Heinkel He 177

https://en.wikipedia.org/wiki/Heinkel_He_177

The Heinkel He 177 Greif (Griffin) was a long-range heavy bomber flown by the
Luftwaffe during World War II. The He 177 was the only operational long-range
heavy bomber available to the Luftwaffe during the war years that had a
payload/range capability similar to the four-engined heavy bombers flown by the
USAAF and RAF in the European theatre; it had higher cruising and maximum
speeds.

Designed to a 1936 requirement known as Bomber A, the aircraft was originally
intended to be a purely strategic bomber intended to support a long-term bombing
campaign against Soviet industry in the Urals. In spite of its large, 30 metres
(98 ft) wingspan, the design was limited to two engines. During the design,
Luftwaffe doctrine came to stress the use of moderate-angle dive bombing, or
"glide bombing", to improve accuracy. Applying the changes needed for this type
of attack to such a large aircraft was unrealistic.

To deliver the power required from only two engines on an aircraft this large,
engines of at least 2,000 horsepower (1,500 kW) were needed. Such designs were
not well established and the DB 606 "power system" engine, combined with the
cooling and maintenance problems caused by the tight nacelles, caused the
engines to be infamous for catching fire in flight. Early models gained the
nicknames Reichsfeuerzeug (Reich's lighter) or Luftwaffefeuerzeug (The Air Force
lighter) from Luftwaffe aircrew.

The type matured into a usable design too late in the war to play an important
role. It was built and used in some numbers, especially on the Eastern Front
where its range was particularly useful. It is notable for its use in mass raids
on Velikiye Luki in 1944, one of the late-war heavy bombing efforts by the
Luftwaffe. It saw considerably less use on the Western Front, although it played
a role during Operation Steinbock (baby blitz), against the UK in 1944.

Flight testing of the He 177 in late summer 1942 revealed deficient stability
around the yaw and pitch axes, resulting in extremely poor bombing accuracy when
using the Lotfe 7 bombsight. The main reason for this was the drifting motion of
the aircraft in flight due to its relatively short, round fuselage. Shortly
after these tests, the third production A-1 example (factory serial number
15153, with Stammkennzeichen of GI + BN) had its fuselage lengthened by 160 cm
(63 in) just aft of the trailing edge of the wing. The modified aircraft, with
the longer distance of the "tail moment", showed a marked degree of improvement
in yaw and pitch axis stability, enough to mandate the construction of the He
177 A-3 and all subsequent models of the He 177 A with the lengthened fuselage.

In early September 1944, the Royal Aircraft Establishment (RAE) was ordered to
supply an aircrew for an He 177 that the French Maquis would capture at an
airfield in Blagnac near Toulouse, where elements of both the He 177 A-equipped
KG 4 and KG 100 bomber wings were based. A transport and two escort fighters
from the RAE flew to the area to leave the Royal Aircraft Establishment Chief
Test Pilot Roland Falk and a flight engineer with the commando group. On 10
September, as Operation Dragoon was wrapping up in the southeast of France, the
aircraft was captured and flown back to the UK by Wing Commander Roland Falk.
Soon afterwards, Capt. Eric Brown, an RN pilot then posted to the RAE as a test
pilot, flew the He 177. He wrote that the in-flight handling characteristics of
the He 177 A-5 were

"...positive about all axes, but the controls were all remarkably light for such
a large aircraft. Indeed I had the feeling that the elevator was dangerously
light and I was all too aware of the intelligence reports of He 177s breaking up
in the air so I decided to treat this control very gently...The aircraft had an
automatic pull-out device and an acceleration warning apparatus fitted, but it
really was nailbiting to have to treat a giant like this immense Heinkel bomber
as if it were made of glass. The stalling characteristics with flaps and
undercarriage lowered, the aircraft buffeted violently at 140 km/h (87 mph)
before the nose dropped at 135 km/h (84 mph). The buffet experienced was so
violent that I had some concerns over structural damage. Somehow the He 177
always conveyed an impression of fragility despite its size." He added that it
was "one of the very few German aircraft of the period that I tested that I did
not enjoy flying".


Role
Long-range heavy bomber

Manufacturer
Heinkel Flugzeugwerke
Licensed to Arado

Designer
Siegfried Günter

First flight
November 1939

Introduction
1942

Retired
1945

Primary user
Luftwaffe

Number built
1,169

Variants
Heinkel He 274
By February 1943:
Heinkel He 277 Amerika Bomber


Beset by technical difficulties in development, the He 177 had a troubled
history in service. Unduly demanding design requirements of long range, high
speed, heavy bomb load, and the formerly required dive bombing capability
compounded the problems. Although the He 177 entered service in 1942, it was far
from operational. In an assessment of the aircraft on 9 April 1942, the newly
activated Erprobungsstaffel 177 reported that the Greif had good flying
characteristics, but had unacceptable engine troubles and problems with its
airframe strength. As an emergency measure, it was used to supply the encircled
6th Armee at Stalingrad, where it was found to be unsuited for the transport
role, carrying little more cargo than the smaller and more reliable Heinkel He
111, and proving useless for the evacuation of wounded. As a result, the He 177s
reverted to bombing and flak-suppression missions near Stalingrad. Only thirteen
missions were flown, and seven He 177s were lost to fire without any action
attributable to the enemy.

As the war progressed, He 177 operations became increasingly ineffective. Fuel
and personnel shortages presented difficulties, and He 177s were sitting on
airfields all over Europe awaiting new engines or engine related modifications.
Of the fourteen He 177 A-3s (the primary subtype in use) that were sent out
during Operation Steinbock, one suffered a burst tyre, and eight returned with
overheating or burning engines. Of the four that reached London, one was lost to
night fighters. These aircraft were brand new, delivered a week before the
operation and not fully flown in, because the air unit had moved to a new
airfield the day before and lacked sufficient maintenance personnel and
material. Constant attacks against Luftwaffe long-range combat units in France
made continuous operations difficult.

While Steinbock was unsuccessful, the He 177 did achieve some successes. During
Steinbock crews typically carried two 1,800 kg (3,970 lb) and two 1,000 kg
(2,200 lb) bombs. Climbing to 7,000 m (22,965 ft) while still over German
territory, the He 177s approached the target in a shallow dive, both engines
throttled back, the pilot putting his aircraft into a gliding descent to take it
across the bomb release-point at about 4,500 m (14,760 ft). After releasing the
bombs the pilot re-opened the throttles, but continued the descent at
approximately 200 m (656 ft) per minute. The bombers typically re-entered German
airspace at an altitude of 750 m (2,460 ft), and headed back to base. By such
means, the He 177s were able to keep up speeds of about 600 to 700 km/h (370 to
430 mph) during their withdrawal phase. The higher speed and constant change of
altitude made interceptions difficult, increasing the survivability of the
aircraft, but decreased bombing accuracy and concentration. With an average loss
rate of 60% for bomber aircraft types used in Operation Steinbock, the He 177's
loss rate below 10% made it the most survivable bomber in the campaign.

On the Eastern Front, the most notable action by the He 177 was a mass raid of
some eighty-seven aircraft against railway targets in the Velikiye Luki area,
about 450 km (280 mi) west of Moscow on 19 July 1944. The participating Staffeln
flew in three large attack wedges of about thirty aircraft, each loaded with
four 250 kg (551 lb) or two 500 kg (1,102 lb) bombs. During this action, carried
out in daylight at altitudes in excess of 6,000 m (19,690 ft), losses were
relatively light. The Soviet Air Force, equipped mainly for low-level
interception and ground-attack roles, could do little to hinder the high-flying
bombers.

In common with most piston-engined German bombers, the He 177 was grounded from
the summer of 1944 due to the implementation of the Emergency Fighter Program as
well as the Allied bombing of German fuel production facilities.

Specifications (He 177 A-5/R2)

General characteristics
Crew: 6
Length: 22 m (72 ft 2 in)
Wingspan: 31.44 m (103 ft 2 in)
Height: 6.67 m (21 ft 11 in)
Wing area: 100 m2 (1,100 sq ft)
Airfoil: He 1.5 36.8 17.3-0.715-36.6
Empty weight: 16,800 kg (37,038 lb)
Gross weight: 32,000 kg (70,548 lb)
Powerplant: 2 × Daimler-Benz DB 610 24-cylinder liquid-cooled piston engines
2,900 PS (2,860 hp; 2,133 kW) (paired DB 605 V-12 engines)
Propellers: 4-bladed VDM constant-speed propellers

Performance
Maximum speed: 565 km/h (351 mph, 305 kn) at 6,000 m (19,685 ft)
Stall speed: 135 km/h (84 mph, 73 kn)
Combat range: 1,540 km (960 mi, 830 nmi)
Ferry range: 5,600 km (3,500 mi, 3,000 nmi)
Service ceiling: 8,000 m (26,000 ft)
Rate of climb: 3.167 m/s (623.4 ft/min)
Wing loading: 303.9 kg/m2 (62.2 lb/sq ft)

Armament

Guns: ** 1 × 7.92 mm MG 81 machine gun in Cabin 3 "fishbowl" nose glazing with
1,000 rounds 1 × 20 mm MG 151 cannon in forward ventral Bola gondola position
with 300 rounds
1 × 13 mm MG 131 machine gun in rear ventral Bola gondola position with 1,000
rounds
2 × 13 mm MG 131 machine guns in Fernbedienbare Drehlafette FDL 131Z remotely
operated forward dorsal turret, full 360° traverse with 1,000 rounds
1 × 13 mm MG 131 machine gun in manned Hydraulische Drehlafette HDL 131/1 aft
dorsal turret with 1,000 rounds
1 × 20 mm MG 151/20 cannon in tail position with 800 rounds

Bombs: Up to 7,000 kilograms (15,000 lb) of ordnance internally, up to 2,500 kg
(5,500 lb) externally on each ETC 2000 underwing rack, or up to 3 Fritz X or
Henschel Hs 293 PGMs (w/FuG 203 Kehl MCLOS transmitter installed) externally 48
× 50 kg (110 lb) bombs (2,400 kg/5,291 lb total)
12 × 250 kg (551 lb) bombs (3,000 kg/6,613 lb total)
6 × 500 kg (1,102 lb) bombs (3,000 kg/6,613 lb total)
6 × LMA III mines (3,000 kg/6,613 lb total)
2 × 1,800 kg (3,968 lb) bombs (3,600 kg/7,936 lb total)
4 × LMB III mines (4,000 kg/8,818 lb total)
2 × 1,800 kg (3,968 lb) bombs + 2 × LMA III mines (4,600 kg/10,141 lb total)
10 × 500 kg (1,102 lb) bombs (5,000 kg/11,023 lb total)
2 × 2,500 kg (5,511 lb) bombs (5,000 kg/11,023 lb total)
2 × 1,000 kg (2,204 lb) bombs + 2 × 1,800 kg (3,968 lb) bombs (5,600 kg/12,345
lb total)
4 × 1,400 kg (3,086 lb) bombs (5,600 kg/12,345 lb total)
6 × 1,000 kg (2,204 lb) bombs (6,000 kg/13,227 lb total)
4 × 1,700 kg (3,748 lb) bombs (6,800 kg/14,992 lb total)
2 × 1,800 kg (3,968 lb) bombs + 2 × 1,700 kg (3,748 lb) bombs (7,000 kg/15,432
lb)
2 × FX 1400 Fritz X + 1 × FX 1400 Fritz X under the wings and fuselage (w/FuG
203 Kehl MCLOS transmitter installed)
2 × Hs 293 or 294 + 1 × Hs 293 or 294 under the wings and fuselage (w/FuG 203
Kehl MCLOS transmitter installed)
2 × 500 kg (1,102 lb) bombs internally + 2 × Hs 293 under the wings (w/FuG 203
Kehl MCLOS transmitter installed)
2 × LT 50 torpedoes under the wing


Avionics
For control of gravity and/or rocket-boosted PGM ordnance:
FuG 203 Kehl radio control transmitting system




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