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View Full Version : Writing an aviation megaquiz for fun (Help with fact-checking needed)


Sleepsleep
26th Mar 2022, 12:41
The challenge is out! Try it here: https://forms.gle/dnhrxZsJ9Prpd3dT9

Feel free to share it with anyone you know!
The original post is below this line. Spoilers ahead! Do not scroll past this line if you do not want to see the answers.

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Hi everyone,
Recently there is a trend of mega-quizzes in HK where people with specific interests write a long trivia and theory quiz on it and let everyone online try them. There have been mega-quizzes about geography, the local football scene, railways, and much more. Being an aviation enthusiast I have decided to make one about aviation myself for fun (no one seems to have done it yet), and at the same time adding more flying knowledge to my base. It may also help get more people interested in aviation by letting them know that there is more to flying than autopilot usage, I guess.

However, some of the more difficult questions in my quiz involve quite a lot of aviation theory, and although quite a lot of research and learning (mostly recurrent, been out of the loop for a while) have been done on my part, there still needs to be assurance that they are accurate (they require more than simple Google searches to write). I am also using this chance to refine the quiz before making it public.

These are the questions that I need your help to fact check:

5.7 In an A320-200, which engine is usually started and why?
A. Engine 1, because of human nature.
B. Engine 1, to provide pressure to aircraft systems.
C. Engine 2, to prevent injuring ground staff.
D. Engine 2, to provide pressure to aircraft systems.
I marked C as the correct answer because from what I have heard it can prevent sucking ground staff into the engine as there are still tasks to be done at the LHS of airplane (mostly related to jet bridges). To twin-jet pilots reading this, is this the norm? If not, what is?
The new marked correct is D. (Suggestions from HOVIS)

6.5 When you fly at a higher altitude while keeping airspeed unchanged,
A. induced drag decreases while parasite drag decreases.
B. induced drag increases while parasite drag decreases.
C. induced drag remains unchanged while parasite drag increases.
D. induced drag remains unchanged while parasite drag decreases.
E. both induced drag and parasite drag remain unchanged.
F. both induced drag and parasite drag decrease.
The marked correct is B. What is wrong with this explanation, if anything? "For a given true airspeed, you will need to fly at a higher angle of attack because of the less dense air. Higher angle of attack causes more induced drag to be generated. Similarly because of the less dense air you encounter less air resistance, so parasite drag decreases."

7.7 What are some advantages of a swept wing for jet aircraft? Check all that apply. (Marks will only be awarded for all correct answers.)
I. stability in turbulence
II. increased maneuverability
III. reduced profile drag
IV. lower stall speed
V. increased angle of climb
Marked correct is I, III and V. I used information from Ace the Technical Pilot Interview to write this question. Is this explanation accurate enough?
"I. A swept wing produces less lift and is therefore less responsive to updraughts.
III. The swept wing is designed with a minimal camber and thickness, therefore reducing profile drag. (source: Ace the Technical Pilot Interview)
IV. In fact the use of swept wings result in higher stall speeds. (source: Ace the Technical Pilot Interview)
V. Angle of climb depends on excess thrust (thrust minus drag). (source: AvStop) Swept wings cause less drag, so there is more excess thrust for the same conditions, the rate of climb would be better as well."

8.4 Sometimes a firm landing is preferable to a softer one. Choose all correct reasons.
I. Reduce gear shimmying.
II. Reduce the stopping distance.
III. To counter drift when there are crosswinds.
IV. The landing gear tires can last longer.
Marked correct: IV
This fact check request is mostly about (I). Before I went out of the loop I heard about firmer landings helping reduce gear shimmying while self-learning more about firm landings by activating anti-shimmy systems much more quickly. Is this true?
This is the explanation that I wrote for this question, any comments?
"I. Irrelevant
II. landing distance depends on touchdown point
III. Use a crabbing approach instead
IV. Firmer landings reduce the risk of hydroplaning on a wet runway. A smooth landing will also scrape off the point of contact of the tires along the runway before friction spins it up to the same speed as the aircraft. (source: KLM Blog https://blog.klm.com/how-to-perform-a-good-landing/)"

9.4 Although gear up usually happens shortly after take-off, sometimes the landing gears are still down for a while after take-off even when there are no other irregularities. Select all probable explanations.
I. The pilot flying forgot to give the gear up command.
II. Positive rate not yet confirmed.
III. To allow the gears to cool down first.
IV. To reduce IAS.
V. It is an emergency procedure when one brake is INOP.
Marked correct is I, III and V. Based on this thread https://www.pprune.org/spectators-balcony-spotters-corner/638157-retracting-landing-gear-china.html
Thanks to HOVIS and FlightDetent for fact checking.

9.6 How does a forward CG affect cruise speed and why?
A. Cruise speed increases because the angle of attack is lower, which can reduce induced drag.
B. Cruise speed decreases because the load is more evenly distributed.
C. Cruise speed decreases because a greater elevator force is required to maintain straight-and-level flight.
D. Cruise speed decreases because a greater angle of attack is required to maintain straight-and-level flight
Marked correct is C.
It is C instead of D because "Angle of attack is more related to the takeoff and landing in this scenario, rather than cruise flight, while elevator (downwards) force is more related to maintaining straight-and-level during cruise". Is this correct? Or is D a better answer?

Lastly, is this video https://youtu.be/AdCcbBhondA about Boeing 777-300ER engine start accurate? I am using it as a source for a question carrying a large amount of marks.

This quiz has a total of 102 questions, divided into 12 levels. Why are so few here? Because many of them only require a google search or two to fact check. There are not only theory questions, there are questions pertaining to aviation history, air travel and more. Some of them are adapted from live ATPL theory exams (or only very slightly modified) and therefore I only need to credit the question bank which I found the question in. Some of them are from short, difficult aviation quizzes written by other pilots and I credited them appropriately. (Adapted questions are few in number, none in lower levels and around 2 to 3 in higher levels.) Some of them are written based on what is in the ICAO documents and do not require fact checking.

Last but not least, links to some popular mega-quizzes for your reference (sorry that only Chinese version is available):
Geography of Hong Kong https://docs.google.com/forms/d/e/1FAIpQLSdy64meNWCRRzfJpabRpIPRrzTVYEq4RNX9YUSi1w1O7bj3OA/viewform
Railway systems of Hong Kong https://docs.google.com/forms/d/e/1FAIpQLSeSCb2Oi3olvIPCD1aHoJdblVbFgf3GiKMoP3le4aWrXjv7pA/viewform
Computers https://docs.google.com/forms/d/e/1FAIpQLSdL6SjqkTTGoG1hhuIGjTGrfz8Mky2PfoDOfjLU7SJoZLftVQ/viewform (creator claims that there are DSE level questions in his quiz)
However for obvious reasons aviation related quizzes should be in English and I will follow this rule.

Any feedback or constructive criticism is welcomed! When the quiz is ready, the link to it will be posted onto this subforum.

UPDATES
Now the quiz has 102 questions and 530 marks.
While waiting for fact checks I also did some test runs of the quiz to make sure there are no other mistakes (e.g. questions without an inputted marked correct answer).

HOVIS
26th Mar 2022, 13:06
Q5.7 It's type specific, usually linked to particular systems architecture such as which engine provides the primary hydraulic pressure for the brake system.
None of your answers are correct. 😁

HOVIS
26th Mar 2022, 13:14
Q7.7 Greater Stability about the longitudenal axis due blanked wing effect increases during a sideslip.
Increased Max Critical Mach due to the 'thinner' wing produced by Sweep (thickness/chord ratio).

HOVIS
26th Mar 2022, 13:18
Q8.4 A positive landing ensures the air/ground sensors are triggered and that wheels spin up immediately. Thrust reversers and auto ground spoilers can then deploy quickly ensuring the aircraft dumps the lift and remains firmly on the ground where brakes will be effective.

HOVIS
26th Mar 2022, 13:22
Q9.4 Essentially correct. Allows hot brakes to cool before they are retracted. Also may be due to an inop wheel speed sensor that is involved in applying the brakes after landing gear is selected up. Avoids overstressing the landing gear with gyroscopic (precession) forces.

Sleepsleep
26th Mar 2022, 15:20
So basically

5.4 should be replaced with another question
Or maybe I specify A320, in this case the answer would be D? (Powers yellow hydraulic system to feed parking brake and the alternate braking)

7.7 is OK and swept wings increase longitudinal stability too, in addition to increasing Mcrit? Cool

8.4 Thanks a lot for these facts next time I know what exactly to reply when someone says "rYaNaIr bAd bEcAuSe mUh hArD lAnDiNgS!!1!" Still what about the gear shimmying, do positive landings help stop/prevent/reduce this?

9.4 nice to hear that it is correct, thanks a lot for the extra info by the way, will include in explanations

Thanks for the feedback! Will include this extra info in the explanations

HOVIS
26th Mar 2022, 16:55
Gear shimmy is not something I've ever heard associated with smooth or firm landings. It's usually due to uneven tyre pressures or wear in the torque link bearings. 737 and A320 have shimmy dampers fitted to the main landing gear, sometimes need bleeding if there's noticeable shimmy.

FlightDetent
26th Mar 2022, 18:08
5.7 (engine start sequence)
A320 and A330 are different in this respect.

8.4 (firm landing)
Calling botox on the aquaplaning, despite that being a popular opinion.
Stopping distance is dependent on the touchdown point, not softness or lack of. Out too.

9.4 (Dunlops hanging)
Pilots forgetting definitely correct. Rare but relevant.
missing answer: special procedure for DDG/MEL (it is for one brake inop on my type)

Sleepsleep
27th Mar 2022, 03:57
Some updates about the quiz

9.4 now includes the reasons FlightDetent mentioned and is now a "check all that apply" question.

In 8.4 the gear shimmy answer is no longer marked correct.

5.7 Clarified, this question now refers to the A320 not just any twin jet. Then D should be correct.

Quiz is now 99% ready (or should be). There is a total of 102 questions and 530 marks.

FlightDetent
27th Mar 2022, 06:24
Are you sure the main reason is not powering the Y hyd for PRK and ALTN brake systems first?

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Sleepsleep
27th Mar 2022, 06:38
Are you sure the main reason is not powering the Y hyd for PRK and ALTN brake systems first?

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I know that starting up Engine 2 first in A320 is mainly for powering parking brakes and ALTN brake systems if that's what you are referring to :)
I aded "some" in front of "aircraft systems" and in the explanations I further stated that the "some aircraft systems" are the parking brakes and the ALTN brake systems. The use of such a broad term is intentional, I don't want the wording to be too obvious to those who don't know this fact - that's part of quiz design.
Or I should just add an option that says "Engine 2, for powering the brakes." and use the aircraft systems ones for tricking people?

FlightDetent
27th Mar 2022, 08:57
Dunno, powering the systems matches my point, I honestly overlooked your change to "D".

Just don't like questions with no clear correct answer. I.e., would you believe the designers put the PRK BRK on the Y HYD from the ENG2 so that it could be started first in order to protect the left-side / bridge area? Horse vs. cart.

Good luck, hard work.

Sleepsleep
27th Mar 2022, 10:01
Thanks for the feedback. Safe flights :)