How to fly a Stirling bomber

Flt Captain Arnold Watson test flew new types before he prepared the famous Ferry Pilots Notes to assist ATA pilots. These extracts from his diary date from March-May 1943 and give a good idea of how thorough he was. Not surprisingly he is fairly technical, but read them and you’ll be ready to fly!

STIRLING, 26/27 March 1943

It is proposed in future that Class V pilots, instead of having a separate course on each machine, will take the basic 4 engine course on Halifax. Then later, two trips as second pilot before flying as Capt. on the other 4 engine types.

Accordingly, I went as second to Doc Whitehurst from Swindon to St. Athan. He had difficulty on take-off & landing due to a crosswind (about 40° 20 m.p.h.) on the starboard ( the worst side).

The enormous keel area which helps her head to wind, to run straight down the runway, is a disadvantage in crosswinds. I flew it for 40 mins & was much impressed by the lightness & effectiveness of the controls & trimmers. She feels right & is most restful to fly.

Next day I did the take-off & landing from the right hand seat & was lucky enough to do it well (head to wind). The following points were noted:-

Taxying Watch brake pressure – it builds up only slowly in flight. The brake lever is awkward (same hand as throttle) & the response is not immediate. More difficult to taxy than Halifax.

Take-off 1/3 flap out. Trim 4 nose down rudder neutral. Clear to zero & set 2000. All clear aft? Throttle levers are light but have over long travel. Brake so awkward as to be useless at start of run.

Climb: 140 – 150 m.p.h. Reduce power. Flaps up after u/c is up.

Landing circuit M = Rich

P = 2400 Prime exactor throttles

150 A.S.I. F = Flap 1/3 out.

140 A.S.I. U = u/c down. Maintain 140 m.p.h. about 2400 & +2.

She flies well with wheels down & 1/3 flap.

Approach Turn in at 140 m.p.h.

Full Flap 120 m.p.h. Trim tail heavy

Landing Maintain 120 & check gently a trifle higher than Halifax. The

throttles are so light they may be used with one hand.

Hold off normally, stick back, close throttles only when all descent has ceased. Stick right back. Watch carefully for swing owing to awkward brake.

One hour with one engine out, 3 April 1943

My first solo Stirling proved rather exciting. Took off from Rochester in a flat calm, with seven air cadets aboard at 4.50. South of London smoke reduced visibility to about 3 miles but we cleared it at Guildford & had 12 miles under 5/10 at 3000 ft.

Passing Farnborough, about 15 mins. after take-off, I noticed the port inner engine was throwing out a lot of oil. I consulted with my Flight Engineer who thought it might run alright. But it seemed to me the leak was getting worse & we should soon have no oil left & wreck the engine. So I feathered it, & put the port outer up to 2200 & +2, leaving the starboard engines at 2000 & zero. This gave an airspeed about 150, & we had not much time to reach St. Athan. I considered landing at Farnboro, & would have done, except that the job was priority P1.

So we opened up all three to 2200 & +2 & gained height to 2500 feet & continued our journey. Levelling out she trimmed level feet off at 170 A.S.I.

Over the Bristol Channel, I decided to restart the dead engine & use it for landing since enough oil was remaining in it, & it was wiser than risking a 3 engined approach with no chance of mislanding, with wheels & flaps down.

So we warmed it up carefully: in full coarse she windmilled at 1800. I was glad we did for when we lowered the undercarriage, the port leg failed to come down. So I held height and did a couple of circuits at 2,500 feet & 140 A.S.I. while the F/E did his stuff. He finally got it down, without hand winding, by selecting up then hard down with all his weight on the lever.

Being worried by the possibility of the engine packing up with the wheels down, I turned in rather close for so light a wind, & made a straight approach at 120 rather overshooting. This caused me to close the throttles more than I intended to do before I flattened out. As a result, she sank on to main wheels & bounced once. Moral:

reduce power in stages, watching boost & revs, & keep sufficient power on until all descent has ceased. (Throttles sensitive at low power but not at high) We came to rest quite straight & easily with only a touch of brake.

Stopped the inners, dispersed the aircraft, made out the snag sheet & signed the flight log, & got out to look at the engine. It was covered in oil & so was the complete undercarriage on that side. They quickly covered the tyre to keep the dripping oil off it. A fitter who saw me on the circuit, said he thought the engine was on fire. I told him I’d had my finger on the fire extinguisher button, & opened its cover, just in case.

Well at least we saved the engine, got the undercart down, & delivered the aeroplane “priority P1”

Home in 50 mins from Llandau (13 in the Anson) landing 10 mins after landing time.

STIRLING

Practise with both Stbd Engines Feathered, 8 April 43

At St. Athan today I enquired about the engine trouble just described. The Sergt. Fitter told me that there was only 2 galls oil left out of the twenty galls. So I stopped it just in time. And they found a lump of piston in the oil filter, so the engine must be changed. Evidently piston failure was the cause of the trouble.

A.I.D. at Rochester said they had a piston go recently & are satisfied that the engine made two or three more flights thereafter – 4 or 5 hours in all. At St. Athan the Sergt Fitter remarked that sleeve valve motors will continue to run after considerable internal damage.

Our Stirling today was not quite ready, & on run up we found a defective oil gauge. Take-off at 2.30 in good vis. 10/10 at 3000 ft, light wind from N.W. Mr Campbell made a special record of head temps. during taxying take-off & climb. The inners went out of limits with gills closed: will experiment with inner engine gills 1/3 open.

At Alton cloud lifted to 5000 feet 5/10, so we climbed up to that level, & checked the performance with stbd outer feathered, then stbd inner as well. It was my first experience with two engines stopped on the same side. She needed about 2200 & +2 at 150 A.S.I. The rudder trimmer was excellent – fully adequate. No aileron trimmer is fitted; I had the wheel over about 70° to port. The total travel is 180° each way. We unfeathered near Salisbury & warmed up carefully before bringing them up to speed.

At Weston Zealand we went through a mislanding practice to check trim changes of flap, u/c, power. She was quite easy to hold. Thereafter, I found the elevator trimmer would trim forward but not back from neutral. F/Eng Gardner went aft & cleared the jam (which was noted on the snag sheet)

Weather at St. Athan was excellent with 15 – 20 m.p.h. wind straight down the runway. I did my circuit at 2000 feet +/- 100. After priming exactors, I shut down to – 4, put revs up to 2400, to reduce speed to 150 for ½ flap. Then u/c down, entering the downwind leg. Zero boost at 140 A.S.I. I allowed about 2 miles straight approach (which was not too much) turning in at 140, & then giving full flap which takes about a mile to come down at 120.

I called out – 2 just before giving full flap, then – 4. I noted that revs began to drop about – 5, so set 2200 by throttles, then immediately 1,500 since we were in an overshooting position at about 800 – 500 feet. Throttles were now almost closed & the attitude of descent very steep, trimmed tail heavy (trimmer well forward!) The check was immediately followed by the hold off, as I was bringing throttles back the last bit gently, she touched smoothly down on the main wheels and it was a perfect wheeler. I shouted “Close” as the tail came quickly down & she slowed up quickly & straight almost stopping in 900 yds without break.

This pleased me so I decided that 1,500 is the minimum sensible revs entering the aerodrome. Probably – 4 (giving 2400) is more desirable. This would give a less steep attitude, & I guess this produces a very slight trust (as distinct from a drag) from the propellers. Static run up needs about zero boost to give about 2400.

Home in 1 hour (wind behind) by Fairchild – to test Barracuda.

My only mistake this trip was exceeding 100 on the climb with flap 1/3 out.

STIRLING in the Rain, Sat 1 May 1943

A lovely clear morning and the Met. Said fine all day but they were optimistic. The first Mk ΙΙΙ Stirling was ready at Rochester to go to Oakington near Cambridge. The C.T.O., Campbell & F/E Cooke came with me in an Anson for test. Near Gravesend the port motor started misfiring & was no better in Rich or after changing tanks. But it kept going. At Rochester at noon but found them just starting the daily inspection. So we had lunch after

Mr Campbell had made his notes & took off at 2.45. There was a light wind from the North & 10/10 at 3000. The Mk ΙΙΙ has cable operated throttles etc. instead of exactors & +8¼ boost instead of +5¾.

We recorded certain figures on run-up (revs against boost in steps of 2 lbs) All heads after run-up were between 150° – 200° C. After taxying gently out they were 150° C, which was nicely cool.

The take-off was much more pleasant than the MkΙ but it is necessary for the F/E to hold the throttles open like a Halifax, since the ratchets have been deleted. The break neck? ratchet was good on take-off but not so good throttling down for landing.

As soon as the wheels were up, we note that all heads were 250° — comfortably under the max of 270°. We crossed the river at Gravesend – Tilbury & soon passed Burtonwood at 190 – 200 m.p.h. cruising at zero, 2200 in weak.

At Bishops Stortford the ceiling came down & we flew at 1000 feet in rain which steadily increased. The windscreen was badly obscured & the only view was sideways. Passing Cambridge, I decided to fly up the railway beyond Oakington to see whether the rain was local. But at St. Ives I could see no break & it seemed likely to get worse rather than better. Therefore I decided to try a landing & turned back to Oakington & flew slowly (140 m.p.h.) with 1/3 flap at 220 & -3.

Having seen the North wind was straight down the runway I increased to 2400 & +4 and went up to 1,500 feet, & lowered the wheels. Then we had difficulty opening my direct vision panel. F/E reported Port outer gill motor failed. Approaching at 120, I found the Mk ΙΙΙ throttles a great improvement, especially throttling back during the hold off. Owing to the rain, I did not attempt a complete three pointer but made a satisfactory wheeler & stopped easily with a little brake at the last. Since we could not open the gills on No.1, we stopped before taxying to dispersal.

Coming back in the Anson, we gave a lift to Capt. Dlugaszewski (Polish, aka Captain Double Whisky) & his crew. At Letchworth the port motor started missing again, but it kept going so I continued, throttling it back on sighting Maidenhead & landed using the starboard only.