Airplane is a 2008 G36 Bonanza. The airport is 3W5, Mears Field, Concrete, WA. Runway 25 is 2609 ft (795m) long, 60 ft wide, elevation 267 ft. Airport notes for runway 25 say: 44 ft. trees, 720 ft. from runway, 11:1 slope to clear. At 90 knots, need 830 fpm to make a 11:1 slope.
Something went seriously wrong because they didn’t climb later, most likely they were below Vx.
Looking at the pilot’s account of the situation, it seems to me he didn’t understand what happened. He states the aircraft was turbonormalized and well below MTOW.
One thing I learned: even when the runway is very short, do not climb directly after rotation but gain speed in the ground effect. You can then pull up the aircraft sharply once you have speed. Some people mix up “soft field” and “short field” whereas the former means rotate as soon as you can behind the power curve and the latter means use all runway and build up airspeed. Nicely explained here.
There is lots of things wrong in pilot training with these maneuvers.
One is that short field take-off and take-off from a runway with obstacles at the end are two different things, yet they are normally mingled together in pilot training.
The truth is that (outside the bush flying world) most runways with significant obstacles at the end are not very short (otherwise they would be _very _ challenging, also for landing). In case of shortish (but not really short) hard-surface runways, but with obstacles at the end, one should normally not use flaps and avoid rotating the aircraft at too low an airspeed. That will yield a healthier initial climb rate.
In the interest of learning something… what do you guys think he did wrong? Was it that he just rotated at a too slow speed and kept on pulling?
Reason I’m asking is that my home base, EGLD is from a slight shorter runway (2557ft), similar elevation (247ft) and also has tall trees at both ends.
In about 150+ takeoffs I’ve never come anywhere close to the tree tops. I’ve been instructed to use 10degrees of flap, and rotate at the right speed. There are frequently other larger aircraft (TBMs) departing from the airfield without any problem.
The pilot thought the POH was lying. There was no mention of any technical problem in all of the discussion.
This basically only leaves what I put in the thread title: too early climb and continued below Vx. If you fly below Vx but above Vs, your aircraft barely climbs at all, you can safely try that at altitude. He should have continued in the ground effect and then pulled up with enough speed. This might sound counterintuitive because you get closer to the obstacles before you start climbing but it will work much better.
795m is a rather long runway and a G36 with only 2 persons on board and “little fuel” (as he said) should have no problem at all with this situation.
The article I linked to says:
For the steepest climb out and best obstacle clearance, the airplane should be allowed to roll with its full weight on the main wheels and accelerated to the liftoff speed. The airplane should be smoothly and firmly lifted off, or rotated, by applying back pressure on the elevator control as the best angle of climb speed (Vx) is attained. Since the airplane will accelerate more rapidly after liftoff, additional back pressure becomes necessary to hold a constant airspeed. After becoming airborne, a straight climb should be maintained at the best angle of climb speed (Vx) until the obstacles have been cleared or, if no obstacles are involved, until an altitude of at least 50 feet above the takeoff surface is attained. Thereafter the pitch attitude may be lowered slightly, and the climb continued at the best rate of climb speed (Vy) until reaching a safe maneuvering altitude.
The takeoff roll (distance or time) looks OK for a very fully loaded aircraft of that type, on a hot day with no wind.
I guess he may have rotated too early and never got out of it.
He is also not going to go public saying it was well over max weight (if it was).
But his rotation point looks OK so if he did rotate too early he must have been way over MTOW.
Otherwise I can’t relate to this situation at all. The TB20 would climb like a rocket and I would hope an A36 would be similar.
This is a weird comment
There was an air pocket at that end of the runway (we knew, because we had flown through it on the arrival) and the aircraft didn’t climb well through that air pocket.
What is an “air pocket”? That’s rubbish, surely. It might be intended to mean sinking air but there doesn’t seem to be terrain in the close vicinity, and air is not going to be sinking into the ground.
Listening to it again, is that the stall warner sounding when he’s trying to speak? That would support the theory that he rotated too early and never reached Vx speed.
It could also be something simple like the throttle slipped back…
It could also be something simple like the throttle slipped back…
Yes, this is how I had my rendezvous with tree tops. In my aircraft, the first half of the throttle controls the manifold and the 2nd half the wastegate of the turbocharger. You must not use full throttle on the aircraft or you will overboost it. Due to the dynamic nature of MP (it builds up as you accelerate due to the turbocharger spinning up and ram air), it is not easy to find the right spot of 31" MP. I once didn’t pay attention and took up with 28" MP which is an entirely different experience. The G36 TN has an automatic waste gate and you use full throttle for takeoff.
Very strange
With my SR22 you could take off TWICE from that runway. I bet I’d clear those trees if I took off from the MIDDLE of that runway.
YOu can’t really tell but it looks like a too early rotation and then he left that plane hanging there. Had he lowered the nose and accelerated in ground effect it should never be a problem – I mean almost 800 m of runway and almost sea level. I would like to know the density altitude, but it doesn’t look THAT hot
I suspect a totally different reason for the lack of climb performance, he was too fast. First, I am an expert in the Bonanza and demonstrate this effect in my insurance checkouts. It is not clear from the video when the pilot raised the gear, but I suspect it was still down at the time. The POH has performance information with the flaps set to the approach setting. The POH lists 67 Kts for rotation and a 50 foot target speed of 77 Kts. It also lists a Vx of 84 Kts and a Vy of 100 Kts. The issue is that the Vx and Vy values are not valid for the configuration with the flaps at approach setting and the gear down. Vy in that configuration is close to 80 Kts and Vx is closer to 67 Kts. The POH doesn’t provide the Vx and Vy values for other than the clean configuration. The older “Owners Manuals used to provide this data, but I suspect the lawyers made them take it out.” They do still include a recommended airspeed for a balked landing of 80 Kts. Now why would they do this? It is because the airplane won’t climb in the landing configuration with flaps and gear down at a Vy of 100 Kts, but will give a solid 500 to 600 FPM at the lower speed, which by the way is Vy in that configuration.
Here are some numbers for my V35A Bonanza from the older “Owners Manual” prior to there being a POH. All speeds are based on 5000 feet.
Best rate:
(Gear and Flaps Up) -- 96 Kts
(Gear down) -—————— 80 Kts
(Gear and Flaps Down – 68 Kts
Best Angle:
(Gear and Flaps Up) -- 83 Kts
(Gear down) -—————— 71 Kts
(Gear and Flaps Down – 61 Kts
Stall speed Level with full Power
(Gear and Flaps Up) -- 64 Kts
(Gear and Flaps Down – 44 Kts
Note the large difference of 20 Kts in the stall speed and the 18 Kt difference in Vy between configurations.
I demonstrate this to new pilots by having them make a normal approach, gear and flaps down, then for the go around, accelerate to Vy of 100 Kts. They see that the A36 simply won’t climb or at best very anemically. Then I have them pitch up to +10 degrees and observe what the airspeed stabilizes at, 80 Kts and note the climb rate of over 500 FPM. The massive point is Vy from the POH is way too fast to conduct a climb in this configuration.
My short field technique in the G36 or A36 is to set approach flaps. Use maximum runway, full power, release the brakes and accelerate to 64 Knots and raise the nose to +12 degrees. The aircraft will come off the ground around the 67 Kt figure. Hold +12 degrees pitch until the obstacle is cleared, then raise the landing gear, lower the nose to +7 to 10 degrees, accelerate to 90 Kts and raise the flaps. In a no wind situation, the wheels will be off the ground in 1200 to 1400 feet.
Each pilot I check out has to determine Vx and Vy for the other configurations and know how to adjust all their operating speeds for three weights, maximum gross, mid weight, and just the pilot. Had this pilot raised the nose he would have gotten all the climb he needed, he was way too fast. The chirp chirp from the stall warning is irrelevant and occurs normally when heavy and one either rotates a little faster than needed or encounters a gust. The airplane is no where near a stall. To stall the Bonanza, you have to have the pitch up above 16 degrees with power on and one probably gets as much as 10 Kts of warning with a blaring stall horn, not a few annoying chirps.
I did a Google earth of the runway. Based on watching the video, he started to rotate at approximately 1150 feet down the runway and broke ground at 1275 feet. This is normal performance for an A36/G36 following the POH procedure for a takeoff with approach flap setting.
