Hornet vs Viper (Part Three)

I once had a simulator instructor tell me to yell “yee haw” when I light the afterburner on takeoff, and I still do it to this day. Whether you’re flying the Hornet or the Viper, both aircraft are a fun ride.

We’ve talked about the basic differences between the two strike fighter types and ground-procedures for both, but now it’s time to get into the cockpit and cover the basic flying characteristics of each.

The Hornet is a very docile aircraft on takeoff. After lighting the afterburners, the nozzles swing open and you’re off to the races. There’s a convenient “Takeoff Trim” button that trims the aircraft’s horizontal stabs twelve degrees nose-up. At rotation, the aircraft requires almost no aft pressure to get airborne.

Once climbing away, all the pilot has to do is raise the gear and flaps prior to two hundred and fifty knots. On a colder day, the gear speed can be something to be wary of, as the Hornet’s roughly 35,000 lbs of thrust can accelerate an air-to-air configured jet fairly quickly.

In comparing the two aircraft, however, the Viper gets the nod on takeoff and climb out performance. It’s just a matter of thrust to weight ratio. The Hornet is heavy, even in an air to air configuration (a clean Hornet with a centerline tank weighs in at just over 39,000 lbs at takeoff).

In comparison, an air to air configured F-16 weighs just under 25,000 lbs with 29,000 lbs of thrust (F-16 Block 30 “Big Mouth”). Lighting the Viper’s five-stage afterburner has a much more pronounced seat-of-the-pants feeling of acceleration, and you can easily see yourself doing 400+ kts by the end of the runway.

Generally speaking, Hornet drivers will do afterburner takeoffs regardless of configuration. Conversely, Viper guys typically do military power takeoffs when “clean” (single or no drop tanks) and afterburner takeoffs when “two-bag” (two drop tanks and/or bombs). Even with a two-bag config (no bombs), the Viper in blower will race down the runway much faster and produce a much better climb rate than the Hornet.

The Viper trims itself for takeoff based on configuration, so there’s no “Takeoff Trim” button to worry with. At rotation, a slight ease back on the sidestick will rotate the nose gear and the jet will fly away effortlessly. The aircraft also schedules the leading and trailing edge flaps automatically, so the only thing to worry with after takeoff is raising the gear handle before three hundred knots.

En route to the working or target area, both aircraft are constantly trimming for 1G level flight. It’s designed to reduce pilot workload and the need to constantly trim for whatever airspeed you’re flying. Both the F-16’s sidestick and the F/A-18’s more traditional center stick require very minimal control inputs and pressure from the pilot. It’s very easy to maintain a light touch using just fingertips to fly in close formation.

Whether the Hornet’s autopilot modes are superior depends on what block of F-16 you’re flying. For Block 30s and 25s, there’s only an altitude hold and heading hold mode. Later Block 40s and 50s have autopilots that will follow preplanned routes. The Hornet is much the same. It also has auto-throttles which hold a true airspeed (or on-speed angle of attack with the gear down) when set. This is great for formation station-keeping or to set a good platform as a flight lead. The auto-throttles are also very useful in the approach to landing, which I’ll talk about later.

Climbing through ten thousand feet, pilots will check the cabin altimeter to ensure the cockpit pressurization system is scheduling correctly. Both aircraft run on roughly the same schedule, but in recent years, the Hornets have had issues with cabin pressurization as the systems have grown older. The designers conveniently placed the cabin altimeter beneath the center display near the rudder pedals in the Hornet, while the Viper’s isn’t much better hidden behind the side stick.

The oxygen system of the Viper is infinitely better than the Hornet. Depending on whether you fly A’s, C’s, or Super Hornets, the Hornet can have either Liquid Oxygen (LOX) or an On Board Oxygen System (OBOGS). Regardless of the system, the biggest issue is that it’s always feeding the pilot 100% oxygen on a steady flow regardless of altitude.

In comparison, the F-16 has a regulator which schedules the concentration of oxygen (using a LOX system) based on altitude. It allows the pilot to select 100% and constant flow in the event of an emergency. This is a much safer and better system. Most pilots hate flying on 100% O2 for hours at a time and end up just dropping their mask. Both aircraft have backup emergency oxygen bottles in the event that the primary system fails.

As I mentioned during the ground ops discussion, the Viper’s bubble canopy gives a much better view than the Hornet’s two-piece system. The Hornet’s canopy bow is often in the way and the Leading Edge Extensions just beneath the cockpit can block a pilot’s view when flying in the low altitude environment. It can also be a downside, however. The F-16’s canopy and forward seating offers no visual reference cues. Spatial disorientation in bad weather or night time flying can and does happen – a condition that can be potentially deadly to pilots.

In level flight at higher altitudes, both aircraft are capable of supercruising at MILITARY power in a clean configuration. Although it has a better thrust-weight ratio clean, the Block 30 takes a bit more to do this than the A model Hornet. I think that is due in part to the drag created by the large intake for the GE engine, but either way it’s fun watching an Eagle have to tap blower to hang on your wing when you’re supersonic in MIL power headed back to the CAP.

Heading back to base, this is where the Hornet wins all its cool points. On a sunny and clear day, a section (two-ship for the AF types) of Hornets will generally request the carrier break over the field. As the name suggests, it’s a maneuver designed for the carrier environment to set the aircraft up for the pattern. Typically, the two aircraft will fly over the runway at 800’ AGL in close formation and begin a descending 180-degree turn to downwind as the wingman gains separation (either through a “fan” break where the two aircraft break at the same time or an “interval break” where the wingman waits a predetermined amount of time before turning).

The book answer is three hundred and fifty knots, but I can tell you that it’s common for guys to bump that up a bit for “safety.” At certain speeds above 400kts, the Hornet’s LEXs will make a buzzing sound as you speed through the air. It’s a maneuver that looks cool in both the cockpit and from a bystander’s perspective.

Viper guys typically fly “tactical initial” at 1500-2000’ AGL, line abreast a mile and a half from each other. Of course, it’s a much more conservative and tactical pattern (harder to hit two aircraft far apart than two aircraft a few feet from each other), but it’s not quite the show that a carrier break can be.

A wise man once told me, “Never save your best for the pattern.” But another wise man told me, “The chicks dig it.” Your mileage may vary.

In bad weather or low ceilings, the Hornet has both good and bad qualities. Performance-wise, the aircraft is great in rain and handles beautifully flying approaches. The ECS has an “anti-rain” switch that can help clear rain from the windscreen using the bleed air of the engine. The autopilot does a great job of reducing pilot-workload, and the auto-throttles I mentioned earlier can help keep the jet on-speed to reduce the workload even further.

This is my real soapbox – this is where the Hornet, and the Navy, fail miserably. The Hornet has no civilian ILS capability whatsoever, which means it cannot do its own precision approaches. The only ability it has to fly in the weather is through non-precision TACAN approaches, Precision Approach Radar (a guy on the ground talking the pilot down using a precision radar for glidepath and azimuth), or Surveillance Approaches (same guy on the ground, except he’s not worried about glideslope). What does that mean?

First, it means that the aircraft has no ability to fly a precision approach at most fields. PARs are few and far between (mostly just Navy bases these days), so you’re limited to the minimums of whatever TACAN is available (usually 500 ft or greater, vs 200 ft for a typical precision approach).

Second, it means that Hornets generally can’t divert to civilian fields at all unless the weather is greater than the approach controller’s minimum vectoring altitude (1500 ft or more usually). Most civilian fields don’t have TACANs. Everything is transitioning to GPS/RNAV (which the legacy Hornet also can’t legally fly) and ILS.

This creates a very dangerous situation in which a Hornet driver can find himself in bad weather with very few (or no) divert options. It’s a relatively inexpensive fix that has been brought up to the Navy for years now, but never gets funded. The fact that these outstanding professional pilots have “made it work” all this time is the Navy’s justification to not fund it. It’s almost criminal.

In comparison, the Viper has an ILS with a HUD certified for flying approaches. Its flight director helps keep the aircraft on course and glidepath by having the pilot simply put the flight path marker on the “tad pole” in the HUD. The biggest downside for flying in the weather is that the Viper’s canopy tends to pool water right in front of the HUD in heavy rain, so much so that sometimes a pilot needs a bit of rudder like a taildragger to see around it to pick up the runway environment in close. The ECS in the Viper also struggles in high humidity environments, where sometimes the vents produce a fog that can completely obscure visibility inside the jet.

Hopping back off my soap box, on final, the two aircraft both fly Angle of Attack (AOA) instead of approach speeds. The only difference is that the AOA bracket in the HUD is 180-degrees different between the jets. In the Viper, the top side of the bracket is fast and the bottom is slow, whereas in the Hornet, high on the bracket is slow and low is fast. Transparent to dudes who have flown the jet their entire career, but it can take some getting used to.

Both jets are relatively easy to land. Hornet guys typically don’t flare to land, but it can be done and results in very smooth/easy landings. The Viper tends to float a bit in ground effect because the FLCS tries to keep the jet flying, so you’ll often see the jet touch down and then hop a bit before it settles onto the runway.

The Viper will then aerobrake (keeping the nose off the runway to use drag to slow down) while the Hornet pilot relies more on the beefy brakes to slow down. Despite being heavier, the Hornet does a much better job of slowing down. Its brakes are far superior to the Viper’s smaller brakes that are prone to overheating at higher weights and speeds.

Well that’s the admin/motherhood of flying these jets. Next time I’ll talk about the handling/fighting employment characteristics of America’s premier fourth gen fighters.