Last & Best of the Piston Engine Fighter Aircraft.

[J.A.W.]

To be fair T-C, the more recent pilot's comments were subjective extrapolations of 'feel' characteristics,
& not a formal 'test pilot' type report with full background included, in other words he may have been
ascribing 'expectations' to the Mustang - without even being aware that the Hawker shared the 'laminar flow'
wing profile, yet knowing its airframe had been carefully modified to function effectively as a
ship-borne fighter, (unlike the Mustang). Or does the semi-elliptical planform ameliorate 'L-F bothers'?

& Capt Brown certainly was a test pilot, but rather a diminutive physical specimen,
- hence his 'struggle' to 'muscle' the Tempest around, in extremis.

Of relevance to this, the most successful Tempest combat unit was the Kiwi RAF outfit, 486 Squadron,
& as number of Kiwi Tempest pilots have noted in their memoirs - the big Hawker rewarded a firm
control input, ( esp' compared to the "dainty" Spitfire) but once "mastered" could be "...thrown around
the sky, like a piece of paper" - as top-scoring RNZAF 'ace' - E.D. Mackie put it.

Most of these Kiwi blokes were sizable chaps, (indeed one of them was the grandfather of the celebrated
Rugby World Championship winning All-Black skipper - Richie McCaw), & were grateful for the robust
construction of the Tempest, as they certainly pushed its high-Mach capabilities hard, in combat.

Interestingly, the Kiwi Tempest pilot who described the Spitfire as "dainty", Bob Spurdle, was one of the few,
& he'd duly survived a Spitfire disintegrating around him - during a terminal dive - in hot pursuit of a 109..

[Tommy Cookers]

it's perfectly clear that 0.87M in the Tempest was more dangerous than 0.84M in the Typhoon
the danger/Mach no relationship of the plane's aerodynamics has nothing to do with the pilot's bicep capacity
ie the Tempest was 0.02M better than the Typhoon for the 2 official criteria and one-off Brown criteria
btw that Tempest flight damaged the cowling

it's screamingly clear to all but you that the Spitfire showed that a thinner wing is better Machwise - ok so what ?
HMG decided thereafter to buy fighter etc planes with wings (eg the Tempest's) slightly thicker than the Spitfire's
there was a global consensus on this
regarding the elliptical planform Camm says he chose it only because HMG wanted it
as I said before about 80 Spits were lost due to 'normal' wing failure ie from aeroelastic factors
the wing was rather good aeroelastically but Mk IX pilots exceeded the placard limits (until elevator cable weights introduced)
later wings had a big margin which was pilotproof
a conventional wing planform seems to me to be somewhat better in this regard


the modern pilot's account you source is using jetspeak
jetspeak for inferior sustained turning performance (of the Mustang) involves frequent use of the jet mantra 'energy'
this pilot is validating the view that LF doesn't give free lunches
('my' Vengeance/Spit XIV/P-47/Meteor/Venom/Hunter etc pilot said Americans were trained to avoid turning matches)

his (your pilot's) words interest me re details of rudder and aileron trim etc for takeoff
but seem surprising re always choosing a taildown takeoff
convention demands the tail is raised during takeoff so that the pilot can see something ....and ....
in case (taildown) the tailfin and rudder are blanketed by the fuselage
(ok 'taildown' ground angle was reduced ie Corsair,P40,P47, but Bearcat has real ground angle,as eg today the Pitts does)

takeoff really has 4 stages
1 tailwheel on ground, 2 tailwheel clear of ground, 3 tail raised more, and 4 tail down (nose up) for liftoff
tailwheel may be steering in 1, 2 must steer rudder only (slipstream helps), 3 will tend to disrupt by gyro etc effects
so 3 can be omitted but gives better acceleration and vision and less instability
headwind and crosswind components make a big difference and tend to compress things

remember that a tailwheel plane when moving on the ground is (mechanically) directionally unstable ie it 'swings'
given half a chance it will swerve off the runway and roll itself into a ball
WW2-speed planes have limited control authority at takeoff speeds to correct swing unless used very quickly and fully
ok a wide undercarriage helps here
aerobatic planes like the Pitts have huge control authority and can over-correct
the better (than Spit's) aerodynamic directional stability of Hurricane, Typhoon, or Tempest could be a liability in takeoff etc


and landings usually must be 3 pointers ie tail down or bounce will cause partial lift off and then a worse bounce
though after touchdown they make you raise the tail for vision and greater steering authority

touching down tailwheel first is considered a fault but it's not usually particularly dangerous
it's very important to know the relationship between the tailwheel and the rudder pedals (it can vary eg with stick position)
you don't want to touch down (or lift off) with the tailwheel steering though a second earlier or later may be necessary
and it's particularly important not be applying any brake

naval stuff has a high cockpit (for vision over the nose) but small wheels (these have killed a lot of people operating on grass)

there's a book (titled 'Stick and Rudder' ?) by Langewische that is said to be a prime source of handling information
no I haven't seen it

[J.A.W.]

No T-C, in fact "it is screamingly (blue note?) clear" that not only was the Tempest a significant advance
on the Typhoon at high-Mach ( the Typhoon's thick wing profile caused excessive vibration which contributed
to tail joint failure, & the Tempest's ailerons were much more effective) yet they still bested the Spitfire
for practical combat dive speed in the high-Mach range & zoom climb, both - by a wide margin.

The ability of the 109/190 to evade Spitfires by outdiving them, was negated in combat, by the Hawker pair.

Indeed, it wasn't until 1945 with the advent of the 20 series Spitfires featuring a comprehensively redesigned
wing that the Spit could match the Typhoon's 1941 Vne/limiting speed of 520 mph, but it never did match the Tempest's 540-550mph.

That unarmed PR Spitfires could do high-speed (out-of-control) dives from very high altitudes - was of no practicable value to a fighter pilot

As a matter of interest here are the diving speed limitations from 'Pilot's Notes' comparing Tempest V,
& Spitfire XI - the PR type used for diving trials (Spitfire figures on the left).

IAS(mph)----@------Height
340/370-----@-----30,000ft
390/410-----@-----25,000ft
430/450-----@-----20,000ft
450/490-----@-----15,000ft
450/540-----@-----10,000ft

Mustang dive speed 'limitations' - although the best of US fighters, were lower than the Spit's - 'cept for
10,000ft & under, where 505mph IAS - is listed.

"Tail down take-offs" were needful due to the (lower) concentric thrust-line requirement of radial engines,
& the prop/deck-clearance margin, the Sea Fury ( along with hi-po Griffon Spits - undercart height limited)
had to go to a 5-blader, while the Sabre-powered Tempest could accommodate a bigger high-line,
- 14ft diameter 4-blade item..

[Tommy Cookers]

what you call out of control dives were any dives exceeding critical Mach no (0.83 Tempest V - 0.81 Typhoon)
because that's what critical Mach no is - the limit of controllabity
why I said 0.87 for the Tempest V is comparable with the much higher Spitfire values (regarding aerodynamic significance)

beyond critical Mach the pitching moment is uncontainable without exceeding strength limitations at the rear of the plane
the tailplane makes stablity by generating a load that greatly increases with speed so a further large load is disaster
ie using the elevator trim wasn't the answer as was found the hard way by Lockheed in the P-38 (till later beefed-up ?)
ie the reason why the placard in RAF P-47s said '...... remove hands and feet from controls and open throttle fully'

the pilot in a decent plane will be saved as his Mach tends at low altitudes to fall below critical even if his speed still increases
(though btw some planes eg Welkin wouldn't stay in a big dive as the uncontainable pitching moment was upwards)

the lesson drawn (according to such authorities as Morien Morgan and Bill Gunston) was that .....
the sudden drag rise/pitching moment rise with Mach was deferred by the %thinner wing of Spitfires but not by LF aerofoils
Gunston said that the Attacker would have been better with the Spitfire wing not the Spiteful's
and that the PR Spitfires deeper nose (for oil tankage) would have hindered their scope Machwise
one paper linked in this sorry series of posts shows that fighter Spitfires 21 and/or 22 were used (albeit without guns)

this flight regime is now served by supercritical ('aft-loaded') aerofoils of notable thickness and LE bluntness (v. unlike WW2 LF)
whether zero or some sweep

btw straight-winged planes could be dived to the supersonic without needing super thin wings (gravity being a mighty engine)
if given enough pitch control authority eg leVier in the F-94C
btw expert witnesses said a P-47 they saw going in gave a sonic boom
I suggest that a piano eg doing 0.99 Mach will also do this - despite some believing not unless it's doing 1.00 Mach

5 bladed props were about keeping available the level attitude for landing or takeoff not making it unavailable
my father was a toolmaker in Rotol's prototype toolroom when their first 5 blader drawings came in

[johnny comelately]

Thinking about the Battle of Britain in here, everything was a compromise: strength for getting home ability; maneuverability; weight for all the obvious reasons and of course it was the ultimate competition.
Thank you both for such insights.

[johnny comelately]

what you call out of control dives were any dives exceeding critical Mach no (0.83 Tempest V - 0.81 Typhoon)
because that's what critical Mach no is - the limit of controllabity
why I said 0.87 for the Tempest V is comparable with the much higher Spitfire values (regarding aerodynamic significance)

beyond critical Mach the pitching moment is uncontainable without exceeding strength limitations at the rear of the plane
ie using the elevator trim wasn't the answer as was found the hard way by Lockheed in the P-38 (till later beefed-up ?)
ie the reason why the placard in RAF P-47s said '...... remove hands and feet from controls and open throttle fully'

the pilot in a decent plane will be saved as his Mach tends at low altitudes to fall below critical even if his speed still increases
(though btw some planes eg Welkin wouldn't stay in a big dive as the uncontainable pitching moment was upwards)

the lesson drawn (according to such authorities as Morien Morgan and Bill Gunston) was that .....
the sudden drag rise/pitching moment rise with Mach was deferred by the %thinner wing of Spitfires and not by LF aerofoils

this flight regime is now served by supercritical ('aft-loaded') aerofoils of notable thickness and LE bluntness (unlike WW2 LF)
ok lightly or somewhat swept

btw straight-winged planes could be dived to the supersonic without needing super thin wings (gravity being a mighty engine)
if given enough pitch control authority eg leVier in the F-94C
btw expert witnesses said a P-47 going in gave a sonic boom
I suggest that a piano eg doing 0.999 Mach will also do this - despite some believing not unless it's doing 1.000 Mach

Tommy, by this comment " Welkin wouldn't stay in a big dive as the uncontainable pitching moment was upwards", do you mean the centre of pressure was way forward?
And pardon my ignorance I know nothing of these things

[Tommy Cookers]

I think the movement of the CoP was forwards at 'high' Mach
certainly some others Tigercat ? had this characteristic ie they wouldn't go really fast because they wouldn't maintain a dive

the Welkin was expected to engage high altitude bombers incl diving from great heights
but its critical Mach no was only around 0.72

btw the photo you posted elsewhere of the Kaye Don Sunbeam car was useful (I thought no photo or drawing existed)

[J.A.W.]

T-C, perhaps you misunderstood my comment re: 5-blade props?
5-bladers were used on the Sea Fury to transmit the power of the Centaurus mill within
a smaller diameter disc, than the 4-blade prop utilized by the similarly powered Tempest II.

Sabre powered Tempests used a still larger 14ft diameter prop, which was accommodated by
the higher thrust line accorded by the Sabre, albeit the Sabre Fury had to use a smaller diameter
prop, due to the prop-disc otherwise overlapping the inner cannon, in its reduced span wing.

& as noted by Beamont in testing, & by pilots in combat, the Tempest did in fact still offer useful
control right up to its speed 'limitations', & proved this effectively by shooting down every kind of
operational German turbo-jet, in high-speed flight.

So the putative "much higher values" attained by non-fighter Spits ( is 0.89M Vs 0.87M - that "much higher"?)
were moot anyhow, esp' given the Spit's much lower structural integrity values..

French Spitfire 'ace' ( & Tempest combat pilot) P.Clostermann - noted that a Spitfire XIV which achieved a similar feat to the Tempest - by downing an Arado Ar 234 jet-bomber, (via terminal dive), had in doing so suffered structural damage ( & the RAE test Mk XI also, AFAIR), which rendered it:
"...fit only for the scrap-heap."

Here is a graph indicating Tempest aileron control/roll-rate, which was still better than the
contemporary Meteor jet ( as was its dive 'limiting speed' range).



& of course, a pilot with anywhere near 'All Black' standard upper-body strength - could apply more than "50lb" force to his 'stick', when wresting around the big Tempest - in high-speed combat situations..

[Tommy Cookers]

Closterman used the trimmer to recover from his dive - dangerous and so presumably against the rules
(btw did he use the 'WI' boost ? I have read of someone who used it only once in hostilities)

the Meteor was a joke until getting the Derwent 1 (RR's development of the Rover-designed B26 straight flow engine)
the B26' 'improvement' in fuel consumption at so-called cruise took it to 1.19 lb/hp-hr (nearly 3x the Merlin's)
Beamont said all the early jets would run out of fuel before reaching their official max speeds

the Meteor killed hundreds postwar in single-engine flying (training and continuation)
one book says trimming for SE was demanded (dodgy when taking power off to land, then retrim with power to 'go-round')
pprune says it was desperate footload at all times
(was there a secret plan to fly SE to increase their miserable endurance eg in WW3 ?)
pprune.org - the thread 'meteor accident statistics' is an education
(sorry, can't get a link to post)
of course many piston twins eg Beaufighter, Mosquito, Neptune were also death traps SE at low speed
regarding SE flying for endurance, remember Nimrods often flew on 2 power engines + 1 idle engine + 1 dead engine

deserting pistons for jets was premature and artificial
the US put WW2 pistons back into production in the 50s and even the 60s - maybe the UK should have done so
maybe the L&B PEFA was the Brewster XA-32
the winning single-seat dive bomber/attack aircraft cancelled for delay and 'replaced' with the P-51 modified into the A-36

and the turboprop XF-88B flew supersonically c.1953, the later XF-84H would have been similarly capable

[johnny comelately]

From this webpage: https://twitter.com/CalumDouglas1

After #WW2, Beverly Shenstone, beind the Spitfire wing - helped reveal why it had taken so long for the Biplane to go. Early wind-tunnels were turbulent not laminar, which produced misleading drag data on monoplanes vs biplanes, perpetuating them well beyond their deserved life.

More:
Beverley Strahan Shenstone MASc, HonFRAes, FAIAA, AFIAS, FCAISI, HonOSTIV (10 June 1906 to 9 November 1979) was a Canadian aerodynamicist often credited with developing the aerodynamics of the Supermarine Spitfire elliptical wing

[Tommy Cookers]

I imagine that paper by Mr Shenstone would not have been news to the postwar aviation community

the introduction of monoplanes required airfield size to be doubled - and then redoubled

early monoplanes had more external wing structures (tripod kingpost and 50 yd of wire) than biplanes
the most popular plane ever (Cessna 150/2/172) has struts

the Fokker triplane had no external wing struts or wires until single struts were added in response to user prejudice
Fokker and Junkers made biplanes without struts or wires

it would be interesting to know which biplanes and monoplanes Mr S had under consideration


btw
an erstwhile colleague worked post WW2 on light aircraft maintenance and inspection - customers included Prince Bira
Bira's plane had a special small mast carrying his royal flag deployable on taxying in after landing
he often complained about functional defects in this mechanism

then one day approaching to land one of his flap rods broke and this one flap retracted - likely to cause sudden death
he avoided any crash and didn't complain to the maintenance and inspection people about this defect

[J.A.W.]

Closterman...did he use the 'WI' boost ?

the Meteor was a joke until getting the Derwent 1 (RR's development of the Rover-designed B26 straight flow engine)
the B26' 'improvement' in fuel consumption at so-called cruise took it to 1.19 lb/hp-hr (nearly 3x the Merlin's)
Beamont said all the early jets would run out of fuel before reaching their official max speeds

the Meteor killed hundreds postwar in single-engine flying (training and continuation)
one book says trimming for SE was demanded (dodgy when taking power off to land, then retrim with power to 'go-round')
pprune says it was desperate footload at all times
(was there a secret plan to fly SE to increase their miserable endurance eg in WW3 ?

...of course many piston twins eg Beaufighter, Mosquito, Neptune were also death traps SE at low speed
regarding SE flying for endurance, remember Nimrods often flew on 2 power engines + 1 idle engine + 1 dead engine

deserting pistons for jets was premature and artificial
the US put WW2 pistons back into production in the 50s and even the 60s - maybe the UK should have done so
maybe the L&B PEFA was the Brewster XA-32
the winning single-seat dive bomber/attack aircraft cancelled for delay and 'replaced' with the P-51...

Here's Clostermann on 'going through the gate'..

"...on my tail were six Focke-Wulfs in perfect close echelon formation - exhausts white hot - pursuing
me at full throttle.
With one movement I broke the metal thread to enable me to go to 'emergency' and shoved the throttle
lever right forward. It was the 1st time I had occasion to use it on a Tempest.

The effect was extraordinary & immediate. The aircraft literally bounded forward with a roar like a
furnace under pressure. Within a few seconds I was doing 490 mph by the ASI & I simultaneously caught
up my quarry & left my pursuers standing."

Notwithstanding Clostermann's proclivity for hyperbole, it is an interesting account.

Other Tempest pilots noted that hard flying suited the Sabre best, including a Kiwi pilot who ran his plane
WFO to chase down & bag an Me 262 - after its primitive metallurgy turbines wilted under the strain, 1st.

(Ron Dennis did though, add a caveat - that Rotol props were dependable, subject to this treatment,
whereas de Havilland units were prone to "shedding a blade"!)

The RAF continued flying their Sabre-Tempests hard for another 10 years post-war, inc' ops against the
pugnacious Israeli Defence Force Spitfires, and later in the fighter air-gunnery training role.

Ex-RAF member John Manly noted that when he, on arrival for such training, doubted the ability of the Tempest to provide a realistic target-tug, & so he was promptly told:

"Make no mistake, without the drogue chute, those Tempests have no trouble giving Vampires the runaround at low-level."

& T-C you are correct about the RAF being 'jet-bent' in 1945, to the extent of 'fudging' the results of
comparative trials between their final piston jobs, & the new-fangled jets.

As for the sorry tale of the Meteor ( quickly nicknamed 'Meatbox' by the sardonic RAF chaps), being
pushed through a 'grandfather's axe' rigmarole of mounting ever more powerful turbines, & airframe
fiddle-faddle, while the US & Soviets got stuck into getting 2nd generation swept-wing machines into
service.. its a shocking indictment of - sadly typical - British political-based dithering..

Yes, the twin engine safety-speed threshold for engine-out flight was ( still is, for some) 'problematic'
- shown when both Grumman F7F Tigercat & DH Sea Hornet required significant additional tail surface area
in order to provide acceptable control authority for carrier ops, along with the awful Meatbox stats, too.

[johnny comelately]

I just watched Guy Martin's Spitfire episode.
Are there any planes of that era that had both of the wings as one piece (right through) and the fuselage on top?

[J.A.W.]

Sure Johnny, more than one..
..many deaths of Lancaster crews were attributed to poor emergency egress prospects,
viz: climbing over the wingspar seriously obtunding the fuselage passage-way.

& Hawker, when developing the Sea Fury from the Tempest, took the wings,
which had been bolted to the sides of a space-frame, & butted them together,
under a new monocoque fuselage, so finally providing a pilot of their fighters - with a cockpit floor!

[Tommy Cookers]

the FW 190 'pioneered' the 1 piece wing
the Fury was a hotrod Tempest desperately cut down to emulate the 190
the Typhoon carried 8 85 lb 5" rockets and was tried with 16

planes with 2 separate wing panels have a 'carry through' structure through the fuselage - which might be called 'spar' ?
2 panels saves the taxpayer money re accident damage
the Lancaster wing position was a surprise benefit to speed as Avro hadn't heard of the NACA advice

I noticed on the Guy Martin programme the prop cost over 100000 pounds - more than the engine