Alex vs Malcolm — Rivas↔Domi XC

XC Route Comparison: Alex vs Malcolm

📅 March 13, 2026 📍 Rivas → Dominical → Rivas 🏔️ Mountain XC corridor

Two pilots launched together from Rivas with the same goal: fly to Dominical and back. They flew identically for the first hour. Then cloud changed everything.

🔵 Alex Montero

🪂 Niviuk Ikuma 3

⏱ 221 min (3h 41m)

📈 2,099m max

✅ Completed out-and-return

🟠 Malcolm

🪂 Ozone Alpina 3

⏱ 87 min (1h 27m)

📈 2,068m max

❌ Landed near San Isidro

11 min

Duration of divergence

630m

Altitude gap at end

30m

Gap at the start

The Route

The Rivas↔Dominical corridor runs roughly NW–SE over mountainous terrain. Rivas launch sits at 1,720m. The route crosses a mountain ridge (terrain 1,000–1,200m) and the Tinamaste gap (650–850m) before reaching the Dominical coast. A pilot needs 1,200m+ to safely clear the ridge in either direction.

Full Flight — Altitude Profile

Both flights from launch to landing. Alex (blue) completed the out-and-return in 3h 41m. Malcolm (orange) landed after 87 minutes.

Phase 1: Together (15:52 – 16:52)

Both pilots launched within a minute of each other and flew nearly identical routes for the first hour. They thermalled the same cores, crossed the same ridgelines, and reached the same altitudes.

At 16:50	Alex	Malcolm
Position	9.3694°N	9.3709°N
Altitude	2,078m	2,048m
Gap	30m altitude, 0.2km apart

Phase 2: The Divergence (16:52 – 17:03)

Top: altitude of both pilots during the critical period. Bottom: altitude gap (Alex minus Malcolm). The purple shaded zone is the 11 minutes that decided the flight.

🌫️ Cloud Context

Malcolm was in cloud when the divergence began. He had zero visibility and no compass access, which fundamentally changes this analysis. He couldn't see terrain or the other pilot.

16:50

Malcolm thermals to peak altitude — inside cloud

2,068m

16:53

Malcolm exits cloud — commits to straight flight at 237° WSW

1,928m

16:53–
16:58

5-min straight glide. Steady -2.0 m/s sink, 38–42 km/h. Loses 600m. Was he still in cloud?

1,928→1,330m

16:58

Malcolm turns east (ESE) — appears to gain visual reference

1,330m

16:59

Alex finds ridge lift at 9.33°N, -83.76 — climbs 160m

1,405→1,563m

17:03

Malcolm reaches low point. Gap: 630m. Flight effectively over.

1,411m 781m

Time	Alex	Malcolm	Gap
16:52	2,016m	1,985m	+31m
16:54	1,837m	1,816m	+21m
16:56	1,714m	1,625m	+89m
16:58	1,561m	1,330m	+231m
17:00	1,454m	1,138m	+316m
17:01	1,563m	1,000m	+563m
17:03	1,411m	781m	+630m

Transition Numbers

Metric (16:52–17:03)	Alex	Malcolm
Altitude lost	605m	1,204m
Average sink rate	-0.9 m/s	-1.8 m/s
Ground speed	30 km/h	40 km/h
Glide ratio	9.1 : 1	6.1 : 1
Seconds climbing (>0.3 m/s)	108s	20s
Track position	Over ridge (-83.76)	Valley interior (-83.72)

Flight Map with Thermals

Flight paths with thermal locations. Circle size indicates altitude gained.

Phase 3: Malcolm's Save Attempt (17:03 – 17:20)

Malcolm found weak lift near 9.345, -83.72 and climbed from 781m to ~1,100m. The thermal topped out — valley-floor thermals over 650m terrain don't develop the same vertical depth as ridge-triggered thermals. He needed 1,400m+ to clear the ridge back to Rivas. After 17 minutes working between 900–1,100m, he landed at 737m near San Isidro.

Phase 4: Alex Completes the Return

Alex continued south to Dominical (9.22°N at 17:50), then turned north:

Thermalling at Dominical (17:50–18:40) — reached ~1,295m
Pushing north through the Tinamaste gap (18:41–19:06) — maintained 1,000–1,300m
Crucial thermal at 9.37°N (19:14–19:18) — climbed 1,267→1,602m
Gliding home (19:18–19:32) — crossed the ridge at 1,400–1,500m

Thermal Detail — Alex

Alex's altitude and vario trace across the full 3h 41m flight.

Thermal Detail — Malcolm

Malcolm's altitude and vario trace. Note the sustained sink from 16:53 onward.

📊 What the Data Shows

The thermalling was equal — both pilots topped at 2,050–2,100m in the same thermal. The divergence came down to three factors:

1. Cloud forced a blind exit. Without visibility or compass, Malcolm picked a heading and committed. The heading (237° WSW) was fine for the plan. The 5-minute straight glide through -2.0 m/s sink burned 600m of altitude that could have funded a retry — but without knowing when he regained visibility, it's hard to say when he could have changed course.

2. Line selection after the cloud. Alex's track stayed over the ridge at -83.76 to -83.77. Malcolm's post-cloud line and east turn took him into the valley interior (-83.73 → -83.72), away from terrain-triggered lift. The ridge was producing pockets of lift all afternoon — Alex hit 108 seconds of climbing during the transition, Malcolm only 20.

3. Speed through the transition. Malcolm flew at 40 km/h vs Alex's 30 km/h, producing a glide ratio of 6.1:1 vs 9.1:1. When every meter of altitude matters, that speed difference is significant.

Open Questions

A few things the GPS can't answer that would sharpen this analysis:

When did Malcolm break out of cloud? Still in cloud for all 5 minutes of the straight glide, or partway through?
What triggered the east turn at 16:58? Visual reference? Landmark? Course correction?
Was Malcolm on speed bar? 40 km/h vs 30 km/h — bar, or wind component?
Any lift felt during the straight glide? Uniformly dead, or bumps not turned in?
What was the plan on cloud exit? Specific thermal target, or just getting clear?
During the save attempt, was heading west toward the ridge considered? Ridge at -83.76 was ~4km away.

About this analysis: Route comparison based on GPS tracks from both pilots. Terrain elevation data from Open-Meteo API. This is not a skill judgment — both pilots thermalled at equal level. The analysis focuses on the strategic decision point and the factors that led to different outcomes.