)
DIRECTIONAL GYRO (DG)
VERTICAL SPEED INDICATOR (VSI)