Flight test: Helio H-295 Super Courier
- Credit: PHOTO: KEITH WILSON
If it had claws, you could land it on a fence post! Originally designed with safety as the primary goal, the Helio H-295 Super Courier offers fabled STOL performance
Those who remember the 1990 classic Vietnam War movie Air America, directed by Roger Spottiswood and starring Robert Downey Jr and Mel Gibson, should quickly recall who the real stars of the film were: Fairchild C-123 Providers and Helio Couriers, the latter being played in the film by Pilatus PC-6 Porters.
Based in Laos and operated by Air America?the clandestine company run by the CIA?the STOL fleet’s mission was the transport of illicit goods into and out of Southeast Asia. However, it may be surprising to learn that the Courier was not conceived for such nefarious purposes, being designed in 1949 by the Helio Aircraft Company of Pittsburg, Kansas expressly for safety, rather than STOL performance.
My introduction to the Courier came when I was invited to visit the facility at Waxhaw, North Carolina owned and operated by Christian mission air service provider JAARS inc (originally formed as Jungle Aviation and Radio Service in Peru in 1948). Enter Chief Pilot Bruce Powell and Mike Maller, Director of the JAARS Missions at the Airport Programme. Both have served overseas?in the Philippines, Papua New Guinea and Indonesia?and Mike has been the demonstration pilot for the JAARS Helio Courier display, putting up a number of memorable performances at both Oshkosh and Sun’n Fun over the last fifteen years or so.
Before I am let loose in the Courier, there is the little matter of an air-to-air photo shoot to complete. Perhaps, somewhat strangely you may feel, the camera ship provided for my use is a Robinson R-66 turbine helicopter. Why employ a helicopter? Well, there are very few, if any, camera ships that can fly as slowly as a Courier when it has all of its slats and flaps deployed (around thirty mph) and stay in good close photographic formation.
The test aircraft, N461FM was acquired new by the JAARS operation back in 1972. During its service life it operated in the Amazon jungle and after a major renovation, was also deployed in Indonesia.
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The first thing that strikes me is its size: the Courier is a big aeroplane. The second is its apparent complexity?this is not a simple machine. The wing, all 39 feet of it, carries barn-door Fowler flaps, taking up seventy per cent of its span. There are automatic slats, two on each side, along virtually the entire length of the leading edge. These deploy independently and automatically, based upon the angle of attack (AoA). When extended, they redirect the airflow across the top of the wing, cleverly maintaining boundary layer control.
Featuring an unusually deep chord, the Courier’s Frise ailerons are assisted by clever ‘interceptors’ (spoilers) that pop out below a threshold speed, once around ten per cent aileron travel is reached, providing enhanced roll control at low speed.
At the back end are a tall rudder and large stabilator, similar to the tailplane fitted to the Cessna Cardinal. However, the engine and propeller combination, a 295hp Lycoming GO-480 driving a 96-inch diameter unit through reduction gear, is not found in many other light aircraft. Takeoff rpm is 3,400rpm, compared to the 2,600-2,700rpm of direct drive engines, but the gearing means that the propeller spins efficiently at around 2,200rpm, providing more thrust and better acceleration.
Claimed to be a safety feature but more probably the legacy of the design’s rather surprising Piper Vagabond origin (see ‘Vagabond origins’, below) the occupant protection afforded by the tubular chromoly-steel fuselage frame has, in N461FM’s case, been enhanced by S-framed, energy-absorbing seats that were designed and tested at Waxhaw, and certified by the FAA by way of a Supplemental Type Certificate (STC). These seats are mounted on Brownline seat tracks (used in airliners). Four-point harnesses are fitted.
The main undercarriage legs appear to be mounted substantially further forward than most taildragger designs?according to Mike Maller, you can land a Courier with the brakes locked and not nose over. That said, I’m not volunteering to try it! However, having the wheels positioned so far forward makes the aeroplane difficult to operate in crosswinds. Originally, the Courier was certified with a ten-knot crosswind limit but to overcome this restriction, the manufacturer designed and fitted a crosswind landing gear that allowed the limit to be increased to 25 knots. As spares dried up, JAARS has over the years had to remove this gear, but it has converted its Courier fleet to upgraded Cleveland wheels and brakes. These provide significantly improved braking, although it is unclear what formal crosswind limitation now pertains. In any event, students on JAARS courses are taught not to slavishly land or takeoff along the runway centreline, but to use whatever space is available across the runway to minimise the crosswind effect.
The Courier was usually built with two wing tanks offering a total capacity of sixty US gallons, although N461FM (like a number of the JAARS fleet) was modified with a four-tank system, giving 120 US gal total capacity.
On the port side, the forward section of the double door allows access to the pilot’s seats, P2 having to climb in and slide across before P1. On the starboard side, a single door allows access to the rear seats only. The large baggage bay is accessible through a good-sized door on the port side. N461FM is fitted with a JAARS-designed and STC’d belly-mounted baggage pod, capable of carrying 350 pounds. This pod is especially useful when carrying any hazardous cargo including cans of avgas, kerosene and battery acid, which needs to kept apart from the passengers. It is big enough to have carried a variety of live animals during the aeroplane’s missionary work, among them chickens, pigs, goats, dogs and an eight-foot python (in a sealed sack, of course!)
Despite its bulk, the cargo pod only gives a speed penalty of around two to three knots. For pilot training purposes, it is occasionally loaded with up to 350 pounds of rocks as an alternative to ‘walk-on ballast’. I was advised to check nothing had been left inside as part of my preflight checks!
Let’s go fly it
When my turn comes, I am occupying the right-hand P2 position and the four seats behind are empty. P1, Bruce reminds me that the ‘door handle’ on my side is in fact the fuel valve?so please would I ensure I do not try to open it in flight or “the engine gets quiet and the people in the back can get loud!”
The immediate impression is of a typical 1970s panel, although this one now features a number of updated instruments and gauges. Throttle, propeller pitch and mixture controls are located in the centre of the panel, the prop being colour-coded black, rather than the conventional blue. Large, dual control yokes display the Helio Courier badge. Below, in the footwell, are four man-sized pedals, with toe brakes on both sets. All controls fall neatly and comfortably to hand, including the two handles in the roof. The smaller one is for the trim, while the larger one operates the flaps, which I find later entails some serious physical exercise!
There’s a modern Garmin GPS/nav/comm in the centre of the radio stack, above a classic Bendix King KX155 TSO nav/comm unit. The replacement oil temperature/pressure gauge, fuel pressure/contents/flow gauge and voltmeter/ammeter are all of the digital/LED variety.
The one item that most of us may feel is a little unusual, sits atop the coaming?the flip-over checklist. I believe this to have originated around 1967 and was manufactured by Saf/Go. Working from left to right, its tabs are flipped down in sequence for takeoff and up for landing checks. What a simple, yet effective invention!
Prior to starting it is: Master on, breakers in, the two auxiliary fuel tank switches off, beacon on, cowl flap open, prop fully in, throttle quarter of an inch open, alternate air closed, primer locked and ignition switches on. The auxiliary fuel boost pump is engaged, providing fuel pressure. As the GO-480 has a pressure carburettor, it needs hand priming on the Kigas pump, three strokes being the norm. Engage the starter with the mixture control in idle cut off and as it starts to fire, move the mixture control into the fully rich position. (If you try and start the engine in fully rich you may flood it and risk starting a fire.) Initially, I set the throttle to achieve around 1,000 to 1,200rpm. Check the fuel pressure is positive and turn off the boost pump. Advance the throttle sufficiently to get the alternator light to extinguish and check the volt/ammeter has a positive charge.
The limitations include waiting until the engine has warmed to a CHT of 200?F before moving the throttle up to 1,500rpm to taxi out. The view is typical of a large taildragger?i.e. in some directions non-existent! Over the nose, it is reasonable?as it is down my side, although I can see nothing down the other side?so S-turns are the order of the day.
For this geared engine, the mag check is conducted at 2,300rpm, with a 100-150rpm drop on either side being permissible. There’s no carburettor heat: instead, you pull out and check the alternate air to ensure the filter has not become blocked.
Today, I am advised to use thirty degrees of flap for takeoff, although twenty is permissible. Forty degrees is used for soft field takeoffs, while zero flap is only used in an emergency. Late production Couriers had electric flaps but N461FM has mechanical ones, so at this point in proceedings I commence my exercise programme! The flaps are activated by a big handle in the roof. Bruce tells me the number of clockwise turns required?from seven for ten degrees up to eighteen for forty degrees?and encourages me to count them out aloud. JAARS has put a visual indicator on each flap to confirm the actual position, which is especially useful if you miscount! On the ground, there is no load on the flaps, meaning the handle is relatively easy to rotate, but later in the flight I will learn quite how much the pressure increases in the airflow!
Otherwise the standard pre-takeoff checks apply, including trim, boost pump on, prop fully in, alternate air in, primer locked, and mags on, both. A quick call on the CTAF frequency and it’s time to go. Bruce cautions that with this geared engine, I am about to see 3,400rpm instead of the usual 2,400 to 2,700. I should also look out for the ‘gear tuck’ which will occur with an increase in speed. As I move carefully onto the centre of the runway, I must admit to being slightly nervous! I needn’t have been...
I could hold the aircraft on the brakes until full power is developing for a full STOL takeoff, but opt for a somewhat easier rolling one, slowly adding power while using small amounts or rudder to correct the swing. As the wings start to produce some lift, I can feel the landing gear moving inward and pushing the nose up, producing a noticeable change in pitch. At this point the tail is definitely ready to fly and I gently move the yoke forward to bring it up, providing some forward view. Holding this position, the aircraft merely takes off gently at around 35 knots?well, it doesn’t so much take off, as levitate! This is about as gentle a takeoff as I have experienced, although what little breeze there is blowing is straight down the runway. Certainly, that tall vertical tail slab at the rear comes alive very quickly, and rudder authority is good throughout the takeoff run. Bruce advises that in windy conditions you can raise the tail further and increase the speed and get more rudder control before lifting off.
Bruce instructs me to fly a constant-attitude departure and accelerate to 55 knots (the best rate of climb with 30? flap). Winding back four turns, I then reduce the flaps to 20? while keeping the same pitch attitude and the aircraft accelerates to 65 knots, Vy (best rate of climb).
Everything appears to happen so slowly. At 400 feet AGL I am instructed to remove all flap (another eleven turns) and gradually accelerate to eighty knots while still retaining the same pitch attitude. Throughout the takeoff and climb ‘little and often’ trim changes are required to minimise pressure on the yoke.
For the record, with 30? flaps, the best Vx (angle of climb) is at just 45 knots, and with 20? of flaps it is 55, although best-angle speeds are not usually used by JAARS. The best rate of climb on a winter’s day is around 1,000 fpm, although on a hot day you can expect to see nearer to 750. The Courier’s rate climb is not particularly spectacular but the point is that it gets you off the ground in very short order.
There is a one-minute limitation on full power (3,400rpm) so using the prop vernier I wind the rpm back to 3,000. Bruce tells me you can fly at full throttle at 3,000rpm all day if you wish, but the fuel burn is high.
At around 700 feet the revs are brought back to 2,700rpm for a cruise climb?especially useful in urban areas where it also reduces noise levels?and the nose is lowered to increase the speed to around ninety knots. Up until now, the view ahead has been slightly limited but at this attitude it is quite spectacular. At 1,000 feet I turn off the boost pump and check the fuel pressure is still positive.
I continue the climb to 3,000 feet, and with 200 feet to go, close the cowl flaps and continue until I am fifty feet above my desired altitude before levelling off, using the extra hight to dip ‘down the hill’ to get to my cruise speed more quickly. Normal cruise is at 65% power, so I throttle back to 23in mp and reduce revs to 2,600. This power setting is good for pretty much all levels up to 5,000 feet. Here, the fuel flow is a steady fifteen US gph. Bruce tells me that at 65% they flight plan for 115kt, although you may see up to 118 at lower levels, where the fuel flow can be leaned to around fourteen US gph.
Slow – and slower still
Before getting into the very slow flight regime, Bruce suggested we explore the speed ranges often used by JAARS pilots in their survey or SAR flights, particularly in mountainous areas or in poor visibility where low speed and good manoeuvrability can become a distinct advantage. In the interest of engine longevity, I follow JAARS practice and maintain a minimum of fifteen inches of manifold pressure while throttling back, and gently pitch up as the Courier starts to slow down. Once below 100mph I am able to reduce the power back to ten inches. Minimum flap speed on a standard Courier is just 69kt, but as N461FM has had the gross weight STC completed, the first 15º of flap is available below 87 knots, which I apply with nine turns on the handle. With the speed below 69 knots I add a further two turns and visually check out of the left window that we have 20º flap. I lower the nose and re-trim. At this power setting we are using just nine or ten US gph, providing a good loiter time on station, if required?while the view and manoeuvrability are both spectacular! In this configuration the aircraft is capable of a level 60? banked turn, almost within the wingspan of the aircraft?ideal if you are in a valley or mountainous area and need to make a rapid but safe exit.
To get down to very slow flight?Bruce has challenged me to hold the Courier at 28mph indicated?I pitch the aircraft up to bleed off some more speed while maintaining altitude. Once below 65 knots I add another four turns on the flap handle and we have 30°. I increase power to almost 3,000rpm in the nose high attitude but continue to slow down and another three turns later (now eighteen in total?it is all good exercise!) we have all 40° of flap in play. I continue to trim as the aircraft slows while in a nose-high attitude.
According to the book, the Courier is capable of flying straight and level at 26mph, although my challenge is a little easier. With patience I manage to have it flying hands and feet off at around 30mph and am happy to settle for that. At this speed I don’t think the aircraft is entirely comfortable and I can feel the stabilator ‘burbling’ through the yoke, almost?but not quite?stalling.
The slats are AoA dependant and their operation is influenced by the weight of the aircraft. The lighter the aircraft, the slower the speed at which they will deploy. Today I hear (and feel) the inboard slats pop out at around 55 knots. The outboard ones deploy at around forty to fifty.
Bruce suggests I increase the back pressure slightly. As the speed reduces, the nose drops very slightly and the aircraft starts to sink, although it does not actually stall in the strictest sense. The Courier is the first (and probably only) aircraft I have flown that has no published Vso. Bruce now suggests I add power and gradually clean the aircraft up for normal flight before heading back towards Waxhaw, where he is going to demonstrate a ‘special performance approach’ to one of the airfield’s more difficult runways.
Unprepared strip operations
In addition to its single hard runway, the JAARS facility at Waxhaw also features a grass strip alongside the main runway and two additional runways?well, sort of runways! The first of these is a relatively long grass one, with a moderate slope as well as a relatively easy approach. However, the second has none of those luxuries, being short, on a steep slope, having a hump half way up and featuring a difficult threshold that is reached through a gap in the trees and over a fence.
Needless to say, Bruce brings the aircraft in to this last strip, passing through the trees, with complete confidence. That said, he was working hard throughout the approach and landing.
Going around, Bruce hands the aircraft back to me for a landing on the relatively easy long, hard runway. Here the Saf/Go flip-over checklist comes into play and I follow its lead, flipping the tabs over as the checks are completed. With the prop lever fully forward (fine pitch) I slow us progressively with the aim of arriving abeam of the runway threshold at 65 knots, at which point the flaps are extended to thirty degress, allowing the speed to further decay to sixty knots.
Reducing power, turn onto a curved base leg, looking to arrive around three-quarters of a mile from the runway at 400 feet AGL. Half way round, at fifty knots, I wind on the last ten degrees of flap and re-trim before pitching up slightly to encourage the slats to pop out. As I turn onto final approach, the inboard slats are fully deployed while the outboards are still floating, clunking in and out, although the aircraft is particularly stable in this configuration.
The runway comes up to meet me and I flare gently. As the aircraft touches down on all three wheels the power comes all the way off, the gear spreads out and, as I know we have finished flying, I pull the yoke back before firmly stepping on the brakes; all while keeping it straight with rudder. We stop very quickly! “Brake before you touch down and it is most unlikely the aircraft will nose over,” observes Bruce “although you will definitely scrub the tyres. Very much shorter landings are possible but inevitably, you will be flying closer to the margins. with a nose-high attitude and more power.” I am just happy to have put this lovely old lady back onto the runway safely!
Daunting, but a pleasure...
The Helio Courier is a capable yet complex, large taildragger, with a considerable range of idiosyncrasies. It is also an excellent training platform for the future JAARS pilots who will find their operations being conducted in out of the way places around the globe.
Designed from the outset to be a safe aircraft, it is clearly a mission-capable platform with spectacular STOL performance and, thanks in a large part to Bruce Powell’s considerable patience, while it may have been somewhat daunting it was actually a pleasure to fly.
I will give the final word to Matt Walsh, who flew the aircraft with Bruce during the earlier photoshoot. His conclusion: “If it had claws, you could land it on a fence post!”
The Helio Courier was designed jointly by Professor Otto C Koppen of the Stout Metal Airplane Division of the Ford Motor Company and Dr Lyn Bollinger. (Koppen had designed the Ford Flivver, an aircraft that was supposed to be mass-produced by Ford.) For what was then called the Helioplane No.1, the Wiggins Airways company cannibalised a Piper PA-17 Vagabond. Only the cabin area of the PA-17’s original airframe remained unmodified, the fuselage being lengthened by four feet and given a taller tail, and shortened wings fitted with full-span leading-edge slats and flaps. Its Continental C85 engine was upgraded with fuel-injection, and uniquely equipped with a multi-belt speed reduction unit to drive an Aeroproducts nine-foot variable-pitch propeller, which contributed greatly to amazing STOL flight characteristics. The Helioplane’s first flight took place on April 8, 1949, from what was then called the Boston Metropolitan Airport.
The first Courier, powered by the 260 hp Lycoming GO-435-C2B2 was certified in July 1954. The Super Courier, a more powerful derivative, was used by the US Air Force from 1958 onward, by the US Army Special Forces in the 1960s and 1970s and by Air America during the Vietnam War as the U-10.
There was even a twin-engine version, the Model 500 Twin Courier - a modification of the single-engine version, primarily for use by the CIA’s Air America in Vietnam. The conversion was quick and simple, leaving the aircraft rather odd-looking and apparently, vaguely dangerous. The Model 500’s type certificate from the FAA was said to be conditional that none would actually be built for commercial sale! The entire production run - seven aircraft - went to unnamed Agencies as the U-5A.
Helio H-295 Super Courier
Wing area 21.46sq m (231sq ft)
Weights and loadings
Empty weight 943kg
Max auw 1,542kg
Useful load 599kg
Internal fuel (normal) 227 lit
Internal fuel (extended) 454 lit
Climb rate 1,150fpm
Range (Standard tanks) 574nm
Range (120 US gal tanks) 950nm
Service ceiling 20,500ft
Take off over 50 ft 196m
Landing over 50 ft 158m
Engine & propeller:
295hp Textron Lycoming GO-480-G1D6 six-cylinder piston engine driving a Hartzell 8ft three-blade constant-speed metal propeller
Helio Aircraft Corporation, Pittsburg, Kansas, USA