A day in a Falcon 900’s front office

by:

Capt. W. Patrick Gordon, M.Sc.

November 1994

It was 05:15 a.m. as I started my Jeep Cherokee and my uniform shirt was already drenched with sweat. I looked at the overhead temperature indicator and saw 34 degrees Celsius. Since I’ve never been able to remember the conversion factor I punched the button and changed it to Fahrenheit, 94 degrees. Sorry I did that! Just another sweltering morning in the Middle East. Actually for those who care to know, the conversion factor is 32°F plus 9°F=5°C


On arrival at Operations, the paperwork for the flight to Geneva, Switzerland, was complete. Stan, my copilot, and I assembled it, signed it, cleared security and walked out to one of our three Falcon 900As. All have new glorious​ paint jobs by Jet Aviation in Basel, Switzerland. Lush, smooth, glossy white, with lots of red trim, they appear to be meticulously dipped instead of spray painted.


The ship du jour was already powered by the APU (Auxiliary Power Unit) and the interior cooled. Our flight mechanic had completed his preflight functions and the smell of coffee informed us that at least one of our two flight attendants was on the job. Okay! So, I’m spoiled!! 


The APU, a GTC36-150(F), is manufactured by Garrett. It’s located in a carbon and titanium container underneath the number two engine and is certified only for ground operations. In case of an APU failure on the road, the number three engine neatly fills the void and is actually quieter, albeit with a slightly higher fuel flow.

 
A slight but steady breeze from the starboard side of the aircraft tends to lift the airstair door from the fully bottomed position. Being familiar with this tendency, the prudent user treads lightly with his first step to fully seat the door. This floating tendency can create an embarrassing and even potentially injurious situation for someone not familiar with it. Dassault has available, through its parts supplies department, a locking, split tube- like device to hold the door down. Remembering to use it faithfully is no problem after witnessing the first stumble and potential face-plant of a principal passenger.


The unpowered airstair door is well balanced and easily managed even by our most diminutive flight attendant. The secret of its ease of manipulation is a lifting and counter-balancing mechanism made up of a glass fiber lead spring that expands until it looks like the wishbone from a turkey on steroids. The tensions of the expanded spring provides the counterbalance to assist in door closing. 


Our walkaround completed, Stan began the checklist litany. Having flown the airplane for over three years, I still value the thought Dassault engineers put into the cockpit. The circuit breaker panel is an example of their logical thinking. Circuit breakers are arranged on an overhead ceiling panel in sensible groupings within color-coded perimeters. Green for engines, yellow for fuel, white for lights, orange for flight controls, etc.


The overhead panel is also clearly laid out, providing switching and controls for a variety of functions from APU command to aircraft electrics, fuel, and pneumatics. The elementary flow of fuel and electrics is etched into the panel and lighted for nighttime use. These flow lines provide a quick visual aid for balancing fuel and controlling electrics.


The main annunciator panel, at first glance, appears to be all encompassing but in your first simulator course you learn the fallacy of that assumption. Numerous other caution lights are spread around the cockpit in the only cockpit engineering oversight that comes to mind. It would be nice to have a master caution warning light to alert pilots to a new or additional failure. In a busy cockpit, it’s surprisingly easy to overlook a second, even adjoining, yellow caution light that would be the first indication of an abnormal situation well on its way to becoming an emergency. 


We stopped the checklist at the Starting Engines phase and while we waited for passengers I pontificated on Stan’s golf swing, as though I knew what I was talking about. I’ve been told that my golf swing brings the axe murderer Lizzie Borden to mind. Stan was happy to interrupt the lecture by bringing my attention to the fact that our batteries were beginning to get warm. We turned on the battery cooling bleed air switch and almost immediately the temperature rise was not only halted but began a decline. 


One of the few engineering oversights by Dassault, this one major for hot weather operators, is the battery location in the hellhole, or aft equipment compartment. Battery number one is installed next to the heat exchanger hot air supply line. This line is downstream from the manifold joining the output from all three engines. Proximity to this hot duct, along with our broiling climatic conditions, rapidly drives battery temperatures into the yellow caution range when the aircraft is powered and waiting on the ground. If nothing is done to cool the batteries, their temperatures will continue to rise into the red, leaving you grounded unless you are a much bolder pilot than I. Prior to the development and installation of the battery cooling modification, which diverts cool, bleed air from just aft of the water separator outlet into now vented battery boxes, we coped with alternative solutions. While waiting at locations with ground support equipment, we called for an air conditioning truck and directed the cool air outlet pipe into the hellhole. The normally elegant Falcon 900 then looked like it was getting an enema. Waiting at desert strips without support equipment, we requested extra dry ice with our catering and whiled away the hours keeping the batteries cool with timed applications of dry ice to the tops of the battery boxes. Rather like cool towels to the forehead of a fever ridden child.


Speaking of aircraft modifications brings up the question of communications. Our Falcons are not U.S. registered, therefore, we get our information direct from Dassault. In the United States, where I'm told the bulk of Falcons operate, this information comes from the Little Rock, Ark. facility. I wonder if these guys talk to each other? On visits to recurrent training at Teterboro [N.J], I get information about aircraft modifications I've never heard about. Conversely, no one there seemed to know about the battery cooling mod. 


Our three passengers showed up on time and the start clearance was received. A larger passenger load was anticipated for the return flight from Geneva. With two flight attendants, we had a total of five in the back and a flight mechanic in the Jump seat. Normally, with a full passenger load, the first thing we typically run out of is luggage space.


At 08:I5, loaded to the gunnels with fuel and right at the maximum gross takeoff weight of 46,500 Ibs., we taxied out for a flaps 7 takeoff. Flaps 20 offer a shorter takeoff roll but at this weight and a temperature now of 40 deg C (104-deg F), we don't have second-segment cIimb requirements. Nonstop to our destination of Geneva was 2,955 nmi, within range at 6 hr. 54 min. at Mach O.8. The route, a little longer than optimum, took account of possible problems across Greek/Brindisi/Rome interfaces. With the shutdown of Yugoslavian airspace, the east coast of Italy is a nightmare of summertime air traffic. Destination fuel was forecast at 3,200 Ibs., well over our company requirement of 2,000 lbs. minimum landing fuel.


I've heard the cockpit of the Falcon 900 described as half-glassed and I tend to agree. It’s a wonderfully sophisticated but benevolent cockpit to transition into. All of the engine indicators, fuel gauges, and various other instruments are the comforting old analog-appearing devices. The altimeter, vertical speed indicator, airspeed, and RMI card are also the standard installations we've been looking at for years. The emergency altimeter, airspeed, and artificial horizon are mounted vertically on the left center of the instrument panel. Five five-inch CRTs, including a multi-function display in the middle of the instrument panel, provide comprehensive EFIS flight attitude and horizontal situational in formation along with ancillary nice-to-have data.


I have my preferred information bits like the vertical airspeed trend indicator. As aircraft speed increases, a red line rises from a numerically indicated airspeed. Decreasing speed results in a descending red line. I immediately found this feature to be extremely useful for basic air work, climbs, and approaches. It took me months of flying, however, before I realized that incredibly accurate cruise speeds were possible with minute power changes by "teasing" the red trend indicator. 


Another indication that holds great appeal for me is the acceleration number in the bottom left-hand corner of each lower CRT unit. The acceleration number is charted prior to takeoff and if it isn't achieved, it would behoove one to abort the takeoff and find out Why. 


At 46,500 Ibs., our runway requirement was 8,000 ft. With 10,500 ft. of runway available, we had plenty of concrete in reserve. V1 = 131, VR V2 = 140, and 1.43VS = 172. Cleared for takeoff, Stan made the standard calls: Acceleration Checks, Power Set, Airspeed Alive, 80 Knots, V1,, Rotate. 


Rotation is the point where you discover the grace and beauty of a Falcon. Hydraulically boosted flight controls do not, in themselves, provide aerodynamic load, or "feel." To compensate for that lack of feel, Dassault uses spring-loaded artificial feel units (AFU) that are incorporated in the primary flight control linkages prior to the servo actuators. As a result of the AFU working in conjunction with another device called the Arthur Q, Falcon flight control pressures at tal1 airspeeds have a fabulous "feel." As aircraft speed increases and decreases, the pivot point of the Arthur Q unit changes, resulting in pressure changes to the spring-loaded AFU.


Our climb schedule called for 250 kt 10 10,000 ft. then accelerating to 260 kt until achieving a climb speed of Mach 0.73. As we passed through FL330, I put the autopilot in the vertical speed mode and gradually decreased the climb rate until we approached our initial flight level at a climb rate of 200 fpm. The climb to FL350 took 37 minutes. 


It would be nice to have more power. The three Garrett TFE731 - 5AR - 1C engines each develop 4,500 lbs. of thrust up to a temperature of 73.4-deg F. At max gross weight, and at that temperature, one pound of thrust drives 3.44 Ib of airplane. It's probably best that I just trust the charts and don’t know what that ratio is at really hot temperatures. Any airplane would rather perform in a more tolerant environment. All manufacturers would rather have their aircraft performance chronicled in a more merciful environment too. The "B" conversion, which increases engine power, changes that power-to-weight spread to one pound of thrust to 3.26 lbs. of airplane. It would be interesting to fly the "B" for a period of time to see just how significant an improvement it is. 


The SPZ8000 digital automatic flight control system (read autopilot) is a dream to operate and is capable of Cat II operations. With a little experience, most pilots find it reliable and positive in both control and response in every mode. On an autopilot maintenance check flight, l once ran through a complete approach to stall series, from clean to full dirty, without hand-flying the airplane. The unit handled every phase, including recoveries, perfectly. 


My favorite use of the centrally located, CRT, multi-function display is the rolling map. An airplane slides across the screen following the route determined by input from either of the two FMSs (flight management systems). It's somewhat comforting to watch your progress throughout the flight, but there is a "gotcha" for careless pilots. I know of one pilot, who shall remain nameless (I swear it wasn't me), who carelessly loaded his position at an airport ten miles away during FMS initialization. He learned of his error when ATC told him he was ten miles off course. All the while his rolling map showed him exactly on course. An FMS is basically a computer and the old saw holds true: GIGO-garbage in, garbage out. 


A sensible practice to avoid this occurrence is to use all of the available navigation information. It’s effortless to display a combination of both VOR needles, use of auto tune function, and check frequencies and airway headings on the map or flight plan to see if the needles point in the right direction. It’s too easy to become complacent with all this wonderful information. 


Two hours and ten minutes into the flight, Jeddah Control cleared us to FL390 approaching the Saudi Arabian city of Hail, on Amber 1. Dassault offers the following rule-of-thumb: In ISA or ISA-plus (warm atmosphere) conditions climb as soon as your aircraft weight is attained for the actual temperature. This works fine as long as you don't unknowingly climb into warmer temperatures; i.e., an inversion. Even a temperature change of 2 degrees has an adverse effect on this temperature-sensitive airplane. 


Over northern Saudi Arabia, the bleed overheat light illuminated on the master caution panel. This abnormal condition calls for several steps to be taken to isolate, then eliminate the problem. Our Pavlovian response learned in conversations with other 900 pilots during a coffee break at Teterboro, was to reach up and turn the wing anti·ice switch on and then back off again. The warning light was promptly extinguished. This issue appears to be widespread throughout Ihe 900 fleet. It certainly manifests itself in all three of our aircraft and I dread to think of the numerous man·hours and untold dollars spent trying to find the element in the system responsible for the bogus illumination of that light.


Leaving the western sector of Greek airspace on Upper Amber I, after five hours and eight minutes, we were cleared by Italian ATC to FL430 our final altitude for the remainder of the trip.


The Honeywell FMZ 800 flight management system with the worldwide database deserves an entire article of its own. Backed up with three IRSs and a GNS-X with AFIS, the amount of information and assistance available to the flight crew is incredible. After an initial course at any approved flight training center, you come away with a basic FMS operating technique. Plan on being surprised with new information, uses and techniques for months, if not years to come. Why, just yesterday, in fact …


Descent on the autopilot is a function of pilot technique. Some prefer the vertical speed mode and others the flight level change mode. Another function available in all phases of flight is Vnav, or vertical navigation. Vertical navigation used in conjunction with flight level change (VFLC) on descent provides the pilot with a glideslope-like readout based on altitude requirements to reach a given point at a given altitude. 


The sound level in the cockpit is comfortable below indicated speeds of 300 kt. A sound-deadening curtain covers the door at cruise altitudes and speeds. As we sweep into a left turn over St. Prex VOR at 7,000 ft. to join the localizer for Runway 23 at Geneva, we complete the in-range checklist. 


I decided to make a coupled approach even though it was severe clear. This gave me the opportunity to sneak a peek at the numerous boats dotting the lake below and a wonderful view of the evening sun reflecting off the towering water fountain near the city center. We extended the gear at a dot and a half on the glideslope. Before I called for the before-landing checklist, I pumped the brakes in all three positions: Brake No.1 on, Brake No. 2 off, and Brake No. 1 off. A pal passed this technique along to me after hearing about it during another coffee break at FSI Teterboro. After extended periods of time at altitude, the brakes creak, groan, and moan when used after touchdown. I'm still in the experimental phase with this technique and I'm not sure why, but it seems effective and the brakes do operate quieter after this in-flight workout. Vref at a little under 30,000 Ibs. was 110 kt. After deployment of the single center engine thrust reverser, there was little need for braking as we made the high-speed turnoff and rolled toward general aviation parking.


The passengers were met, whisked away and the airplane quickly shut down. While waiting for the crew bus, we discussed checking into the hotel made famous by its garishly colored plastic walls. We reminded ourselves to avoid the bilious "green floor."  


The crew bus arrived and as we were driven across the ramp, I looked back at our airplane. The transition from the Gulfstream III to the Falcon 900A had been easy, but for a long time I had missed the raw power and performance of the thirsty Spey engines. As a pilot with a reasonable amount of experience in both types, it's my personal opinion that, with a like number of bodies on board and operating in the environment I'm in, there's not much the Falcon 900A doesn't do compared with the GIII, with very few exceptions - extended range operations limitations, for example. However, the Falcon 900A does perform far more quietly, gracefully and with a lot less fuel.