PrepTest 103, Section 2, Question 10
Commercial passenger airplanes can be equipped with a(56 more words not shown)
Which one of the following(8 more words not shown)
- APassengers feel no(15 more words not shown)
- BWarnings given by(13 more words not shown)
- CThe frequency of(12 more words not shown)
- DCommercial passenger airplanes(13 more words not shown)
- EThe greatest safety(14 more words not shown)
Reading the argument
A warning about a nonexistent plane could still cause a real maneuver.
If the pilot swerves to avoid a phantom airplane, could that action create a danger of its own? That is my first concern about calling passengers safer. Avoiding real collisions would help, but the frequent false alarms might introduce costs too.
I would also want to know whether the equipment could interfere with other aircraft systems, such as power or landing gear. We have no evidence that it does. These are possible problems to check before concluding that the added system improves safety overall.
What we’re looking for
The question asks for an assumption the argument needs. My initial prediction concerns the evasive maneuvers: their risks must not wipe out the safety benefit. They do not have to be entirely risk-free for the system to help. More broadly, the argument needs the warnings to produce a real safety advantage despite the false alarms.
Working the answers
- A
Feeling safe is different from being safe. Passengers could feel more secure, less secure, or no different while the equipment still changed their actual risk. The argument does not depend on passengers failing to feel safer.
- B
We do not need this particular account of what does or does not cause the false warnings. They could result from distorted signals while the system still provided a useful safety benefit. The argument concerns the effect of having the equipment, not establishing the origin of every mistaken alert.
- CCorrect
This identifies a different danger from the one I first considered. Instead of causing risky maneuvers, repeated false alarms could make pilots stop responding to the warnings. Think of an alarm that goes off so often without a real problem that people start ignoring it.
The argument's benefit depends on the warnings prompting action when a collision threatens. If invalid warnings routinely cause pilots to disregard the system, that connection breaks down. The author therefore needs to rule out that habitual disregard. C does not say pilots must react identically to every alert; it protects the warning-and-response mechanism the argument relies on.
- D
Whether military or private airplanes can use the equipment does not establish its effect on these passenger airplanes. The comparison is between comparable commercial planes with and without it. No claim about other kinds of aircraft is required.
- E
A danger need not be the greatest danger for reducing it to improve safety. Engine failure could be a larger risk than collision, and avoiding some collisions could still help passengers. The argument needs a safety benefit, not a ranking that puts midair collisions first.
More Necessary Assumption questions
Learn the LSAT our way
Our platform drills Necessary Assumption questions at your level and adjusts as you improve.