FAA Airline Transport Pilot (ATM)Navigation, Air Traffic Control and ProceduresEasy
A departure procedure chart shows a crossing restriction of 'at or above 5,000' at a fix. How should a pilot comply with this restriction?
- ACross the fix at exactly 5,000 feet
- BThe altitude is advisory only and may be disregarded
- CCross the fix at 5,000 feet or any altitude higher
- DCross the fix at 5,000 feet or any altitude lower
Show answer & explanationAnswer & explanation
Correct answer: C. Cross the fix at 5,000 feet or any altitude higher
'At or above' restrictions establish a minimum crossing altitude; the aircraft may cross the fix at that altitude or any altitude higher, but not lower.
Why the other options are wrong
- A. Exact altitude is required only for 'at' restrictions, not 'at or above.'
- B. Published altitude restrictions on SIDs are mandatory, not advisory.
- D. Crossing lower would violate the minimum altitude restriction.
SID Altitude Restrictions
Published crossing restrictions on departure procedures use terms like 'at,' 'at or above,' and 'at or below' to define mandatory, minimum, or maximum altitudes at a fix.
- 'At' means exact altitude required
- 'At or above' sets a minimum altitude
- 'At or below' sets a maximum altitude
Memory trick: 'At or above' = floor, not ceiling