Flight Time Decides the Workday

Pressure, flow, software, and accessories all matter. Flight time and working height come first because they decide whether the aircraft can remain on the work face and whether it can reach the scope from the planned setup.

The B2 flies up to 32 minutes and reaches up to 195 feet. The Sherpa flies up to 19 minutes and reaches 150 feet. The arithmetic: (32 - 19) / 19 = 68.4%, stated as approximately 70% more flight time. For height, (195 - 150) / 150 = 30% more reach.

The two aircraft work in materially different operating envelopes. Test conditions differ between manufacturers, so square-foot production can vary.

AirTrace automates a selected cleaning grid under active pilot supervision. The battery cycle remains. Once the aircraft leaves the work face, cleaning pauses until it lands, changes batteries, relaunches, and returns to position.

A battery change costs far more than two minutes. Cleaning stops while the pilot backs away from the surface, descends with the hose, lands, secures the aircraft, changes the batteries, completes checks, relaunches, climbs, and finds the exact restart point. The crew may also reset hose slack and reopen a controlled work area.

To make that visible, the planning model below applies the same assumptions to both aircraft: a 15% reserve, 45 seconds to land, two minutes to change batteries, 45 seconds to take off, 90 seconds to return to position, and one minute of ordinary interruption per cycle. The result is modeled time availability.

Hillcrest Tower at 12720 Hillcrest Drive in Dallas is a useful public example. The property page describes a 10-story, 168,189-square-foot office building with a 16,818-square-foot typical floor. To model the exterior, estimate the building perimeter and cleaning height separately from floor area.

Assume a roughly square 16,818-square-foot footprint, about 130 feet per side, 12 feet per story, and 20% deductions for areas outside the cleaning scope. That produces approximately 50,000 square feet of modeled cleanable vertical surface. Hold application speed constant at the B2 maximum of 5,000 square feet per hour to isolate endurance. The model then requires 600 airborne cleaning-clock minutes.

At 24.2 usable cleaning minutes per B2 sortie, the scope requires 25 modeled sorties and 24 battery transitions. At 13.15 minutes per Sherpa sortie, it requires 46 modeled sorties and 45 transitions. Under the shared transition assumptions, the longer-flight case produces 48.1 cleaning-clock minutes per elapsed hour versus 41.2, turning the same modeled cleaning clock into approximately 12.5 versus 14.6 elapsed hours.

That is roughly 2.1 crew-hours of difference before any production, quality, weather, or site-access difference. Each landing multiplies fixed overhead across a large facade.

A 45-foot difference matters. At an assumed 12 feet per story, it represents about 3.75 story-equivalents. A 10-story property like Hillcrest Tower may fit inside both height envelopes from a suitable ground setup. On a taller building, 195 feet can keep additional elevations inside the drone scope before a separate launch point or access method becomes necessary.

The FAA altitude rule and the cleaning system's working height are separate limits. Hose mass, fluid, wind, facade geometry, standoff, obstacles, people, vehicles, airspace, and the operating plan can all reduce practical reach. Height belongs beside flight time at the top of the hardware decision because it controls addressable scope.

Five practical checks decide the purchase.

• The reserve the pilot will hold.
• The length of a full land, change, and relaunch cycle.
• The cleaning minutes the scope requires.
• The height left with the actual hose and fluid load.
• Whether one approved setup reaches the surface.

Flight time and height tell you where a field demonstration starts. At 32 versus 19 minutes and 195 versus 150 feet, SkyPSI treats both as first-order constraints.