Flight directors – a fatal attraction

My first encounter with flight directors was in 1966 while undergoing conversion to the Avro 748. The RAAF had seen fit to send me to Woodford in Cheshire, all the way from Australia, to ferry the second of several new 748s for the RAAF VIP squadron at Canberra. The conversion was conducted on a battered 748 demonstrator: G-ARAY, known as Gary. The contract allowed four hours of dual for the captains and nothing for the co-pilots. G-ARAY had the basic instrument flying panel of that era and no flight director.

Our instructors at Avro’s were well-known test pilots Bill Else, Tony Blackman and Eric Franklin. Jimmy Harrison was chief test pilot. Unlike the bog-standard civilian 748, the RAAF 748s were to be equipped with a Collins FD 108 FD. So the situation existed that the RAAF 748s had a British Smith’s autopilot system which was married (somewhat expensively and painfully) to the American Collins FD 108.

For the life of me, I could not see why a flight director was needed in the RAAF 748. After all, the approach speed was that of a DC-3 (80 knots) and the aircraft a delight to handle compared with the venerable Dak.

Avro 748
Did the Avro 748 really need a flight director?

In retrospect, I think the old Wing Commander Transport Ops at Department of Air, who was charged with the procurement of the 748 for RAAF service, and hadn’t flown for years, was perhaps conned by the Avro sales people, in conjunction with Collins, into buying the Collins systems. Certainly in my view as the squadron QFI, flight directors were not operationally needed. In the event, the RAAF machines came with Collins FD 108 flight directors and, as the contract specified, each captain would be given only one hour of dual instruction once the 748 came out of the factory. We needed to learn how to operate the FD.

First, a course was arranged at the Collins establishment at Weybridge in Surrey. The two RAAF captains and their co-pilots attended and our two navigators and our instrument fitters also turned up to enjoy the Collins hospitality. We learned about 45 degree automatic intercepts of the VOR and ILS beams and other goodies including V-bar interpretation. We were showered with glossy brochures of the flight director by white dust-coated lecturers and shown a film.

By lunch time, the presentation was complete and we were shouted to a slap up pub meal with lots of grog, all paid for by Collins. We asked what further lectures were to take place after lunch. We were told the course was over – it was just a morning’s job and we were free to leave unless we would like more drinks. Naturally it was churlish to refuse and hours later we staggered to the railway station (I think), smashed to the eye balls and having forgotten all about the marvels of 45 degree auto intercepts on the FD 108. I must say it was a bloody good three-hour course what with the free grog and all that.

A few weeks later, I flew the second RAAF aircraft out of the factory, A10-596, under the watchful eye of Eric Franklin DFC and he demonstrated flight director stuff. For example, to climb using the FD, you first put the aircraft into a normal climb and when settled you switched on the FD and carefully wound up the pitch knob so that the little aeroplane sat in the middle of the V-bars.

I quickly realised that you hand-flew the basic artificial horizon to whatever attitude was appropriate for the manoeuvre then told the FD 108 V bars where you wanted them. The ILS intercept of 45 degrees was never used because radar vectors didn’t do such angles. I became more and more convinced the 748 didn’t need flight directors and that they were a load of bollocks in that type of low speed aircraft. We were told the USAF used the FD 108 in its F4 Phantoms and that Collins was anxious to makes sales in the UK market.

The RAAF Wing Commander got sucked in by good sales talk and from then on all RAAF 748s became so equipped. I held personal doubts about the usefulness of flight directors in general as I could see even then their extended use could lead to degradation of pure instrument flying skills. Today’s flight director systems are light years ahead in sophistication compared with the old Collins FD 105 and 108 series. But the problem with blind reliance on FD indications and thus steady degradation of manual instrument flying skills is as real now as it was back in 1966.

Now to the present day – although first some background history. First published in 1967, Handling the Big Jets, written by the then British Air Registration Board’s chief test pilot David Davies, is still considered by some as the finest treatise still around on jet transport handling. Indeed, the book was described by IFALPA as “the best of its kind in the world, written by a test pilot for airline pilots… the book is likely to become a standard text book… particularly recommended to all airline pilots who fly jets in the future… valuable to those pilots who are active in air safety work.”

Flight director
Do these flight directors make flying safer or pilots lazier?

All that was back in 1967 and little has changed since then – apart from an increasing propensity for crashes involving loss of control rather than simply running into hills. LOC instead of CFIT. Mostly these accidents were caused primarily by poor hand flying and instrument flying skills, which certainly explains why aircraft manufacturers lead the push for more and more automatics.

A colleague involved with Boeing 787 training was told by a test pilot on type, that the 787 design philosophy was based on the premise that incompetent crews would be flying the aircraft and that its sophisticated automatic protection systems were in place to defend against incompetent handling. Be it a tongue-in-cheek observation, it contains an element of truth. With the plethora of inexperienced low-hour cadet pilots going directly into the second-in-command seats in many airlines in Asia, the Middle East and Europe, these protection systems are important.

Towards the end of his book, David Davies discusses the limitations of the flight instruments in turbulence and in particular the generally small size of the active part of the basic attitude information or the “little aeroplane” as many older pilots will remember it. He continues: “The preponderance of flight director and other information suppresses the attitude information and makes it difficult to get at” and “the inability, where pitch and roll information is split, to convey true attitude information at large pitch and roll angles in combination.” Finally Davies exhorts airline pilots “not to become lazy in your professional lives… the autopilot is a great comfort, so is the flight director and approach coupler… but do not get into the position where you need these devices to complete a flight.” There is more but go and read the book.

Having done the unforgiveable and quoted freely from an eminent authority, it is time to say something original and accept the no doubt critical comment that is freely available. Flight Directors can be a fatal attraction to those pilots who have been brain-washed by their training system to rely on them at all times. While Boeing in their FCTM advise pilots to ensure flight director modes are selected for the desired manoeuvre, it also makes the point that the FD should be turned off if commands are not to be followed.

Recently a new pilot to the Boeing 737 asked his line training captain if he could turn off the FD during a visual climb so he could better “see” the climb attitude. His request was refused as being “unsafe” and instead he was told to “look through” the FD. I don’t know about you, but I find it impossible to “see” the little aeroplane when it is obscured by twin needles or V-bars. In fact, it takes a fair amount of imagination and concentration to do so. Which may be why Boeing recommends pilots to switch off the FD if commands are not to be followed.

I well recall my first simulator experience in the 737 of an engine failure at V2 where I was having a devil of a time trying to correct yaw and roll and the instructor shouting at me to “Follow the bloody flight director needles.” I learned a good lesson from that tirade of abuse on how not to instruct if ever I became a check pilot. In later years, having gravitated to the exalted – or despised maybe – role of simulator instructor, my habit was to introduce the engine failure on takeoff by first personally demonstrating to the student how it should be done on raw data; meaning without a flight director. I hoped by first demonstrating, the student could see the body angles or attitude rather than imagine them by trying to “look through” the dancing needles of the FD. I have always been an advocate of the Central Flying School instructional technique of demonstrate first so the student then knows what he is aiming for. Of course in the simulator, the instructor runs the risk of stuffing up (been there – done that!) but it at least proves he is human and not just another screaming skull.

G1000 FD
General aviation pilots are no strangers to flight directors either, especially as glass cockpits become more popular.

Recently, a 250-hour pilot with a type rating on the 737-300 (and trained overseas) booked a practice session prior to putting himself up to renew an instrument rating. His last rating was on a BE76 Duchess. As part of the 737 instrument rating would include manual flying on raw data, he was given a practice manual throttle, raw data takeoff and climb to 3000 ft. He protested, saying he had never flown the simulator without the flight director.

His instructions were to maintain 180 knots with Flaps 5 on levelling. He was unable to cope and when the instructor froze the simulator to save more embarrassment, the student was 2000 ft above cleared level and 270 knots – still accelerating with takeoff thrust. The student had been totally reliant on following flight directors with their associated autothrottles during his type rating course, and without this aid he was helpless.

I believe this is more widespread than most of us would believe, especially as we tend to move in our own narrow circle of experience.

At a US flight safety symposium, a speaker made the point that it is the less experienced first officers starting out at smaller carriers who most need manual flying experience. And, airline training programs are focused on training pilots to fly with the automation, rather than without it. Senior pilots, even if their manual flying skills are rusty, can at least draw on experience flying older generations of less automated planes.

Some time ago, the FAA published a Safety Alert for Operators (SAFO) entitled Manual Flight Operations. The purpose of the SAFO was to encourage operators to promote manual flight operations when appropriate. An extract from the SAFO stated that a recent analysis of flight operations data (including normal flight operations, incidents and accidents) identified an increase in manual handling errors and “the FAA believes maintaining and improving the knowledge and skills for manual flight operations is necessary for safe flight operations.” Now let me see, I recall similar sentiments nearly 50 years ago published in Handling the Big Jets when David Davies wrote that airline pilots should “not become lazy in your professional lives… the autopilot is a great comfort, so is the flight director and approach coupler but do not get into the position where you need these devices to complete the flight.” See my earlier paragraphs.

It is a good bet that lip service will be paid by most US operators to the FAA recommendation to do more hand flying. It may have some effect in USA but certainly the majority of the world’s airlines, if they were even aware of the FAA stance in the first place (very doubtful), will continue to stick with accent on full automation from lift off to near touch-down and either ban or discourage their pilots from hand flying on line.

If you don’t believe that, consider the statement in one European 737 FCOM from 20 years ago that said: “Under only exceptional circumstances will manual flight be permitted.” After all, when at least two major airlines in Southeast Asia have recently banned all takeoff and landings by first officers because of their poor flying ability, then what hope is there to allow these pilots to actually touch the controls and hand-fly in good weather? One of those airlines requires the first officer to have a minimum of five years on type before being allowed to take off or land while the other stipulates the captain will do all the flying below 5000 ft. It might stop QAR pings and the captain wearing the consequences of the first officer’s lack of handling ability, but it sure fails to address the real cause and that is lack of proper training before first officers are shoved out on line.

Airline pilots flying
Sometimes you have to put your hands on the controls and fly raw data.

I think the FAA missed a golden opportunity in its SAFO to note that practicing hand flying to maintain flying skills will better attain that objective if flight director guidance is switched off. The very design of flight director systems concentrates all information into two needles (or V-bar) and in order to get those needles centered over the little square box, it needs intense concentration by the pilot. Normal instrument flight scan technique is degraded or disappears with the pilot sometimes oblivious to the other instruments because of the need to focus exclusively on the FD needles. Believe me, we see this in the simulator time and again. Manual flying without first switching off FD information will not increase basic handling or instrument flying skills.

The flight director is amazingly accurate provided the information sent to it is correct. But you don’t need it for all stages of flight. Given wrong information and followed blindly, it becomes a fatal attraction. Yet we have seen in the simulator a marked reluctance for pilots to switch it off when it no longer gives useful information. Instructors are quick to blame the hapless student for not following the FD needles. This only serves to reinforce addiction to the FD needles as they must be right because the instructor keeps on telling them so. For type rating training on new pilots, repeated circuits and landings sharpen handling skills. Yet it is not uncommon for instructors to teach students to enter waypoints around the circuit and then exhort the pilots “fly the flight director” instead of having them look outside at the runway to judge how things are going.

First officers are a captive audience to a captain’s whims. If the captain is nervous about letting his first officer turn off the flight director for simple climbs or descents, or even a non-threatening instrument approach, then it reflects adversely on the captain’s own confidence that he could handle a non-flight director approach. The FAA has already acted belatedly in publicly recommending that operators should encourage more hand flying if conditions are appropriate. But switch off the flight directors if you want real value for money, particularly with low-hour pilots. It may save lives on the proverbial dark and stormy night and the generators play up.

4 Comments

  • EXCELLENT post. I try to practice all possible combinations: autopilot usage, manual flying with FD, and raw data only. The challenge many pilots face is keeping the instrument scan going even when using the FD. But it’s important to do that. Otherwise you’re blindly relying on the flight director without any cross check. At that point you’re almost more of a passenger than a pilot.

  • Mr. Laming’s piece brings to mind an accident at Boston Logan in the 1970s. A Delta DC-9 struck a seawall short of the runway at the end of a low ILS approach. They had departed with one of the FDs inoperative and the second FD became unreliable in the initial stages of the approach. The crew attempted to continue the approach using “raw data” with tragic results.

    There was an uproar from the pilots’ union about the minimum equipment list used by Delta which allowed operations with one FD out. I do not recall any mention of training to proficiency using raw data (LOC and GS needles). It seems that Mr. Laming’s issue has been with us for a long time.

  • I know pilots likely don’t embrace the idea of pilotless airliners flown only by computers. But if a human pilot is unable to fly the aircraft without the aid of a flight director, what’s the difference??

  • Very good address of basic aviation, Fly the airplane! Having slogged through general aviation and retired with a major carrier I can appreciate the hesitation to “spend good money” on basics when checking out on a transport category airplane. However the return on investment can be well worth it.
    During part of my career I was a 737 simulator instructor dealing with a few new hires from general aviation and centerline thrust military aviators. The fighter jocks were highly qualified to fly around with their hair on fire (so to speak) but in some cases struggled with the basics of rudder use in an engine out situation and control of the yaw produced.
    An example of basics in a multi-million dollar simulator was not part of the curriculum for those few that struggled with engine out:
    Problem? MTOW, Engine failure, control wheel locked over trying to control the roll, little if any rudder input, airplane skidding through the air and sinking!
    With a simple demonstration and these new hires got it!
    Engine failure just as initial climb attitude reached, yaw and roll starting, let go of the wheel grab the control column to control the pitch, (you really don’t need ailerons and flight spoilers extended adding to the problem) use rudder to level the wings, stabilize ? trim = wings level, climbing, everyone will live for another day. 15 minutes and back the the curriculum with proper rudder and control wheel inputs.
    ( I did remind them that this was a “demo” not a substitute for proper control procedures.)
    Only took once to remove a little bump in the road! these guys/gals were aviators!

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