Dudley HenriquesInternational Fighter Pilots FellowshipCommercial Pilot. CFI RetiredSomeone asked about rudder control on takeoff.The Spitfire with a Griffon/5 blade Rotol combination is probably the ultimate challenge on takeoff for a pilot flying hot props. The Mustang with the Merlin V1650-7 and either the Hamilton Standard or an Aeroproducts prop is hard enough to handle at a takeoff power setting of 61" and 3000RPM, but the Griffon Spitfire is in a class even above the P51. You ham hand a Griffon, and the term Pilot in Command transfers immediately to the Spitfire instead of you!Here's how to handle a Griffon on takeoff.First of all, for the simulator, RealAir has modeled the effects for this potential Griffon style nightmare on takeoff VERY WELL, so be advised. There are several ways to learn about takeoffs with the Grif. You can trim back the realism sliders to the left if you like, but I know none of you are going to do that anyway, now that you finally have your mitts on something as challenging as this airplane obviously is, so let me just go ahead and put you in the cockpit and tell you how to do it right. You folks in the sim community are a real intelligent bunch, and I know that even tha ladies out there will want to get in this airplane and start flying it the right way, so here's how to handle a Griffon on takeoff.First, when you enter the runway off the taxi entrance, you will be in a turn. Complete that turn to the line up point and then line up carefully. This means letting the Spitfire move forward just enough to straighten the tailwheel. Make sure that tailwheel is STRAIGHT!This is a common error that is made by many pilots checking out in hot tailwheels, so watch it carefullyNow, do a final line up check; engine temps and pressures, prop and mixture settings, fuel on the center position. The Spitfire, like the P51, is virtually an automatic airplane, and RealAir has it programmed that way. I like to check the pitch trim just a tad above the center line.You all know about misusing power by this time so let's just concentrate on what we have to do to do things RIGHT!There are 3 things that are prime on take off in a Spitfire. The first is proper use of power, the second is nose attitude, or where the airplane is actually tracking during the run. The third are the forces in play during the takeoff run.It would be nice if you could handle these three things one at a time, but it doesn't work that way. You have to be able to handle these 3 things ALL AT ONCE...and at varying degrees of intensity and at various times during the run. In other words, if you are going to get a Griffon Spitfire into the air without scaring the hell out the rabbits over there in the grass on the right side of the runway, you're going to have to take a deep breath, think about what's going to happen, then stay ahead of the airplane.Here's how you do that.First of all, get those two little triangles set and in your peripheral vision and make sure they're equal on both sides of the lower windshield. Now here's the hard part. Start easing in the power slowly while you divide your attention between the two triangles and the boost gauge. You know you are going to go to + 7 lbs boost, but you can't just sit there staring at the boost gauge can you? You do that, and the airplane will be flying you in about 2 seconds. Here's where you learn the proper way to read instruments on takeoff in ANY airplane, ESPECIALLY one like the Spitfie.What you do concentrate on the triangles. THEY are prime to you, and your FIRST visual cue. Now, as you begin applying power slowly, you GLANCE at the boost gauge.....just glance at it. Now go immediately back to the triangles. In that split second you note what the gauge is reading and how far it has to go to reach +7lbs. Now here's the secret. As you are back looking at the two sides of the windshield, you are advancing the throttle and adjusting it's use based on your MENTAL picture of the boost gauge when you last saw it. You are now concentrating on the nose, but making the power correction at the same time. Finally, as the nose comes down during the run, you REGLANCE the boost gauge and confirm and/or adjust for reaching +7lbs.It would be wonderful if doing this was all we had to worry about when taking off in the Spit, but I'm afraid it isn't. While you're playing all this eye tag with the throttle and the boost gauge, you also have to worry about the forces in play on the airplane during the take off run....and I mean FORCES!!!!!You all know that the Griffon torques right instead of left, and I'm sure you all know about P factor; slipstream effect, and gyroscopic precession, but the way these things work is not as easy as it seems just knowing they are in play. In fact, each one works more strongly at any given time as different things are taking place during the run. This means that there are varying degrees of each force in play as the Spit picks up speed, and especially as it transitions in pitch, first with the nose coming down during the run, and then as the aircraft rotates off the runway.I'm not sure how deep RealAir went into programming these forces each individually. I believe that if you understand them, and how they would be acting on the real Griffon Spitfire, you will be ready for them regardless. My guess is that RealAir programmed in all they could considering the sim limitations, which would be considerable for a right torqued engine like the Griffon. For practical purposes, you can consider what you have to deal with as "right turning tendency forces" with power applied on this airplane.In real life, here's what happens.As the airplane is sitting in a 3 point attitude, if power is applied to the Griffon, there is torque applied to the right main strut. This is not correctable standing still, and in the take off run is corrected in ROLL by opposite aileron (left aileron).Also standing still in a 3 pont attitude, with power applied, you have slipstream effect acting on the rudder and vertical stabilizer.The tendency is a right yaw, standing still, it isn't correctable, but in motion it's corrected with LEFT rudder.Notice there are 2 additional factors in play, but I haven't mentioned them yet. These are P factor and gyroscopic precession.P factor is a comprehensive explanation, so I'll let you read up on it yourself, but basically what you have to know as far as takeoff in the Spitfire is concerned is that unless the airplane is in motion and the prop disk is rotating at an angle to the relative wind, there is no P factor. In other words, as you apply power to the Spitfire, P factor comes into play as the airplane starts it's run with the tail down because the prop plane is angled to the relative wind. As the tail comes up to meet the flight path, the relative wind equalizes on both sides of the prop disk and the prop's angle of attack becomes even on both the upswing and the downswing sides of the disk..... P factor is nullified until non existant in exact level flight. In reality, there is always some P Factor in play as the airplane has to fly at some degree of positive angle of attack to maintain lift, so there's always some angular difference between the relative wind and the prop disk, but for all practical purposes, P Factor on the Spit is the most prevelant during the early part of the takeoff run because the prop disk is angled to the relative wind. Because of the prop rotation direction on the Griffon, consider P Factor a right turning tendency force anytime the prop disk plane is angled to the relative wind with the tail down. Correction for P Factor on the Griffon is with rudder; on the Griffon Spit, that is LEFT rudder.Now, for gyroscopic precession.This is a force on the Spitfire's prop disk applied at a point 90 degrees ahead in the direction of rotation on the outer edge of the prop disk when the disk is rotated either way in pitch.This force is only in play if the airplane is being rotated in pitch, so it's strongest at the exact instant of takeoff. Again, because of the direction of the prop rotation, and the fact that takeoff is a rotation in positive pitch (upward) you can consider this force a right turning tendency force for a Griffon Spitfire, correctable by LEFT rudder.So there you have it; the forces in play on your Griffon Spitfire on takeoff. Your correction will be left rudder to correct the nose swing to the right and left aileron for the torque on the roll axis as airspeed allows aileron application to be effective.As for techinque; the following;RealAir has programmed everything they could into the Flight model that MS gave them to work with. For the most part, when you start the takeoff roll, EXPECT to be correcting with LEFT rudder. You might notice a slight initial swing to the left side however. This is due to base level MS programming in the sim itself and I understand this slight left tendency was unavoidable, but it's no big deal. Forget it! If you're flying the Griffon Spitfire as you should be, and that means adjusting with gentle rudder corrections ANY tendency of the nose to swing either way on takeoff, you'll catch this immediately and correct it instinctively. But don't worry, even if MS has declared from the mount that the nose might go a bit left as you begin to apply power, REALAIR has come along just in time to "inform MS of the error of their ways" :-)))) and the nose will go right soon enough on you, so be careful!!!You keep those triangles equal and you'll have no trouble with the Spitfire. Just go easy with the power coming in and watch where that nose is pointing; correct gently and immediately and you'll have no trouble flying this airplane'In fact, I've given you folks exactly the same information I would have given any real world pilot coming to me for a checkout in this airplane.I sincerely hope these little tutorials have helped all of you enjoy this wonderful piece of work by a great team of software designers.Have fun, andCheck six,

If you keep this up I'm going to have to part with US$35 :-)

> If you keep this up I'm going to have to part with US$35> :-)Dudley HenriquesInternational Fighter Pilots FellowshipCommercial Pilot. CFI RetiredIf I keep this up, my wife is going to kill me; since I'm supposed to be doing yardwork!! :-))

"If you keep this up I'm going to have to part with US$35"If you don't have it yet, Doug, you're losing valuable time. :-) Greg

Dudley,Thank you so much ! My sliders are a little left of what is recommended in the manual, but I hope to move them gradually to the right as I master the take-off, and your Pilots' Notes are a big help !Cheers,Alastair

Hi Dudley,Thanks so much for taking the time to put together these valuable lessons in flying this powerful beast. I've got a question about a term you use frequently... is a "hot prop" just a powerful propeller-driven aircraft or is it a more specific term I'm not familiar with? Not being a real pilot (yet) sometimes the terminology eludes me.Keep up the great work!thanks,

Hey Bill!Great job (as always) on West Malling!Ken

Thanks a ton, Ken! I'm glad it's out there now and not just on my hard drive. I have to remind myself to stick to airports that still actually exist in future projects.;-)

>Hi Dudley,>>Thanks so much for taking the time to put together these>valuable lessons in flying this powerful beast. I've got a>question about a term you use frequently... is a "hot prop">just a powerful propeller-driven aircraft or is it a more>specific term I'm not familiar with? Not being a real pilot>(yet) sometimes the terminology eludes me.>>Keep up the great work!>>thanks,Dudley HenriquesInternational Fighter Pilots FellowshipCommercial Pilot. CFI RetiredThank you. I'm glad the information proved useful.The term "hot prop" is simply a term we used back in the days when we were flying these machines. In our demonstration community, you could say that anything heavier and more powerful than an AT6 would be referred to in this way, especially if a tail wheel fighter.D

You're right Greg. I couldn't stand it any longer. I just downloaded it and now I'm off to do the install. With the help already offered here by Dudley I should be off the ground sometime tonight. I've never flown any kind of fighter aircraft before so it should be an interesting evening :-) .Doug

...what a blast. I just completed the first flight. All the way from Duxford to Cambridge :-) . I didn't grease the landing but I didn't stuff it either. What a marvelous aircraft. Retirement is great..I'm going to be up all night...whoopie...Doug

Dudeley,Are they more tutorials you have? Is it possible for you to consolidate and post them? That would really help. Time permitting, possible for you to write more to cover more basic and advanced stuff? I think that would be invaluable.....Like I'm totally new to the Spitfire and to fighters like this as such...so I'm sure if there's something which is documented (like a tutorial) will be awesome!Cheers,

>Dudeley,>>Are they more tutorials you have? Is it possible for you to>consolidate and post them? That would really help. Time>permitting, possible for you to write more to cover more basic>and advanced stuff? I think that would be invaluable.....Like>I'm totally new to the Spitfire and to fighters like this as>such...so I'm sure if there's something which is documented>(like a tutorial) will be awesome!>>Cheers,Dudley HenriquesInternational Fighter Pilots FellowshipCommercial Pilot. CFI RetiredThe information included in RealAir's software for the Spit is very well written out and should be of great help to you. Also, I believe they included an actual manual for the airplane.For aerobatics, please feel free to drop me a line and I'll help in any way I can if I have time.