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FDNY A-35 Certificate of Fitness — Air
Compressor Operation and Maintenance:
Questions With Verified Solutions And
Rationales 2026/2027
1. An air compressor system is primarily used for:
A. Fire fighting operations
B. Storing and making use of pressurized air
C. Forcing water through fire sprinklers in a building
D. Running elevators in a high rise apartment building
Correct Answer: B
Rationale: The primary purpose of an air compressor system is storing and making
use of pressurized air for powering tools and machinery .
2. When air is pressurized by an air compressor it:
A. Collects water from the surrounding air
B. Becomes cold
C. Becomes hot
D. Forces dirt out of the storage tank
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Correct Answer: C
Rationale: When air is compressed, it becomes heated due to the increase in
pressure. This is why an intercooler is installed between stages in multi-stage
compressors .
3. A FDNY permit is required for an air compressor that compresses
nonflammable gas at pressures exceeding:
A. 50 psi
B. 75 psi
C. 100 psi
D. 150 psi
Correct Answer: C
Rationale: A FDNY permit is required if a compressor is used to compress any
nonflammable, corrosive or oxidizing gas, including air, to a pressure exceeding
100 psi .
4. Outdoor air compressing (other than at a fair or festival) requires what type of
FDNY permit?
A. A full operating permit
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B. A limited permit
C. No permit is required
D. A temporary permit
Correct Answer: C
Rationale: Outdoor air compressing, other than at a fair or festival, does not
require a FDNY permit, regardless of pressure level .
5. The person operating an air compressor that requires a permit must hold a:
A. Driver's license
B. Certificate of Fitness (A-35)
C. Boiler operator license
D. Electrician's license
Correct Answer: B
Rationale: The air compressor must be operated by or under the supervision of a
person holding a Certificate of Fitness (A-35) .
6. Which type of air compressor is the most commonly used?
A. Centrifugal
B. Rotary
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C. Reciprocating
D. Scroll
Correct Answer: C
Rationale: The reciprocating air compressor is the most commonly used type .
7. The most common power source for an air compressor is:
A. Internal combustion engine
B. Steam turbine
C. Electric motor
D. Manual crank
Correct Answer: C
Rationale: The most common power source is an electric motor, though internal
combustion engines and steam turbines are also used .
8. Air compressors are sometimes called:
A. Air movers
B. Air pumps
C. Air blowers
D. Air circulators
FDNY A-35 Certificate of Fitness — Air
Compressor Operation and Maintenance:
Questions With Verified Solutions And
Rationales 2026/2027
1. An air compressor system is primarily used for:
A. Fire fighting operations
B. Storing and making use of pressurized air
C. Forcing water through fire sprinklers in a building
D. Running elevators in a high rise apartment building
Correct Answer: B
Rationale: The primary purpose of an air compressor system is storing and making
use of pressurized air for powering tools and machinery .
2. When air is pressurized by an air compressor it:
A. Collects water from the surrounding air
B. Becomes cold
C. Becomes hot
D. Forces dirt out of the storage tank
,2|Page
Correct Answer: C
Rationale: When air is compressed, it becomes heated due to the increase in
pressure. This is why an intercooler is installed between stages in multi-stage
compressors .
3. A FDNY permit is required for an air compressor that compresses
nonflammable gas at pressures exceeding:
A. 50 psi
B. 75 psi
C. 100 psi
D. 150 psi
Correct Answer: C
Rationale: A FDNY permit is required if a compressor is used to compress any
nonflammable, corrosive or oxidizing gas, including air, to a pressure exceeding
100 psi .
4. Outdoor air compressing (other than at a fair or festival) requires what type of
FDNY permit?
A. A full operating permit
,3|Page
B. A limited permit
C. No permit is required
D. A temporary permit
Correct Answer: C
Rationale: Outdoor air compressing, other than at a fair or festival, does not
require a FDNY permit, regardless of pressure level .
5. The person operating an air compressor that requires a permit must hold a:
A. Driver's license
B. Certificate of Fitness (A-35)
C. Boiler operator license
D. Electrician's license
Correct Answer: B
Rationale: The air compressor must be operated by or under the supervision of a
person holding a Certificate of Fitness (A-35) .
6. Which type of air compressor is the most commonly used?
A. Centrifugal
B. Rotary
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C. Reciprocating
D. Scroll
Correct Answer: C
Rationale: The reciprocating air compressor is the most commonly used type .
7. The most common power source for an air compressor is:
A. Internal combustion engine
B. Steam turbine
C. Electric motor
D. Manual crank
Correct Answer: C
Rationale: The most common power source is an electric motor, though internal
combustion engines and steam turbines are also used .
8. Air compressors are sometimes called:
A. Air movers
B. Air pumps
C. Air blowers
D. Air circulators
