list your toughest checkride questions

[TurboS7]

Declare an emergency 7700 get on an ILS and fly it down till the wheels touch. End of story.

 

[TurboS7]

B-727-200, you are dispatched with number 3 generator inop. Should you be concerned? If you are what profile would you use if it just happens to not be your day.

 

[scottm]

Simon says,

I dont know if you are seriously looking for help explaining the effect of an aft CG on an aircraft but I wanted to share a piece of information with you that helps me visualize the concept and understand it better.

Obviously we know that because of the aft CG, the arm of the CG to the control surface is relatively short compared to a centered or forward CG. They tell us that the shorter the arm is, the less control friendly it is, ie we will have less deflection ability. If you imagine a door, normal door in the open position. Now, if you take your hand and attempt to close it by exerting force when your hand is close to the wall or nearest the door hinge, it takes a greater amount of force and is very difficult to close the door. If you place your hand on the outer part of the door, near the handle, it takes little force to swing the door shut. This translates to the handle, outer area representing a longer arm and the hinge side a shorter arm. The benefit of this is you can demonstrate this to your students in the briefing very easily.

I hope this helps.

 

[ILLINI]

You've been flying along at FL 190 for a couple of hours and you lose your radios. The weather is crap for 300 miles all around you (not all that uncommon in the upper midwest). You're getting low on gas and dont have the range to fly to better conditions. What do you set your altimeter too and how do you re-adjust the minimums for the approach you are going to fly?

Declare an emergency 7700 get on an ILS and fly it down till the wheels touch. End of story.

Just out of curiousity... what are the chances that you would lose only the radio communications part of your stack? I would imagine that because the radio and avionics are part of the same radio package, you would lose both communication and navigation capabilities. I know it is possible to only lose one part, but it seems to me that odds favor losing both as opposed to only one.

Thoughts....?



Also, a question that I have heard many different answers to:

What would you do if you lost your entire electrical system in solid, low IMC that is surrounding you for 500 miles? Assuming you are flying a GA aircraft (C-172 or light twin etc...)

 

[TurboS7]

You are really right, if you are going to loose anything more than likely you are going to use everything. I used to carry a hand held com and nav radio when I was doing serious single engine IFR in the midwest. I also carried it when I was flying BE-18's, did I ever need it NO. Was it nice to have along, YES. That is why checkride questions are just there to pick your brain, they have nothing to do with reality. I quess that is the way with most "education". They just try to get you to think. If you answer my 727 question right you know the systems very well, will it ever happen in real life? It never has happened and how many hours have the 727's flown-you get the picture. I always remind myself of all this as I am flying on a dark night across the North Atlantic. Always be ready if, but in reality the chances are .00002 percent, but then when it does happen to you it just became 100%. About the same odds are true for the lotto and people do win, hence all our training.

 

[Saabslime]

This whole losing your radios and altimeter question was one I was asked on my instrument checkride years ago. I don't have an AIM handy but I do believe this is covered to some extent. Something like setting the altimeter to 31.00 and adding 100 feet to the approach?? Its been a long time since I looked this up so I cant remember the specifics. But like turbo said, if I ever was so unfortunate as to be in this situation , I'd fly an ILS all the way till I touched the ground. Better off touching down at 700 - 800 f.p.m on a runway than to run out of gas and come down who knows where.

 

[jaybird]

I just heard a good one

For people who land and takeoff at sea level and that fly a complex aircraft.

If you takeoff in your aircraft and your manifold pressure reads about 30in. at sea level. What will your manifold pressure read in Denver on takeoff? It's not too hard just requires you to think a little.

 

[mpower]

"You've been flying along at FL 190 for a couple of hours and you lose your radios. The weather is crap for 300 miles all around you (not all that uncommon in the upper midwest). You're getting low on gas and dont have the range to fly to better conditions. What do you set your altimeter too and how do you re-adjust the minimums for the approach you are going to fly?"

And your answer was?

well, pretty easy actually. don't we check the weather before we go? hopefully and if you did you got the current which is better than nothing, no they do not forecast alt settings. the idea of doing an ils is excellent, don't forget to check the altitude published on the plate that tells you your msl altitude, on gs over the faf. as you cross the faf twist that little knob and make that instrument read what the plate tells you it should be at. also if the navs are working and you are near a big airport often times the atis is broadcast over the vor, mia is an example.

 

[A Squared]

OK, Simon Says,

If you were asleep that day during your Private Pilot ground school, here's how CG affects stability. Assume a conventional airplane: one wing, horizontal stabilizer or stabilator aft of the wing, standard empennage, T-tail, or Cruciform tail. Stability of delta wings, canards, flying wings and other types are outsde of the scope of this explanation, but unless you're doing your Private Checkride in a Piaggio or an F-102, I doubt you'll be asked to explain gc and stability for one.

First, you have to understand why an airplane like this is longitudinally stable. The cg is ahead of the center of lift of the wing. Because of this, the horizontal stabilizer must provide a downward force to keep the airplane from pitching forward. What happens to your airspeed when you pitch up and start climbing? It decreases right? The downward force of the horizontal stabilizer (like any airfoil) is a function of airspeed. Pitch up, less airspeed, less downward force, aircraft pitches down. The change in airspeed changes the downward force of the horizontal stabilizer, causing it to be stable. The same effect causes the airplane to respond to downward pitching by pitching up. Pitch down, more airspeed, more down force on the horizontal stabilizer, aircraft pitches up

Now, up to this point, we have assumed the cg is where it is supposed to be. The question is: Why does an aft gc cause an airplane to be less stable? Well, let's look at the extreme example of aft cg, where the cg is actually aft of the center of lift of the wing. In this case, the force of gravity acting behind the wing will cause the airplane it pitch up, so the horizontal stabilizer must provide a force UP to keep the plane from pitching up. You make it create a force up by trimming the angle of incidence of the stablizer (if it's trimmable) or by trimming the position of the elevator or stabilator. With the gc this far aft, what happens when the plane pitches up? When the airspeed decreases the UP force on the tail decreases, this allows the plane to pitch up more, more pitch up, less airspeed, less up force, more pitch up, and it just builds on itself. Without any control inputs from you pretty soon you're pointing at the sky, wishing you hadn't loaded those bricks in the tail. In engineering terms, this is what is known as a "positive feedback loop" The opposite happens in response to a pitch down, more airspeed, more up force on the tail, tail goes up, nose goes down, airspeed builds more, and if you don't do something, pretty soon you're pointing at the ground, watching your wings come off.

This is what happens when the cg is well aft of the cg limit. The airplane doesn't go instantly from "stable"to "unstable" as the cg is moved aft of some magic point, rather the stability gradually decreases as the cg is moved aft, until you reach a point where you have a plane that is a handful to keep level. Even within the acceptable cg range, you can sense the difference in stability.

Now, we could go a lot deeper, examining how changing angle of attack on each of the airfoils adds to or decreases stability, How the location of center of pressure on each airfoil moves with aoa, changing each airfoil's contribution to pitching moments, thus affecting stability, etc. I'm sure I could write pages, and not come close to covering it all. However, the increasing/decreasing airspeed explanation is fundamentally correct and substantially complete. It can be found in most good private pilot texts, and as such, seems reasonable fodder for a checkride question at any level.

regards

 

[navigator72]

my hard ????'s

I was finshing up my Commercial checkride and was supposed to be doing a soft field landing. It was all going great until I got caught up in some swirling winds at the end of the runway, I should have done a go-round but being so focused on landing, I managed to slam the poor little C172RG on the runway. His next question was "What the hell was that?"
My only response was:
"That was a soft field landing sir"
I went back 2 days later and made the best **CENSORED****CENSORED****CENSORED****CENSORED** soft field landing the examiner had ever seen...
Live and Learn!