How to use this AS350 HOGE and HIGE calculator
- Pick your variant: H125 (B3e), B3+ or B2, and choose HOGE or HIGE.
- Enter your gross weight. If you have just done your weight and balance on this site, the takeoff weight carries across.
- Enter the outside air temperature at the landing site or pad.
- On the B3+, tick the electrical consumption correction if you are drawing more than 50 A.
- Read the maximum hover altitude. It is a pressure altitude, so compare it with your altimeter set to 1013 hPa / 29.92 inHg. The chart shows the manual's OAT lines, your interpolated OAT line in blue, the limits, and the crosshair going up from your weight and across to the answer.
How the AS350 hover ceiling chart works
The Airbus hovering flight performance charts plot gross weight against pressure altitude with one line per 10 °C of outside air temperature. To read one by hand you go up from your weight to your OAT line, then across to the altitude axis. Between two OAT lines you interpolate. This calculator does exactly that: each line is stored as a series of points traced from the manual page, the two lines either side of your temperature are read at your weight, and the answer is interpolated between them. The crosshair on the chart is the ruler.
The authorised part of each line is drawn solid (blue on the B3e) up to 2,250 kg and starts on the maximum demonstrated density altitude curve (Hσ = 23,500 ft) or the 23,000 ft chart top. The calculator caps light-weight answers there, and caps hot-day answers at ISA +35 °C, the limit printed in the chart conditions.
Which AS350 hover charts are included
- H125 / AS350 B3e: HIGE and HOGE, AS350 B3e Flight Manual Section 5.1, revision 20-50.
- AS350 B3+ (Arriel 2B1): HIGE and HOGE, AS350 B3 Arriel 2B1 Flight Manual Section 5.1, revision 15-45.
- AS350 B2 (Arriel 1D1): HIGE and HOGE, from the Tool in the Cockpit app, not yet checked against the B2 flight manual.
AS350 hover ceiling FAQ
What is the difference between HIGE and HOGE?
HIGE is hover in ground effect, measured at a 5 ft (1.5 m) skid height in the AS350 flight manual. The ground cushion reduces the power needed, so HIGE ceilings are higher than HOGE. HOGE is hover out of ground effect, which is what you need for a vertical departure or arrival over obstacles, a confined area, a pinnacle, a hoist or a long line. If your HOGE ceiling is below the landing site's altitude you can still land and lift off in ground effect, but you have no margin to hover away from the ground.
What is the H125 HOGE ceiling at max gross weight?
At 2,250 kg on a standard day the H125 (B3e) can hover out of ground effect up to about 11,100 ft pressure altitude, and at ISA +20 about 8,600 ft. In ground effect the figures are about 13,300 ft and 10,800 ft. The B3+ is within a few feet of the B3e on these charts. The B2, with the Arriel 1D1, is far lower: about 7,700 ft HOGE at 2,250 kg on a standard day and 4,400 ft at ISA +20. Use the calculator for your exact weight and temperature.
Which AS350 hover chart should I use?
The H125 is the AS350 B3e, with the Arriel 2D. The B3+ has the Arriel 2B1 and its own charts in the AS350 B3 2B1 flight manual. The B2 has the Arriel 1D1. Pick the matching variant in the calculator. The B3e charts are from Section 5.1 of the B3e flight manual (revision 20-50) and the B3+ charts from the B3 2B1 manual (revision 15-45); check your own manual for a later revision or a supplement that changes performance.
What limits the AS350 hover charts?
Each chart is drawn for Hp up to 23,000 ft and OAT from -40 °C to ISA +35 °C, and the lines stop at the maximum demonstrated density altitude of 23,500 ft (the curve at the top left of the chart). For a light aircraft on a cold day the calculator caps the ceiling at that curve or at 23,000 ft; on a hot day it caps it at ISA +35 °C, which is tighter than where the warm lines are drawn. The status line tells you which limit applied.
Does electrical load or the heater change the answer?
The charts assume the heating and demisting system off. The B3+ chart adds that with an electrical consumption over 50 A performance is reduced by 50 kg (110 lb); tick that in the chart corrections and the calculator reads the chart 50 kg heavier. The B3e chart prints no electrical correction.
What about hover performance with an external load above 2,250 kg?
The HOGE charts continue to 2,800 kg in a region marked for external, jettisonable load only. This calculator covers the internal-load part up to 2,250 kg; for heavier external loads read the manual's chart directly.
The answer is a pressure altitude. How do I compare it with my landing site?
Set 1013 hPa (29.92 inHg) on the altimeter subscale and read the altitude, then check it is below the maximum hover altitude. If you only know the site elevation and the QNH, add roughly 27 ft for every hPa the QNH is below 1013 (about 1,000 ft per inch of mercury below 29.92), or subtract if it is above.
How accurate is the chart data?
The B3e and B3+ charts were digitised from the flight manual pages at 400 dpi, tracing each line to within about a pixel, and the two manuals' charts, traced independently, agree to within 20 ft. The B2 lines come from the Tool in the Cockpit app; we did not have a B2 flight manual to check them against, so treat them with more caution.
