Aerosoft official retail partner for Microsoft Flight Simulator !! 
Click here for more information

Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

5 Neutral

About g5flyer

  • Rank
    Flight Student - Groundwork
  1. Another aspect that people forget is that aircraft are designed to a standard for certification. The FAA will tell you that a certified aircraft will not require exceptional flying skills. They mention this when discussing engine out performance and abnormal control situations. The aircraft has to meet minimum standards in regard to handling and responsiveness. The control authority, roll and pitch rates has to be sufficient to allow the aircraft to remain flyable in varying situations. For example, think of an aircraft that's miss trimmed, an engine out, a jammed flight control with a fuel imbalance. Throw in a little crosswind and you surely will have your hands full. This is the reason why modern aircraft have to be responsive. In your mind, you may think, that scenario is impossible. Well, it's already happened and very possible. All you need is a catastrophic engine failure and you're in that scenario where shrapnel has damaged a flight control and caused a fuel leak. It's that easy. That's why they have minimum standards for certification. Looking back at my beloved C141, they always recommended doing controllability checks anytime you suspected a control issue, because extensive flight testing wasn't done. In fact, we had a tab operable system in case you lost all hydraulics. Cables went to a tab on each flight control. The aircraft was responsive, but took effort on the controls and the roll rates were slow. They warned never go below 180kts operating this way because the test pilots refused to do so. You flew the approach at 180kts. That's military aircraft for you. Lastly, the heavies and light jets I've flown took about a half second to respond to input. It has always felt to me that the jet is out of control and you are just trimming and putting in small inputs to keep her on a straight and narrow path. Unlike a car that grips the road and attempts to do what ever you tell it immediately. During my Air Force time and my second civil flying gig, I did what we called functional check flights and acceptance flights. When our jets went down for heavy depot Mx, we did those flights to return it them to service. We did flight control and trim checks, shut down/restart engines inflight, max pressurized to check the safety valve, single generator and down to battery checks, manual flight control checks without hydro, adjusted the AOA system and then stalled them to ensure the warnings and stall recovery systems activated on cue. I learned a lot about controllability during those flights. Routinely you had to fly it two to three times until they got the trim set properly on the flight controls and speed brakes. Good times and a great confidence builder. Though modern aircraft are responsive, we don't fly them at full rates day to day. Normally you use small gentle anticipated inputs unless you are slow and dealing with rough air. Here's a good one for ya. We had a crew down at Edwards AFB doing some F22 air refueling support while the F22 was in flight test phase. Right down the middle of the area is a supersonic corridor that you would pass through on your way to certain areas. The whole area is pretty much VFR with a controller that called out traffic, basically low budget flight following. TCAS was just put in the jet and it was still new to military airlift. The crew was crossing the corridor when ATC informed that a supersonic F18 was opposite direction closing in on their position. At the same time the controller announced, the TCAS gave the a climb and then a immediate climb now callout. The pilot flying instantly pulled back hard on the yoke. The jet pitched up instantly and entered an accelerated stall. Once climbing like a banshee, they realized the jet had a tendency to continue climbing. That's when they realized that the horizontal stabilizer was jammed and pitch trim would not move it. After talking with Boeing, they dumped fuel, moved some fuel to the forward body tank and landed on the salt flats. They found that two elevator panels were missing from the elevators and the horizontal stab was very wrinkled on both sides. Instead of using vert speed to get the VVI into the green, he clicked off the AP and pulled with might. The jet pitched quickly from the data recorder, but loaded up the airframe and the violent accelerated stall damaged it. Of course this led to everyone having to redo TCAS training, but the plane was repaired and I flew it while deployed. The elevators were still shiny, they hadn't bothered to paint them yet. Rich
  2. Greetings, Keep in mind, most jets will fly the same and will only differ in inertia and characteristics. I flew C-141Bs, KC10s, DC10s, G3s and now current and qualified in the Gulfstream 5 and 550. Three heavies and three light aircraft. All of these jets flew the same, but had some differences in inertia and characteristics. The C141 flew like a giant Cessna. It had big ailerons and felt as if you were flying a mack dump truck when slow. It didn't feel that way because it was a heavy, it felt that way due to the feel springs/cartridges and the artificial feel system for the pitch. It only had those ailerons so it felt sluggish when slow and when flying in turbulence or in formation wake turbulence. During minimum interval takeoffs or in formation being #3 on back, you routinely had to input full aileron input to keep her stable and stop rolling moments. The KC10 and DC10 was a more modern jet compared to the old C141. It had inboard and outboard ailerons and roll spoilers. The elevators were sectioned in a way that each side had two panels giving the ability to fly with only one panel. The rudder was segmented and sectioned giving you upper and lower rudder panels. You could fly it with one section and offset 52500 pounds of thrust from each can under the wing. Even at 590,000 pounds, she was responsive to input. Sensitive actually. Easy to over control even though the yoke was rigid. You had to fly it with light hands using your finger tips and wrists. Inertia was the only way to know it was heavy. It responded to thrust input slowly at heavy weights causing you to anticipate thrust changes. If you chopped the throttles to slow and waited to see airspeed changes before adding power back in, you're too late because she will slow more than you thought. When landing, you flared earlier when heavy because of the lag in response. When light, leave the power in longer because she will slow quickly from the power pull. But as a heavy, it was nimble. The G3 and all the other Gulfstreams had a heavier yoke than the DC10. I had to add a tad bit more input to get the same response as a DC10, but they were responsive to thrust changes. G5/550 are very slippery and you have to pull power at 100ft on the 550 vs the G3 and G5 at 50ft. The G3 took a 3 degree pitch change on the flare and the 5/550 barely took 2. I canvassed these planes to demonstrate that size in modern jets don't have anything to do with handling, it's the design that matters. Airbuses are designed with commonality in mind so that from a pilot stand point, you fly them the same. Similar to 757s vs 767. They are actually the same type though the weights are different. The 757 is only considered a heavy due to the wake turbulence it generates. They lowered the heavy numbers to include it. I hear the 757 can get a little sporty during landing compared to the 767 because of the amount of roll spoiler use per yoke degrees of input. Even when you think about fly by wire in the airbus, the pilot feels what the computer directs. Looking at the side stick while an a320 is landing , it appears it would feel heavy also. There's a lot of input with the stick compared to the way the jet responds. Rich
  3. Yes, pitch stability is important. Imagine pitch being unstable on turbulent approaches. It requires a lot of input to counter the wandering and leads to passengers becoming sick. This is one of the issues you face during air refueling where new pilots get into PIO. When I flew KC10s, it would get a little pitch sensitive when the CG was aft of 25%. Many would ask the engineer to bring the CG forward of 25 before refueling. To me, you are fast and the DC10 is nimble and sensitive anyway. I taught guys to fly with their finger tips and wrist during refueling instead of their hands. Kept you from entering PIO behind the tanker and things were smoother. It's ok if a plane has a little bit of lag in the pitch axis, but it should be stable enough to allow you to counter axis divergence during bumpy approaches. You may find yourself putting in a lot of input to counter the axis moments, but the trajectory stays the same. This is also coming from a guy without fly by wire experience lol.
  • Create New...