Flight Instruments

The standby airspeed indicator & altimeter uses aux pitot & alternate static sources and no ADC/ADIRU’s.

The Integrated Standby Flight Display started to appear in 2003 to replace the mechanical standby artificial horizon and ASI/Altimeter. Personally I find the new ASI & Altimeter much easier to read but the ILS more difficult. The + - buttons are just brightness controls.

The ISFD also sends inertial data to the FCCs which use the data during CAT IIIB approaches, landings and go-around.

Interestingly the ISFD cannot be switched off from the flightdeck - even by pulling the ISFD c/b on the p18 panel. It has its own dedicated battery and the ISFD c/b only removes power from the battery charger, so let us hope that one does not start to smoke in-flight! The battery will give 150 mins of power.

Finally, if all else fails there is a standby magnetic compass!

Flight Data Recorder (FDR)

The FDR is located above the ceiling above the rear galley. Despite its common name of a "Black Box" it is not black but high visability orange.

There have been several different models of FDR in the life of the 737 which can collect anything from 30 minutes to hundreds of hours of data of 8 to hundreds of parameters.

The FDR is located above the rear galley

Early FDR's, as fitted to 737-200's, comprised metal scribes which etched their data into a 150ft long roll of metal foil. These would last about 300hrs but only recorded vertical acceleration, heading, IAS and altitude, plus binary traces such as date, flight number and time of R/T transmissions. A gauge on the panel (see below) shows the recording hours remaining before the foil spool needs replacing.

Later second generation Digital FDR's (late 200's & early classics) record onto a 1/4-inch wide, 450 feet long magnetic tape. These can record up to 25 hr of data.

The newest Solid State FDR's (later classics, NG's & MAX) record 25 hours of data onto memory chips.

737-200 FDR panel

The protective casing includes an inner aluminium cover, isothermal protection shield, an outer stainless steel casing and an exterior stainless steel dust cover. This enables it to withstand a crush force of 20,000 pounds per axis, and provides impact protection of 1000 g's for 5 msec. It is protected from heat by an isothermal insulation which maintains the inner chamber at a safe temperature.

The FDR of the 737-NG is similar to that described above but can withstand 3400 g's of impact, 20,000ft depth of water and temperatures of 1,100C for 30mins.

FDRs and CVRs have an underwater location device that, when activated by water, emit an ultrasonic pulse at 37.5 kHz every second for a duration of at least 30 days.

The FDR starts recording as soon as the first engine N2 exceeds 50% and will remain recording whislt either engine is running or the aircraft is in the air.

For information on the Cockpit Voice Recorder (CVR) click here

This video covers the CVR, FDR, ELT, LF-ULB, DFDAU and QAR on the 737. It also discusses the use of ACMS data within an airline and how hard landings are measured.

Electronic Flight Bag (EFB)

EFB is becoming the latest “must-have” device in the cockpit. They have the ability to do the following tasks:

• Calculate take-off or landing performance.
• Calculate weight & balance.
• Contain the aircraft technical log.
• Store navigation charts & plates.
• Store company manuals, FCOMs, crew notices, etc.
• Retrieve & display weather.
• Display checklists.
• Display on-board video surveillance cameras.

The advantages to crew are the accuracy of the data and ease of use. The advantages to the airlines are the cost benefits of a less paper cockpit and real time data transfer.

There are three classes of EFB:

• Class 1: Fully portable. Eg a laptop.
• Class 2: Portable but connected to the aircraft during normal operations. Eg tablet & docking station.
• Class 3: Installed (non-removable) equipment.

BBJ Avionics

The Boeing Business Jet stands at a crossroads in avionics technology—exploiting all the flight deck systems available to airlines operating the 737, while serving as a showcase for advanced bizjet avionics that air carriers may one day want.

The BBJ often serves as a pathfinder for the latest systems that eventually could find their way onto commercial 737 flight decks.

Improved situational awareness is a case in point. Gulfstream, for example, pioneered the use of enhanced vision systems (EVS) with a forward-looking infrared (Flir) camera on large-cabin bizjets. This allows pilots to look through a head-up display (HUD) to see Flir imagery of a runway at night and in smoke, haze, rain and snow (but not in large-droplet fog).

The enhanced vision capability is more than just a safety feature. The FAA allows business jet pilots to use EVS images to fly as low as 100 ft. AGL (instead of 200 ft. during a Category-1 approach) before having to see the runway visually. Currently, airline pilots can’t do this. However, the FAA and the European Aviation Safety Agency are considering changing this rule to allow airlines to descend to 100 ft. with EVS, according to several avionics company officials. This could happen as early as next year.

There’s already substantial airline interest in enhanced vision, says Steve Taylor, the BBJ chief pilot. “I’ll wager if the FAA grants that OK to the airlines [for 100 ft. ], they will be beating on our door,” he adds.

Rockwell Collins is working with Boeing on the EVS program. And Max-Viz Inc., of Portland, Ore., is developing a multisensor, uncooled camera to meet a Rockwell Collins specification. It has both a short-wave and a long-wave infrared sensor and a visible-light camera in one unit.

The BBJ also will have a new version of the Rockwell Collins HGS-4000, called the -4000E. This modification of the head-up guidance system includes new hardware and software to allow the display of video imagery from the Flir camera. The BBJ has head-up guidance for the pilot as a standard feature, while the system is optional on the 737NG. Taylor says every avionics system that’s optional on the airline version of the 737 is standard on the BBJ.

Meanwhile, Rockwell Collins just began flight testing the BBJ enhanced vision system on its Sabreliner test­bed, and the EVS will be flown on a customer’s BBJ during the winter. Certification should occur in mid-2008. Should airlines become more interested in having it on a 737NG, it wouldn’t take much additional work to commercialize the system, says Taylor. “The aircraft certification rules are the same—Part 25,” he notes, so the certification effort on the BBJ should transfer easily to the 737NG.

The plan is to display the EVS imagery not only on the HGS for the pilot but also on one of the six Honeywell cockpit displays (the one on the pedestal so the copilot also can see the Flir imagery).

Taylor notes that head-up guidance systems made their first entry at Boeing on the BBJ and then moved to the commercial aircraft production line. But earlier, HUDs were already flying on existing airline aircraft because carriers such as Southwest and Alaska Airlines had installed them as retrofit items.

However, avionics is not the only area where technical innovation started in the BBJ program and was then incorporated on commercial transports. Winglets, a key fuel-saving device, is an example. “In a sense, we are a Skunk Works for commercial airplanes,” says Taylor.

As for the next big thing in business aviation, it will likely be another situational-awareness advance called synthetic vision. A 3D digital map of the terrain and obstacles ahead of the aircraft will be shown to the pilots of Gulfstream business jets soon, thanks to Honeywell. Rockwell Collins is developing a similar system for Bombardier. This Aviation Week & Space Technology pilot saw a Honeywell prototype last year on a Cessna Citation V (AW&ST Oct. 16, 2006, p. 66). Our night flight passed over the Phoenix area where I attended U.S. Air Force pilot training in the early 1970s. The view out the windscreen was often pitch-black, with mountains below shrouded in darkness. But I could see the “synthetic” terrain on the primary flight display created from a database that portrayed the scene ahead as if it were broad daylight. In 1971, a T-38 crashed into a nearby mountain in the era before synthetic vision.

A key question is, How long will it take for the huge safety advance of synthetic vision to show up on commercial flight decks? Since I no longer fly T-38s, I have to travel economy class on narrow- or wide-body jets. If airline pilots had EVS and SVS, I would feel safer as a passenger flying into airports surrounded by high terrain. But as with EVS and the possible FAA rule change on 100 ft., SVS will need a business case to earn its way onto an airline flight deck. At the moment, it’s not clear what that rationale will be.

Taylor says technology specialists at Boeing are looking at synthetic vision, and he believes its adaptation will follow a path similar to the one for enhanced vision. In the business jet market, “the customer base is much more interested in technology and willing to pay for it,” he notes.

Another way the BBJ benefits from 737 avionics is that the standard-fit radar is an airline-class system—Rockwell Collins’ multiscan WXR2100, which is flying with 100 airlines. It’s a more capable system than many of the radars currently installed in business jets. Keith Stover, Rockwell Collins’ radar marketing manager, says the main benefit for BBJ pilots is automatic adjustment of the radar as well as ground-clutter suppression.

In September, Rockwell Collins said it will provide a multiscan radar for bizjets to accommodate the smaller antenna sizes they need of 12 and 18 in. So this is an example of airline-class avionics technology flowing to business aviation by way of the BBJ flight deck. The airline version, which is already standard on the BBJ, has a 28-in. antenna and includes wind shear protection.

Last summer, I flew on a BBJ over the North Atlantic. During the flight, Rockwell Collins radar engineers were perfecting new software to allow the multiscan radar to improve its automatic detection of storms in a particular region (AW&ST July 9, p. 44). This new geographic-discrimination software will be available soon on the BBJ.

Additional fuel tanks are added after the aircraft leaves the factory and goes to DeCrane Aerospace at Sussex County Airport in Georgetown, Del. This is also where the new enhanced vision system will be fitted.