Aircraft height-keeping performance monitoring is a quality check on the engineering work and approval process associated with the safety of RVSM operations.

Yes, all operators are required to participate in the regional monitoring program. This participation usually means an operator will need to monitor two (2) individual aircraft of each type that they operate.

Monitoring can take place any time after the engineering upgrade work for RVSM compliance is completed. At this point, the aircraft will be airworthiness approved for RVSM.

Aircraft can be monitored for RVSM by scheduling a GPS-based monitoring system flight or flying over a ground based monitoring system.

The cost of a GMU monitoring flight will vary depending on factors which include monitoring location and technician time. Generally, the cost for one aircraft is approximately $2,100 plus travel and per diem if travel to monitoring location is required.

Typically a monitoring flight can be scheduled with 3-5 business days of lead time.

A typical monitoring flight should take no more than two hours and consists of the following: the monitoring technician will temporarily install the GMU in your aircraft (this takes approximately 10 minutes); the technician needs to collect no less than 30 minutes of data at an RVSM altitude (FL290-410).

Yes, for a fleet of 5 or more aircraft self-monitoring is generally available. Operator self-monitoring includes a training charge of approximately $1,595 and a processing charge of approximately $750 for each flight. What is required to conduct a GMU monitoring flight? The basic requirements to conduct a monitoring flight are:

1.  30 minutes of straight and level flight at FL290-410
2.  5-amp plug-in power (not lav/shaver outlet)
3.  Pre-flight access to cabin or cockpit windows to fix suction cup mounted GPS antennas
4.  limited access to flight crew by monitoring technician for transponder code changes and flight information


*this charge is only applicable to those operators who train at CSSI HQ…the training charge is more if we travel to their facility to conduct training (again not including travel)

Only one GMU has ever been purchased by a commercial concern. All other GMUs are the property of the FAA. CSSI is a qualified and FAA-authorized provider of GMU services.

Monitoring results are typically completed within 10 business days of the monitoring flight. The data is initially processed by CSSI and then forwarded to the FAA’s Wm. J. Hughes Technical Center (WJHTC) for calculation of the aircraft’s altimetry system error (ASE) value. Upon completion of the results, the WJHTC will send your RVSM letter to your FSDO representative (this is contingent upon there being a record of your aircraft’s airworthiness approval in the FAA’s Program Tracking and Reporting System [PTRS]).