The analysis
An average speed of 136.7 km/h is 73.8 knots. The Grand's maximum cruise is 155 knots. The record was set at roughly half the speed the aircraft is capable of, which means the circumnavigation record has never really been a speed record. It is a record about how little you stop.
For the 1996 flight both numbers were published, so the split can be computed exactly: 20,508 nm flown in 165.1 flight hours, inside an elapsed time of 414 hours 14 minutes. That leaves 249.1 hours, or 60.1 percent of the entire record, spent not flying.
For 2008 the equivalent number was never published. Anywhere. So the honest thing to do is bound it rather than guess it.
Bower's published 20,508 nm in 165.1 hours implies a block speed of 124.2 knots. The crew's own aircraft page independently states that the Bell 430 averaged 230 km/h, which is 124.2 knots. The two agree exactly. The same arithmetic applied to 2008 is therefore sound; only the input is missing.
| If block speed was | Airborne | On the ground | Ground share |
|---|---|---|---|
| 155 kt max cruise | 129.0 h | 142.1 h | 52.4% |
| 150 kt | 133.3 h | 137.7 h | 50.8% |
| 145 kt | 137.9 h | 133.2 h | 49.1% |
| 140 kt | 142.9 h | 128.2 h | 47.3% |
| 135 kt | 148.1 h | 122.9 h | 45.3% |
There are only two places to find time, and both are close to closed.
The 2008 flight was already run near the top of its aircraft's cruise envelope, so this means bringing a quicker helicopter. That is available: several civil types cruise faster than the Grand. But speed in cruise buys less than it looks like it should, because at 78 stops the aircraft spends roughly half the record on the ground, where cruise speed is worth nothing.
Either make fewer stops, which requires exactly the auxiliary fuel and weight exemption that Kasprowicz publicly refused, or make faster ones. And 78 turns averaging well under two hours each already has customs, fuel, maintenance, weather and whatever sleep the crew got folded into it.
Which leaves a challenger in an awkward position. To beat the record convincingly they would have to accept the ferry tanks, the bunk, the over gross exemption and the factory crew, and so attempt it with every advantage the 2008 team declined in writing. That is a strange place to stand, and it may be the real reason the sentence on the aircraft page came true.
One day of slack
The crew lost an entire day in Okhotsk to airport construction, an empty fuel bowser and a tower that would not release them, and still finished almost six days clear. A challenger does not just have to be better than the 2008 flight. They have to be better than the 2008 flight minus its worst day.
Everything above is bounded rather than solved, for a single reason. The FAI record lists elapsed time and average speed. The press coverage lists elapsed time. The crew's own site, which published Bower's 165.1 hours, never published its own equivalent figure.
The live tracking page went up during the flight, but the Internet Archive only ever captured it in its placeholder state, and the satellite track was never archived. So the number does not appear to exist in public anywhere.
Total airborne hours, New York to New York. It is one line in a logbook, and it would turn a range into an answer.